CHAPMAN'S BLOWPIPE PRACTICE AND MINERAL TABLES. HY THE SAME A VTUOR. AN OUTLINE OF THE GEOLOGY OF CANADA, BASED ON A SUBDIVISION OF THE PROVINCES INTO NATURAL AREAS, Wiih six sketch-maps and 86 figures of characteristic fossils. By E. J. CHAPMAN, Ph.D., LL.D. This work presents a synoptical view of the geology of the entire Dominion. It is used as a book of reference in University College, Toronto ; in Queen's College and University, Kingston ; and in the University of Halifax and Science Department of Dalhousie College, Nova Scotia. COrP, CLARK & CO., 1877. 7 BLOWPIPE PRACTICE. AN OUTLINE OF BLOWPIPE MANIPULATION AND ANALYSIS, WITH ORIGINAL TABLES, FOR THK DETERMINATION OF ALL KNOWN MINERALS. BY E. J. CHAPMAN, Pn.U., LL.D. PROFESSOR OF MINERALOGY AND (lEOLOOY IN UNIVFUSITY COLLEOE AND SCHOOL OF PFACTICAL SCIKNCK, TOUONTO, TORONTO : OOPP, CLARK & CO., 47 FRONT STREET EAST. 1830. INTRODUCTORY NOTICE. The title-page to this little work indicates siiccinctly the scope and character of the book. The woi"k comprises two distinct parts : an introductory sketch of the use of the Blow})ipe in qualitative mineral examinations ; and a series of Tables, with chemical and crjstallo- graphic notes, for the practical determination of minerals, generally. In the first portion of the woi'k, the writer's aim has been to sys- tematise and condense as far as possible : but, although confessedly a mere outline of the subject, this introductory portion will not be foimd altogether devoid of original matter. The sixth section, more especially, contains a new and gi'eatly simplified plan of Blowpipe Analysis, by which the general composition of an unknown sub- stance may be determined in most cases very rapidly and Avitli comparatively little trouble. As a rule, the methods of Blowpi[>e- Analysis, hitherto publislied, are little more than Tables of Reac- tions. They attempt no separation of electro-negative bodies ftom; bases, but mix up the two, very illogically ; and they exact the- per- formance of many unnecessary ex[)eriments, by which certain, com- ponents become detected over and over again, whilst others escape detection, altogether, or are recognized only after much unneoessary delay.* These defects are remedied very materially, it is tHought, in the method now proposed. The Determinative Tables, which occupy the second and principal portion of the work, are alw origi- nal. In their arrangement, an attempt is made to place botlies of related composition, only, under the same subdivision : so as; to avoid, wherever possible, the unnatural collocations so commonly seen in Tables of this character. It will be evident, however, thut. without greatly increasing the number of the Tables, complete succest^in this, respect is not always attainable. The Tables include, praciically, all * After tlie first part of this worlt was in tjpe and entirely struelt oflT, tiio aiitlior received from Hkrh L\xdadeb, of IBrunswiclf, a ropy of his " SystcmatUcher Gany t&r Luthrohr- Aiu-ilyse." Ilerr Landaner's method entirely ineets the ahove objections, and i» without doubt the most satisfactory plan of Blowpipe Analysis hitlierto piililislied. It has been subsetpiently- incorporatod by its author into a littln work on tlie Blowpipe, an English trauslatiou of whicli, under the title of " Blowpipe Analysis," haa recently appeared. VI BLOWPIPE PRACTICE. known minerals ; but as many of those are rarely mot with, or are com))arativoly of little im}»ortance, an Explanatory Note, ref(;n'ing only to species of ordinary occurrence, is attached to each Table. In these Notes, more especially in those which relate to the concluding Tables of the series, additional information is given respecting the crystallization, sjiectroscopic reactions, and other distinctive chai'ac- ters of leading species. The spectroscope recommended for use, in these investigations, is a simidc, direct-vision pocket-spectroscope, such as can be carried very conveniently, with accompanying Bun- sen-burner (the foot unscre\ved), in a spare corner of the blowpipe case. School of Practical Science, Toronto : Auijust 13th, 1880. BRIEF SKETCH OF THE HISTORY OF THE BLOWPIPE. The use of the Blowpljie, in the arts, dates from a very distant period — a simple form of the instrument having been long employed, in the process of soldering, by jewellers aiul otlur workers in gold and silver. This employ- ment must naturally hove suggested its use to the alchemists ; and in the curious collection of woodcuts known as the Liber 7nutus, in which an alchemist, assisted by his wife, is depicted in the perfoi'manee of various chemical opera- tions, the use of the blowpipe is clearly indicated. The Liher viutuH is of very uncertain date, but it belongs, in all probability, to the beginning of the seven- teenth century. The alchemist is here employed, it is true, not in the actual examination of a substance by his blowpipe, Init in the construction or sealing up of a glass vessel. Nevertheless, the use of the instrument in the conversion of calc spar into lime is pointed out by Erasmus Bartholin in his treatise on Ice- land Hpar, written in 1G70 ; and in the Ars vitraria experimentnlls of Kunckel, published in 1679, the blowpipe is recommended for use in the reduction, on charcoal, of metaMiolding bodies, the requisite blaat being produced by a pair of air-tight bags. In 1702, the celebrated alchemist Johann Georo Stahl distinctly refers to the reduction of lead and antimony, by the fusion of Avhat are now known as the oxides of these metals, on a piece of charcoal, l>y means of a "soldering pipe" or tiihulo ccementorio nurifahrorum. Johann Andreas Cramer, in his Ekmentl^ dodmaMiae (Vi^Si) describes the use of the instrument in the examination of small particles of metallic bodies, and suggests the use of borax (long previously employed in soldering, and also by the alchemists in crucible operations) for this purpose. He gives also a description of a mouth blowpipe provided at its lower end with a cylindrical reservoir for the retention oi the moisture which coudeusea from the operator's breath. , INTRODUCTOUY NOTICE. Vll In Swollen, a few years later (174(>), Swkn Rin:«av published some details on the examination of ferruginous tin-ore, and other minerals, by the l)lnwpipe ; and, in 1748, Anton von Swab — usually, but erroneously, cited as the first person by whom the blowpipe was used in its scientific applications — referred to the use of the instrument in a paper on the occurrence of native antimony. BKR(iMAN states that V"uN Swab employed the blowpipe in 17HS, but the date of his iirst publication in which reference is made to its use is ten years later, as pointed out by Dr. Hehmann Koi'F in his valualde Gcxchiclitc dcr Vlion'if : 1844, Uj) to this time, however, no general or systematic use of tlie blowjripe appears to have been attempted ; but in 1758, Axel Fkkdkktc Cuonstedt, who had i)reviously employed the blowpipe in his researches on nickel (1751), publislied anonymously at Stockholm his celebrated treatise on Mineralogy, in which a chemical classification of minerals was first definitely essayed. In this work, the pyrognostic ( haracters of minerals, as determined by tlie blowpipe, are brought prominently into notice ; and in addition to borax, the two general reagents still in use, bicarbonate of soda (".:>•«/ sodte ") and microcosmic salt or phosphor-salt (" HulfaslbUe microcoiimicum") are employed as blowiiipe fiuxes. To the English translation of C!ronstedt's work published in 1770, (Ustav von Engestrom {;2)pended a short but complete sketch of the use of the Ulowpipe, as then known ; and Jous Hyacintu de Magellan added somewhat to this sketch in the second (English) edition of the work, published in London in 1788. The plate which a ^companies Von Engesteom's essay, exhibits a portable case of blowpipe ap paratus, comprising, in addition to the blow pipe as devised by Cronstedt, a hai'.mer, anvil, magnet, silver spoon and other articles (but none, of course, of jlatinuni), with candle, charcoal, and three small bottles for fluxes. This essay of Von Engestrom, attached to his translation of Cronstedt's work, was translated into Swedish by Ketzius in 1773 ; and in the same year the Swedish chemist Torbern Bergman pul)lished a memoir on the blowpipe reactions of lime, magnesia, alumina, and silica ; whilst, in 1774, Scheele described the action of the blowpipe on manganese ores, molybdenite, and other minerals. A few years later (1777) a complete treatise in Latin on the use of the Blowjjipe was drawn up by Bergman, and published, soon after, under the editorship of Baron von Born, the metallurgist, at Vienna (Commentatio de tubo ferrum'matorio, etc. : Vindobonoe, 1779). A Swedish translation, by Hjelm, was issued at Stockholm in 1781. In the preparation of this work, Bergman was very materially assisted by Johann Gottlieb Gahn. The latter chemist subsequently carried out an extended series of experiments with the blowjiipe, and discovered various new methods of research. Berzeliu«, to whom at an after period he communicated personally his mode of operating, states that Gaun always carried his Idowpipe with him, even on his shortest journeys, and submitted to its action every new or unknown substance that came in his way. In this manner he acquired great skill in the use of the instrument. He published nothing, however, ou the subject ; but, finally, drew up at the instigation of Beuzeliuh the short sketch of the blowpipe an Opaque-white when saturated ) Colourles8(permanentlyclear) ) Slowly dissolved iVccunder Phosphor-sal t,below Lead Bismuth . ... Silver Antimony . . . , Cadmium Aluminium. Silicon Tin OoloiirlesB. When saturated, opaque-white on cooling or by naming Tantalum ... Zirconium ... Glucinum . . . , Yttrium, Ac. . , Thorium , Magnesium. . . , Calcium Strontium . . . , Barium Lithium Natrium Kalium J Colourless or yellr>%*'ish. ( Oi)aque-white, if saturated. r Yellow or yellowish-brown. J Enamelled light-blue by flam- ing. See under Phosp. -salt, below. Yellow or yello^Vi8h-brown. Enamelled by flaming. AVeunder Phosphor-salt.beloW (Brown or gray, semi-opaque, often with separation of black specks. •9feunderPhosphor-salt,below Gray and opaque on cooling ; but after continued subjec- tion to the flame, the glasei becomes clear : the reduced metallic particles either col- lecting together or volatil- . izing. Colourless — the reduced metal being volatilized. Colourless: permanently clear. (Tin compounds dis- solve in small quantity only. On charcoal, they become reduced to metal, especially if a little carb, soda be added to the glass). Colourless. When saturated, opaque-white oh cooling or by naming. See Reactions, § 5. OPERAflONS. 15 PHOSPHOR-SALT. The glasses produced by the fusion of constituent bodies with this reagent are for the greater part identical with those obtained by the use of borax, although somewhat less deeply coloured as a general rule. The principal exceptions are the glasses formed in a reducing flame with compounds of inolybdenum, tungstenum, and titanium, respectively. The molybdenum glass presents, when cold, a tine green colour, and the tungstenum glass becomes greenish-blue. If the latter contain iron, the colour of the glavis is changed to blood-red or broWnish-red. Titanium in the presence of iron gives a similar reaction ; but when free from iron, the glass is yellow whilst hot, and violet- coloured when cold. Phosphor-salt is an important reagent for the detedtion of silica in silicates, as the silica remains for the greater part undis' solved in the glass, in the form of a translucent flocculent mass, technically known as a "silica skeleton," the associated constituents being gradually taken up by the flux. A small amount of silica is also generally dissolved, but this is precipitated as the bead cools, rendering it semi-transparent or opahne. Phosphor-salt is likewise employed for the detection of chlorides, &c. {See under Rkactions, § 5. ) In other respects, it is especially adapted for fusions on charcoal, as it does not spread out like borax, but forms a globule on the support. CARBONAtE OP SODA. This reagent is principally used to promote the reduction of oxidised and other bodies to the metallic state, as explained below, under that process, It is also of very frequent employment as a test for sulphur in sulphides and oxidized bodicjs. (up of sulphates. Native sulphur is readily inflammable, burning with blue flame, and vola- tilizing (with the well known odour of burning brimstone) in the REACTIONS. 2i tbrm of sulphurous acid SO*. Metallic sulphides and sulphur-salts (especially if previously reduced to powder and moistened into a ]i!iste), when roasted in an oi>en tube of not too narrow diameter, ojivt! ofl" the same compound (SO'-), easily recognized by its odour, and by its action on a slip of moistened litmus paper placed at the top of the tube, the paper becoming reddened by the acid fumes. In very narrow (as in closed) tubes, jjart of the evolved sulj)hur may escape oxidation, and may deposit itself on the inside of the tuV)e near the test-substance. The sublimate, thus formed, is distinctly red whilst hot, and yellow on cooling. From many arsenical and antimonial su]])hides also, a coloured sublimate of this kind, but consisting of As-'S'', or 2Sb-'S'' -{- Sb^O^, &c., may be deposited in narrow tubes, especially if the tube be held more or less horizontally. Sulphides of all kinds, if fused on chax-coal with carb. soda (or better, with carb. soda mixed with a little borax) readily form an alkaline sulphide or " hepar." This smells, when moistened, more or less strongly of sulphuretted hydrogen, and imparts a dark stain to silver, or to paper previously steeped in a solution of lead acetate, A glazed visiting card may be used as a substitute for the latter. The stiiin is removed from the silver surface by friction with moistened boueash. Sulphates fused with carb. soda and a little borax (the borax in the case of earthy sulphates greatly assisting the solvent power of the flux) produce the same reaction. This reaction is of course produced also by sulphites (which do not occur, however, as minerals), and by bodies which contain selenium in any form. Sulphites, treated with hydrochloric acid, evolve sulphurous acid, easily recognized by its sDiell and its action on litmus paper ; and, in acid solutions, they yield no precipitate with chloride of barium. Sulphates, on the other hand, emit no odour of SO'^ when treated with hydrochloinc acid ; and chloride of barium produces an insoluble precipitate in their acid or other solutions. Bo readily splits up or decomposes, or which characterize it directly by their reactions. This metliod, therefore, is adhiTcd to in the present handbook. It may be urged that a formula of the kind represented by CiiO, C03 asserts too much, and that conseqiiently the more modern Ca CO3 is preferable. But riglitly considered, the old formulw necil not be assumed to make any^assertions regaitling the actual condition of bodies in combination, but only to indicate clenrly the well known siiiijili' compounds into which (in the great majority of cases) substances may be more or less readily decomjiosed, and the reactions which substances exhibit. As a strict matter of fact, moreover, the new formulae are not free from assertion. They carry upon their face, at least, a seiMiiiiig assertion that tlie elementary bodies in compounds are present in an absolutely free, se|)aiate and independent state; or tliat unknown problematic^al compounds, as CO3, SiO*, SiOr,, SiOo, etc., etc., are present in the substances to which these formula; refer. To take aiiothtsr illustration. A student has t.t'o minerals before him : ime he llnds to be the well known mineral, corundum, and consequently Al^O* (alumina) ; and the second hq finds to bo iii'tliiiiiry quartz, and consequently SiO'» (silica), according to the coHimonly received formula. He lias also before him a third mineral, one that gives the reactions of aluiiiiiia and silica, and yields these separate bodies on analysis. Naturally, therefore, he writes tlie formula (assuming the two components to be in equal atomic jiroportions) Al^oa, siO*. Hut, to his bewilderment, lie tliids it given in modern books as AlaSiOj. Practically, we do not want te know how iiiuch aluminium, silicon and oxygen, are present in a body of this kind, but how much alumina and silica ; and the first formula .shews us this, or enables us to determine it at once. Wore only siiujile elements and their complex combinations known to us, the new views, carried out l>riipcriy to their full conception, might pass without opposition ; but the question becomes "•iitirely altered by the occurrence of simple binary compounds bo abundantly in the free state. Ill mineral analysis, and in the piactica' stmly of minerals, it is not possible to ignore tliest) binary formula! without great inconsistency. Among other works, they arc retained essentially, w« are glad to find, in the standard and very copious " Handworterbuch der Chuniie,' now being publisiied under the editorship of Dr. Von Fehling of Stuttgart. See also Von KobcU'a remarks uu this subject ia tUe 6tU edition of Lis "Miueralogie :" 1878. 28 BLOWPIPE PRACTICE " ' ing tlie latter, is to boil or warm the powdered substance in a test-tube with a few drops of nitric acid, and after lialf-filling the tube with distilled water, to drop into it a small fragment of molybdate of ammonia. In the presence of phosphoric acid, this will turn yellow immediately, especially if the solution be warmed, and a canary- yellow precipitate (soluble in ammonia) will rapidly form. All natural phosphates, with the exception of the rare phosphate of yttria. xenotime, are dissolved or readily attacked by nitric acid ; and xenotime, if in fine powder, is generally attacked sufficiently to yield the reaction. Phosphates may also be decomposed by fusion, in fine powder, with three or four parts of carbonate of soda in a platinum spoon or loop of platinum wire. An alkaline phosphate, soluble in water, is formed by this treatment — with xenotime as with other phosphates — and the solution, rendered acid, may then be tested by molybdate of ammonia. Or it may be rendered neutral by a drop of acetic or very dilute nitric acid, and tested with a fragment of nitrate of silver, in which case a canary-yellow precipitate will also be pro- duced. Or it may be tested by adding to it a small fragment or two of acetate of lead, and fusing the resulting precipitate on charcoal. On cooling, the surface of the fused bead shoots into ciystalline facets. (11) Boron^ — Present in nature in an oxidized condition only, us boracic acid. Tlds occurs : (1), in the hydrated state; (2), in combi- nation with bases, in the group of borates ; and (3), in certain so- called boro-silicates. Boracic acid (or anhydride) and many borates and boro-silicates impart per se a green coloration to the flame-border, and all produce this coloration if previously saturated with sulphuric acid. In some few silicates, however, in which little more than traces of BO^ are present, the reaction is scarcely or only very feebly developed unless the test-substance, in fine powder, after treatment with sul[)huric acid, and partial desiccation, bo moistened with glycerine, according to a process first made knovvn by lies. But a similar flame-coloration is produced by phospltates and certain other bodies. For the proper detection of borates, therefore, the followiu;; long-known method should be resorted to. The test-matter, in fine ])owder, is saturated with sulphuric acid, and allowed tc stand for it minute or two; a small (piantity of alcohol is then added, and the mixture is stirred and inflamed. The prebcnce of BO'' — unless in ' REACTIONS. ■ »8 very minute or accidental quantity — communicates to the point and edges of the flame a peculiar green or yellowish-green colour, Phos- pluites do not colour the flame under this treatment. (12) Carbon. — Occurs in the simple state in the diamond and gnij)hite, and v.-actically so in the purer kinds of anthracite; also combined with Irogen, &c., in ordinary coals and bituminous sub- stances ; and in an oxidized condition, as carbonic acid (or anhydride) ill the gi'oup of carbonates. Free (mineral) carbon is infusible and very slowly combustible in the blowpipe-flame, a long continued ignition being necessary to effect the com})lete combustion of even minute splinters. Ignited with nitre, it tleflagrates and is dis8olved, carbonate of potash resulting. With other blowpipe reagents it exhibits no characteristic reactions. The presence of carbonic acid in carbonates is readily detected by the effervescence which ensues during the fusion of a small particle of the test-substance with a previously-fused bead of borax or phosphor-salt on platiimin wire, C(T" being expelled. All carbonates, even in comparatively larg(; fragments, dissolve readily under continued effervescence in these riuxi's. A mixture of carbonate of lime in silicates, sulj)hates, and otiit'r bodie.'!. may thus be easily recognized. {See Appendix, No. ID), It should be remeuibered, however, that bodies which evolve oxygen on ignition, produce also a strong effervescence by fusion with borax . but, with the exception of binoxide of manganese, very few of these bodies are of natural occurrence. ( 1 3) Silicon. — This element occurs in nature only in an oxidized condition, as Silica, SiO"''. The latter compound, in the form of quartz and its varieties, is the most widely distributed of all min- erals. In the various opals, it occurs combined with water, and in combination with bases (especially with Ar^O\ Fe'^0^, Cr,0, MgO, FeO, Na'-O, and K^O), it forms the large group of silica<^es. In the siniple state, silica is quite infusible in the ordinary blowpipe-flame. With carb. soda, it dissolves with ofiervescence (due to tlie expulsion of (!()'■ from the flux), and it forms with that reagent, in proper pro- portions, a permanently clear glass — i.e., a glass that remains clear on coo'ing. To obtain this, the flux should be added little by little, until perfect fusion ensue: with too much soda, the bead is opaque. 30 BLOWPIPE PRACTICE. Borax attacks silica very slowly, and in phosphor-salt it is still more slowly attacked. A portion may be taken up by the hot glass, bnt this is preci2)itated on cooling, and the glass becomes opalescent. (See Appendix, Ko. 15). Silicates vary greatly in their comport- ment before the blowpipe, the variation depending chieHy on the relative proportions of silica nnd base, and on the nature of the base. Many silicates are infusible ; others become vitrified on the thin edges j and others, again, melt more or less readily, — most of the so-called zeolites (hydrated silicates of alumina, lime, soda, &c., espe- cially characteristic of trap rocks) exhibiting the phenomenon of intumescence. Silicates, as a rule, are very readily detected by their comportment with phosphor-salt: the bases are gradually taken u]». whilst the silica remains for the greater part undissolved, forming a " silica-skeleton." This is seen as a diaphanous, flocculent mass (of the shape and size of the test-fragment) in the centre of the hot bead. A small portion of the silica, or in one or two exceptional cases the greater part of it, may be dissolved with the bases, but this precipi- tates as the glass cools, and renders it semi-translucent or opalescent. Practically, silicates are readily distinguished from phosphates, car- bonates, sulphates, &c., by these reactions with phosphor-salt : namely, very slow or partial solution, and formation in most cases of a silica skeleton or opalescent glass. The trial is best made on platinum wire, and the test-substance should be added, if possible, in the form of a thin scale or splinter. (See Appendix, No. 15). 'II. — UNOXIDIZABLE METALS. As regards their blowpipe reactions, th'^ metals of this gro\ip fall into two series : Injusihle metric, C(unprising [)]n,timmi (with palladium, mmable. Arseniates, on the other hand, never present a metallic lustre, and none are inflammable. Many cupreous arseniates deflagrate strongly when ignited on charcoal. Arsenic acid, As'-O"' (both alone, and in some ar.seniates), gives off" oxygen on strong ignition, and becomes volatilized in the condition of As'"'0''. * (20) Osmium. — This metal is of quite exceptional occurrence. It is found in only one mineral, Osmium-Iridium, and is thus often classed as a so-called "platinum metal;" but its gene)-al characters and reactions give it a place near arsenic. Osmium-Iridium remains unchanged before the blowpipe, unless the osmium greatly prej)on- (lerate (as in the variety known as sisserskite), in which case part of the osmium is volatilized. All varieties when fused with nitre in tlie closed tube or on charcoal, emit the penetrating disagreeable odour of osmic acid. Osmium, itself, volatilizes without fusing, emitting necei^sarily the same odour ; and in a finely divided state it is iutlammable. If volatilized in the pale flame of alcohol, or that of the Bunsen burner, it renders the flame highly luminous. (21) Mercury. — Occurs .sparingly in the simple state; in silver and gold amalgams ; and in certain selenides. More abundantly as a Hulpliide — Cinnabar, the only ore of mercury.'" Sparingly, also, in some varieties of grey cop))er oi-e (tetrahedrite) ; and in combination with chlorine, in native calomel. In these compounds, its presence may be readily ascertained by mixing the test-matter with some perfectly dry carb. soda, iron filings, neutral oxalate of potash, or other reducing substance, and igniting the mixture in a closed tube of narrow diameter. The metal volatilizes, and deposits itself on the neck of the tube in the form of a dark grey s'ablimate. If this be rubbed by an iron wire, it runs into fluid globules which can be * Hed ochre is frequently mistaken by explorers for cinnabar. Ajiart from the liit,'li sp. gr. >if tlii; latter, tlie two may ))e easily distinguished by an ignited luoifcr match. Held (in the loriji ofasmall fragment) in the match ilame, cinnabar takes lire and volatilizes; red ochre Mackens and becomes magnetic. 36 BLOWPIPE PRACTICE. poured out of the tube, and whicli are easily recognized as metallic mercury. Without the reducing agent, many of these morcui-ial compounds (cinnabar, calomel, &c.) sublime without or with only j)artial decomposition. When mercury is present in traces only, a piece of gold-leaf, twisted round an iron wire or glass rod, may be inserted into the mouth of the flask. The gold is whitened by a irere trace of the volatilized metal. (22) Bisiimth. — Occurs in nature chiefly in the simple metallic state. Found also, but more sparingly, in combination with tellu- rium, selenium, and sulphur, and with bases in sulpho-bismuthites. (Occasionally, likewise, in an oxidized condition (BiH)^) as bismuth ochre (commonly mixed with some carbonate of bismuth), and in a single rare silicate, arseniate, and vanadiate. Metallic bismuth fuses readily, and gradually volatilizes, depositing a dark yellow ring of oxide on the charcoal. The latter volatilizes in the inner flame without colouring the flame-border. Bismuth oxide is at once reduced and volatilized on charcoal. It dissolves in carb. soda in an oxidating flame, very readily, if a platinum wire or other non- reducing support be used. The glass is yellow or yellowish-brown whilst hot, pale yellow and opaque when cold. In borax and phos- phor-salt, it dissolves also readily. The borax glass in the O. F. is yellowish, hot, and very pale yellow or white aud opaline when cold. In the R. F. the glass becomes clear from separation of th(! reduced metal. The phosphor-salt glass in the O. F. may be rendered milk-white by flaming or saturation. In the R. F., with tin, it is transparent whilst hot, and very dark-grey or black on cooling. In this respect, the reaction resembles that produced by antimony. The presence of bismuth, in bodies generally, is detected by the dark -yellow coating or ring-deposit formed on charcoal by the fusion or ignition of the test-substance with carb. soda. This deposit is distinguished from that formed by lead, by its deeper colour, and by imparting no colour to the flame. Also, by the black bead formed by it (or by another portion of the test-substance) with phosphor-salt and tin in a reducing flame, as described above. The button of reduced bismuth, moreover, is brittle ; that of lead, malleable. These metals may also be dis- tinguished by the sublimates which they form when ignited on charcoal with iodide of potassium, according to the method of Merz ; REACTIONS. '8f or by fusion, first with .sulplmr, and then witli iodide of potassium, according to the more delicate process of Von Kobell. With lead, the sublimate is lemon-yellow, or in thin layers, greenish-yellow ; whilst with bismuth it presents a vivid scarlet colour, or jt ling of this around the outer edge of a yellowish deposit. When a very small amount of bismuth oxide is associated with excess of lead oxide, (-ornwall recommends a modification of the {irocess, as follows : the substance, mixed with about an equal quantity of a mixture of five parts sulphur and one part iodide of potassium, is ignited in a test- tube by the spirit-flame or bunsen burner. Th(> [)reseuce of bismuth is indicated by a scarlet or orange-coloured band, which forms above the yellow sublimate occasioned by the lead. {See, also, page G7, the chai-acteristic reaction with hydriodic acid, lately disco vei-ed by Dr. Haanel.) (23) Lead. — The occurrence of native lead is quite exceptional. The metal occurs most commonly as a sulphide (galena), and not imcommonly as a sulphantimonite (and to some extent as a sulph- aisenite). Also, frequently in an oxidized condition, as a sulphate, carbonate, phosphate and arseniate. Among rarer (natural) com- pounds, it occurs as a selenide, telluride, chloride, oxide, chromato, vanadiate, tungstate, molybdate, antimoniate. The presence of lead in bodies generally is made known in blowpipe testing by the two following characters : the formation of a yellow ring-deposit on charcoal, and the ready formation of a malleable metallic globide — these reactions requiring, however, in some few cases, the assistance of carb. soda or other reducing flux for their proper manifestation.* Load oxide is immediately reduced on charcoal, colouring the flame light-blue. It dissolves readily in the blowpipe fluxes if the fusion be performed on a non-reducing support. The glasses, produced by an oxidating flame, are colourless or yellowish, and become opaque by saturation or flaming. (See Ajipendix, No. 6.) (24) Thallium. — This new metal is only known to occur (in very minute quantities) in certain examples of iron pyrites, copper pyrites, zinc blende, native sulphur, and some few other minerals. Its chief characteristic is its i)ropei'ty of imparting a brilliant green coloration " In the presence of sulphur, more especially, the leduutiou is facilitated by the addition of a small piece of iron wire. See note at foot of page 19. 38 BLOWPIPE PRACTICE. to tlie Bunsen or })lowpipe flame. In other respects its reactions much resemble those of lead, but the oxidized ring-deposit (best seen on a porcehiin support or on the surface of a boneash cupel) is dark brown. (See Appendix, No. 14). ("25) Cadmium. — As an essential component, tliis metal occurs only in a rare sulphide, greenockite. It is present, however, in small quantity in many examples of zinc blende, and in certain varieties of the carbonate and silicate of zinc. Metallic cadmium, on charcoal before the blowpipe, shrinks somewhat together, blackens, takes fire slightly, and becomes volatilized in dense brown fumes. These deposit themselves in the form of a brownish-ldaek and reddish- l)rown coating (CaU), with a tinge of brownish-yellow towards the outer edge. The deposit is at once reduced and dissipated by either flame, witliout communicating any colour to the flame border. In both the closed and open tube, if the latter be of narrow diameter, a metallic sublimate is formed near the assay-matter, and a dark-brown sublimate, with yellowish edge, higher up the tube. Fused with phosphor-salt on charcoal, metallic cadmium (like metallic zinc) gives rise as the bead cools to slight detonations and flashes of light. Cadmium oxide on a non-reducing support is infusible, and remains unvolatilized. With borax and phosphor-salt it forms colo irless beads which become nulk-white and opaque by saturation or flaming. On charcoal the oxide is rapidly reduced and volatilized, but yields no metallic globule. The dark red -brown sublimate, formed on char- coal or better on a porcelain support by the fusion of a cadmiferous substance witli carb. soda, is the principal blowpipe-reaction of the metal. In the presence of much zinc, the blast must not be con- tinued too long, otherwise the dark deposit of cadmium oxide, formed before the deposition of the zinc oxiile, may l>o obscured by the lattor. For the detection of cadmium in the presence of ziuo generally, see A})pendix, No. 17. (26) Zmc. — Of doubtful occurrence in the native state. Found principally as a sul{)hide, oxy-sulphide, oxide, sulphate, carbonate, silicate and aluminate. Metallic zinc, when ignited on charcoal, burns vividly with transient flashes of green, blue and greenish-white flame, and throws off" dense fumes which become oxidized and deposited as a coating on the charcoal. This coating (ZnO) is pa]( - REACTIONS. M ypllow and pliosphorescont wlion hot, and white wlien coKl. It is not (h'iveu oil" l)y the reducing tlanie, uidess the blast bo long con- tinued. If moistened with a droj* or two of niti'atc; of cobalt, and ignited by au oxidating tianie, it becomes of a light-green colour on cooling. Zinc oxide forms with borax and phosi)hor-.salt colourlea.s beads, which become milk-white and oi)a((ue by saturation or when flamed. Metallic zinc fused with a bead of phosphor-salt on char- coal, detonates slightly any first fusing the test- substance with phosphor-salt, and then crushing the saturated bead on the anvil, and ve-melting it with carb. soda on charcoal. (27) Tin. — Native tin is of doubtful oeourrenoe. The metal of commerce is obtained entirely from the binoxide, known in its natural occurrence as cassitorite or tinstone. Tin occurs also, but rarely, as a sulpliide in tin pyrites ; and the binoxide is jjresent in small quantities in tantalates genei-ally, and in certain titaniates, sili- cates and other comi)ounds. Metallic tin melts easily, withoiit colour- ing the flame. Before the outer flame it rapidly oxidizes and gives off slight fumes, which form a coating on the fused globule and on the charcoal immediately around the latter. The coating is slightly- yellowish whilst hot, and white or greyish-white when cold, and it is not driven off by the flame, but in a long continued blast it may become reduced. When moistened with a drop of cobalt solution ♦ I have tried, but without success, to make this reaction available for the detection of phosphates by fusing these, in jiowder, with boracic acid, borax and other reagents, and then aililing a iiii'ce of njetallic ?inc to the glass. The reaction, although sonictimc!* produced by this treatment, is too uncertain to serve as a teati 40 BLOWPIPE PRACTICE. and ignited, it becomes on cooling blueish-green. SnO and Sn'O' (neitlier of any interest, mineralogically) burn on ignition, and ])ecome converted into binoxide. Tlie latter SnOz, is infusible bv the blowpi2)e, but on charcoal, in a well-sustained blast, it is reduced to metal. The reduction is greatly facilitated by the addition of cai'b. soda, neutral oxalate of potash, or a mixture of carb. soda and cyanide of potassium, the latter acting most ra])idly. In borax, the binoxide is very slowly attacked and dissolved ; and phos[)hor-salt acts upon it still more slowly. With both reagents the glass remains clear when tlamed. With soda in the outer flame, it forms, Avith effervescence, a greyish-white infusible mass. In a good reducing flame (especially if a little borax be added to pi'omote fusibility) it yields reduced metal. As j>ointed out by Berzelius, a small portion of borax should always be added to the soda in the examination of tantalates and infusible bodies, generally, foi; the presence of tin. A malleable, easily oxidizable, metallic glol)ule is then, as a rule, obtained without difhculty ; but when a trace only, or very small percentage of tin is present, the regular reducing process (explained on l)age 17) must be resorted to. A button of metallic tin may be distinguished by its malleability, feeble sublimate and ready oxidation, from other metallic globules as obtained by the blowpipe. In nitric acid it becomes converted into a white insoluble powder (SnO'^), behaving in this j-espect like anti- mony ; but the latter metal gives a brittle button, and also a copious sublimate or ring-deposit which volatilizes wholly or in chief pai-t, and communicf\tes to the flame a greenish coloration. From silver, the tin globule is distinguished by its ready oxidation, and its con- version into insoluble binoxide by nitric acid — silver, in that reagent, dissolving rapidly. From lead and bismuth, it is distinguished also by this acid reaction, and by the non -formation on charcoal of a yellow sublimate. When small pieces of tin and lead (or tin and thallium, or tin and bismuth), are melted together, a remarkable oxidation ensues — -the fused mass becoming rapidly encrusted, and continuing, after withdrawal from the flame, to push out excrescences of white and yellow oxides. [See A})pendix, No. 21). IV. — FLUX-COLOURING MKTALS, The oxides of the metals of this group possess, in common, the property of communicating distinct and more or less characteristic REACTIONS. M colours to borax and phosphor-salt glasses before the blowpipe. By some, also, a colour is imparted to the soda bead ; but most of these oxides are insoluble in carb. soda. They fall into two leading sections, as in the following arrangement : •6. — Xot reducible from an oxidized or oth'-r condition by the blowpijio. -B'.— Tlie borax-glass not rendered opaque by Naming : Manganese. Chromium. Vana- dium. B^. — The l)orax-gla8s converted by flaming into a dark or bglit enamel : Uranium. C, rium. 'Jitanium. A. — Reducible from an oxidized or other condition by the Idowpipe. A^. — Fusible, and therefore obtained by reduction in metallic globules : C'<>pi)er. A'^. — Infusible (practically), and therefore obtained by reduction in the form of sej)arate grains or scales : tiMagnetic: Nickel. Cobalt. Iron. +t Non-magnetic: Tungstenum. Molybdenum. (28) Copper. — This metal occurs frequently in the native state. Also as a base in numerous sulphides, and in certain arsenides, selenides, sulpharscnites and sulphautimonites. In combination like- wise with chlorine. Also in an oxidized condition as Cu^'O and CuO ; and in the latter form, as a base, very commonly in arseniates, phos- phiit(,'s and carbonates; and less commonly as a sulphate, chromr.te, vanadiate and silicate. Metallic copper, on charcoal, molts before the blowpipe into a malleable globule, the surface of which, if exposed to the outer flame, becomes quickly tarnished by a black coating of oxide. This oxide imparts to the flame-border a rich green colour, (.'upreous suli)hides, arsenides and related compounds become con- verted by careful roasting, with avoidance of fusion (see the 0[iera- tioii, page 11), into the same black oxide; and a roasting of this kind is always necessary as a preliminary to the reduction of the cop- per, and its detection by fusion with l)orax. Both the red and black oxides fuse i-eadily and become reduced on charcoal. With borax and pho.s])hor-salt, the glass after exposure to an oxidating flame, is green whilst hot, and clear-blue when quite cold — unless much iron or nickel be present, in which case it retains its green colour on cooling. In a niducing flame, especially on charcoal, the gla.s.s liofomes almost colourless, and on cooling turns brick-red and <>pa(pie. This reaction (which serves for the detection of copper in the presence of most other flux-colouring bodies) is developed more 42 BLOWPIPE PRACTICE. easily with borax than with phosphor-salt, but when very little copper oxide is present in the glass, it is not always obtained witliout long blowing. If, however, a small piece of tin or iron-wire be stuck through the soft glass, and the bead be then again submitted for a few moments to a reducing flame, the opaque red glass (due to the reduction of the CuO to Cu-0) is readily i)ro(luced. In place of iron- wire, a small fragment of any substance containing FeO (as iron- vitriol, magnetic iron ore, spathic iron, itc.) may be used to promote the reduction, tlie FeO becoming converted into Fe'O* at the expense of some of the oxygen of the copper compound. The fusion may then })e })erformed on platinum wire ; but, in any case, the bead must not be kept too long in the flame, as the whole of the copper oxide might be reduced to metal, and the glass become colourless by prolonged fusion. By this reaction, the presence of co])per in bodies generally (after the preliminary roasting of those which contain sulphur, antimony, &c.) is unmistakably revealed. Another charac- teristic reaction is the bright azure-flame })roduced by chloride of copper. The slightly-roasted substance may be moistened with a drop of hydrochloric acid — or fused Avith chloride of silver — and held just within the point of an oxidating flame. If copper be pre- sent, the flame around the test-substance will exhibit a brilLant azure coloration. The test may also be made by simply fusing the substance on platinum wire with phosphor-salt, and then adding some chloride of sodium to the bead. (<)'ee, also, Appendix, No. 12). (29) Nichel. — Occurs in small and variable proportions in most examples of meteoric ii'on, and also in some meteoric stones as a phosphide and sulphide. In minerals j)roper, it is found more especially as an arsenide, aiitimouide, sulpliide and suli)har.senite. It occurs also in an oxidized condition, at times as a simple oxide in coatings on nickel ores, but more commonly as an arseniate, car- bonate, sulphate and silicate. In some (mostly nuignesian) silicates, and in the apple-green variety of calcedony, known as chrysoprase, it is present in minute quantity as the colouring material of tlie substance. Metallic nickel is infusible in the blowpi[)e flame. As obtained by reduction of the oxide NiO by carb. soda or other reducing agent on charcoal, it forms numerous minute particles of a shining white colour. Those are strongly maguetic. Sulphides, REACTIONS. 43 arsonides and related compounds, become converted by roastinp: into tliis oxide. The latter is unaltered ^^e?* se l^y the blowpipe flame. With borax, it forms in the O.F. a glass which is amethystine in I colour whilst hot (if the NiO be in moderate quantity), and pure I brown or yellowish-brown when cold. If not too deeply coloured, the glass on the addition of a carbonate or other salt of potash in excess, is rendered more or less distinctly blue or greyish-blue. The reaction, however, is not very strongly marked, and except under special conditions it can scarcely be regarded as characteristic. In tlie R.F., the borax glass becomes grey and opaque on cooling, from })recipitation of reduced particles of metal. This is the characteristic blowpipe-reaction of nickel. It serves for the detection of that metal (when occurring in more than a very small percentage) in the presence of col)alt and iron oxides, but i^ is masked by the presence of cnjiper. Wluui co})per and nickel occur together, however, the presence of the latter may be suspected by the boi'ax glnss, after exposure to an oxidating flam'>, remaining green when cold ; whereas with co})per oxide alone, it becomes clear blue on cooling. The reaction, nevertheless, is merely suggestive, as it is produced by other metals, Fe, Cr, lijc, when associated with copper. With })hosphor- salt, NiO produces much the same reactions as with borax, only the glass in the oxidating flame is less distinctly coloured. With carb. soila on charcoal, as stated above, it is reduced to minute shining particles of magnetic metal. (30) Cobalt. — This nietal, as an essential constituent, occurs only ill a small number of minerals, and chiefly as an ar.senide and sul- phide, separately and combined. More rarely it is found as a selenide and oxide, and occasionally as an arseniate ; but it is present in traces, as an accidental eom])onent, in many sulphides and arsenides, us in varietiiis of arsetiical jyyrites, cubical pyrites, ike. The metal itself is practically infusible. Sulphides, arsenides, itc, become; con- verted by roasting into the oxide UoO. This, with carb. soda on I'liarcoal, is readily reduced to shining, magiujtic particles of metal. With both borax and jthos^thor-salt, and in both flames, the oxid«^ fi)rnis glasses of a deep blue colour, even when present in traces only. This is the characteristic reaction. When much iron, nickel, or cop})er is present, the glass however is dark greeu ; but copi)er and 44 BLOWPIPE PRACTICE. nickel may bo rpraoved by reduction in the inner flame (especially if a small piece of tin be added to the glass on charcoal), and the tint derived from iron is generally overpowered in the outer flame by the much stronger reaction of the cobalt. (31) Iron. — Occurs in the simple state in meteoric iron, though commonly alloyed with a small percentage of nickel. Occui's also, and in numerous localities, in various sulphides, arsenides and sul- phur-salts ; and in an oxidized condition as FeO -f Fe^O' in magnetic- iron ore, as Fo^'O^ in ha'matite, &c. ; and as FeO or Fe^O^ in numerous silicates and other oxygen salts. Metallic iron is practically infusible in the blowpipe-flame, but the extremity of a very thin wire may be oxidized and then fused. Hard wires fuse in general the most easily, and the fusion is accomj^anied by a rapid scintillation or emission of sparks, whilst very frequently a thin green flame streams from the point of the wire. The latter reaction is due to the presence of phospliorus. {See Appendix, No. 11.) Sulpirides, arsenides, &c., become converted into the sesquioxide Fe'-'O^ (often termed "red oxide") by roasting. Tliis oxide, by fusion with carb. soda and a little borax on charcoal, is easily reduced to shining particles of metal, strongly attractable by the magnet. On 2)latiuum wire or other non-reducing support, it forms with soda a slaggy infusible mass. It dissolves reralily, on the other hand, in borax and phos- phor-salt, forming glasses which are reddish or yellowish whilst hot, and very pale-yellow or almost colourless when cold, after exposure to the OF ; and more or less of a bottle-green colour after treatment in the R. F., especially if a small piece of tin be added to promote reduction, Fe'^O^ becoming thus converted into FeO, All minerals which contain 5 or more per cent, of iron become magnetic after ignition or fusion. By this reaction, ferruginous substances may be easily I'ecogiiized, as although cobaltic and nickeliferous bodies also become more or less magnetic on ignition, these latter bodies are of rare occurrence. They are readily distinguished, moreover, from ferruginous substances by the colours, kc, of the glasses which they form with borax. When the presence of iron has been recognized in .'I silicate or other body, it is often desirable to ascoi'tain whether the iron iii [yresent as sesijuioxide Fe^O", or partly or wholly as pi-otoxide. FeO. This may be determined by adding some of the test-substanee, REACTIONS. 4t) in ]iowcler, to a bead of borax coloured blue by previous fusion with a f(3\v particles of oxide of copper, and exposing the bead (in a loop of platinum wire) to the point of the blue flame until the substance begins to dissolve. If any FeO be in the sul)stance, it will become converted into Fe'''0' at the expense of some of the oxygen of the eo))j)er oxide, and the latter will thus become reduced to suboxide Cu^O, causing red streaks and spots to appear in the glass, as this cools. If no FeO be present, the glass will, of course, become green on cooling, but will remain transparent. {See Appendix, No. 5.) A very minute trace of iron may be detected by the following process : Fuse into a bead of phosphor-salt, on platinum wire, as much of the substance, in powder, as the bead will take up. Then siiturate the bead with successive portions of bisiilphate of potash (or treat the crushed bead with that reagent in a platinum spoon), and dissolve out the soluble matters in warm water. Finally, place in tlie solution a very small particle of ferrocyanide of potassium ("yellow prussiate"). If iron be present, a deep-ljlue preci[>itate will necessarily ensue. (32) Tanr/stenum or Wolframium.—DnH comparatively rare metal is known in nature only in an oxidized condition, as VVC, a comj>ound Aviiich occurs occasionally alone, but more commonly in combination with bases, thus forming the small group of tungstates. Tungstic ;icid or anhydride WO*, is scarcely aflected by the blowpipe-flame ; l)ut on charcoal, after long ignition in the R. F., it becomes blackened, l)y conversion into W^O'. With carb. soda or neutral oxalate of potash, it is reduced on charcoal to minute particles of metallic tungstenum ; but if nmch soda be used, the portion of test-matter absorbed l^y the charcoal is generally ol>tained (by washing in the agate mortar, page 17) in the form of minute yellow specks, of m(!tallic lustre, consisting of a com}x)und of soda and tungstic oxide. On platinum wire, with carb. soda, it dissolves more or less readily into a yellowish glass, which becomes opaque and somewhat crystal- line on cooling. Borax dissolves it readily. After exposure to the 0. F. the glass is yellowish and clear, but becomes enamelled by ttaniing. In the R. F., with excess of test-matter, the glass is yellowish-brown, and by flaming or on cooling it becomes opaque. With phosphor-salt, in a reducing flame, a deeply coloured greeniah- 46 BLOWPIPE PRACTICE. blue glass is obtained. Tliis is the cliaracteristic blowpipe reaction of tiuigsteniim compounds ; but if much iron be present, the glass becomes deep-red. The presence of tungstenum may also be detected by fusing the powdered test-substance with 3 or 4 parts of carb. soda and a little nitre in a platinum spoon or loop of thick platinum-wire, dissolving out the soluble alkaline tungstate (as explained on page 20), decanting the clear sohition, acidifying it with a few drops of hydro- chloric acid, and placing in it a ])iece of zinc. A dark-blue coloration (from reduction of the WO^ to \V-0'') will ra})idly result. (.33) Molt/bdenum.—Thh metal occurs in nature most commonly in combination Avith sulphur, in the sulphide molybdenite, a mineral which presents a curious resemblance to graphite in many of its pro- perties (foliated or scaly-granular texture, softness and flexibility, soapy feel, detonation with nitre, infusil)ility, itc). It occurs also, though rarely, in an oxidized condition as MoO^, this latter compound being found at times alone, but more commonly combined with lead oxide in the molybdate wulfenite. Molybdic acid or anhydride, MoO^, melts easily on charcoal, tinges the flame yellowish-green, and become>5 gradually volatilized, forming a deposit which is slightly yellowish whilst hot, and white when cold. When touched by tlu* reducing flame, this deposit assumes a dai'k-bluish tinge from partiivl conversion into Mo'^0'. In addition to the white coating, an indis- tinct reddish deposit is also formed near the test-matter. With carb. soda, reduction to minute steel-grey particles is easily effected on charcoal. On platiniim wire, solution takes place with effervescence. With borax,before the 0. F., a yellowish glass, which becomes grey and opaque by flaming, is formed ; and in the R. P., a brown or grey glass, with separation of dark flecks, the latter best seen by pressing the bead flat before it cools. With phos])hor-salt, on cooling, and especially after exposiire to a reducing flame, a tine green glass results. By this reaction (combined with the pro})erty of colouring the flame pale yellowish-green,* and yielding per se or with carb. sodii a white sublimate and reduced particles of non-magnetic metal), molybdenum compounds are chiefly recognized in })lowpipe practice. Molybdic acid and molybdates, as flrst made known by Von Kobell, •Although iiiolyluUnmn coiniKJunds colour the Uunscii flame very distinctly, they give ih' coloured bauds iu the spectroucope, but merely o continuous spectrum. REACTIONS. 47 wlicn warmed with sulphuric acid, produce a rich Wue solution on the addition of alcohol. If the test-substance be fused with carb. soda and nitre, and the solution of the alkaline molybdnte be treated with hj'drochloric acid and metallic zinc, a bluisli colour may appear at first, but tliis quickly changes to dark-br-iwn. {See under Tungstelium, No. 32, above.) (.34) Manganese. — "Does not occur, in nature, in the metallic state. Occurs occasionally as an arsenide and sulphide, but is chiefly found in an oxidized condition — mostly as MnO'^ and Mn'''0^ (these com- pomids occurring alone, combined together, or as hydrates) ; and as MnO in various silicates, carbonates, phosphates, tungstates, &c. As an accidental or inessential component it is present in the latter state in very numerous minerals. In these, the MnO generally ro])laces small poi-tions of MgO, CaO, or FeO. Manganese oxides are not reduced by carb. soda on charcoal. Very little of the oxide dissolves in the flux, but this communicates to tlie bead a gi'een colour whilst hot, and a blue or greenish-blue colour when cold. The reaction is bi'ought out more prominently by the addition of a little borax to the soda, as this promotes solution {see Appendix, No. D) ; and it is also increased in intensity by melting a small })ortion of nitre into the bead, or by pressing the hot bead upon a small fragment of nitre. A greenish -blue bead of this kind is known technically as a " turquoise enamel." Manganese oxides dissolve readily in borax and in phosphor-salt, and the solution in the case of the higher oxides (MnC^ especially) is accompanied by great effer- vescence or ebullition, due to the escajie of oxygen from the test- mutter. Oxygen is also evolved when these oxides are strongly ignited per ae, as in a closed tube, «kc. {See under "Oxygen," above.) The liorax glass after exposure to an oxidating flame presents a beautiful amethystine colour. In a reducing flame it becomes colour- less, but if allowed to cool slowly it absorbs oxygen, and the ame- thystine or violet colour is restored. This may be prevented by uigiiig a stream of air from the blow})ipe upon the bead, directly the latter is removed from the flame. When very little manganese is present in the test-matter, the formation of a violet-coloured glass is facilitated by the use of a sniall fragment of nitre. The phosphor- salt glasses resemble those produced with borax, only the amethystine 48 BLOWPIPE PUACTICE. colour is palei", and when very little manganese is }»resent it is scarcely dev(iloj)etl without the aid of nitre. The great test for the })i-esence of manganese in bodies, is the formation of a turtiuoise enamel by fusion on platinum wire or foil with carb. soda and a little borax. Less than one part in a thousand may be easily detected by this re- action ; and by the addition of nitre, as described above, the reaction becomes still more delicate. Chromium compounds when fused with carb. soda in a reducing flame form a yellowish-green mass, which might in some cases be thought to arise from the presence of man- ganese. But if a greenish mass of this kind be fused with sufficient boracic acid or silica to form a clear glass, the latter in the case of manganese will present an amethystine colour, whilst in that of chromium it will be emerald-green. (See Appendix, No. 16.) (35) Chromium,. — Traces of this metal occur in some varieties of meteoric iron, but otherwise chromium is found in nature only in an oxidized condition, as CrW and as CrO^ In the former state it occiu'S occasionally alone, as in chrome ochre ; but more commonly in combination with iron in chromic iron ore, or, as a base, in certain silicates, and in varieties of spinel. In many silicates it is present as an inessential component, as in the emerald, })roper. In the condition of CrO^, it occurs in combination with lead oxide or coj)per oxide in the small group of chromates. The heading blowpipe reactions of chromic oxide are as follows : Per se, the oxide is practically un- changed. With carb. soda, it dissolves more or less readily, forming a yellowish, opaque bead in the outer flame, and a yellowish-green bead in a reducing flame. If a particle or two of nitre be fused into the bead, the latter becomes blood-red whilst hot, and light-yellow "when cold — a soluble alkaline chromate resulting. With borax and phosphor-salt, clear, emerald-green glasses are produced, especially by treatment in a reducing flame, and after complete cooling. Whilst hot, the glass is yellowish or red, as in many other cases. The pro- duction of an emerald-green glass with borax generally serves for the detection of chromium compounds ; but the character becomes neces- sarily masked to some extent by the presence of other flux-colouring bodies, as iron, copper, and cobalt oxides, for example. In the presence of bodies of this kind, chromium is best detected by fusing the test-matter (iu powder) with three or four parts of carb. soda, REACTIONS. 4l0f and a little nitre in a platiniun spoon or loop of stout platinnm-wire. A soluble alkaline chroniate then results. The solution (see page 20), tiltoied or carefully decanted from the insoluble residuum, may be divided into two portions. One portion may be evaporated to dry- ness, and the resulting deposit tested by fusion with borax. The other portion may be carefully neutralized by a drop or two of dilute nitric acid, or acetic acid, and tested with a fragment of nitrate of silver : a red [)recipitate should be produced. Chromates, also, wheii treated with sulphuric acid and alcohol, form a rich green solution whicli remains green on dilution. Chromic acid, CrO'*, per se, blackens when ignited, gives off oxygen, and becomes converted into chromi<; oxide. Bichromates, and many chromates also (but not neutral alkaline salts), produce tlu; same reaction. (36) Vanadium. — Occurs, in nature, only in an oxidized condition, !is V^Qs, combined with lead-oxide, and more rarely with other bases, ill the small group of vanadates. On charcoal, vanadic acid, fuses and becomes in part reduced to dark-grey or black shining scales of suboxide. If heated on a fragment of porcelain or other non-reducing support, it fuses without decomposition, and congeals with vivid t'lnission of light, on removal from the flame, into a red or dark orange-coloured crystalline mass. With borax, it forms a clear yellowish-green glass, and with phosphor-salt a yellow glass, on cool iiig, after exposure to the outer flame ; and emerald-green glasses with both fluxes, on cooling, after exposure to a reducing flame. With hydrochloi'ic acid and alcohol, vanadates give a green solution which becomes light-blue on dilution (Von Kobell). In addition to tins test, it may be observed that whilst chromium compounds give ill the O. F. with phosphor-salt (on cooling) a green glass, the glass formed by vanadium remains yellow^ when cold — in the absence, at least, of copper or other flux-colouring bodies. (37) Uranium. — Occurs only in an oxidized condition: chiefly as 1^0. U^O^ ill the mineral jiitchblende, and as IJ'O^ in uran ochre and a few comparatively rare phosphates, suli)hates, carbonates, and silicates. The sesquioxide is infusible per se, but is blackened in the R. P. from oartial reduction to UO. It is insoluble in soda, and is not reduced to metal by that reagent, but it is readily dissolvf^d by borax and phosphor-salt. The borax glass is deep-yellow in the 50 BLOWPIPE PRACTICE. O. F., and dingy brownish-green, when cold, after subjection to a reibicing iliune ; and, if tlioroughly saturated, it may be rendered bhick by flaming. The phosphor-salt ghisse.s present a striking con- trast, in being briglitly coloured : yellowish-gi-een in the O. F,, and clear chrome-green in the R. F., especially when cold. This reaction serves to distniguish uranium compounds from those of chromium, tfec. ; but in the presence of other llux-colouring bodies uranium is not readily detected. (38) Cerium. — Occurs in only a few comparatively rare minerals — chiefly as a fluoi-ide, or in an oxidized condition in certain silicates, pliosphates, &c. On ignition, CeO becomes converted into yellow or reddish Ce'^0\ This remains unchanged. With carb. sodit, on char- coal, it is reduced to grey (JeO, but gives no metal. With borax in the 0. F. a reddish or yellowish glass is obtained, and in the R. F. a colorless glass. Both glasses become opa([ue when flamed, if tolerably saturated. With phosphor-salt, the glasses on cooling are colorless, but they are not rendered opaque by flaming, even if strongly satu- rated. As a rule, the presence of cerium in minerals cannot be safely proved by the bIowpi[)e alone. (39) Titanium. — Occurs, in nature, in an oxidized condition only — as TiO'^ in three separate forms (Kutile, Octahedrite, Brookite), and combined with lime, yttria, zirconia, &o., in the small group of titaniates. In this condition it is present also in certain silicates ; and as Ti'^O' it partly replaces Fe^O' in titaniferous iron ores. TiO'^ becomes yellowish on ignition, but remains infusible, and re- assuraes its white colour on cooling. Moistened with nitrate of cobalt, and ignited, it becomes green when cold. With soda, on charcoal, it is not reduced to metal, but it fuses with effervescence, and on cooling the surface of the bead shoots into broad crystalline facets of a pearly-grey colour. Witli borax, it forms in the O. F. a yellowish glass which loses its colour on cooling, and when satiirated becomes on cooling or by flaming milk-white and opaque. In the R. F., the glass, moderately saturated, assumes on cooling a brownish- amethystine colour, and with more of the test-matter it becomes blackish-blue and opaque on congealing. When flamed, a light greyish-blue film spreads over the surface of the bead. The dark- blue tint (Plattner calls it "brown") arises from Ti'''0'; the light-blue REACTIONS. ftl Rurf..ce-film from tlie pavtial oxidation of this into TiO^ With jiliosphor-salt, the ghiss in the 0. F. is colorless or pale yellowish ami ill the R. F., on cooling, it assumes a fine anusthystine colour. When titanium comjtounds contain iron, however, the ji;lass is cUrj) red-brown or blood-ied. ]n the case of Menaccanite or Titaniferous Iron On;, ju'oper, this reaction is very marked; hut it is not vsuf- tifiently dt^finite to serve for the detection of small tpiantities of titiUUunj in ordinary iron ores. In these, the presence of titanium- is most readily detected as follows : — Keduco a ))ortion of the ore to as tine a powder as {»ossiltle ; warm this with hydrochloric acid in a small covered beaker-glass for about half an-hour on a sand bath, k',!C'i>ing the acid just at the boiling-point; add a little water, and tilter from the insoluble rock-matter, Ac. ; place a piece of metallic tin in the filtrate, and boil for ten or fifteen minutes. Thus treated, the deep-yellow solution will quickly become greenish and then color- less, and on the boiling being continued, a pink tinge will appear and gradually dee[»en into a distinct amethystine colour. In tlie absence of titanium, the solution will of course remain colorless, but the boiling must not be discontinued too soon. The presence of titanium in iron ores, &c., n)ay also be detected by fusing the test- matter, in fine [)cwder, with six or eight parts of bisulphate of potash (added in successive poi'tions) in a platinum spoon ; ti'eating the fused mass with a very small quantity of warm water ; decanting or filtering from insoluble matters ; adding a few drops of nitric acid, and then five or six volumes of water ; and, finally, boiling for ten or twelve minutes. Titanic acid, if present, is precipitated in the form of a white or pale-yellowish powder. This may be fused with plios))hor-salt, in a reducing flame, for the ])roduction of a characteristic amethystine glass. As pointed out by Gustav Rose, a glass of this kind, rendei'ed colorless or nearly so by the O. F., and then slightly flamed, becomes opalescent from the precipitation of numerous crys- tals of TiO*. These are best examined, in the flattened bead, by a microscope with object glass of moderate but not too low power. V. — EARTH METALS. This group is to a great extent conventional. Tantalum is placed in the group, because in a scheme of this kind it can scarcely be placed elsewhere. The representatives of the grouj) are separated, from those of the preceding series by their property of forming 52 BLOWPII'E PRACTICE. uiicoloured glasses with the bk)W])ij)() fluxeH ; and fVoni thoso of the next series by their non-alkaliiK^ chai-acter. With reference purely to blowpipe characters, it would pc^rhaps be a more satisfactory arrange- ment if magnesium were also referred to this group, the other metals of Group 6 and those of Group 7 being jjlaced together in a single group under the name of F lame-colour er 3. Keei)ing, however, to the i)resent distribution, it may be pointed out that aluminum compounds are distinguished from those of the associated metals by not forming an opacpie glass with borax, and by tlie blue colour assumed after ignition with nitrate of cobalt. Conij)ounds of the other metals belonging to the group are of comparatively rare occurrence. (40) IWatahivi. —Occurs only in an oxidized condition as tantalic acid (Ta^'O'') commonly associated with columbic or niobic acid (Nb'^O^) and combined with iron oxide and other bases, in a few minerals of exceptional occurrence. Tantalic acid becomes pale yellowish on ignition, but resumes its white colour on cooling, and remains iufusible. After treatment with cobalt-solution it becomes pale flesh- red. With cai'b. soda it dissolves with effervescence, but is not reduced. With borax, it dissolves easily, the saturated glass becoming opaque on cooling or by flaming. With phosphor-salt it forms a permanently clear bead. Its presence in minerals cannot bo safely detected by the blowpipe alone. (41) Aluminum. — Occurs in nature as a fluoride (in cr_yolite, &c.), but essentially as an oxide, APO*. The latter compound occurs alone and in a hydrated condition (corundum, diasj)ore, gibbsite) ; and in combination with magnesia and other bases as the electro- negative principle of the small group of aluminates. It occurs also, and more frequently, as a base, in various silicates, phosphates, and sulphates. Exceptionally, also, as an arseniate ; and in combinaticn with an organic acid in the mineral mellite. Alumina presents the following blowpijje reactions : (1) Per se, it is infusible and imchanged. ('J) Moistened with nitrate of cobalt, and ignited, it assumes, on cooling, a fine blue colour. The reaction is exhibited by all aluminous silicates, phosphates, &c., which are free from iron oxides or other strongly coloured bases (»9ee page 12.) (3) Alumina is not attacked by carb. soda. (4) It is very slowly dissolved by borax and phos phor-salt, forming colorless, permanently clear beads. (5) It is REACTIONS. 53 «lissolvo(l, in fino powe?' .se, and in.soluble in w till' tjii'i'ii ami ri'il cftlriiini lines ami the red K-liiiu vt'iy distinctly. Thi; lithiuiu-liuo is iilso sliewii by some kinds of tobacco. GO BLOWPIPE PRACTICE. over the opening of the tube. Most ammonium compounds impart a fe(?ble blueisli-green or brownish-greeii colour to the flame, but none give a distinctive spectrum. § 6. PLAN OF ANALYSIS. In the examination of a mineral substance with a view to determine its general nature by the blowpipe — aided by such liquid reagents and processes as are available in blowpipe practice — it is advisable, in the first place, to determine the electro-negative element or compound in the substance (or, in other words, to ascertain the chemical grouji to which the substance belongs), and afterwards to determine the base or bases tliat may be present in it. The methods of Blowpipe Analysis usually followed, although well adapted to convey a knowledge of the special reactions of bodies, have two essential defects : they draw no line of separation between electro-negative substances and bases, but mix up the two together in a loose and confusing manner ; and they exact the performance of a great number of experiments, by which many substances are detected over and over again, whilst others may easily escape detec- tion altogether. In the plan now proposed, these detects are in a great measure remedied, and a knowledge of the chemical nature of an unknown mineral— so far as tliis can be obtained by the Blowpipe — is arrived at without unnecessary trouble or dehiy. If the electro-negative 2)rinciple in the substance be not detected by one or the other of tlie eight easily and rajjidly performed experiments given under the fii'st section of the scheme, the substance — unless it be a telluride, tantii- late or other rare compound, properly omitted from consideration in an outline of the present character — will be either a simple Ixisio- oxide oi' metal, and its true nature will be revealed in the examina- tion for bases, as given under Table B. It will, of course, be understood, that, as a rule, the entire series of experiments for the detection of electro-negative bodies need not be carried out. Sulphates, for exiun[)le, will be I'ecognized by the first experiment, carbonates and silicates Ijy the second, and so on as regards representatives of other groui>s. ICxcept, theicfore, in certain rare cases indicated in the text (as in the combination of a })hosphate and fluoride, &c.), it PLAN OF ANALYSIS. 61 Avill only be necessary to continue the experiments until the chemical •jrrotip to which the substance essentially belongs has been ascertained. The base or bases, present in the substance, may then at once be sought for. A.— DETECTION OF ELECTRO-NECIATIVE BODIES. EXPERIMENT8. 1. Fuse the test-snl)- staiice, in ])owder, with carl', soila (and a small aildition of l)orax) in R. I'\ on charcoal. Moisten fused mass, and place on lead test- ]iajier or silver-foil. N.B.-Tffhefusion beeffootcfl liy a pis tlaiiK^ tlu^ {,'iis should li.- U'stiil iirc\i(m.sly tor jircs- ciice (if siil[iliur. See under ' f!iil]iliui'" in ji 5. 2. Fuse solid particle (if test-sul'stance with (previously fused) bead of phosjihor-salt on jjluti- iiuni wire. .'1. Fuse test-substance in [Hiwdcr with phosjdior- ^;ilt and copper oxide on plat, wire, or with phoa- plior-salt alone on copper wire. Results moiie Especially TO BE Looked Fob. ( 1 ) Emissi(m of arseni- cal odour. (2) Emission of copious fnme.s, and dcjK'sition of dense whito coating on the charcoal. (.S) Formation of "he- par," or alkaline sulph- ide. OtliPT results (if nny) such us reduction to metal yellow coating on charcoal, &c. , may lie noted down for after refer- ence. ( 1 ) Very slow solution, with formation of silica- skeleton or opalescent bead. (2) Rapid solution, ac- comi)anied throughout by efl'ervescence. other resnlt.s (as rapid solu- tion without cirerve.sccnce, itc.), may he notid iloAvii, but an; not to be taken into ac- count here. Substances Indicated. (1) As., Arsenides, Ar- seniates, (1 and .3) AsS., As'^S^, Sulpharsenites. (2 and .'}■) Sb^S'; Sul phantinuun'tcs. m S. Sulphides, Sul- jihates, also the rare Selenides. S( (! siKHial reactions § 5, for distinctive and tonliiinaioiy (tharacter.s. Rich azure blue flame. Note.- If a blue and green, or an inten.scly vivli! green llanic lie iirodiu'ed, l!r. and I may be suspected, but natural Ufomidcs and lodulcs are of very ran) occurrence. Teat with (ilry) bisulphate of pot- ash in closed tube over Hun- sen llame (for yellow or violet fumes). (1) Silica, generally. Silicates (2) Carbonates (also bodies winch evolve oxygen, as MnO*, Bichro- mates, Chlorates, &c. ). C'jiijirmtitnry s of sulphuric acid, add a little alcohol, stir and iutiame the mix- ture. G. Heat the substance, in powder, with a few drops of strong sulphuric acid in a narrow test-tube. 7. Fusetest-substance, in fine powder, with about 3 parts of carb. soda and 2 nitre in a platinum spoon or loop of platinum wire, l^issolve resulting soluble matters in hot water; decant clear solution into a small porcelain cajisule, add a few drops of hydro- chloric acid, and place in the solution a jjiece of zinc. Results moke Espkciali.y TO BK Looked Fok, A canary-yellow pre- cipitate. (1) A deep-green solu- ticm. (2) A rich blue solu- tion. (3) A green coloration of the Hame. Note. — A gi'cen flame is prn- (liK'P.d by most Ixiratcs pi'r .sc, ill all, by iiioisteiiitiij; the test- substance with snliiluirieacul, rir with glycerine. Phosphates, however, jiroduee the same re- aetion when thus treated, but do not give a. green tlame with uluoliol. (1) Corrosion of inside of tube. (Wash out thoroughly, and dry be- fore coming to conclu- sion.) (2) Evolution of ruddy (nitrous) fumes. A dark-blue coloration. Note. - • ■ Molybdenum com- pounds when thus treated may also jiroduce a blue Cdloration at first, but this, on standing, becomes rapidly dark bi'own. Substances Indicated. Phosphates. Note.— Most i)hosphates, especially if moistened with sul|iluirie acid, impart a green tinge to the tlame. Many natiiial iihosphate-t aie combined with chlorides or fluorides, or with both. CI., if present, will have l«:en deteetej by ICxpt. 3 ; Fl. must besouylit for by Expt. 0. (1) Cliromates. (2) Molybdates. (3) Borates, also "Boro- Silicates." Note. — Sin.'tU portions of B*()3 in silicates, &c., miiy escape detection by this Exjit. but the object of the ])reseiit scheme is not to detect minuli' or inessential comjuments, but (o determine the eiieiiiical group to whiidi the test-siili- stijice may belong, See under Ueactious, § 5. ( 1 ) Fluorides, also com- binations of Fluorie. ^foTK. — This cxiicriiiiinit iiiny be omitteii as a riili^ in the lust; of minerals of lUL'tallic iisimct. 2. Ignite or fuse pi-r w in platinum forceps, or, if metallic, on charcoal. 3. Fuse (after thorough roasting, if necessary) with carb, soda and a little borax on charco;vl ; or, if the substance jiresent a non-metallic aspect, on platinum wire. (1) Presence of moisture ("J) Assumption of dark colour anil magnetism. <)th(!r I'psults (if any; may be disregarded. ( 1 ) Coloration of flame : lo Hcddaiiic; 1* Yellow Miiiiie; Ic (Jreeii Haiiie ; \d Blue Hame ; 10 Violet Bauie. (2) Ring-deposit on char- coal : 2a White dep. ; 21" Red-brown dep. ; 2« Yellow dop. (3) Assumption of mag- netism. (4) Assumption of caus- ticity. ( Page y. ) other results (if any) may be disre'^arded. (1) White or yellow ring-d(^posit on charcoal. (2) Reduced metal : 'JO Fusible, non-oxidizable };lnbule; ■.'*Infns., non-ox. par- ticles ; 'Jfi Infusible, oxidiziUile, ni;i}ead, not affected by flaming. (4) A colourless bead which becomes opac[ueou saturation or by darning. (1) Copper ; Nickel ; Cerium ; Uranium (the glass becomes black in llF). Also Molydenum (to some ex tent l/l'ungstenum and Titanium ; but these metals occur mostly in minenals as oxidized elec- tro-negatives, and thus come under detection in 'I'aiu.e a. {'2, Manganese ; Chro- mium (see Table A); Iron; Col)alt. (3) Alumina ; Tin oxide (to some extent). Both very slowly attacked. (4) Zircoiiia ; (llucina ; Yttria; Zinc oxide; Alka- line earths (MgO, CaO, etc.) ; Alkalies. 0. Additional experi- ments — (as ignition with cobalt solution ; testing for Hg. with reducing agents in closed tube ; eu- pullation, &c.,) if thought necessary ])y physical characters of t le test- substance, or by indica- tions resulting from the al)ove blowpipe trials. .'■ ' • s ADDENDUM TO TABLE B. A Classification, according to their Blowpipe Characters, of the more commonly occurring Mineral Bases. Section 1. — Giving per se, or with card, soda, on charcoal, METALLIC globules OR METALLIC GRAINS. Gro\ip 1. — Yielding malleable metallic glohides, without deposit on (he charcoal. 6 ■"^""■' ":■"■'" 60 BLOWPIPE PRACTICE. (laid. Silver. Copper. Gold is insoluble in the fluxes. Silver is not oxidized j^er se, but retains a bright surface after exposure to an oxidating flame. Copper b(^coines encrusted on cooling with a black coating. It iniitarts a green colour to the flame-border ; and forms strongly coloured glasses with borax and phosi)hor-salt : (green (hot), blue (cold), in O F ; red-brown, opaque, in E, F : see above). Gold and silver may be separated from copi>er, &c., by fusion with lead, and subsequent cui)ellation. If gold and silver be present together, the bead is genei"ally more or less white. By fusing it in a small platinum- s[)oon with bisulphate of potjish, the silver dissolves, and the surface of the globule becomes yellow. If the, globule be flattened out into a disc on the anvil, before treatment with bisulphate of potash, tha silver is more rapidly extracted. The sulphate of silver must bo removed by treating the sjioon, in a porcelain or platinum capsule, with a small quantity of water, over the spirit-lamp. By evaporation, and fusion of the residuum with carb. soda on charcoal, metjxllic silver can be again obtained. Group 2. — Yielding infusible metallic grains, without deposii on the charcoal. Platinum. Iron. Nickel. Cobalt. Molybdenum. Timgstenum. Platinum is not attacked by the blowpipe fluxes. Iron, Nickel, and Cobalt, or their oxides, are reiwlily dissolved by fusion with borax oi phosphor-salt, producing a coloured glass. {See under " Borax," pages 13, 14, above.) These metals are also magnetic. As a general rule if a substance become attractable by the magnet after exposure to the })lowpipe, the presence of iron may be inferred, cobalt and nickel com- pounds being comparatively raie. The presence of cobalt is readily detected by the rich blue colour of the borax and phosi)hor-salt glasses, in both an oxidating and reducing flame ; but if much iron be present also, the glass is bluish-green. With borax in the R F, nickel com- pounds give reduced metal, and the glass becomes gray and troubled. Molybdenum, and Tungstenum give non-magnetic grains of reduced metal. They are commonly present in minerals as the electro-nega- tive principle, and their presence is best detected by the method given under Experiment 7, Table A, above. PLAN OF ANALYSIS. 67 Group 3. — Yielding metallic ut a precipitation of bismuth would ensue, in the absence of lead, if either zinc or iron were present. These metals, however, may be eliminated from the test-globule by exposing this on charcoal for some minutes, with a mixture of carb. soda and borax to a reducing flame. The zinc becomes volatilizc^d, and the iron is gradually taken up by the borax. If a single opera- tion do not eflect this, the globule must be removed from the saturated dark green glass, and treated with further portions of the mixture, until the resulting ghiss be no longer coloured. 1848. 7.— DETECTION OF LITHIA IN THE PRESENCE OF SODA. This test may be ap])lied to ntixtures of these alkalies in the simplo state, or to their carbonates, sul[)hates, nitrates, or other conipouiids capal)le of being decomposed by fusion with chloride of barium. The test-substance, in powder, is to be mixed with about twice its volume of chloride of b.irium, and a small portion of the mixture is to be APPENDIX. • TB exposed on a loop of platinum wire to the point of a well-sustained oxidating flame. A resence of lithium compounds ; and the colour will endure sufliciently long to prevent the slightest clianee of misconception or uncertainty. The presence of strontium compounds does not affect this reaction, as these compounds, when fused with chloride of barium, cease to imjMii't a red colour to the flame. {See No. 4.) In order, however, to ensure success in the aj)plication nf this test, it is necessary, in some cases, to keep up a clear and sharply-defined flame for about a couple of minutes. If the red coloration do not apj>ear by that time, the absence of lithia — uidess the latter substance be present in minute traces only — may be safely concluded. 1850. 8.— ACTION OF BARYTA ON TITANIC ACID. Fused with borax in a reducing flame, titanic acid, it is well known, forms a dark amethystine-blue glass, Avhich becomes liglit blue and 0])a([ue when subjectetl to the flaming process. The amethystine colour arises from the presence of Ti'-H )•'• ; the light blue enamelled sur- face, from the precipitation of a certain ])ortiou of TiO^ The presence of l)aryta, even in conipai-atively small quantity, quite destroys the latter i-eaction. When exposed to an intermittent flame, the glass (on the addition of bai-yta) remains dark blue, no ])reci})itatioii of tilaiiic acid taking ])lat^. Strontia acts in the same manner, but a much larger quantity is required to pix)duce the reaction. 1852. 9— DETECTION OF OXIDE OF MANOANESE WHEN PRESENT IN MINUTE QUANTITY IN MINERAL BODIES. It is usually statixl in works on the blowpipe, that the smallest traces of juauganese may be readily detecteil by fusion with carbonate of soda, or with a mixture of oarbonate of smla and nitr.ite of potash : but this statement is to some extent erroneous. In the presence of much lime, magnesia, alumina, sesquioxide of imn, or other bodies, 76 ELOAVPIPE PRACTICE. insoluble, or of difficult solubility, iu carbonate of soda, traces of oxide of manganese may easily escape detection. By adding, however, ii small portion of borax or phosphor-salt to the carbonate of soda, these bodies become dissolved, and the formation of a " turquoise enamel " (manganate of soda) is iv^dily effected. The pi'ocess may l)e varied by dissolving the test-substance first in borax or phosphor-salt, and then treating the fused bead with carbonate oi" soda : the latter being, of course, added in excess. By this treatment, without the addition of nitrate of potash, the faintest traces of oxide of manganese in lime- stone and other i-ocks, are at once made known. 1852. Note. — This method of examining bodies for the presence of manganese, was recomnifiuded by Dr. Leop. H. Fischer in 1861 (" Leonh. Jahrbuch ' [1861 J, p. ()5.S), but the writer had forestalled him by nine years, having already described it iu 1852. 10.— THE COAL ASSAY. In the practical examinition of coals, the following operations are essentially necessary-* (1) The estimation of the water or hygro- * To these might he addcil, the de.tenuinatiou xT the heating powers or "absohite wariutli ' of the coal, but this may iilways be estitiiatetl witli suffieieiit exactness for practical purposes by the amount of coke, asli, anil moisture, as compared witli otlier coals. Properly considereil. the lith.arge test, resorted to for the determination of the calorific power of coals, is of very little actual value. The resjiective results furnished V)y good wood charcoal and ordinary eolartnient of the Basses Alpes iu south-eastern Fran<;e, and those ot Cuba, yield with litharge from 25 to 20 parts of reduced lead; whilst many caking coals, practically of much higher heat- ing power, yield scarcely a larger amount. When pyrites also is jiresent in the coal— a condition of very common oecurreucc— the litliarge ttst becomes again unsatisfactory, the pyrites exerting a reducing action on the lead comjiound. As described, however, by Bruno Kerl, in quoting the writer's coal assay (" Lfithrohr-Unter- fiuchungeu:" Zweite Aufl. 18(52, p. 140) the so-called absolute warmth or heating power of a coal sample may be determined, if desired, in lilowpipe pra(!tiee, by the following modification of Berthier's method: 20 milligrammes of the coal, in line powder, are to be mixed intimately with 500 milligiaiumes of oxy-chloride of lead (consisting of three jiarts of litharge -I- 1 part of ehloriile of lead, fused together and llnely jjulverized). The mixture is to bo placed in a blow- pijie enuuble, and covered with about an equal amount of tlio lead compound, a second cover of 8 blowpipe- spoonfuls of jiowdered glass + 1 spoonful of borax being spread over this. The crucible, covered with a clay capsule, is then to be lltted into a charcoal block in the ordinary l»lowi)ipe furnace, over whi<'h a cbarcoiJ lid is placed, and the flame directed against its under side, so as to keep it at a red heat for from 5 to 8 minutes. The woiglit of the reduced lead divided by 20 gives the aiuouut of the lead mixture reduced by one part of the coal. One part of pure carbon reduces 34 jiarts of this mixture ; one part of charcoal, 30 to 33 parts ; one jiart of liiluminous coal, 19 to "3 ; one part of brown coal, 11 to 26 ; oue part of peat, 8 to 27 ; and one part of wood, 12 to 15 parts. APPE^'DIX. 77 metiic moisture present in the coal ; (2) the determination of tlie weiglit and character of the coke ; (3) the estimation and examination of the ash or inorganic matters; and (4) the estimation of the sul- phur, chiefly present in the coal as FeiP. Estimation of Moisture. — This operation is one of extreme sim- plicity. Some slight care, however, is required to pi'event other volatile matters from l>eing driven off during the expulsion of the moistui'e. Seven or eight small particles, averaging together from 100 to 150 milligrammes, are to be detached from the assay specimen by means of the cutting pliers, and carefully weighed. They are then to be transferred to a porcelain cai)sule with thick bottom, and strongly heated for four or five minutes on the support attached to the blow- pilielamp, the unaided flame of the lamp being alone employed for this puqwse. It is advisable to place in the capsule, at the same time, a small strip of filtering or white blotting-paper, the charring of which will give indications of the temperature becoming too high. The coal, whilst still warm, is then to be transferred to the little brass capsule in which the weighings are performed, and its weight ascertained. In transferring the cor 1 from one vessel to the other, the larger pieces should be removed by a pair of fine V»rass forceps, and the little parti- cles or dust afterwards swept into the weighing capsule by means of the camel's-hair {>encil or small colour-brush belonging to the balance case. The weighing capsule should Jilso be placed in the centre of a half sheet of glazed writing-paper, to prevent the risk of any acci- dental loss during the transference. After the weighing, the opera- tion must always be repeated, to ensui'e that no further loss of weight occur. In place of the blowpipe-lamp, the spirit-lamp may be employed for this opei'ation ; but, with the fonner, there is less danger of the heat becoming too high. By holding a slip of glass for an instant, every now and then, over the capsule, it will soon be seen when the moisture ceases to be given off". It should be remai-ked that some anthracites decrepitate slightly when thus treated, in which case the porcelain capsule must be covered at fix-st with a small watch-glass. In good samples of coal, the moisture ought not to exceed 3 or 4 per cent., but in coals that have been long exposed to damp it is often as liigh as G or 7, and even reaches 15 or 20 per cent, in certain lignites. Where large quantities of coal are consumed, therefore, a serious loss is 78 BLOWPIPK PRACTICE. entailed on the purchaser unless the moisture be properly det n-mined and allowed for. Estimation, dx., of Coke. — In this operation, a .small crucible of platinum is most conveniently employed. The ci'ucible may con.sist of a couple of rather deep spoons — the lar<^er one without a handle, so as to admit of being placed over the smaller spoon, thus serving as a lid. The long handle of the cru- cible-spoon must be bent as shewn in the annexed figure, in order that the spoon may retain an ui)right position when placed on the pan of the balance. About 150 milligrammes of coal are detached as before, in several small fragments, from the assay-specimen. These may be weighed directly in the crucible, the latter being placed in the little weighing capsule of horn or brass, with its handle-snpport projecting over the side of this. The crucible, with its cover on, is then taken up by a pair of spring forceps, and is brought gradually before the blowpipe to a red heat. The escaping gases will take fire and burn for a few seconds around the vessel, and a small amount of carbonaceous matter may be deposited upon the cover. This rapidly burns off, however, on the heat being continued. As soon as it disappears, the crucible is to be withdrawn from the flame, and placed on the blowpipe-anvil to cool quickly. Its weight is then ascertained, always without remov- ing the cover. The loss, minus the weight of moisture as found by the first process, given the amount of volatile or gaseous matter. The residue is the coke and its contained ash. The coke in some anthra- cites exceeds 89 or 90 per cent. In anthracitic or dry coals it usually varies from 70 to 80 per cent., and the fragments are sometimes slightly agglutinated. In ordinary bituminous or caking coals, it amounts in general to about 65 or 70 per cent., and presents a fused and mamil- lated surface. In oannel or gas coals, the percentage of coke may be assumed to equal 50 or 60, but it is sometimes as low as 30. The coke fragments are often partially agglutinated, but they never present a fused, globular aspect. Finally, in lignites or brown coals, the coke may vary from 25 to 50 per cent. It forms sharp-edged fragments of a dull charcoal-like appearance, without any sign of fusion. Estimation of Ash or Inorganic Matters. — A platinum capsule is employed for this operation. One of about half an inch in diameter, with a short ear or handle, is suflSiciently large. A somewhat smaller APPENDIX. 79 capsule, with its liandle cut off, may be fitted into this (in reversed position) to servo as a lid. The coal must l»o i-eductid to a coarse powder, and about loO milligratnmes wcnghed out for the experiment. Tlie platinum capsule is then to be fixed in a slightly-inclined posi- tion above the spirit-lamp, and heated as strongly as possilde. If the wick of the spii'it-lanip be raised sufiiciently, and the ca])sule be light ■and thin, the temperature will be sufficient to burn off the carbon, at loist in the majority of cases. The lid of the capsule must be placed above the coal powder until combustion cease, and the more gaseous pioilucts are driven off, as otherwise a portion of the j)0wder might very easily be lost. During the after combustion the powder must be g(Mitly stirred, and if agglutination take place the i)articles must be carefully broken up by a light steel spatula, or by a piece of stout platinum wire flattened at one end. If the carbonaceous matter be not burnt off by this treatment, the blowpipe may be used to accelerate the process ; but the operator must blow cautiously, and direct the flame only against the under side of the capsule, in order to avoid the risk of loss. Finally, on the ash ceasing to exhibit in any of its particles a black colour, the lid of the capsule is to be carefully replaced, and the whole cooled and weighed.* In good coals, the amount of ash is often under 2 per cent., and it rarely exceeds 4 or 5 per cent. In coals of inferior quality, however, it may vary from 8 or 10 to even 30 per cent. As regards its comj)o- sition, the ash may be — (1) argillaceous, consisting essentially of a silicate of alumina ; (2) argillo-ferruginous ; (3) calcareous ; and (4) calcai'eo-feiTuginous. If free from iron, it will be white or pale gi'ay ; but if more or less ferruginous, it will present a red, brown, or yellowish colour. Phosphor-salt, so useful in general cases for the detection of siliceous compounds, cannot be safely used to distinguish the nature of the ash obtained in blowpipe assays. Owing to their fine state of division and to the small quantity at command, argillaceous ashes dis- solve in this reagent with as much facility as those of a calcareous nature, and without producing a characteristic silica skeleton, or causing the opalization of the glass. With calcareous ashes also, the * If the ash be very ferruginous— in which case it will present a red or tawny colour — the results, as tlius obtained, will require correction, the original iron pyrites of the coal being weijjhed as sesquioxide of iron. In ordinary assays, however— as distinguished from analyses— this may be fairly neglected. When also the ash happens to be calcareous and to occur in large quantity, it should be moistened with a drop or two of a solution of carbonate of ammonia, and gently heated, previous to being weighed. 80 BLOWPIPE PRACTICE, amount obtained is rarely sufficient to saturate even an exceedingly minute bead o; phosphor-salt or borax, and hence no opacity is pro- duced by the flaming- process. The one kind of ash may be distin- guished, nevertlieless, from the other, by moistening it, and placing the moistened mass on reddened litmus paper. Calcareous ashes always contain a certain amount of caustic lime, and thus restore the blue colour of the paper. The calcareous ashes, also, though princi- pally composed of carbonate of lime, sometimes contain small poi tiois of phosphate and sulphate of lime. The presence of the latter may Virf readily detected \)y the well-known production of an alkaline sul- phide by fusion with carbonate of soda in a reducing flame — the fused mass exiiibiting a reddish colour, and imparting when moistened a dark stain to a plate of silver or i)iece of lead test-j)apei. The latter may be replaced by a glazed visiting-cai*d In examining earthy sulphates by this method, a little borax caght always to be added to the car- bonate of soda, in order to promote the solution of the test-matter. If oxide of manganese i art at lca.st of the sublimate will bo dis- solved. Some bisulphate of potash — eithi^r alone, or mixed with some • carb. soda and a little borax, the latter to prevent absorption — is theui ' In thp rousting of mctnllio sulphides, &c.., tlie writer Ims employed, for some yearn, Rinall . fragnionts of Berlin or Meissen porcelain, such as result from the breiikn^e of eriHMhles and , ntlier vessels of that material. The test-substanee is crushed to powder, moistcmsd slightly, and spread over the surface of the porcelain ; and when the operation is linishud, thp powder is - t.'isily scraped off by the point of a knife-blade or small steel-spatula. In ronistiBa operations, rarely more than a dull red heat is requireil ; but these porcelain n-agment^ .iiKyr ,lie rendered . white-hot, if such be necessary, without risk of fnv ture, Tliey are hold, myatiiunv/iiiitjutly, by.- ii pairof spring-forceps.— "Canadian Journal,'* Septeuibor, 1860. 84 BLOWPIPE PRACTICE. to be fused on chai'coal in a reducing flame ; and the alkaline sulphide, thus produced, is to be removed by the point of a knife-blade, and placed in a small porcelain capsule, Tlie hepatic mass is njost easily- separated from the charcoal by removing it before it has time to soli- dify. Some of the tartaric acid solution is then to be dropped upon it, when the well-known orange coloured precipitate of Sb'S^ will at once result. In performing this test, it is as well to employ a somewhat large fragment of the test-substance, so as to obtain a thick deposit in the tube. It is advisable also to hold the tube in not too inclined a posi- tion in order to let but a moderate current of air pass tln'ough it ; and care must be taken not to expose the sublimate to the action of the flame — otherwise it might be converted almost wholly into a com- pound of Sb'^O' and Sb'^O^, the greater part of which would remain undissolved in the tartaric acid solutioii, A sublimate of arsenious acid, treated in this manner, would, of course, yield a yellow precipi- tate, easily distinguished by its colour, however, from the deep orange antimonial sulphide. The crystalline character, etc., of the sublimate, would also eflectually prevent any chance of misconception. 14. —ON THE REACTIONS OF METALLIC THALLIUM BEFORE THE BLOWPIPE. Tlie following reactions ai'e given from direct experiments by the writer : * In the closed tube, thallium melts easily, and a brownish-red vitreous slag, which becomes pale yellow on cooling, forms around the fused globule. In the open tube, fusion also takes place on the first application of the flame, whilst the glass becomes strongly attacked by the formation of a vitreous slag, as in the closed tube. Only a small amount of •Tlie reactions given by Crooltes are as follows: "The motal melta instantly on charcoal, And evolves copious brown fumes. If the bead is lieated to redness, it glows for some time after the source of heat is removed, continually evolving vapours which appear to be a mixture of metal and oxide. A reddish amorphous sublimate of proto-peroxide surrounds the fused globule. When thallium is heated in an open glass tube, it melts and becomes rapidly con- verted into the more fusible protoxide, which strongly attacks the glass. This oxide is of a dark red colour when hot, solidifying to a bro^vn crystalline mass. The fused oxide attacks glass and porcelain, removing the silica. Anhydrous peroxide of thallium is a brown powder, fusing with difficulty and evolving oxygen at a red heat, becoming reduced to the protoxide. Xbe phosphate and sulphate will ataud a led beat vUhout change." APPENDIX. Bfi su^)Hmate is produced. This is of a grayish-white colour, but under the magnifying-ghiss it shews in pbxces a fjiiut iridescence. On cliarcoal, per se, thallium melts very easily, and volatilizes in dense fumes of a white colour, streaked with brown, whilst it imparts at the same time a vivid emerald-green coloration to the point and edge of the flame. If the heat be discontinued, the fused globule con- tinues to give off copious fumes, but this action ceases at once if the globule be removed from the charcoal. A deposit, partly white and partly dark brown, of oxide and teroxide is formed on the supj)ortj but, compared with the copious fumes evolved from the metal, this deposit is by no means abundant, as it volatilize;! at once where it comes in contact with the glowing charcoal. If touched by either flame, it is dissipated immediately, in imparting a brilliant green colour to the flame-border. The brown deposit is not readily seen on charcoal ; but if the metal be fused on a cupel, or on a piece of thin porcelain or other non-reducing body, the evolved fumes are almost wholly of a brownish colour, and the dejiosit is in great part brownish- black. It would appear, therefore, to consist of TIO^, rather than of a mixture of metal and oxide. On the cupel, thallium is readily oxidized ^nd absorbed. It might be employed, consequently, as suggested by Crookes, in place of lead in cupellation ; but, to effect the absorption of copper or nickel, a comparatively large quantity is required. When fused on porcelain, the surface of the supj)ort is strougly attacked by the formation of a silicate, which is deep red whilst hot, and pale yellow on cooling. The teroxide, as stated by Crookes, evolves oxygen when heated, and becomes converted into TIO. The latter compound is at once reduced on charcoal, and the reduced metal is rapidly volatilized with brilliant green coloration of the flame. The chloride produces the sauie reaction, by which the green flime of thallium may easily be distinguished from the green copper-flame ; the latter, in the case of cupreous chlorides, becoming changed to azure-blue. With borax and phosphor-salt, thallium oxides form colourless glasses, which become gray and opaque when exposed for a short time to a reducing flame. With carb. soda, they dissolve to some extent, but on char- coal a malleable metallic globule is obtained. The presence of soda, unless in great excess, does not destroy the green coloration of the flame. 86 BLOWPIPE PRACTICE. Thallium alloys more or less readily with most other metals before the blowpipe. With platinum, gold, bismuth, and antimony, respec- tively, it forms a da;rk-gray brittle globule. With silver, copper, or lead, the button is malleable. With tin, thallium unites readily, but the fused mass immediately begins to oxidize, throwing out excres- cences of a dark colour, and continuing in a state of ignition until the oxidation is complete. In this, as in other reactions, therefore, the metal much resembles lead. 1876. 15.— ON THE OPALESCENCE PRODUCED BY SILICATES IN PHOSPHOR-SALT. It is well known that most silicates when fused with phosphor-salt are only partially attacked ; the Ijases, as a rule, gradually dissolving in the flux, whilst the silica remains in the form of a flocculent mass technically known as a " silica skeleton." Very commonly, almost invariably indeed, if the blast be long continued, the bead becomes more or less milky or opalescent on cooling. This latter reaction was apparently regarded by Plattiier as essentially due to the presence of alkaline or earthy bases, such as exhibit the reaction ^jer se. He states, " Probirkunst," Dritte Auflage, ]). 468 : " Da man nun von mehreren Hilikaten ein Ghis bekommt, welches, so lange es heiss ist, zwar klar erscheint, aber unter der Abkiililung mehr oder weniger opalisii't, so muss man sich von der ansgeschiedenen Kieselsaure iiberzeugen, so lange das Glas noch heiss ist, und dabei die Loupe zu Hiilfe nehmen. Die so eben erwilhnte Erscheinung tritt gewbhnlich bei scichen Sili- katen ein, deren Basen, Kalkerde, Talkerde, Beryllerde oder Yttererde sind, die fii/ sich mit Phosphorsalz, bei gewisser Siittigung des Glases, unter der Abkiihlung oder durch Flatteini milchweiss oder opalartig werden." Dr. Theoy the addition of a veiy small amount of borax. 187I-7G. 17.— ON THE DETECTION OF CADMIUM IN THE PHESENCE OF ZINC IN BLOWPIPE EXPERIMENTS. When cadmiferous zinc ores, or furnace-products derived from these, are treated in powder with carb. soda on chai'coal, the charac- teristic red-brown dei>osit of cadmium oxide is generally formed at the commencement of the experiment. If the blowing be continued too long, however, this deposit may be altogether obscured by a thick coating of zinc oxide. When, therefore, the presence of cadmium is suspected in the assay-substance, it is advisable to employ the fol- lowing process for its detection. The substance, if in the metallic state, must firat be gently roasted on a support of porcelain or other non-reducing body. Some of the resulting powder is then fused with borax or phosphor-salt on a loop of platinum wire, and bisul[)hate of potash in several successive portions is added to the fused bead. The latter is then shaken off the wire into a small poi'celain capsule, and treated with boiling water. A bead of alkaline sulphide is next pre- pared by fusing some bisulphate of potash on chai'Coal in a reducing flame, and removing the fused mass before it hardens. A portion of the solution in the capsule being tested with this, a yellow precipi- tate will be produced if cadmium be present. The precipitate can be collected by decantation or filtration, and tested with some carlt. soda on charcoal. This latter o[)erationis necessary, because if either antimony or arsenic were present, an orange or yellow precipitate would also be pix>duoed by the alkaline sulphide. By treatment with ci'.rb. soda on charcoal, however, the true nature of the precipi- tate would be at onc« made known. 1876. 18.— ON THE SOLUBILITY OF BISMUTH OXIDE IN CARBONATE OF SODA BEFORE THE BLOWPIPE. Neither in the treatise of Berzelius, nor in the more modern and advanced work of Flattner, is any reference made to the behaviour of oxide of bismuth with carb. soda in an oxidating flame. In Plattner's " Tabellarishe Uebersicht des Verhaltens der Alkalien, Erden, und Metalloxyde fiir sich und mit Reagentien im Lothrohr- feuer," whilst oxide of load is stated, correctly, to ho soluble in carb. APPENDIX. 89 soda in an oxidating flunje, the reference to oxide of hismutli is, siini)ly, that with carb. soda on charcoal it becomes immetliately reduced to metailic bismuth; and none of his transhitors seem to have thought it necessary to su{)[)ly the omission. In Hai'tmann's tabular " Untersucliungen mit dem Lbthrolir," in the handy little work of Bnino Kerb (" Leicfaden bei qualitativen und quantitativen Lbthrohr-Untersuchungen "), in the " Lbtnrohr-Tabellen " of Hirsch- wald, and all other blowpipe books that I have met with, the same singular omission occurs. This seems to bear out very forcibly the somewhat cynical adage that " books are made from books." To supply the omission, it may be observed that bismuth oxide dissolves in carb. soda very readily in an oxidating flame, if the supporting agent be platinum wire or other non-reuucing body. The glass is clear yellow whilst hot, but on cooling it assumes an orange or yel- lowish-brown colour, and becomes pale yellow and opaque when cold. As regards their solubility by fusion in carb. soda, metallic oxides fall into three groups: (1) Easily soluble, e.g., PbO, Bi'^0^, BaO, &c.; (2) Slightly or nartially soluble, e.g., Mn*0*, CoO, «fec. ; and (3), Insoluble, e.g., Y i'0\ Ce•^0^ NiO, CaO, MgO, &c. 1876. 19.— ON TliE DETECTION OF CARBONATES IN BLOWPIPE PRACTK.^E. A mineral substance of non-metallic aspect, in nine cases out of ten, will be either a silicate, sulphate, j)liosphate, borate, carbonate, fluoride, or chloride : more especially if the streak be nncoloured or merely exhibit some shade of green or blue, or if the substance evolve no fumes when heated on charcoal. Simple fusion with phosphor-Sivlt on a loop of platinum wire serves at once to distinguish a silicate from any of the other bodies enumerated above, as, whilst the silicate is but slowly attacked, these other bodies are readily and rapiilly dissolved. Among the latter, again, the cax'bonates are distinguished very readily by the marked eifervescence which they produce in the bead by the evolution of carbonic acid during fusion — the phosphates, sulphates, &c., dis- solving quietly. The reaction is quite as distinctive as that pi'oduced by the application of an ordinary acid ; but, of course, it may arise in both cases not only from a carbonate proper, but fi-om the presence of intermixed calcite or other carbonate in the su bstance under ex ami 90 BLOWPIPE PRACTICE. nation ; and it is also occasioned by bodies which evolve oxygen on ignition ; but these latter, manganese oxides excepted, are of rare occurrence among minerals proper. By this reaction, upwards of twenty years ago, the writer detected the presence of carbonate of lime in certain specimens of Wernerite (the " Wilsonite " variety, portions of which had previously been analyzed without the impurity having been discovered. It need scarcely be stated that the test- substance must be added to the phosphor-salt, on the platinum loop, only after the quiet fusion of the flux into a transparent glass. The reaction is, of course, manifested equally well with borax. 1871-76. 20.— ON THE DETECTION OF BROMINE IN BLOWPIPE EXPERIMENTS. When fused with phosphor-salt and copper oxide, the bromides, it is well known, imjjait an azure-blue coloration to the flame, much like that produced by chlorides under similar treatment, althougli streaked more or less witli green, esi)ecially at the commencement of the operation. To distinguish these bodies more closely, Berzelius recommended the fusion of the test-substance with 6 or 7 volumes of bisulphate of potash in a closed tube. Bromides by this treatment become decomposed as a rule, and give ofl" strongly-smelling brownisli or yellowish-red vapours of bromine. But this process does not always give satisfactory results, as in some instances the bromide is very slightly attacked. In this case, the following method, based on a peculiar reaction of bromide of silver, first pointed out by Plattner, may be resorted to : I' insoluble, the bromide is fused with 2 or 3 volumes of carb. soda. A soluble bromide of sodium is thus formed, with separation of the base. To the filtered or decanted solution of the fused mass, a small fragment of nitrate of silver is added, in order to precipitate bromide of silver. This, collected by decanta- tion, is fused with a small quantity of bisulphate of potash in a little flask or test-tube. The bromide of silver will quickly sepai-ate from the flux in the form of a blood-red globule, which becomes pale- yellow when cold. The little globule, washed out of the tube by dissolving the fused bisulphate in some warm water, is carefully dried by being rubbed in a piece of blotting or filtering paper, and is then placed in the sunlight. After a short time it will turn green. Chlo- ride of silver, as obtained in a similar manner, melts into an orange- i-ed globule, which changes to clear-yellow on cooling, and finally APPENDIX. 91' becomes white, or nearly so. Placed in sunlight, it rapidly assumes a dark-gray colour. Iodide of silver, under similar treatment, forms wliilst hot an almost black globule, which becomes amethyst-red during cooling, and dingy-yellow when cold. In the sunlight it retains the latter colour. A mixture of chloride and iodide of silver assumes a greenish tint somewhat resembling the colour acquired by the bromide globule. This, however, can scarcely give rise to any error, as the presence of iodine is revealed — even if no violet-coloured fumes be emitted — by the dark amethystine colour of the bead whilst hot. 1876. 21.— BLOWPIPE REACTIONS OP METALLIC ALLOYS. ■ In examining these reactions, about equal portions of the metals (forming the alloy) may be placed together, on charcoal, and subjected to the action of a reducing flame. 1. Platinum and Tin unite with violent deflagration and emission of light, forming a hard, brittle, and infusible globule. 2. Platinum, Zinc and Tin unite with violent action, the zinc throwing off" long flakes of oxido. , 3. Platinum and Zinc, per se, do not combine, the zinc burning into oxide. 4. Platinum and Lead unite quietly, forming a brittle globule. 5. Platinum and Thallium unite quietly ; the resulting globule is dark externally, giMy internally, and quite brittle. 6. Platinum and Bismuth unite quietly, or with merely slight spitting, into a dark, brittle globule. 7. Platinum and Copper combine quietly, though not very readily, into a hard, light-coloured, malleable globule. 8. Platinum and Silver unite quietly, but net veiy readily, unless the silver be greatly in excess, into a white malleable globule. 9. Platinum and Gold unite quietly, forming (if the gold be some- what in excess) a yellow malleable globule. 10. Gold and Tin unite quietly into a very brittle globule. ■ 11. GoM and Zinc do not combine joer se; the zinc bums into oxide. 12. Gold and Lead combine quietly, forming a gray brittle bead. . 13. Gold and Thallium unite quietly, but separate again to some extent during cooling. The globule may thus fi-equently be flattened out, but not without cracking at the sides. If the metals remain united, the button is dark blackish-gray, and quite brittle. 92 BLOWPIPE PRACTICE. 14. Gold ani Bismuth unite quietly and readily, forming a very brittle globule. 15. Gold an I Copper, and 16, Gold and Silver , unite, and form a malleable globule. 17. Silver and Tin unite quietly into a malleable globule. 18. Silver and Lead unite readily into a malleable globule. 19. Silver and Thallium combine readily : the globule is malleable. 20. Silver and Bismuth unite readily and quietly : the globule is biittle, but admits of being slightly flattened out. 21. Silver and Cojyper, and 22, Silver and Gold, form malleable globules. The gold alloy, even with gold largely in excess, is quite white. If it be flattened out and heated in a platinum spoon wiiii some bisulphate of potash, it will become yellow from the silver on the surface being dissolved. On re-melting the flattened disc, a silvei'-white globule is again obtained. 23. Cop2)er ami Tin unite into a gray and partially malleable bead, the surface of which, in the O F, becomes more or less thickly encrusted with cauliflower-like excrescences of oxide. 24. Copper and Zinc do not xinite, per se, into a globule, the zinc buniiiig into oxide. Under carb. soda, or carb. soda and borax, brass is readily formed. 25. Copper and Lead form a dark gray globule, which is sufficiently malleable to admit of being extended on the anvil. 26. Copper and Thallium melt into a dark gray malleable globule. 27. Lead and Tin unite readily, but the globule commences imme- diately to oxidize, throwing out excrescences of white and yellow oxide. On removal from the flame it still continues in ignition, and l)ushes out further excrescences. The unoxidized internal portion (if any remain) is malleable. 28. Lead and Bismuth unite i*eadily : the molten globule acquires a thin dark coating of oxide on the surface only, and admits of being flattened out, more or less, upon the anvil. 29. Lead and Thallium form a malleable globule. 30. Bismuth and Tin unite readily, but the fused mass immediately throws out excrescences, and becomes covered with a dense crust of oxides. The reaction, however, is not so striking as with lead and tin. 31. Thallium and Tin exhibit the same reaction as lead and tin. but the cauliflower-like excrescences are brownish-black 1876. PAET II. ORIGINAL TABLES (BASED ESSENTIALLY OX BLOWPIPE CHARACTERS) FOB THE) DETERMINATION OF ALL KNOWN MINERALS. PAET II. INTRODUCTION. In these Tables for the Determination of Minerals, an attempt has been made to place in the same Table, or nnder its secondary sub-divisions, those minerals only which are related to each other : relaf^ed, that is, not by a single determinative character, but by their composition and characters generally. It is not, of course, possible to effect this with complete success in all cases; but the preSv^nt Tables, it is thought, will be found for the greater part to be at least free from the startlingly incongruous, and hence objectionable, group- ings seen in Determinative Mineral Tables hitherto published. At the same time, as regards ready application and efficacy in a purely determinative point of \iew, the present Tables will compare favour- ably, it is hoped, with other efforts in this direction. In using the Tables, the student is assumed to be familiar with the more common blowpipe-operations and reactions, as given in Part I of this Essay. It has not bf.en thought necessary, therefore, in prefixing to subordi- nate sections the headings ** Cu reaction," " Pb reaction," *' Na re- action," &c., to give these reactions in full. The present work is not, of course, intended to serve as a substi- tute for an ordinaiy text-book, but simply as an adjunct to the latter. To add, however, to it/f usefulness, the leading charactera of each species, including Composition, System of Crystallization (with an occasional angle), Hardness, Specific Gravity, Coloift', &c., are briefly given. The composition is stated in percentage values in mo3t cases > 9fi BLOWPIPE PRACTICE. but in others merely the components, as separated by analysis— e. gr., CaO, FeO, APO', Fe'^0', CO^ SiO», &c.— are stated. The student will thus be able, after determining a mineral by the Tables, to verify its composition as a confirmatory test. Tne names of the Crystal Systems are printed chiefly in abbrevi- ated form, as follows : — -Reg. ( = Regular, Tesseral, Isometric, Mono- metric, &c.); TbL ( = Tetragonal, Quadratic, Dimetrio, &c.) ; Hex, ( = Hexagonal), or Hemi-Hex, ( — Rhorabohedral and other Hemi- Hexagonal forms) ; Rh. ( = Rhombic, Ortho-Rhombic, Trimetric, &c.) ; Clino-Rh. (== Clino-Rhombic, Monoclinic, Oblique Rhombic, &c.) ; Anorth. ( =Anorthic, Triclinio, Clino-rhomboidal, «fec.) In Rhombic and Clino-Rhombic crystals, the prism angle ( = oo P : go P. Nau- mann) is sometimes given under the symbol of V : V, and othev interfacial angles are occasionally stated.* Hardness ( = H) refers, of course, to the universally adopted Scale of Mohs. This scale h given below, together with a roughly corres- ponding scale (published by the author in 1843) to serve as a substi- * In the system of crystallograpliic notation lorig followed by the author- one that possesses the advantage of allowing the symbols to be readily translated into words— all forms (apart from those of the Regular System, and certain special forms of the H;ixagcnal System, in the case of which it is more convenient to employ arbitrary symbols) are referred to one of three Bets, namely : Vertical forms (parallel with the vertical axis) ; the Basal form (parallel with the basal or middle axes); and Polar or Pyramidal forma (inclined towards the vertical axisur principal pqles of the crystal). Vertical forms, generally, are denoted by the common symbol V ; the basal form, by B ; and polar or pyramidal forms, by P. When a form lies parallel to any axis, the sign of the axis (where this is lecessary to indicate the ]i08ition of the form) is placed above the symbol. Thus V denotes a vertical form consisting of planes parallel with the vertical axis only, as the unright planes of a rhombic prism, for example ; whilst V (in verbal language, a " Front Vertica ," = a Macro- Vertical or Ortho-Vertical, according to the System) denotes a form parallel with the right-and-left transverse axis (= the macrodiagonal or ortho- diagonal, as the case may be); and V or V denotes a "Side-Vertical," " Brachy- Vertical " or " Clino- Vertical," parallel with vertical and brachy-axis, or vertical and clino-axis, according to the System. B, the symbol of the basal form, needs no axial signs, as it cannot vary. The polar forms comprise : Polars or Pyramids proper. Front Polars, and Side Polars (or jnacro- polars, brachy-polars, &c.), and are indicated, respectively, by the symbols P, P, and P or P (with secondary signs where necessary, as in the Clino-Rhombic and Anorthic Systems). Values placed before a symbol, as 2P, ^F, &c., refer to the vertical axis ; those placed after a symbol, as V2 or V2, refer to one of the middle axes, either understood conventionally, or indicated by its sign above the figure. It is of course evident that uo other forms than Vertical, Basal, or Polar forms can possibly be present in any crystal. Hence, by the employment of the sym- bols V, B, and P, with modifications as described above, the position of a given form becomes taken up by the eye at a glance, and without risk of misconception. INTRODUCTION TO MINERAL TABLES. 97 tute where the minerals oT which the scale of Mvihs consists may not be at hand. SCALR OF MUUS. 1 . . . Talc. 2 . . . Rock Salt. 3 . . . Calcite. 4 . . . Fluor Spar. f» . . . Apatite. <■)... Orthoclase. 7 . . . Rock Crystal (Quartz). 8 . . . Topaz. ft ... C )ruii lum. 10 . . . Diaiuand. Chapman's Convenient Scal»:, to correspond WITH THAT OF MciUH. 1 . . Yields to the finger-nail. 2 . . Does not yield to the nail, but is scratched by a copper coin. 3 . . Scratches a copper coin (i. e., a copp jr coin proper, not a modern bronze coin), but is also scratched by one. 4 . . Not scratched by a copper coin, but easily scratched by a peuknife. Does n >t scratch ordinary window-glass. 5 . . Scratches glass very feebly, leaving its powder on it. 6 . . Scratches glass strongly. Not scratched by a penKnife, but yields to a hard file. Readily scratched by a piece of quartz. 7 . . Scarcely touched by a file. 8 - 9 - 10 . . Harder than quartz. Convenient objects for the comparison of minerals possessing a higher degree of hard- ness than No. 7, cannot readily be found ; but these minerals are few in number, and, as a rule, they are easily distinguished by other characters. The sign G indicates specific gravity. This character is ascertained very expeditiously by the spring balance contrived by Professor Jolly of Munich ; but where an instrument of this kind is not at hand, a small pair of ordinary sciiles m;iy be conveniently used. The centre of one pan is perforated for the passage of a horse-hair with running noose (to hold the mineral), or is ])rovided on its under-side with a small hook to which the hair is attached, and the strings of this pan should be somewhat shortened. The mineral — a small crystal or fragment of about a gramme or couple of grammes in weight — is weighed first in the ordinary way, and the weight is then taken whilst the mineral is suspended in distilled water. If a equal the the weight in air, and w the weight in water, G = . Bodies £t — W which are soluble^ in water may be weighed in alcohol or other . suit- fthle liquid of kriown sp. gr. Calling this latter, G', and the weight of the mineral in the liquid, W, the true sp. gr. becomes - — —, G'. a- w 8 98 BLOWPIPE PRACTICE. In other words, the sp. gr. of the substance as found by the liquid, must be multiplied by the sp. gr. of the latter. In te ting the solubility, «fec., of minerals in acids, a small frag- ment of the substance should be reduced to powder; and some of the latter (inserted into a test-tube by a narrow strip of glazed paper ' folded gutter- wise) may be covered to the depth of about half-an-inch with the acid to be employed. The tube may then be warmed, so as to bring the acid gently to the boiling-point, over the flame of a small spirit lamp or Bunsen burner. Or, in place of the test-tube, u small porcelain capsule, provided with a short handle, may be used. In the examination of minerals for the presence of earths and alkalies, a small direct-vision spectroscope will be found very service- able. The small pocket spectroscopes, 3^ inches long, with attached scale, made by Browning of London, cannot be too highly recom- mended. Many minerals (Calcite, Gypsum, Polyhallite, Strontianite, Celestine, Barytine, Lepidolite, &c., &c.) give characteristic spectra by sufficiently prolonged ignition in the outer border of a Bunsen flamo, but the reaction becomes in most cases gi'eatly intensified by moisten- ing the ignited substance with hydrochloric acid, as described at page 55 and in many of the following Tables. In the Tables pi'oper, all, or practically all, known species are inserted ; but each Table is followed by an Explanatory Note, in which the commonly occurring or important species of the Table are alone referred to. In these notes, crystallographic and other distinctive characters arc given in somewhat greater detail. II^DEX TO THE TABLES. A.-THE MINERAL PRESENTS A METALLIC LUSTRE. A'. — A small fragment ignited, BB, on charcoal volatilizes wholly or partly. (1) It gives As fumes, but no sulphur-reaction with carb. soda. . . . Table I. (2) It gives As fumes and sulphur-reaction Table II. (3) It gives reaction of Sulphur or Selenium, but no fumes of Sb or Te. Table III. (4) It gives sulphur-reaction, and fumes of Sb or Te Table IV. (5) It gives fumes of Sb or Te, but no sulphur-reaction Table V. (6) It gives no reaction of S, Se, Te, Sb, or As Table VI. A^ — A small fragment ignited on charcoal does not perceptibly volatilize. (1 ) It fuses, BB, on charcoal into a globule .„ Table VII. (2) It is infusible, or fuses only on me thin edges Table VIII. B.-THE MINERAL PRESENTS A SUB METALLIC ASPECT. (1) It is easily fusible or reducible per se Table IX. (2) It is infusible, or fusible only on thin edges Table X. C.-THE MINERAL PRESENTS A VITREOUS, PEARLY, EARTHY, OR OTHER NON METALLIC ASPECT. C*. — A small fragment takes fire when held aijainst a candle or Bunsen-flame. (1) It bums with blue flame and sulphurou or alliacceous odour. . Table XI. (2) It bums with bituminous or aromatic odour Table XII. C. — 2Vtc mineral is not biflammMhle. It is readily dissolved or attached by fusion with borax or phosphor-salt. (1) It is attacked with effervescence by dilute hydrochloric aciJ, Table XIII. (2) Itemi'.^ As fumes by fusion with carb. soda on charcoal. . , . Table XIV. (3) It emits Sb fumes by fusion with carb. soda on charcoal Table XV. <4) It gives Bulphur-reaetion with carb. soda T^tLK XVI, iCO INDEX TO THE TABLES. (5) Its solution in nitric acid* gives a canary-yellow pre. with molyb- date of ammonia Table XVII. (6) Its powder, moistened with sulphuric acid and alcohol, communi- cates a green colour to the flame of the latter Table XVIII. (7) It gives chlorine (I or Br) reaction (azure or green flame) by fusion with phosphor-salt and copper oxide Table XIX. (8) It evolves orange-red fumes when warmed with a few drops of sulphuric acid in a test-tube Table XX. (9) It corrodes the glass when warmed in powder with sulphuric acid in a test-tube Table XXI. (10) It forms by fusion with carb. soda and nitre an alkaline mass partly soluble in water, the solution assuming a blue, brow a, or green colour when boiled with addition of hydrochloric acid and a piece of tin or zinc Table XXII. (11) It does not produce any of the above reactions Table XXIII. C'. — The mineral ia very slowly dissolved, or is only partially attacked, BB, by borax or phosphor-salt. t It is infusible, or fusible oidy on the thinnest edges : (1) It is hard enough to scratch ordinary glass distinctly, Table XXIV. (2) It is not hard enough te scratch glass distinctly. . . . Table XXV. t+ It is more or less readily fusible: (1) It yields no water (or merely traces) by ignition in bulb- tube Table XXVI. (2) It gives off a distinct amount of water by ignition in bulb- tube Table XXVII. Note.— In order to appreciate the distinctive character of the respective sections C^ and C». the student is recommended to add n small fragment of calcite, gypsum, fluor spar, barytine, ur apatite, on the one hand,— and a small particle of orthoclase, pyroxene, amphibule, garnet, talc, quartz, or corundum, on the other— to a previously fused bead of phosphor-salt ; and to observe the rapidity with which the flrst-named minerals are dissolved under the action of the blowpipe, whilst the minerals of the latter group remain practically unaffected, or are very slowly or inconipletely attacked. * Crush a small fragirent of the substance to powder. Pla,ce this, by a bent slip of paper, in a test-tube. Drop a little nitric acid upon it, and warm or boil. Then add some distilled water and a grain or two of the molybdatu, and warm again. TABLES FOR THE DETERMINATION OF MINERALS. TABLE I. [Mtitallic aspect. Wholly or partly vol. with As fumes, but yielding no S reaction.] A.— Entirely vol. (or leaving merely a feeble residuum)- Native Arsenic: Hemi-Hex. ; H 35 ; G 60 ; tin-white with dark tarnish. Allemontite : differs merely by having part of the As replaced by 8b. Native Bismuth — Arsenic-holding varieties. G 9*7, BB, a yellow deposit on charcoal. See Table VI. B.— Partially vol., leaving distinct residuum. Bi. -residuum magnetic. Smaltine: (CoNiFe) 28, As 72. Reg.; H 5 5-6; G 65; greyish tin-white. Chloanthite (Chathamite) is a highly nickeliferous smal- tine. Skutterudite is probably a mixture of smaltine and arsenic ( = CoAs' + As). LiiLLiNGiTE : Fe 272, As 72-8. Rh. ; H 5-55 ; G 7-74 ; greyish silver-white. Leucopyrite (Fe 322, As 668 (1) ) is closely related. In both, a little S is often present. (AS'ee below). B«.— RESIDUUM NOT MAGNETIC. (Ni reaction). Rammelsbergite : Ni (CoFe) 28, As 72. Rh. ; H 55 ; G 71 j greyish silver-white. Nickeline: Ni (Fe, &c.) 436, As 56-4. Hex.; H 5-5; G 7-5-7-7; pale copper-red. {Cu reaction). Domeykite: Cu 717, As 28 3; H3-3-5; G 7-7-5 ; ailver-white or tin- white, tarnished. Algodonite (Cu 835, As 165) and "V^uit- neyite (Cu 684, As 11 6) are closely i-elated, but with higher sp. gr. (8-8-3). , 102 BLOWPIPE PBACTICK. {Ag reactiott). E.ITTINOER1TE ; Normally, AgAs (?) with 577 Ag, but commonly contains sulphur. Iron-black, red by transmittetl light ; streak orange-yellow, lusti-e, mostly, sub-metallic. Clino-Rh. ; H 25-3 > G 5-63. (See Table IX). NOTE ON TABLE I. The only minerals of general occnrrence belonging to this Table are Native Arsenic, Smaltine, and Nickeline. N. Arsenic is commonly in botryoidal masses with dark surface-tarnish, and is readily distinguished BB by volatilizing rapidly without fusing. Smaltine occurs most frequently in small tin-white octahedrons of sufficient hardness to scratch glass, but is also found in reticu- lated groups of minute indistinct crystals, and massive. After roasting, the smallest particle imparts BB a rich blue colour to borax. Nickeline is rarely found otherwise than massive. Its light copper-reaper and otherwise much resemble graphite, but easily distinguished l»y communicating a distinct yellowish-green colour to the outer flaDie, as well as by sulphur reaction, and higher sp. gr. \ 108 BLOWPIPE PRACTICE. (Zn reaction). Sphalerite or Zinc Blende : Some varieties, only, are metallic or sub-metallic in lusti-e. Streak pale-brown. See Tables X. and XVI. {3fn reaction). Alabandine : Mn 63-2, S 3G-8. Black, brownish, dark steel-grey. Streak greenish. Lustre sub-metallic. See Table X. Hadebite : Mu 462, S 53-8. Dark red-brown, blackish-brcwn. Streak brownish. Lustiut up for the smelting of lead ore, but wliicli had turned out a failure. The ore, it api)eared, got into a pasty mass lioldiiig a little reduced lead, and would not work. After examining tlie furnace, and seeing nothing particularly amiss in it, the writer asked to look at the ore. Thin was regarded at the furnace as a tolerably clean galena, but was found to consist of nearly two- tiiiidd " Black Jack " mixed witli galena in a calcareous gangue. The " pasty stuff " wliicli had given tlie furnace a bad name was thus easily accounted for. The old name Blende (and the newer Sphalerite) is based on this deceptive aspect. In general, however, the lustre is non- metallic, or at most, sub-metallic. [110] TABLE IV. • [S reaction. Sb or Te fumes.] A— On oharooal, BB, a white deposit- Ai.— ENTIRELY AND RAPIDLY VOL. Stibnite (Antimony Glance, Grey Antimony Ore): S 2824, Sb 71-76. Rh ; H 2; G 4-5-4-7. Lead-grey, often with iridescent or dark tarnish. Melts per se in outer edge of the flame without the aid of the blowpipe. iSee also the note below. CiNN.»BAR (HgS). Some dark or lead-grey varieties. Streak red. G 7*7-9. Inflammable. Lustre, as a rule, non-metallic. {See Table XI). AS.— PARTIALLY VOL., A LARGE SILVER-GLOBULE REMAINING. (The minerals of this section present as a rule a dub-metallic aspect. The three first are slightly translucent in thin pieces, and have a red streak). Miarqyrite: S 21-8, Sb 41-5, Ag 36-7. Clino-Rh. ; H 2-25; G 518-5'26. Iron- black, streak dull-red. Pyrargyrite (Dark Eed Silver Ore): S 17-7, Sb 22-5, Ag 598. Hemi Hex. ; H 2-2 "5 ; G 5 •75-5 '85. Iron-black, reddish, streak red. Polybasite : S, Sb (As), Ag 64-74 p. c. ; Cu sometimes present. Rh. ; H 25 ; G 6-0-62. Iron-black ; streak, black, red. Polyargy rite is closely related, but is Regular in crystallization. Stephanitb (Melanglanz, Brittle Silver Ore) : S, Sb (As), Ag (Cu) 68 p. c. H Rh. j H 2-5 ; G 63. Iron-black, dark lead-grey, often iridescent. A3. -partially vol , the residuum magnetic. Berthierite: Average comp. S 30, Sb 57, Fe 13. Rh. (!): H 2-5-3 ; G 4-4-3. Dark steel-grey, often with variegated tarnisli. Ui.lmannite (Antimonial Nickel Glance): S 15, Sb 57*5, Ni 27-."). Reg. ; H 5-0-5-25 ; G 6-2-6-5 ; lead-grey or steel-grey, with dark or variegated tarnish. Sc me examples are arsenical. A*.— partially vol., the residuum giving strong copper-reaction. Tetrahedrite (Grey Copper Ore; Fahlerz): S,Sb (A.s), Cu 33-44 p. c, Ag, Fe, &c. Reg. (tetrahedral); H 3-4; G 48-5-4. Steel- grey, iron-black. MrXERAL TABLES : — IV. Ill Chalkostibite (Wolfsbergite): S 25-7, Sb 25-4, Cu 48-9. Eh.; H 3 5 ; G 4*7-5 ; dark lead-grey, iron-black, often with variegated tarnish. B— On charcoal, BB, a yellow (or white and yellow) deposit. Bi.-PARTIAr,LY VOL , A GOLD OR SILVER GLOBULE FINALLY REMAINING. ( If the blowing be stopped too soon, a rich gohi-lead or silver-lead globule will of conrse result. This may be freed from leail on the cupel). Freieslebenite (Donacargyrite). S 18*8, Sb 26*9, Ag 238, Pb 30-5. Clino-Rh. H 2 25 ; G 6-2-6-5 ; metallic grey. Diapho- rite (v. Zepharovich) from Przibram is closely related, but is Rhombic in crystallization, G 5-9. Brongniardite : S 19-5, Sb 29-5, Ag 26, Pb 25. Reg. ; H 2-5 ; G 5-9-6"0; dark metallic-grey. Nagyagite (Leafy Tellurium Ore, Blattererz); S, Te, Pb, An, Ag, (fee. Au, commonly, 6-9 p. c. Tet., but mostly in thin flexible laminae. H 1-1-5; G 68-7 2. Blackish lead-grey. Melts per se in edge of candle-flame. Ba.— partially VOL., THE RESIDUUM GIVING STRONG COPPER-REACTION. Bournonite: S 1966, Sb 24-98, Pb 42-38, Cu 12-98. Rh. ; H 2-5-3; G 5-7-5-9. Dark steel-grey, iron-black. See also Teti-ahedrite, some examples of which contain Pb or Bi ; and Zinkenite and Jamesonite, which sometimes contain a small percentage of copper. B8.-PARTIALLY VOL., BUT GIVING NO MARKED REACTION OF Ag, An, or Cu. (Sp. gr, under C'O). Zinkenite: S 22, Sb 42, Pb 36. Rh., acicular; H 2-5-3-5 ; G 5-3-5-4. Steel-grey, lead-gi-ey, often with variegated tarnish. Plagionite : S 21, Sb 37, Pb 42. Clino-Rh. ; H 2-5 ; G 5-4. Dark lead-grey. Jamesonite: S 19-6; Sb 29-8, Pb 50-6. Rh. H 2-5; G 5-5-5-62. Metallic-gi*ey. Cleavage basal, strongly marked. Boulangerite: S 18, Sb23, Pb59. Crystn.1; H 2-5-3; G 5-7-5-95. Dark lead-grey. {Sp. gr. over 6-0). Meneohinite: S 173, Sb 188, Pb 639. Clino-Rh., acicular. H 2 5-3; G 6-34-6*4. Lead-grey. Some examples appear to be Rhombic in crystallization. ' 112 BLOWPIPE PRACTICE. Geokronite ; S, Sb, Pb 65 p. c. Some examples contain also a little Cu. Rh. ; H 2-3; G 6-44-6-54; lead-grey, tarnishing darker, Kilbrickenite is identical or closely related. Kobellite: S 16-8, Sb lO-7,Pb 543, Bi 18 2. Crystn. ]; H 2 5; G 6 15-6 -30. Dark lead-grey. . Tetradymite : Normally, a compound of Bi and Te, but frequently containing small amounts of S or Se. Light steel-grey. H 1-3; G 7 4-7 9 ; flexible in thin pieces. Wehrlite is a var. containing S. Some vars. also contain a small percentage of Ag. See Table V. NOTE OX TABLE IV. The only minerals of common or general occurrence belonging to this Table, comprise: Stibnite, Tetrahedrite, Pyrargyrite, Bournonite, Zinkenite, and tfamesonite. Stibnite or Antimony Glance (also known as Grey Antimony Ore) is dis- tinguished (if pure: id eat, if unmixed with lead sulphide, &c.) by its rapid volatilization before the blowpipe ; and by its powder becoming orange-yellow in a hoi; solution of caustic potash. It is generally in masses of a more or lesj iibrous structur'e and light lead-grey colour, or in small Rhombic prisms (with V : V = 90°54') terminated by the planes of a rhombic octahedron. The prism- planes are longitudinally striated, but the crystals are usually acicular or more or less indistinct. The only species which somewhat resemble it are the sul- phantimonitcs Zinkenite, Jamesonite, Bournonite, &c., but these give a lead sublimate on charcoal, and Bournonite gives also a strong copper-reaction. They are attacked but not rendered yellow by caustic potash, but an orange precipitate is thrown down if the potash solution be neutralized by hydro- chloric acid. Jamesonite is chiefly distinguished by its ready cleavage in one direction ; and Bournonite by its copper-reaction. The latter mineral is often found in small, fiat. Rhombic crystals with largely developed basal plane, and V : V = 93°40'. These crystals are frequently in craciform or other twins. Tetrahedrite is dark-grey or iron-black in colour, and when crystalhzed is in small tetrahedrons or tetrahedral combinations. It gives strong copper- reactions, and some examples (Rionite) contain zinc ; others, silver, mercury, &e. Pyrargyrite or Dark Red Silver ore is iron-black or reddish l|ead-grey in colour, except in thin piec.d by transmitted light, when the colour appears blood-red. The st:eak is red ; and the crystals are mostly combinations of the hexagonal prism with the planes of one or two rhombohedrons (R : II = 108°42' ; 4 R : 4 R = 137° 58'), but the mineral is most commonly massive or in indis- tinct crystal aggregations. It melts per se in the outer edge of the flame with- out the aid of the blowpipe. On charcoal, BB, a silver globule is easily obtained. Like other sulphantimonites, it is attacked by hot caustic potash, and hydrochloric acid precipitates orange-red Sb*S3 from the solution. [113] TABLE V. [Metallic Aspect. Sb or Te fumes, but no S reaction.] A.— Entirely volatilizable, or leaving merely a minute globule of metal. A».-ON CHARCOAL, BB, A WHITE DEPOSIT. Native Antijiony : Hemi-Hex., cleavable ; H 3-3-5 ; G 67 ; tin- white. Converted by nitric acid into yello^fish-white powder (Sb^O* + i>l.'0*). Native Tellurium: Hemi-He .:., cleavable; H 2-2'5 ; G6-1-6-3; tiii-whita Soluble in nitric acid. Warmed with strong sulphuric noid (the acid being iised in excess) forms a purplish-red solution, which becomes colourless on addition of water — metallic Te falling H.S a dark-grey piecipitate. Forms also a red solution when boiled iu powder with caustic potash. A«.— ON CHARCOAL, BB, A YELLOW (OR WHITE AND YELLOW) DEPOSIT. Tetradymite : Bi 52, Te 48, but S and Se often present in small proportions. Hemi-Hex.; H 15-2; G 7'4-7'9; pale metiUlic-grev ; flexible in thin pieces. Altaite: Pb 61 2, Te 38-8. Reg.; H 2 5-3-5; G 8 1-8-2; tin- white, yellowish. B —Partially volatilizable- B>.— YIELDING, BB, ON CHARCOAL A LARGE GLOBULE OF Ag Oil Au. Dyscrasite : Ag and Sb iu several proportions ; Ag 64-84, Sb 15-8-36. Rh. ; H 3-5 ; G 9-4-10. Silver-white or tin-white, with dark or yellowish tarnish. Hessite: Ag 628, Te 372. Rh. ; H 2-3-0; G 81-8-5. Dark inetalUc-grey. Petaite is a closely related mineral, but with a large part of the Ag replaced by Au (G 8-7-9-4). Sylvan ite (Graphic Tellurium): Ag, Au, Te, in variable propor- tions. Sb and Pb also present in some examples, Au 25-45, Ag 1-1 o, Te 45-56. Clino-Rh. (or Rh. 1); H 15-2; G 8-84. Light steel- gi-ey inclining to silver-white or pale yellowish. Calaverite is a yellow var., with Au 44*5, Te 55-5. Miillerine is also an auriferous vi\r., containing Pb and Sb in addition to the normal comi>ouent9. 9 114 BLOWPIPE PRACmCE. B«. -YIELDING, BE, A MAGNETIC (NICKGLIFfflftOUS) GLOBULE. Breithauptite (Antimonial Nickel Ore): Ni 32*2, Sb 67 8. Hex. ; H 5 ; G 7 5-7 '6 ; pale copper-red, mostly with bluish tarnish. Com- monly massive, or in small tabular crystals with striated base. Isomorphous with Nickeline, Table I. Part of the Ni usually replaced by Fe. Melonite : Ni 235, Te 76*5. Hex. ? Pale reddish-white. NOTE ON TABLE V. All the minerals of this Table are of exceptional or merely local occurrence. Those which contain gold or silver are easily recognized by the metallic globule which they yield, BB, dn charcoal. The presence of antimony is revealed by the copious fumes emitted, BB ; and by the formation of a yellowish-white powder (Sb^ or SbK)*, or a mixture of the two) in nitric acid. The presence of tellurium, revealed by its blowpipe reactions, is readily con> firmed by warming a small portion of the substance in a test-tube about half filled with strong sulphuric acid, when a reddish solution will result. On addition of water, a dark precipitate of metallic tellurium is thrown down. [lis] TABLE VI. [Aspect metallic. No S reaction. No fumes of As, Sb, or Te.] A— On oharooal, BB, no sublimate. (In closed tube, Hg Reaction). Al.-ENTIRELY VOL. Native Mercury. In small fluid globules of a tin- white colour. G 13-6. A».— PARTIALLY VOL., A SILVER-GLOBULE REMAINING. Amalgam : Properly an isomorphous union of Ag and Hg : hence these com{M)nents are present in variable proportions. Reg. ; H 2-35 ; G 108-1 4-10; brittle. Arquerite is a variety containing 86^ p. c. silver. Kongsbergite, a var. containing 95 p. c. silver. Some amalgams contain gold : in these the sp. gr. is usually 1 5 ormore. B— On charcoal, BB, a yellow^-sublimate. B».— malleable. Native Lead: Reg.; H 1-5; G 11 -3-11 -4; lead-grey; ductile. B«.-CLEAVABLE (OR NOT MALLEABLE). Native Bismuth: Hemi-Hex. H 2-5; G 9-6-9-8. Reddish silver-white, mostly with yellowish or variegated tarnish. NOTE ON TABLE VI. Native Bismuth and Native Amalgam are the only minerals of ordinary occurrence belonging to this Table. N. Bismuth is readily distinguished by its (practically) complete volatilization before the blowpipe, with formation of a yellow deposit of oxide on charcoal. It dissolves rapidly in nitric acid, ^ the solution yielding a white precipitate on the addition of water. Some 'varieties contain traces of As, S, Te, &c. It occurs commonly in small cleavable masses, but occasionally in dendritic and other examples. When crystallized, it is mostly in small rhombohedrons with basal plane, the principal cleavage being parallel with the latter. Amalgam is often in small crystals of the Regular System, commonly in dodecanedrons or combinations of cube and octahedron. In ordinary varieties the sp. gr. exceeds 13*5. This latter character, together Mrith the large bead of silver which it yields, BB, and its mercurial reaction, serve sufficiently to distinguish it. [116] TABLE VII. [Lustre metallic. Not perceptibly vol. Fusible on charcoal into a globule. ] A— Malleable- Native Gold: Reg.; H 2-3; G 15-5-1 9-4. Gold-yellow. Not attacked by nitric acid, nor by blowpii)e fluxes. Always contains a small amount of Ag. Native Silver: Reg.; H 2-3; G 105 (or 10-11). Silver- whito, often with black surface-taraish. Easily dissolved by dilute nitric acid on heating : a white curdy pre. (turning dark-gi-ey on exposure) is formed by hydrochloric acid, or any soluble chloride, iw the solution. Native Copper: Reg.; H 2-5-3; G 85-8-9. Copper-red, often with dull-brown tarnish. Easily sol. in nitric acid, forming a gi*een solution, which becomes deep-blue on addition of ammonia. The fiised bead blackens in the OF, its surface becoming encrusted with CuO. This tinges the flame green. B — Not malleable. {Cu reaction). Cuprite (Red Copper Ore). Colour and streak red. Lustre occasionally sub-metallic. {See Table IX). Tenorite (Black Oxide of Copper): Cu 7985, O 2015. Rh. 1 in small, tabular crystals, massive, &c.; H 2-3; G 6*9-6-5. Steel-grey to black. Melaconite is an earthy or scaly var., sometimes pseu- domorphous. {Mn and Fe reactions. ) Wolfram. Brown, black. Lustre sub-metallic only. li 5-5 5 ; G over 7. An iron-manganese tungstate. {See Table IX). NOTE ON TABLE VIT. All the minerals of this Table, Tenorite excepted, are of tolerably common occurrence. They are readily distinguished by the characters given above, or by the following condensed scheme : Malleable : Colour yellow — N. Gold. " white — N. Silver. " red — N. Copper. Brittle: Streak red — Cuprite. •* black or brown : BB, Cu reaction — Tenorite. " Mn reaction — Wolfram. These three latter intnerala belong, propeily, to other Tables. Exceptional varieties, wlf, come under notice here. [1171 TABLE VIII. [Lustre metallic. Not perceptibly vol. Infusible'; or fusible at the extreme point or edges, only.] A —Not dissolved, BB, by borax or phospliorsalt. _A».— VERY SOFT. BLACK, MARKING OR SOILING. Graphite (Plumbago). Normally, pure carbon : usually slightly ferruginous, . Native Iridium or Platinum-Iridium : Ir, Pt, Rh, -magnesite) is a volcanic variety in which the FeO is essentially replaced by MgO. G 4"6-4'7. Jacobsite is anolher variety, containing both MgO and MnO. G 4*75. Many examples of Magnetite are also titaniferous. These might fairly rank as a distinct species, having the same relation to Magnetite proper that Ilmenite bears to Heematite. Franklinite : ZnO, FeO, MnO, Fe*0*, in variable proportions, but yielding the general formula RO, R'0». Reg. ; H 6-65 ; G 5-51 ; iron-black, streak dark reddish-brown. Usually, more or less mag- netic. BB, in powder with carb. soda and borax, gives coating of ZuO on charcoal. / Chromite ; no»-mally, FeO, 32, Cr'0» 68. Reg. ; H 55 ; G 43 4-6. iron-black, streak dark-brownish. Lustre, in most examples, sub- metallic only. HEMATITE (Specular Iron Ore): Fe 70, O 30 ( = Fe»0»). Hemi- Hex. ; H 5-5-6-5 ;* G 5-0-5'3. Steel-grey, often with variegated tarnish ; streak cherry-red. Sometimes feebly magnetic. Martite is a var. in small oc.ihedrons altered from Magnetite. Ilmenite or Menacannite (Titaniferous Iron Ore). Fe*0', Ti*0' in variable proportions. Hemi-Hex.; H5*5-6; G 4'5-5*3. Iron-black, dark steel-grey; streak black to brownish-red. Dissolved or attacked in fine powder by hot hydrochloric acid, the diluted solution by boiling with tin becoming first colourless and then assuming an amethystiiic tint. Arkansite (variety of Brookite). Black, sub-metallic lustre. See Table X. ( Yield water in bulb-tnbe). TuROiTE. Red, blackish-red J lustre sub-metallic. See Tables X., XXIII. G(ETHITE. Red, brown; lustre sub-metallic in some examples, ^ee Tables X., XXIII. * As regards ordin«ry examples ; hut the scaly varitty, »'though showing luctaUlc lustre, soil^ the hands. MINERAL TABLES : — VIII. 119 LiMONiTE (Brown Iron Ore), Brown, streak yellowish. Lustre occasionally sub-metallic. See Tables X., XXIII. B«.-NON-MAQNETIC AFTER IGNITION. (Strong Mn rfaetion.* Anhydrous), Pyrolusite (Black Manganese Ore): Mn 63'2, O 368. Rh. ; H 1-1-5; G 4-7-4-9; iron-black, dark steel-grey, streak black; soils nml marks. Ignited, and moistened with HO acid, shews Ba-lines in spectroscope. Polianite : Identical with Pyrolusite as regards composition and geneml crystallization, but with H = 6-7. Bbaunite — Hausmannitb. Aspect commonly sub-metallic. See Table X. Crednerite. Gives copper reactions. Aspect commonly sub- metallic. See Table X. {Strong Mn reaction, and yielding aq in bulb-tuhe). Manoanite : MnO' 909, H'O 910. Rh. ; H 35-4 ; G 4-3-4-5 ; dark steel-grey ; streak, brown, black. Psilomelane : MnO, BaO, etc., with about 4 or 5 p. c. H'O. Amorphons (reniform, to Table XI. MINERAL TABLES : — IX. 1 23 Kermesite resembles Cinnabar as regards rapid volatilization, but it forms on charcoal a dense white coating of SbW or Sb^O*, and its sp. gr. does not exceed 4*6. It occurs commonly in tufted groups of acicular crystals, or in radiated tibroi'sj examples. In a hot solution of caustic potash it is rapidly converted into an orange-red powder. Pyrargyrite and Proustite are closely akin by crystallization and chemical f iiTiulag ; but Pjmirg5rrite is very dark in colour, and it emits, BB, denas \. onial fumes (commonly accompanied by arsenical odour) ; whilst Pfoustite is distinctly red, with commonly an adamantine or non-metallic lustre and certain degree of translucency, and it is essentially a sulpharseniie. Both occur commonly massive, or in small (usually indistinct) crystals of the Hexagonal System, the more frequent forms comprising a combination of hexagonal prism and rhombohedron, and scalenohedral combinations. Twins and hemimorphous examples are common. Both species fuse per se when held against the edge of a candle-flame. The powder becomes immediately black in a hot solution of caustic potash. Hydrochloric acid precipitates orange- brown Sb'S', or yellow As'S', from the solution. See, also, Notes to Tables IV. and XIV. Cuprite is separated from the preceding minerals by yielding no sulphur- reaction before the blowpipe. It occurs frequently in octahedrons and rhombic dodecahedrons, with green coating of malachite covering the entire surface of the planes ; more rarely in acicular shapes arising from elongated cubes. It is also frequently in massive examples. It dissolves in nitric acid with strong effervescence and production of orange-red nitrous fumes, the Cu'O being con- verted into CuO at the expense of some of the oxygen of the acid. The solution is of course green or blue in colour, and becomes intensely blue on sufficient addition of ammonia. Wolfram is readily distinguished by its dark-brown or black colour, and high sp. gr. (over 7). It occurs massive, and very frequently in somewhat large crystals of the CUuo-Khombic System : mostly, flattened six-planed prisms (composed of the forms V and Y) terminated by a sliarply sloping base and several polar planes. V : V = 10O°37' j V : V = UO'IS' ; B : V = IIS-G'. It fuses into a magnetic globule with crystalline surface. Melted, in powder, with carb. soda and nitre in a platinum spoon, it forms an alkaline tungstate soluble in hot water, the bases remaining for the greater part undissolved. The solution (which at first is green from some dissolved manganate of soda) when boiled with hydrochloric acid and a piece of tin or zinc, becomes r&pidly colourlev, and then assumes a deep indigo-blue ooiour. [124] TABLE X. [Lustre sub-metallic, lafusible ; or fusible on thinnest edges only.] A —Yielding Sulphur-reaotion with oarb. soda on charcoal. (Zn reartion). Sphalerite or Zinc Blende : Zn 67, S 33. Reg.; H 3-5-4 ; G. 3-9-42. Brown, black, red, Cassiterite or Tinstone scarcely belongs to the present table, as in most examples the lustre is essentially non-metallic. Its great weight and hardness, tetragonal (often twinned) crystallization, and its property of yielding tin globules by reduction with mixture Qt carb. soda (ind borax, are its more distinctive characters. Kutile and Anatase (two of the natural representatives of binoxide of Ti> tanium, the comparatively rare Brookite being a third representative of that compound), have in most examples a non-metallic (adamantine) lustre, with a certain degree of translucency. But some examples are opaque. Rutile resem- bles Cassiterite (and also Zircon, Table XXIV.) in its crystallization. The crystals are commonly composed of two square prisms (forming a pseudo- 8-sided prism) with pyramidal terminations. The prirm-planes are striated vertically in most cases, and the basal plane (as in Zircon) is constantly wanting. Geniculated twins are common. The colour is generally dark brownish-red or blood-red, but light-brown And other tints also occur. Ana- tase occurs in small pyrfunidal crystals, usually composed of two or several square octahedrons, the more common one having the angle over a polar edge = 97°50', and over a middle edge = 136°36'. Prism planes and basal plane are also occasionally present, and some crystals are tabular from predominance of the latter. The colour is usually indigo-blue, brown, or greyish-blue. Both Rutile and Anatase, when fused in fine powder with caustic potash (or with carb. soda and borax), are attacked or dissolved by hydrochloric Acid, the diluted solution becoming of a deep amethystine .tint when boiled with metallic tin. Anthracite is at once distinguished from other minerals of the Table by its low s{)ecific sp. gr. (I '2-1 '8). The lustre, moreover, is properly non-metallic. See Table XXV. 10 [1301 TABLE XI. [Aspect non-metallic. Readily inflammable : * burning with sulphoroaf or aUiaceoQS odour.] A.— Burning with sulphurous odour. (Streak, yellow j. Native Sulphur : Rh. ; H 1 •5-2-5 ; G l-9-2'l ; yellow, brownish, reddish-yellow. See Note, below. (Streak, red or hrovm). Cinnabar : Hg 68-2, S 13-8. Hemi-Hex. ; H 2-2-5 ; G (normally) 8-9, but often lower in dark carbcnaceoiis varieties. Red with red streak; but sometimes brown from admixture with carbonaceous matter. iDRiATiiNE : A mixture of Cinnabar with earthy matter and CH'. Brownish-black ; streak brown or reddish. H 1-1 '5; G 1*4-1 -6. Kermesite : (Sb, S, O). Inflammable in some varieties only ; mostly fibrous or acicular. G 4'5. See Tables IX, XV. BB, copi- ous antimonial fumes. (Streak, black). CovELLiNE :: Cu 6646, S 33-54. Hex. ; H 1-5-2 ; G 4-4-6. Dark eoppery-blue, blackish-blue. BB, copper reaction. B — Burning with alliaceous (arsenical) odour. (Colour, yellow). Orpiment : As 6, S 39, Rh. ; H 1-5-2 ; G 34-3-5. Bright yellow, commonly with metallic-pearly lustre ; streak yellow. In thin pieces, flexible. (Colour, red). Realgar : As 78, S 30. Ciino-Rh. H 1-5-2 ; G 3-5-3-6. Red, streak orange-yellow. NOTE ON TABLE XI. The principal minerals of this Table are N. Sulphur, Orpiment, Realgar, and Cinnabar. The latter is distinguished more especially by its high sp. gr. and its red streak. * To test this property, a small piece of the minora! may be taken up by the steel forceps and lield for an instant against the edge of a Bunaen-flame or the flame of a conunon caadU. MINERAL TABLES : — XI. 131 Native sulphur, when vrystallized, is commonly, in acute rhombic-octahe- drons of flmall size. It occurs generally in indistinct druses, massive or efflorescent on pyrites, &o. It melts into red-brown drops which become pale yellow on cooling. From Orpiment, which is equally inflammable, it is dis- tinguished by its low sp. gr. and by the absence of amenical odour during combustion. Orpiment is occasionally in small prismatic crystals, but occurs generally in foliated or other examples. It dissolves entirely in caustic potash, and is re- precipitated from the solution by hydrochloric acid. Realgar is distinguished from Cinnabar by its orange-yellow streak, as well as by its lower sp. gr. , and the arsenical odour evolved on combustion. Its crystals are small Clino-Khombic prisms with largely developed basal plane, but are generally in druses, or otherwise indistinct. Most commonly it occurs in granular or other masses. In caustic potash it leaves a brown residuum of sub-sulphide. Otherwise like Orpiment. Cinnabar is the essential ore of mercury. Under normal conditions it pre- sents a scarlet red colour (whence its old name of Native Vermilion) and un- changed streak, but the surface is usually brownish, and many examples are dark-brown from intermixed earthy or bituminous matter (Liver Ore, ftc.) The crystals are combinations of rhombohedrons and hexagonal prism, the triangular basal plane being especially apparent. Tetartohedral forms have been recognized, but in general the crystals are small, and more or less in- distinct. Cinnabar occurs more commonly in granular masses, and occasionally in thin coatings or incrustations. Metallic mercury is easily sublimed from it by ignition with dry carb. soda, iron filings or other reducing agents, in a small flask or test-tube. Scarcely attacked by caustic potash, or by nitric or hydro- chloric acid. Soluble in aqua regia. [132] TABLE XII. [Aspoot tioD>metaIlic. Inflammable in candle flame, burning with bituminous or aromatic odour.] A —Coaly, ligneous, or pitch-like aspect. Burning with bituminous odour. Bituminous Coal : C 74-96, H 0-5-5-5, O 3-20. Black, often iri- descent ; streak, black. H 2-25 ; O 1-2-5. Lignite or Buown Coal: C 55-80; H 3-6; O 17-27. Dark- brown or black (jet) with brown streak. H 2-2 5 ; G 1-2-1.4. Mas- sive, 11: "form, sometimes foliated (Paper Coal), and earthy. Imparts a brown coloiu* to caustic potash. "Torbarnite" is sometimes referred to this variety, but it is properly a mere bituminous shale. Bitumen or Asphalt : C, H, O. Black, greenish-black. H 0-5- 2'0 ; G 1"0-1'2. Semi-fluid or pasty in ordinary examples, also in stalactltic and other more or less brittle masses with conchoidal fracture. Passes into Petroleum. Albertite : C, H, N, 0. Black, highly lustrous, brittle. H 2- 2-5; G 1-1*1. Scarcely attacked by alcohol, but partially dissolved by oil of turpentine. Stellarite and Graham ite are related sub- stances. Elaterite (Elastic Bitumen) ; C, H, O. Dark-brown or black. Soft and flexible, resembling caoutchouc. Passes into ordinary bitu- men. G 0-8-1 '2. DopPLEftiTE is a closely related substance. B-— Besinous (or when dark coloured somewhat coaly) in aspect, but burning with aromatic (non-bituminous) odour. PiAUZiTE : dark-brown, with yellowish-brown streak. H 1 -5-2 ; G 1-18-1-22. Soluble in ether and in caustic potash. Pyroretine is apparently related. Amber (Succinite, Bernstein) C, H, O (= C 79, H 10-5, O 10-5?). Yellow, brownish, reddish, greyish-white. Mostly in nodular masses. H 2-2-5 ; G 10-1-1. Electric by friction. Ketinitb, Krantzitb, IxoLiTE, SiEOBUROiTE, Pyropissite, and other obscurely known amber-like substances, belong also to this group. MIKKRAt TAW.BS :— Xfl. 133 O— W8X'Iik0 ftt flE8pe TUBE. (No reaction of S or CI). Cerussite : PbO, 8352, CO* 1648 - Pb 77-6. Rh. ; H 3-35 ; G (normally) 6'4-6'6, but lower in impu'^e earthy varieties. Colour- less, or grey, nearly black, yellowish, «fec. ; streak white. Ioleasite is a zinc-holding variety. Plumbo-Calcite : = Plumbiferous var. of Calcite or Calc Spar. Tarnowitzite = Plumbiferous var. of Arragonite. G about 2-8. Both give a lead sublimate on charcoal, but metallic globules are not readily obtained. (8 reaction). Leadhillite : PbO, C0» 72-56, PbO, S0» 2744 = Pb 75. Eh. ; H 2-5-3; G 6 •2-6*6. Yellowish- v/hite, grey, brownish, &c., streak white. Susannite is a supposed rhombohedral variety (G 6-55). Maxite is probably an altered var., containing a small percentage of water. Caledonite : PbO, CuO, SO' (CO- by alteration or admixture). Light-green. See Table XVI.) (CI reaction). Phosgenite (Kerasine) : PbO, C0» 49, PbCl« 51, = Pb 738. Tet. ; H 2-5-3 ; G 6-6 3. Yellowish- white, grey, yellow, green ; streak white. A«— yielding water on ignition. (Cu reaction). Malachite: CuO 71-95, C0» 19-90, H'O 8 15. Clino-Rh., but rarely crystallized. H 1-0-4; G 3-7-4. Green, often zoned in dif- ferent shades ; streak light-green. Some varieties are calcareous. Atlasite is a variety containing copper chloride. AzuKiTE (Chesgylite) : CuO 692, C0» 25-6, H'O 52. ClinoRh.; H 1-4 ; G 3-7-3-8. Blue, paler in the streak. 136 BLOWPIPK PRACTICE. See also Tirolite, Table XIV, m&ny examples of which contain intimately intermixed carbonate of lime. Gr6en or blue radiated masses, or eaiiihj. BB, strong arsenical odour. (Cu and Zn reactions), AuRicHALCiTE : CuO 28, ZnO 46, 00^6, H'^O 10 (i). Acictilar or fibrous. H 2 ; G about 3*3. Green or bluish ; streak paler. BuRATiTE is a calcareous variety. ( Bi reaction). BiSMUTiTE : BiO, CO, H*0. H 4-45 (1) G 6-8-6-9 (?). Yellow, grey, green ; streak paler. A doubtful species, more or less variable in characters and composition. B— No metallic globules obtained by fusion with carb soda on charcoal- B»— ANHYDROUS SPECIES. NO WATER. OR TRACES ONLY, IN BULB TUBE. (NoTE: — The precHence Of Ca, Ba> Sr, singly or together, in carbonates of this group, is very readily ascertained by a small, direct vision spectroscope. See Outline of Blowpipe Practice, pp. 55, 57. t Magnetic after ignitiori. SiDERiTE (Spathic Iron Ore) : FeO 62, CO^SS, = Fe 48-2 ; part of the FeO, however, often replaced by MgO, MnO, CaO. Henii-Hex. ; H 3 5-4-5 ; G 3"7-4*l ; yellowish-grey, yellow, brown, olive-green, &c., streak paler. Spherosiderite is a fibrous-spherical variety from trap rocks ; Clay-Ironstone, Black Band, &c., are impure argillaceous or bituminous varieties from coal strata. Siderople- siTE, Mesitine and Pistomesite (G 3-3-3-6) are crystalline magne- sian vars. ; and Oligon Spar, a variety containing 25 5 p. c. of MnO CO'. In the typical rhombohedron, R : R == 107'', whilst in the Mg and Mn examples it varies from 107°3' to about 107° 18'. Crystals, however, commonly present curved planes. Ankerite : (CaO, MgO, MnO, FeO) C0». Hemi-Hex., with RR about 106°12'. White, yellowish, brownish,- streak, in nnweathered examples, white. H 3-4 ; G 29-3'3. Merges into Siderite, Calcite, and Dolomite. See also dark-coloured varieties of Magnbsitb and Dolomite. ft Hfot magnetic on ignition, and no marked alkaline reaction. MllifBltAL TABLEfS :— XIII. 137 (Strong reaction of Mn), Hhodochrosite (Diallogite, Manganese Spar): MnO 6174, CO' 38-26, but MnO often in part replaced by CaO and MgO. Hemi- Hex, with R : R (normally) 106*^5'. H 3-5-4 -5 ; G 3-3-3-6. Rose- red, pink-brownish when weathered ; streak very pale red, reddish- white. Blackens on ignition. Rcepperite is a calcareo-raagneaian variety. (Co reaction), SPKiEROCOBALTiTE (Cobalt spar) : CoO 63, CO' 37. H 4 ; G 4-0- 4-1. In spherical conci-etions, black externally, red within. A doubtful species. (Zn reaction). Smithsonite (Calamine, Zinc Spar) : ZnO 64*8, 00^35 -2. Hemi- Hex., with R:R^ 107^40'. H 5; G 4-4-5. Colourless, pale- gi-eyish, greenish, brownish ; streak, white. Many varieties contain FeO and MnO. Herrerite is a cupreous variety. t|t Alkaline reaction, after strmig ignition. (Ba reaction : flame, coloured pale-green). Witherite: BaO 77-67, CO' 22-33. Rh., with pseudo-hexagonal aspect. H 3-35 ; G 4-2-4-4. Colourless, pale-grey, yellowish ; streak white. BB, entirely soluble in carb. Rod», Alstonite (Biomlite) : EaO, CO^ 66-33 + CaO, C0» 3367. Rh. ; H 4-4-5 ; G 3-6-3-8. Colourless, greyish ; streak white. BB, only in part sol. in carb. soda. Baryto-Calcite : Composition and general characters as in Alsto- nite ; but crystallization Clino-Rhombic, with V : V 84^^52'. (Sr rtaction : crimson flclnie-coloration). Strontianii'e : SrO 70-27, CO' 29-73. Rh. (V : V = 117*19') ; H 3-5 ; G 36-3-8. Colourless, greenish, yellowish, CO", H'^O. In white or yellowish earthy crusts on certain examples of Gadolinite. Lanthanite : LaO 52-6, CO* 21 -3, H»0 261. Rh. (V : V 92^50' — 94*^), gener'ally tabular. H 25-3-0; G 2-67 ; greyish or yellowish- white, pale red. BB, with borax, a pink or pale violet bead, appa- rently from the presence of Didymium. tjt Insoluble in water. Giving, with borax, a strongly-coloiured glass. Wiserite : MnO, CO*, H^'O. In yellowish or pale-red fibrous coatings on certain examples of Hausmannite and other manganese ores. Zaratite (Texasite) : NiO, C0^ H^O. In thin emerald-green coatings on nickle ores. Also on examples of Chromic Iron Ore from Texas, Penn. Reminotonite : CoO, CO*, H*0. In pinkish, or greyish-blue coatings on cobalt ores. LiNDAKERiTE (Calc-Uran Carbonate). In coatings and crusts on Pitchblende. Yellowish-green. Contains (according to Lindaker) UO 3703, CaO 15-55, CO* 24-18, H»0 23-24. Voglite is a cupi-e- ous variety. Liebiqite is also a closely related compound, but with 45 p. c. aq. All occur in connection with pitchblende. NOTE ON TABLE XIII. The more important minerals of this Table comprise : (1) Calcite, Dolo- mite, Magnesite, Siderite, Rhodochroaite, and SmitLsonite, of the group of 140 BLOWPIPE PRACnc*. RhomhoMdrdl Cathonalen; (2) AHigamie, Withe*he, .^rd«ilH*nite, aftd Cemg* Bite, of the group of PriamaHc Carbonates; and (3)j the Cupreous Carbonates, Malachite and Azurite. ■ Calcite, in its crystalization, chiefly aflfects three series of forms : (i) Rhom- bohedrons, acute and obtuse ; (ii) Scalenohedrons ; and (iii) Hexagonal Prisma, the latter commonly terminated by the three planes of a rhombohedron, pen- t igonal in shape in some cases, rhombohedral in others. The basal plane, when present, is usually rough or dull. Some of the more common rhombohedrons ooiAprise: - ^R (polar angle ISS'') ; - 2 R (polar angle 79*") ; and 4 R (p. a. 66"), The most common scalenohedron has the following interfacial angles : over long polar edge 159''24' ; over shorter polar edge ISS^S' ; over middle edge 64''54'. All crystals and lamellar examples cleave readily into a rhombohedron of about loss's' and 74*'55', but these angles vary to within about SIX in con- sequence of isomorphoQB replacements, a small portion of the Kme carbonate being almost constantly replaced by carbonate of MgO, PeO, or MnO. Trans* parent examples show strong double refraction in the direction of the longer diagonal of a rhombohedral face. Pseudomorphs, after Orthoclase, Fluor Spar, Barytine, Celestine, Gypsum, Gaylussite, &c., are not uncommon. Calcite occurs likewise in rock-masses, fottnmg crystalline limestone (marble), ordinary limestone, oolitio limestone, ohalk, ftc, and in various stalaotitic, tufaceoua, and other conditions. Calcite, after simple *^it'.on (without the aid of hydro' chloric acid, although it is always advisable to add a drop of this), shews the red and green calcium lines in the spectroscope very distinctly. Dolomite mnch resembles calcite in its general characters and rhombohedral crystallization, but it dissolves, as a rule, in cold acids with comparatively feeble efl'ervescence. Both hardness and sp. gr. are also slightly higher. The most certain method of distinction is ttie determination of magnesia in the hydrochloric acid solution. For this purpose the diluted solution is first* boiled with a drop or two of nitric acid, and ammonia is then added in slight excess. This Will cause a slight flocculent precipitate if iron be present. Oxalate of ammonia is then added to precipitate the lime ; this is filtered off ; the filtrate tested with another drop of oxalate of ammonia to make sure that aU the lime has been thrown down, and the magnesia is precipitated by some dissolved phosphor-salt. It can be collected, if necessary, and ignited with nitrate of cobalt for the production of the characteristic flesh-red tinge. Many so-called limestones when examined in this manner are found to be "dolomitic." Ferruginous varieties of Dolomite pass into Ankerite. Magnesite is comparatively rare in crystals, but occurs commonly in more 01' less compact or granular masses, beds, or layers of a white, pale-grey or' yellowish colour. The small rhombohedrons show over a polar edge the angle 107" 16' to 107''29'. The powder by ignition with a drop of cobalt solution, is distinctly reddened. The absence of lime can be proved by the spectroscope ; and the presence of magnesia by the cobalt test or by precipitation, as explained under Dolomite. Siderite or Spathic Iron Ore occurs under various conditions : crystallized in metallic veins, &c. ; flbro-botryoidal ; in spherical concretions in basaltio MINERAL TABLES: — XIII. 141 rocks ; pisolitic in Jurassic and other strata ; massive ; and lithoidal. The crystals are usually small rhomboh^drons of a yellow colour (with R : R 107*', but frequently with curved faces), also acute rhombohedrons and scalenohe- drous. The spheroidal basaltic variety is usually dark-green or yellowish - brown, with radio-fibrous structure. The pisolitic variety, dark-brown or grey, and opaque ; and the lithoidal and massive examples dark-grey, brown or black, and also opaque. These latter kinds commonly occur in oval or nodular masses in coal strata, or in layers mixed with coaly matter. Under the name of Clay Iron-Stone, Black Band, &c., they furnish a large part of the iron of commerce, but are always very impure from admixture with clay, silica, &c. They are also more or less altered, as a rule, into brown iron ore. The nodules, when split open, are usually found to contain the impression of a fern-frond or other organic body. Rhodochrosite or Manganese carbonate is of less frequent occurrence than the preceding carbonates. Its crystals are mostly small rhombohedrons (with usually curved faces) sometimes shewing a triangular basal plane (R : R 106" 51' — 107**) ; but it occurs commonly in botryoidal, granular or lamellar masses, of a pink or rose-red colour, with dark-brown altered patches. As in Magnesite and Siderite, it effervesces feebly unless the acid be heated. Its red colour and intense manganese reaction, BB, with carb. soda, generally serve to distin- guish it at once from other carbonates ; but many examples of Magnesite, Siderite, &c., give a more or less strongly-marked manganese reaction. No very dehnite lines of demarcation^ in fact, can be drawn between the rhombo- faedral carbonates generally. Smithsonite, or zinc carbonate, occurs mostly in aggregations of minute rhombohedrons, or in botryoidal or Incrusting examples of a white, brownish, gi'cy> yellowish, or green colour. It is usually more or less vitreous an<} transparent; but is sometimes in opaque, grey or brown, earthy or porous masses. The streak is white, and the hardness just sufficient to scratch glass ; or sufficient, at least, to scratch fluor spar very strongly. In powder, with a mixture of oarb. soda and borax, it yields on charcoal a sublimate of ZnO, — bright-yellow and phosphorescent, hot ; white, cold ; {^ud l\ght-gree;i after ignition with cobalt solution. Aragonite — the typical representative of the group of Prismatic carbonates — is identical in composition with the rhombohedral calcite. It occurs frequently crystallized, and in fibrous, coralloidal, and other masses. The crystals belong to the Rhombic System, and are generally six-sided prisms, composed u of four V planes with the two side planes of a brachy-prism V, terminated by a brachy-dome P, and by the planes of a rhombic octahedron P ; but the latter form is often absent. V : V = 116°10' ; V : V = 12r55' ; V : ^ = 125°47'. Twins and compound crystals are very common. Some of the latter, com- posed of three or more individual crystals, are strikingly pseudo-hexagonal in character, presenting the appearance of a simple six-sided prism with large base. The colour is white, yellow, brownish-violet, &c. All examples dis- 142 BLOWPIPE PRACTICE. solve with strong effervescence in cold acids, and show, after moderate ignition, the characteristic red and green calcium lines in the spectroscope. Witherite, carbonate of baryta, also presents in its crystallization a pseudo- hexagonal aspect. The crystals are, very generally, six-sided pyramids, but are regarded as compound crystals, made up of interpenetrating rhombic- octahedrons. Columnar, botryoidal, and massive examples are however its principal forms of occurrence. Its high sp. gr. (over 4'0), and the green colour which it imparts to the flame border, sufficiently distinguish it from other carbonates. Strontianite, like Witherite, is entirely dissolved by fusion with carb. soda; and its sp. gr. is comparatively high (.3*6-3"8). It is readily distinguished, however, by the intense crimson coloration which it communicates to the flame-border, and by the characteristic blue, orange, and red lines, of its spectrum. Its crystallization is identical with that of Arragonite, and is characterized by pseudo-hexagonal combinations and twin forms (V : V = in^lO'; V : V = 121°20'30" ; V : 2P = 145°22'). Strontianite occurs more commonly, however, in columnar, fibrous, granular and other examples. Cerussite, or lead carbonate, is also identical in crystallization with Ara- gonite, and is particularly characterized by its stellate and cruciform groups (V:V = 117°14', V:2P = 145"'20'). The lustre is strikingly adamantine. This character, with the high sp. gr. (6*5) of the species, its remarkable fragility, and its blowpipe reactions, sufficiently distinguish it. The copper carbonates. Malachite and Azurite, yield water on ignition, and are otherwise distinguished by their deep green and blue colours, and their copper reactions. Malachite (although often, as a prod act of alteration, entirely coating octahedrons and dodecahedrons of red copper ore, Cu^O) is very rarely crystallized, but occurs commonly in botryoidal, fibrous and massive examples, and as an earthy coating on copper ores generally. Azurite, the blue carbonate, is frequently in groups of small clino-rhombic crystals, more or less indistinct in form. It occurs also in colimmar and other jiasses, and in earthy coatings on copper orei. [US] TABLE XIV. [Aspect non-metallio. BB, on charcoal, arsenical fumes or odour.] A —Entirely volatilizable, or leaving only a minute reBiduum< {Streak white). Arsenolite (Arsenious acid): As 758,0 24-2. Eeg.; H 1-2; G 37 ; in white, crystalline or acioular groups and coatings, and in earthy crusts. Claudetite (Dana) is a rhombic species, in small sub-pearly laminse. G 3 85. (Streak bkick), Native Arsenic, weathered examples. In dull, black, earthy masses, often coating the metallic-grey or tin-white unaltered metal. See Table I. B — Yieldinff, BB, metallic globules on charcoal, (A mixture of carb. soda and borax assists the reaction). {BB, a silver globule). Proustite (Light-red Silver Ore). Ag 65*46, As 15-15, S 19'39. Hemi-Hex. ; H 2-25 ; G 5'4-5-6 j red, more or less translucent, with adamantine lustre ; streak, red. Xanthocone : Ag 6408, As 1483, S 21-09. Hemi-Hex., mostly tabular. H 2-2*5 ; G 5-0-5-2. Orange or brownish-yellow, trans- lucent or transparent, with adamantine lustre. Streak orange-yellow. KiTTiNGERiTE : Normally AgAs (with 67-7 Ag), but S commonly present. Clino-Rh. ; H 2*5-3; G 5-6 3. Iron-black, red by trans- mitted light ; streak orange-yellow. Lustre in general strongly sub- metallic. See Table IX. PoLYBASiTB, arsetiical varieties. Ag (64-74), Sb, As, S ; Eh. ; H 25 ; G 6-0-6*2. Iron-black, red in thin pieces by transmitted light; streak, commonly dark-red. Lustre, usually metallic. See Table IV. All the above arsenical silver ores fnse per ne. in the flame of a candle, with* out the aid of the blowpipe. Rittingerite and Polybasite are still imperfectly known. {Cu reaction), Olivenite: CuO 56-15, As'O* 40-66, H»0 3*19. Rh. (V:V 92°30'); H 3; G 43-4-6; dark-green, brownish; sti-eak, paler. 144 BLOWPIPE PRACTICE. Euchroitb: CuO 4715, As^O 3415, H»0 18-70. Rh. (V:V 117°20'); H 3-4; O 3-3-3-5 j emerald-green, leek-green; streak, paler. Chlorotile is closely related. Erinitb : CuO 60, As'O* 34-6, H*0 6'4. Mostly in concentric- lamellar examples ; H 45; G40; emerald-green; streak, paler. TiROLiTB (Kupferschaum) : CuO 50-32, As^O* 2915, H*0 20'53. Mostly in i*adio-fibrous mammillary examples. H 1-2 ; O 3'1. Green or greenish-blue ; sti-eak, paler. Most examples are intimately mixed with CaO, CO*. The i)resence of Ca, readily shewn by spectroscope. Clingclase (Abichite, Aphanese, Strahlerz) : CuO 62-65, As'O^ 30-25, H'O 710. Olino-Rh.; H 2-5-3; G 4-2-4-4; dark-green, bluish-green, blackish externally ; streak, paler. LiROKONiTB (Linsenerz) : CuO, As'O*, Al'^O', H^'O (25 per cent.). Clino-Rh.; H 2-2-5 ; G 2'8-2*95; light-blue, sometimes green; streak, paler. Chalcophyllite (Copper Mica) : CuO, As'0«, Al^O', H'O (23-32 per cent.). Hemi-Hex., tabular, micaceous. H 2 ; G 2-5 ; bright emerald-green ; streak, paler. Zeunerite: CuO 7-71, U*0» 55'95, H*0 14. Tet., isomorphous with Chalcolite or Torbernite. H 3-6 ; G 5*76; orange or wax-yellow, with adamantine lustre ; streak, paler. Adamite : Cupreous varieties. Green, G 4-35 ; ziac sublimate with carb. soda on charcoal. See below. {Pb reaction). Mimetesite : PbO, As'O* 90-7 ; PbCP 9-3. Hex. (crystals often Bub-spherical). H 3*5-4; G7-7'3; yellow,'green, greyish, colourless, ■wdth resino-adamantine lustre. Kampylite and Hedyphane (G 5 '5) are more or less calcareous and also phosphatic varieties. Some of the orange-yellow examples contain lead chromate. All give CI reaction with phosphor-salt and CuO. Ar/BOXene: PbO, ZnO, V*0*, As»0«. Radio-fibrous; H 3; G5-8; brownish-red; streak, yellow. Carminite (Karminspath) : PbO 2362, Fe*0' 29*14, As'O* 47-24. Acicular, mammillated. H2'5; G 41 ; red; streak, reddish-yellow. Beudantite : PbO, Fe*0», P»0*, AB^^ S0», H^O. Hemi-Hex. (?) ^3'5;^G4'0. Qlive-green ; Btrecik, yellowish. A doubtful species. MINERAL tables: — XIV. 149 {Si reaction), Rhaoite : Bi»0» 79 5, As'O* 15G, H'O 4'9. Mostly botryoidal or in small spherical examples. H 4 5-5 ; G6*82; light-green; streak, very pale gi'een or white. In bulb-tube crumbles into yellow powder. Accompanies uran ores at Schneeberg. Walpurginite : Bi«0«, U'0», As^O*, H'O (4-5). Clino-Rh.?; orange or wax yellow, with resino-ndamantine lustre ; streak, paler ; H 3'5 ; G 5-76. Accompanies uran ores at Schneeberg. Atelesite is apparently related. C— No metallic globules, BB, on charcoal. {Zn reaction. Characteristic eublimate with carb. soda on charcoal), Adamite: ZnO 566, As'O' 402, H'O 32, but some green examples contain CuO, and red examples, CoO. Rh. ; H 3*5 ; G 4*3-4'35. Noi-mally, yellow ; but often violet, red, or green ; streak, paler. KoTTioiTE : Zinc-holding var. of Erythrine. See below. {Co reaction). Erythrine (Cobalt Bloom) : CoO 37-56, As'O* 38-40, H»0 2404. Clino-Rh. ; H 2'5 ; G 2-9-30. Red, purplish-red; streak, paler. Some earthy varieties contain intermixed arsenolite. Kottigite is a zinc-holding var. RosELiTE : CaO, MgO, CoO, As»0*, H'O (8-20). Rh. or Cl.-Rh. H 3-3-5 ; G 3-46 ; deep i*ose-red ; pale-reddish or white streak. The presence of Ca easily shewn by the siiectroscope. Cabrerite : A cobaltiferous var. of Annabergite. See below. {Ni reaction). Annabergite (Nickel Green): NiO 3725, As'O" 38 59, H*0 24-16. Acicular, efflorescent; H 1-2-5; G 3 ; apple-green, greenish- white. Cabrerite is a variety containing CoO and MgO. Green and yellowish anhydrous nickel arseniates have also been recognized (O 4-9). {Pe reaction, BB, magnetic slag or bead). Pharmacosiderite (Cube Ore). Fe'O" 40, As'O* 431 3, H'O 16-87. Reg. {See Note at end of Table). H 25 ; G 2-9-3 ; dark- green, yellow, brownish ; streak, paler. Mostly in uinute cubes tetrahedrally modified. 11 146 BLOWPIPE PRACTICE. Scorodite: Fe'0» 3463, Aa'O* 4978, H'O 15-59. Kh. ; H 3-5-4; G 3"l-3*3 ; dark-green, brownish, indigo-blue ; streak, paler. Arsenigsiderite : Fe'O* 394, CaO 13-8, As'O* 379, H'O 8-9. Fibrous-botryoidal. H 1-2 ; O 39 ; bi-ownish-yellow, with silky lustre. Symplesite : FeO, Fe'0», As'0», H^O (25-28 per cent.). Clinc Kh., acicular ; H 25 ; G 2'9-30 ; pale blue, green, with pearly lustre. PiTTiziTE : Fe»0», A8'0^ SO', H*0 ( 1 2-29 per cent.). Amorphous, stalactitic. H 2 5-3; G 2 3-2 5; brownish-yellow, dark-brown; streak, paler. Carminite ; Beudantite : Contain PbO. See above. {MnO reaction). Chondro-Arsenite : MnO, MgO, CaO, Aa'O*, H'O (78 per cent.). In small granular concretions of a wax yellow colour. H 3 0. Berzelite : Gives Mn reaction in most examples ; Ca-lines in spectroscope ; no water. See below. DuRANoiTE : Strong Na and F reactions. Orange-red. See below. ( t/*0' reaction). Troeoerite: TT'O' 65-95, As'O" 17-55, H'O 16-50. Clino-Rh., tabular; H 2-25; G 3-23-327; lemon yellow; streak, yellowish- V'hite. Easily fusible. Uranospinnite : U^'O" 5918, CaO 5-47, As'O" 1937, H"0 16-19. Tetr. 1 scaly or thin tabular ; H 2-2-5 ; G 3-45 ; yellowish-green. {MgO and CaO reactions. Ca-lines well sheum in spectroscope). Berzelite (Kuhnite) : CaO, MgO, MnO, As'O*. Massive ; H 5 (or 4-5) ; G 2-5-2-55 ; yellow, yellowish-white. Nearly infusible. No water evolved in bulb-tube. Pharmacolite ; CaO 2490, As'O" 5110, H'O 24. Clino-Eh., but mostly acicular, fibrous, eai-thy, &c. ; H 1-5-2-5; G 273. Normally colourless or white. Easily fusible. Haidingerite: CaO 28-81, As'0» 56-87, WO 14-32. Rh.; G 2-9; otherwise like Pharmacolite, but of rare occurrence. Wapplerite: CaO, MgO, As'O*, H*0 (18-20 per cent.). Clino- Kh. ; H 1-5-2-5; G 2-5; colourless or white. Very easily fusible. HoERNESiTE is a related, but purely magnesian, arseniate (with H*0 29 per cent.), recognized by Kengott in the kaiserlichen min. Cabinet of Vienna. MINERAL TABLES : — XIV. 147 {Na reaction). DuBANQiTE (J. O. Brush): Na'O, Li'O, Al'O*, Fe«0«, MnO, As'O*, F. Clino-Rh. ; H f> ; G 3-94-407 ; orange-ml. Easily fusible. With sulphuric acid, fluorine reaction. Hitherto, only vecoguizod as accompanying tin ore and colourless topaz in the Pro- vinje of Durango, Mexico. NOTE ON TABLE XIV. This Table is oomposod oasentially of arseniates. The exceptions comprise a few silver sulpharsenites ia which the lustre is mostly non-metallic, and the naturally occurring arsenious acid or anhydride Aa*0'. The only minerals of the Tahiti likely to come under ordinary observation, include : (1 ) The "Light- Rid Silver Ure," Proustito ; (2) The Cupreous Arseniates — Olivine, Clinoclase, Liroconite, Chalcophyllifeo and Tirolite ; (.3) The Cobaltic Arseniate, Erythrine; (4) The Fernjginous Specits, Pharmacosiderite and Scorodite ; (5) The Lime Arseniate, Pharmaoolite ; and (6) the Lead Chloro- Arseniate, Mimetesite. Proustite or light-red silver ore, the arsenical silver blende of some nomen- clatures, is readily recognized by its deep or bright red colour, red streak and adamantine lustre ; as well as by the large silver-globule obtained from it by the blowpipe. It frequently accompanies Native Arsenic. It occurs both crystallized and massive. The crystals are generally small, and are not always readily made out in consequence of distortion by irregularity in the size of corresponding planes. Commonly, they consist of hexagonal prisms terminated by a rhombohedron (with R : K = 107°o()'), or of sualenohet Irons. Small fragments melt in. the candle flame, without the aid of the blowpipe. Boiled with caustic potash, the powder becomes immediately black, and As'S' is dissolved. This is thrown down, as a yellow flocculcnt precipitate, by a drop or two of hydrochloric acid. The copper arseniates are green, or more rarely blue, in colour, and, as a rale, they detonate or deflagrate somewhat strongly when ignited on charcoal. Olivine and Clinoclase are usually dark -green or blackish-green (though some- times brown or brown-yellow), and both occur frequently in small crystals, and in radiated-fibrous, reniform, and other uncrystallizcd examples. The Olivine crystals are rhombic, and the Clinoclase crystals clino-rhombic com- binations. Clinoclase w almost constantly in radiated groupings, whence its old G«rman name of StrahUrz. Olivine yields only 3'20 per cent. aq. Clinoclase 7 per cent. Liroconite is very usually of a light-blue colour, though sometimes green. It occurs mostly in very small clino-rhombic crystals which present in general an ortho-rhombic aspect, and sometimes resemble slightly distorted octahedrons. In the bulb-tube it yields (without decrepitation) a large quantity of water (25-26 per cent. ). Chalcophyllite is rarely in distinct crystals, but generally in micaceous or thin tabular examples of a bright 148 BLOWPIPE PRACTICE. emerald-green colour, with metallic-pearly lustre on the broad surfaces of the laminae. In the bulb-tube it decrepitates strongly and yields a large amount of water (23-32 per cent. ). Tirolite or Tyrolite is unknoMTi in crystals. Most commonly it occurs in bright green or blue radiated examples, or in reniform or fine scaly masses. Thin folise are flexible. The specimens hitherto examined contain 13-14 per cent, carbonate of lime, either in combination, or as an intermixture. The presence of Ca is readily shewn by the spectroscope, especially if the copper be first reduced by fusion with carb. soda on charcoal, and the resulting slag be moistened with a drop or two of hydrochloric acid. The amount of water equals 20-21 per cent. Erythrine, the cobaltic arseniate, is especially distinguished by its peach- blossom red colour, and by the deep-blue glass which it forms by fusion with borax. It occurs in small clino-rhombic crystals, but more commonly in bladed, acicular and efflorescent examples. The thin fohse are flexible. Easily fusible. Water, 24 per cent. The ferruginous arseniates, Pharmacosiderite and Scorodite, distinguished from the cupreous and other arseniates by the magnetic slag which they yield, BB, on charcoal, are distinguished individually by their crystallization. Pharmacosiderite is almost always in very minute cubes, truncated on alternate angles by the triaiigular planes of the tetrahedron. Its colour is dark-green, passing into brownish-yellow and brown, and the little crystals are usually in drusy aggregations. Scorodite when crystallized is commonly in small prisma terminated by an acute rhombic pyramid, but it occi'rs also frequently in fibrous and other examples. The colour is dark-green or indigo-blue, inclining to reddish-brown in some specimens. The hardness exceeds that of calcite, whilst Pharmacosiderite is slightly under culcite in hardness. Pharmacolite, the ordinary lime arseniate, is comparatively unimportant. It occurs mostly as a white efflorescence, or in acicular crystals, on arsenical cobalt and iron ores. Mimetesite, chloro-arseniate of lead, is readily distinguished from other minerals of the Table by its high sp. gr. (7 "0-7 "3), as well as by the lead globule which it yields, BB, on charcoal. It belongs by its crystallization anr' chemical formula to the Apatite group, and often passes into Pyromorphite, the corresponding lead phosphate. The crystals, hexagonal prisms, or com- binatio is of prism and pyramid, are very commonly curved into almost globular shapes. The colour is generally j'ellow, more rarely grey, brown, or green, with resino-adamantine lustre. Fused in the platinum forceps, the bead crystallizes on cooling, but on charcoal it becomes reduced. [149] TABLE XV. [Lustre non-metallic. BB, on charcoal, antimonial fumes and deposit.] A —On oharooalt reducible to metailio antimony and rapidly volatilised- {S reaction with carb. soda). Kerhesite (Pyrostibite, Red Antimony Ore, Antimony Blende). Sb'S' 70, SWO* 30. Red, bluish or brownish red, with red streak and adamantine lustre. Rh. (or Ciiiu) Rh. 1 ), but mostly acicular or fibrous; H l-l'5j G 45 46, Fusible in candle-flame. {No S reoetion). Valentinite : Sb 8356, 16 -44. Rh., mostly tabular or acicular. H2-3; G5*3-5'6; normally white, but sometimes pale reddish or brownish from admixtures. Becomes yellow on ignition, and melts very easily. In the bulb-tube, sublimes entirely, if pui-e. Senar- MONTITE has the same composition (Sb'O*) and general characters, but is Regular in crystallization. The crystals are commonly octahe- drons, often ^ith curved planes. Cekvantite: Sb*0» 47-40, Sb'O"* 52-60. Rh. 1 acicular, encrusting; H 3-0-40 (or 51); G 408. Yellow, yellowish-white. Infusible, but reducible on charcoal. Not volatile in the bulb-tube. (No S reaction ; aq in bulb-tube). Antimony Ochre : Sb'^O*, mixed more or less with Sb'O*, and yielding H^O on ignition. Earthy, encrusting ; G 3*8 ; yellow, yel- lowish-white. Reduced and volatilized on charcoal. Stiblitb: Sb'O*, Sb'O*, H'O (5-6 per cent.). Compact, pseudo- morphous after antimony glance. Yellow, yellowish-white. Reduced and volatilized on charcoal, the reduction (as in all compounds of Sb'O* -f- St*0') assisted by addition of carb. soda. B.-^On oharooal partially vol . a metallio globule remaining. {Ag reaction). Pyrostilpnite (Fire Blende in part) : Ag (62 per cent.) Sb, S. Clino-Rh. 1 tabular, foliated. H 2 ; G 4-2-43 ; orange-yellow, brownish-red ; streak, re*' or yellow ; lustre peiirly-adamantine. BB, antimonial fumes and la^o'e silver-globule. 150 BLOWPIPE PRACTICE. Pyrargyrite ; Polybasite : Ag, Sb, S. Iron-black, or deep-red ju thin pieces by transmitted light. Streak, red. Lustre essentially metallic or sub-metallic. See Tables IV. and IX. (Cw reaction). RivoTiTE : CuO, Sb*0', mixed with carb. lime, &c. A doubtful species. Compact; yellowish-green; H 35-4'0; G 355-3*62 (Ducloux). (Pb reaction). BiNDHEiMiTE (Blcinicre) : PbO, Sb*0*, H'O (6 per cent.). A doubtful compound. Massive, earthy, &c. ; H 1-4 ; G 3-9-4-7. Greyish-white, yellowish, brownish, green, &c. Often veined or clouded in different tints. Nadorite : PbO, Sb'^O'' -f PbCR Rh., tabular. H 3-0 ; G 7 02 ; yellowish or gi'eyish-brown. Hitherto found only in calamine deposits in Algeria. C — On oharooal partially vol , an earthy mass remaining. RoMEiTE : CaO 195, Sb 638, O 16'7. In groups of small tetra- gonal octahedrons of a yellow or reddish colour. H 5-5 (1), G 4-67- 4"71. The presence of Ca in the residuum, left on charcoal after roasting, is easily recognized by the spectroscope. Part of the CaO is commonly replaced by MnO and FeO. , NOTE ON TABLE XV. The minerals of this Table consist chiefly of rare or obscurely known examples of antimonial oxides, alone, or combined with lead oxide, &c. None of these compounds are of mineralogical importance. The only species of ortlinary occurrence referred to in the Table is the mineral Kermesite or Pyrostibite, a compound of 2Sb*;S' with Sb^O*. This occurs commonly in association with Antimony Glance. It is usually in ra^liating-fibroua or tufted plumose masses of a deep bluish-red or brownish-red colour, with red streak and ailamantine (more or less sub-metallic) lustre. In caustic potash, the powder assumes a yellow colour, and on boiUng is rapidly dissolved. Fusible and volatilizable in the candle-flame without the aid of the blowpipe. [151] TABLE XVI. [Lustre non-metallic. BB, with carb. soda strong sulphur- reaction.] A— Anhydrous species. No water (or traces only) in bulb-tube- A».— REDUCIBLE TO METAL PER SE OR WITH CARB. SODA. (SB, a lead globule). Anglesite : PbO 736, S0» 264. Rh. (V : V 103°44') ; H 3 (or sometimes slightly lower) ; G 61-6-4 (commonly 6-3) ; colourless, grey, yellowish, &c. ; streak, white. Sol. in caustic potash. Sar- manite is a supposed clino-rhombic species of similar composition. Lanarkite : PbO, SO' 57-6 + PbO 42-4. Clino-Rh. ; H 2-0-2-5; G 6-5-6-9 ; pale greenish-white, ^^Jlowish, grey. Flexible in thin pieces. By alteration, partially converted into carbonate, and then effervesces in acids. Leadhillite : PbO, CO^ -f- PbO, SO ; effervesces in acids. See Table XIII. (Pb and Cu reactions. Flame coloured strongly green. With carb. soda, lead sublimate. With boracic acid, copper globule). Caledonite ; PbO, CuO, SO' (C0» and H*0 by alteration 1) Rh. (or Clino-Rh.]) V: V 95°. Light bluish-green; streak, greenish- white ; H 2-5-3 ; G 6*4. Generally effervesces in acids. A«.-N0T reducible TO METAL, BE. ATTACKED OR DISSOLVED IN POWDER BY HOT HVDROCHLORIC ACID, WITH EMISSION OF H»8 ODOUR. { With carb. soda, zinc subUniate on charcoal). Sphalerite or Zinc Blende : Zn 67, S 33. Reg. (mostly inclined hemihedral); H 3-5-4; G 39-4-2. Brown, black (often red by transmitted light), green, yellow, rarely colourless ; streak, mostly pale-brown. Many yellow examples are phosphorescent by surface- abrasion. Practically infusible. The lustre varies from adamantine to sub-metallic and metallic proper. See Tables III. and X. Hae- matite and Christophite are dark, ferruginous varieties. Voltzine: ZnS 82-7, ZnO 173. H 3-5-4-0; G 35-3-8. Brownish- red, yellow, greenish ; streak, pale-brown. Practically infusible. ( With carb. soda, red-brown cadmium-subliTnate). Greenockite : Ca 778, S 22-2. Hex., hemimorphic (crystals mostly small acute pyramids, with lower half entirely replaced by 152 BLOWPIPE PBACTICE. basal plane). H 3-3-5 ; G 4-8-4 -9. Yellow, orange, brownish, with yellow streak and adamantine lustre. Infusible. On ignition, becomes deep-red whilst hot, but generally decrepitates. ( With carh. soda, strong manganese reaction). Alabandine: Mn 63-2, S 36-8. Black, brownish-black, with greenish streak, and, in general, sub-metallic aspect. No sublimate in closed tube. See Table X. Hauerite : Mn 46-22, S 53-78 ( = MnS"). Keg., parallel-hemi- hedral, and thus resembling Iron Pyrites in crystallization. Dark red-brown, brownish-black, with brownish-red streak, and, in general, sub-metallic lustre. In closed tube, turns green, and gives sublimate of sulphur. See Table X. A».— NOT REDUCIBLE TO METAL. NO ODOUR OP H«8 EVOLVRD BT TREATMENT WITH HYDROCHLORIC ACID.* TASTELESS, INSOLUBLE. t Entirely diss dveJ, BB, hy carb. soda. {Flame coloured apple-green). Barytine (Heavy Spar) : BaO 65-7, SO' 34-3, a portion of the BaO sometimes replaced by SrO or CaO. Rh. (V : V 101°40'). H 3*5 ; G 4-3-4-7 ; colourless, white, yellow, flesh-red, brown, &c., with white streak. BB, generally decrepitiites. Fusible into a white caustic enamel, the flame coloured pale-green. Bahyto- Celestine (G 4-24) is a mixture or i8omor})hous union of BaO, SO' and SrO, S0\ Baryto-Calci.e (G 4-0-4-3) := BaO, SO' -f CaO, SO'. As regards the latter, see below. (Flame coloured crimson). Celestine: SrO 5652, SOa 43-48. Rh. (V : V 103°40' - 104° 10'); H 3-3-5; G 3-9-4-0; colourless, pale-blue, indigo-blue, yellowish, die, with white streak. BB, generally decrepitates. Fuses into a white caustic enamel, and imparta a crimson coloration to the flame. if In part, only, dissolved, BB, by carb. s ,da. Anhydrite: CaO 41-18, SO' 5882. Rh. (V : V 100°30') : H 3-3-5 ; G 2-8-3. Mostly in colourless, white, bluish, or reddish lamellar masses, with peai-ly lustre on cleavage planes ; streak, white. BB, fusible into a white caustic enamel. Coloui-s the flanie- horder red, after prolonged expasure. Ill — ■ — — — ' — __— .-^-^-^^_^— ^^.^-^— — -_^___.^— — ____»_^__^___„_____„^__^..^_ * The presenoe of Ba, Sr, and Ca, In minerals of this sectiou, U readily (UteiKuned hy Um ap«ctrQBCope. Se* OutUa« of Blowpipe PrAutlce, pa^je 65. umERAL tables: — XVI. 153 Baryto-Calcite : A compound of tbe suljAates of baryta and lime. Properly, a calcareous var. of Heavy Spar, but referred to here as being only partially soluble, BB, in carb. soda, the lime remaining unattacked. G 40-4-3. Imparts a pale-green tint to the flame-border ; but the orange-red Ca-line comes out prominently in the spectroscope. A*.— SOLUBLE. SALT OR BITTER TO THE TASTE. {Ammonia reaction. BB, entirdj vol.) Mascagnine : Am 394, SO' 606. Rh. (V : V 121°8'), btit chiefly in white or yellowish crusts or mammillated masses on certain lavas. H 2-2-5 ; G 1-7-1 -8. Taste, sharp and bitter. {Flame coloured violet. Bed K-line well defined in spectroscope). Glaserite (Arcanite) : K'O 54, S0» 46. Rh. (V: V 120°24')» but mostly in white earthy crusts. H 2-5 ; G 2*7. Taste, bitter. BB, generally decrepitates, melts easily, and crystallizes over the surface on cooling. Apthalose is a rhombohedral potash sulphate from Vesuvius. {Flame coloured intensely yellow. Na-line, only, in spectroscope). Thenardite: Na'O 43-66, S0» 56-34. Rh., but mostly in dnisy or earthy crusts and coatings of a white or greyish colour; H 2-5 ; G 2 -67. Taste, saltish, alkaline. Easily fusible, and on charcoal reduced to sulphide, and absorl>ed. {In spectroscope, green and orange-red Ca-Hnes, and yellow Na-line), Glauberite: Na^O, S(>» 51, CaO, S0» 49. Clino-Rl».; H 3-5-3-0; G 2-7-2-8. Taste, saltish and bitter. White, grey, yellowish, red, &c. Somewhat deliquescent. BB, decrepitates, fuses easily, and becomes reduced to sulphide. In carb. soda, the lime remains undis* solved. In water, only partially soluble. B— Hydrous oompoundg. Yielding water by ignition in bulb-tube Bl.—FORMTNQ. BB, WITH BORAX A PRACTICALLY UNCOLOURED BlIAD. t Readily soluble in tvater, and possessing a bitter or otfier ta»t«. (On charcoal, BB^ entirely absorbed. Flame coloured intensely yellow).. MiRABiLiTB (Glauber's Salt): Na"0 19 3, SO' 24-8, H»0 55-d. Clino-Rh., but mostly efflorescent, above. Voltaite: FeO, Fe^O', ATO', S0», H'O (15-3 per cent.). An altered Iron-Alum 1 Reg. ; dark-green, black ; streak, greenish -grey. H 2-5-30 ; G 2-8. Slowly soluble in water. Taste, feebly metallic. Other ferruginous sulphates, Glockerite, Pissophane, Apatelite, Copiapite, Jarosite, &c., are insoluble or very slightly soluble in water. See below. {Co reaction). Bieberite (Cobalt Vitriol) : CoO, S0», H'O, but part of CoO often replaced by FeO or MgO. Isomorphous with Melanterite, but occurs only in efflorescent coatings of a pale roso-red colour. Easily dis- tinguished by its blue borax-glass. {Ni reaction). MoRENOsiTE (Nickel Vitriol). NiO (MgO), S0», H^O (40-45 per cent.). Isomorphous with Epsomite, but occurring only in efflo- rescences of hair-like crystals or in amorphous coatings. Green, greenish-white. ( Uranium reaction). JoHANNiTE : UO, S0», H'^O. Clino-Rh. ; H 2-25; G 3-2. Grass- green ; streak paler. Slowly soluble in water. Various other uranium sulphates (in some of which U'O' is present) have been recognized (Medjidite, Zippeite, VogUanite, «fec.), but the composition of these is more or less inconstant, and %)i&j: characters are very imperfectly kn iwn. 158 BLOWPIPE PRACTICE. {Mn reaelion). Apjohnite (Manganese Alum) : Essentially an alum with MnO replacing part of the other bases. In hair-like efflorescences of a pale reddish or brownish colour. Fauserite (Mangane.se Vitriol) : MnO, MgO, S0«, H^O (4266 percent.). Rh. (V:V Ul" 18'); H 2-2-5; O 1-9. Pale reddish, yellowish-white. 1 1 Jnsoluldfl (or practically insol.') in water. Taste, 0, or very slight. {Ph ami Ca reactions. BB, on charcoal a yellow coating). Linarite: PbO 557, CuO 19-8, SO' 20, H'O 4-5. Clino-Rh.; H 2-5-3 ; G 5-3-4-45. Azure-blue; streak pale- blue. (C« reaction). Brochantite : CuO 70-34, SO* 17-71, H»0 11-95. Kh. ] (V:V 104° 32'); H 35-4; G 3-8-3-9. Emer.ald-green, dark-green; streak pale-green. Krisuvioite is identical. Tanoite and Warrinotonite are closely related, but yield 15*33 per cent, water. All form a deep-blue solution with ammonia. Lettsomite (Velvet Copper Ore). CuO, APO», Fe^O' S0», H^O (23-34 per cent.). In delicate hair-like crystals of a deep blue colour, Woodwardite, in blue mamillated masses, is identical. {Fe reaction: BB, a magnetic »lag or crust), Copiapite: Fe'O', SO', H^O 24-5 per cent. In six-sided i)early tables, and granular masses. H 1-5; G 214. Yellow. Stypticitb : Fe'O', SO', H^O 36 per cent. In greenish or yellowish- white fibrous crusts. Fibro-ferrite is appai'ently identical, but some so-called Fibro-ferrites are soluble in water. Owing to their incon- stancy of composition, due to alteration and intermixture, no veiy strict definitions ai e possible as regards ferruginous sulphates generally, Glockerite: Fe*0», S0», H'O (20-7 per cent.). Stalactitic, botry- oidal. Black, dark-brown, yellowish, dark-green; streak brownish- yellow. PissoPHANE, in dark-green and brown botryoidal and earthy masses, is apparently a variety, or a closely related substance, but yields 40-41 per cent, water. Vitbiol-Ochre is an earthy, ochre- yellow variety (H^O 21 per cent.). Apatelite : Fe'O', SO*, H^O (4 per cent.). In small nodular earthy masses of a yellow colour and streak, from Auteuil, near Paris, Chiefly distinguished by its low amount of water. MINERAL TABLES : — XVI. 159 Jarosits : K'O 9-38, Fe'0» 47'91, SO* 31-93, H'O 1078. Hemi- Hex. (R : R about 89°), mostly tabular from predominance of the basal plane, al»o in scaly and fine granular examples j H 3-4 ; CI 3-2-3'6. Daris-brown, browni»li-yellow, red by transmitted li^ht ; atreak ochre-yellow. Shews the retl K-line in si)ectro8co|)e. DiADOCHiTE: Fe'0», S0», P*0», H'O 303 per cent. H 2-5-3; Or l'9-2-5. Brown, brownish-yellow; streak somewhat lighter. Mostly in mammillated, concentric-lamellar examples. BB, on char- coal, a magnetic bead. In the forceps, tinges the flame-i)oint green. PiTTiciTE (Iron Sinter) resembles Diadochite in general characters, but contains As'O*. The composition, however, varies greatly in dififerent examples. NOTE TO TABLE XVI, This Table is compoaed, apart from a few sulphides of non*inctaIlic aspect, entirely of sulphates. Sphalerite or Zino Blende is the only commonly-occurring sulphide referred to in the Table. This mineral presents in many of its varieties a more or less metallic lustre ; but in others, the light-coloured varieties especially, the lustre is non-metallic and usually adamantine. Sphalerite is commonly in lamellar masses (of easy cleavage parallel to the planes of the rhombic dodecahedron), or otherwise in crystals of the Regular System. These consist chiefly of tetrahedrons, twinned octahedrons, rhombic-dodecahedrons, and ft com-' bination of rhombic-dodecahedron with a half-trapezohedron or pyramidal tetrahedron — ~ . Sub-fibrous and granular examples are also known, and some of these, more especially, are cadmiferous. Certain Blendes, likewise, contain thallium in minute quantity ; and in almost all the dark Blendes small proportions of Fe and Mn are present. Many varieties also contain traces, and even workable amounts, of gold and silver. The more common colours are dark-brown and black, with light-brown streak, and these dark examples are often blood-red in thin pieces by transmitted light. Less common colours are dark-green and yellow: colourless examples are still more rare, and hitherto have been found only in New Jersey. Yellow varieties (especially) often shew strong phosphorescence when scratched or abraded in the dark. All varieties give a zinc-sublimate on charcoal if fused in powder with carb, soda and borax ; and all emit the odour of sulphuretted hydrogen when warmed in powder with hydrochloric acid. Natural sulphates fall into five more or less well defined groups. These, compiise : (1) Anhydrous Prismatic Sulphates; (2) Gypsums; (3) Bitter-Salts and Vitriols ; (4) Alums ; and (5) Alumstones, The anhydrous prismatic sulphates are principally represented by Angleaite, Barytine, Celestine, and Anhydrite. These have the common formula BO,-' 160 BLOWPIPE PRACTICB. SO<, and a common Rhombio orystallizatiun, with V : V (the prism-angle in front) 100° 30'— lOr 30', acconling to the •pecies. Anglesite (PbO, SO") ocoura in small oryatals, mostly colourless or greyish, with strong adamantine lustre ; and also in small mamillated and lamellar examples, and in earthy masses, white, yellowish, &c., arising from deuom* position of galena. The crystals are generally in drusy aggregations, and are very brittle. They are either tabular, from predominance of B or V ; prismatic, vertically, from predominance of V ; prismatic, transversely, from extension of i P or i P ; or pyramidal from preponderance of P. It much resembles the lead carbonate uerusaite, but ib distinguished (when the two are not intermixed) by blowpipe and acid reactions. Barytine or Heavy Spar, sulphate of baryta, is very widely distributed, and is especially abundant as a gangue or veinstone in lead, zinc, silver, and other metallic veins. It occurs most commonly in lamellar or fibrous masses, but is also very common in crystals. The latter are sometimes of comparatively large size, and are almost always sharply-defined and distinct. They belong to the Rhombic System, and present chiefly four leading types : (1) tabular, with V . — u and B, or rectangular-tabular with ^ P, P, and B, as principal forms, B pre- dominating ; (2) transversely prismatic in a macro-diagonal direction, with V and i P as chief forms, the latter elongated ; (3) transversely prismatic in a — u brachy-diagonal direction, with ^ P and P as chief forms, the latter elongated ; and (4) pyramidal, from about equal predominance of the common front and side polars 1^ P and P. More common angles are as follows : V : V 101° 40' ; i P : i P over summit 102° 17' j B : i P 141° 8' ; P : P over summit 74° 36' ; B : P 127° 18'. Barytine is commonly colourless, white, or yellow, but also frequently grey, reddish, bluish, &c., and in some stalactitic and radio- spherical examples, deep-brown or greyish-black. BB, it melts into a bead which reacts alkaline after prolonged ignition, and it communicates to the flame-border the apple-green tint characteristic of barium compounds. In carb. soda, BB, it is rapidly and entirely dissolved. In acids, insoluble. In Bunsen flame, after sufficient ignition, it shews the green bands of the barium spectrum very distinctly. Celestine, the strontia sulphate, differs remarkably from Barytine in its geological relations, occurring very rarely in metallic veins, but chiefly in cavities and fissures in stratified calcareous rocks. The flnest crystals occur in connection with native sulphur in Sicily. These are colourless, but when in fibrous or lamellar masses celestine very commonly presents a pale-blue colour, whence its name. It is also white, {Jale-yellowish, &c. The crystals are Rhombic combinations, and are generally elongaf'«d in the direction of the brachy-diagonaL More common forms comprise B, V, P, i.n i J P, with angles as follows : V : V about 104', but varying from 103° SC to 1*H° 30' ; P : P over summit 76' 62' ; B : ^ 127° 66' ; i P : i P 62' 40' ; B : i P 12i» iW. BB melts, colours the flame-border crimson, aad reacts aUwliae. Entlrvl; tUasolved, MINERAL TABLES: — XVL 161 BB, by carb. soda. Insoluble in auids. In Bunsen flame, after short ignition, shews very distinctly the blue, orange-re«l, an«l group of crimson lines, of the strontium spectrum. These lines come out still more prominently by cnishing the ignite binations of V and V with several brachydomes or side-p62 . BLOWPIPE PRACTICE. The group of Bitter-Salta and Vitriols falls into three sections : a rhomLic | section, with the analytical formula RO, 80* + 7H*0, represented by Epsomite, Goslarite, I»5orenosite ; a clino-rhombic section, represented by Melanterite, Bieberite, &c., also with the formula RO, S0' + 7H*0; and a triclinic or atorthic section, with the formula KO, SO' + SH^O, represented by Chalcanthite or Copper Vitriol. These compounds in their actual occurrence as minerals, however, are of comparatively liti'"-? interest, as they occur chiefly in solution or in the condition of efflorescent coatings, &c., rarely in distinct crystalliza- tions. All possess an intensely bitter or metallic taste, and give oflf sulphurous acid on strong or prolonged ignition. The water, evolved in the bulb tube, has thus an acid reaction. The group of Alums, characterized by octahedral crystallization and the general formula RO, SO' + R'O', 3SO» + 24H«J, is represented primarily by ordinary or potaesic alum, and subordinately by soda alum, magnesia alum, iron alum. Sec. These compounds in tiieir natural occurrence, present them- selves merely in efflorescent crusts and coatings, and, as minerals, are of no special interest. All are soluble and sapid, and evolve SO' on strong ignition. The alum of commerce is essentially a manufactured product, derived chiefly from decomposing pyritous shales. The Alumstones are insoluble aluminous sulphates, represented chiefly by Alunite and Aluminite or Websterite. Alunite is a rhombohedral potassic species, occurring essentially in connection with volcanic or trachytic rocks. It differs from most sulphates by its hardness, which, in grani^^ ir varieties especially, often exceeds that of flucr spar. It is infusible, jut becomes decomposed on strong ignition, f id evolves SO*. In the Bunsen flame (especially if the ignited tejt-matter be moistened by hydrochloiic acid), it shews the red line of the K-spectrum very distinctly.* Aluminite or Websterite is of little importance. It is a simple sulphate of alumina with 47 per cent, water, mostly in white or yellowish-white earthy or nodular masses, which adhere strongly to the tongue and are scratched by the finger-nail. BB, infusible, but evolves SO'. " .See Part I., page 68, 59. [163] V ^f TABLE XVII. [liUstre non-metallic. Easily soluble, BB, in borax or phosphor-salt. Nitric- iiciil solution (on warming) yielding yellow precipitate with amm. niolybdate.J A. —Pluo-Phosphates -Chloro-Phosphates. Giving, in powder, with sulphuric acid in glass tube, strong fluorine-reac- tion; or with phopphor-salt and copper oxide, BB, an azure flame-coloration. A».— VIELDINO METALLIC LEAD, BB, WITH CAUB. SODA ON CHARCOAL. Pyromorphite : PbO P'O* 897, PbCP 103, but part of the PbO sometimes rej)liiceychroite, ai-e merol}' varieties (in some cases more or less decom}K)sed) of apatite proper. In these, ns well as in many unaltereil crystals, &c., intermixed carbonate of lime is often present. Sec Note at close of present Table. Wacnerite: MgO, P'O*, 81, MgFP 19. Clino-Rh. ; H 5-5-5; Vx 30-3'I5 ; yellow, yellowish-white. BB, fusible on thin edges only. Very rare. The Norwegian Kjerulfin is closely related, ii not an altered variety. » A*. -VERY EASILY FUSIBLB. , {Sirong Mn reaction with carb. soda), Triplite: (FeO, MnO) Y0\ R FR Clino-Rh.]; H 5-5 5; G 3 6.39; durk-bruwn; streak yellowish-grey. Occurs only in chavable 164 BLOWPIPE PBACTICB. masses of vitreo-resinous lustre, tlasily fusible into a dark globule. With carb. soda, strong manganese-reaction. Zwieselite is closely related, but is apparently Rhombic in crystallization. {Bed flame-coloration, and distinct Li-line in spectroscope). Amblygonitb: AW, FO', (LiNa) Fl. Anoi-thic; H 6; G 3-0-3'12; greenish-white, gi'eyish or bluish-gi-een. Esisily fusible into a white opaque bead, with red coloration of the flame. With cobalt-solution, after ignition, assumes a fine blue colour. Hebbonite (Montebrasite) is closely allied, but yields water on ignition. Perhaps an altered amblygonite ] * The imperfectly known Herdeeite or Allogonite (Rh., with pseudo- hexagonal aspect ; yellowish-white ; H 5 ; G 2 "9-3), and some varieties of Wavellite (mostly in greenish-white or green radiated fibrous examples, we under D, below), are ako fluorine-containing phosphates. These assume a fine blue colour after igoitiun, in powder, with nitrate of cobalt. Kakoxene, in yellow silky tufts (see under C, below), shews also, in most examples, a sliglit fluorine-reaction. BB, a magnetic slag. B.— No Fluorine reaction. No water evolved by ignition in bulb-tube. B'.— EASILY FUSIBLE. {Fusion-globule magnetic), Triphyline: Li^O, Na'O, K'O, MnO, FeO, T'0\ Rh., but occurring only in cleavable masses of a greyish-green, light grey, or grey-blue colour. H 4-5 ; G 3'5-3-6. Colours the flame distinctly red, if moistened with hydrochloric acid, or fused with chloride of barium, and shews the red Li-line in spectroscope.* ■ B«.— INFUSIBLE, OR FUSIBLE ON EXTREME EDGES ONLY. Xenotime: YO 6213, P'O* 3787, but with part of the YO always replaced by CeO. Tetr. ; H 45 ; G 4 •45-4-6 ; yellowish, brown, red-brown, pale-red. Scarcely attacked by boiling acid ; but, on dilution with water, sufficient is dissolved to give a yellow coloration to a fragment of amm. molybdate dropped into the solution and gently wanred. Cryptolite ; CeO, LnO, DiO, P^O*. Pale-yellow or reddish ; G 4*6 ; in minute acicular crystals in certain Apatites. Phosphocerite, • Borne examples of Triphyline shew this l linson line very distinctly per se, but lu general it is only obtained by moisU-'ning the mineral with hydrouhloric add, or mixing it in powder with chloride of barium. The latter reagent answers perfectly, and has the advantage of bvicg conveniently carried in the blowpipe case. MINERAL TABLES: — XTtl. ' 165 in very minute, apparently Tetragonal, crystals in certain Swedisli examples of cobaltine, is ideutical in composition. G 4"78 ; pale greenish-yellovr. • Moxazite: CeO, LnO, ThO, F0». Clino-Rh. ; H 5-5-5; G 4-9-5-3 ; reddish-brown, yellowish-red, pale-red. Many examples give traces of tin by the reducing pi-ocess : *SV page 17. Eremite (Monazitoid) and Turnesite ai-e varieties. In some of these a small percentage of Tautarc acid is present. C— Hydrous Phosphates. Water evolved on ignition in bulb-tube. Ci.-MAGNKTIC AFTER FUSION OR IGNITION, OR GIVING STRONG REACTION Of MANGANESE WITH CARB. SODA. (This section inclutlea a series of iron or manganese-phosphates, in most of which the composition is very uncertain, owing to changes in the oxidation of the base, or loss or gain of water. Many of these phosphates can scarcely rank as definite species. Ill the present Table they are arranged after the average percentage of water which they contain. Where the iron is in the coucbtion of protoxide, the ignition-loss will necessarily be slightly lower (about I per cent.) than the actual percentage of water present in the mineral). Kakoxene: Fe'0» 47, P'O* 21, H'O 32. In delicate tufts and fibro-maminillated examples of a yellow colour with silky lustre. G 2 4. BB, a dark magnetic slag. ViviANiTE : FeO (rapidly changing into Fe'O'), P'O*, H'^0 28 per cent. Clino-Rh., but commonly in bladed and fibrous examples of a greeuLsh-blue or deep indigo-blue colour ; rai-ely colourless, smd then containing FeO only; H 2; G 2 6-27. Flexible in thin pieces. BB becomes red, and fuses into a magnetic globule. Ludlamite, from Cornwall, is closely related, but has less water (17 per cent.). Strengite : Fe'^O', P*()*, H^O 19-20 per cent. ; llh., but chiefly in fibrous mamillated exami)les of a bluish-red or pink colour, rarely colourless; H 3-4 ; G 2-9. BB, easily fusible into a magnetic globule. Childrenite: MnO 10, FeW 29, A1«0» 14, P*0'' 29, H'O 10. Rh. ; H 4-5-5; G 32-3 3. Yellowish-white, yellow, blackish-brown. BB, intumesces, and forms a dark magnetic slag or semi-fused mass. Bebaunite: Fe'G*, P^O*, H'O 16 5 per cent. In radiated and leafy examples of a red or red-brown colour and yellow streak; U 2; G 2-9-3; BB, fusible, magiK-tic. 166 . BLOWPIPE PRACTICE. Hureaulite: MnO 41, FeO 8, T'O' 39, H'O 12. Clino-Rh., mostly tabular ; also coai"se-fibrous, &c. H 3'5 ; G 3-2 ; yellowish- red, red-brown, ttoiO rarely violet or reddish-white. BB, easily fusible into a dai'k, feebly-magnetic globule. Heterosite : FeO (changing into Fe"^0'), MnO (changing into MnG'j, P*0*, H'O 4-4 per cent. Massive; H 4-5-5; G 3 '4-3 5 ; greenish or bluish-grey, violet, brown. BB, fusible, magnetic. C— with borax, BB, A GLASS COLOURED BY COPPER OR URANIUM OXIDE' STREAK LIGHT-GREEN OR YELLOW. f Water-percentage li-lO. ■ , " Lime-Uranite (Autunite) : CaO 6-10, U'O" 6275, P'0> 15-47, H^O 15 '68, but sometimes, and normally, nearly 19 per cent, of water present. Tet., or Rh, with marked tetragonal aspect, mostly tabular from predominance of basal j)lane, and thus passing into foliated examples. Yellow, greenish-yellow ; H 1-2 ; G 3-32 ; BB intumesces slightly, and fuses into a dark bead with crystalline sui-face. In nitric acid forms a yellow solution. Uranosph(ERITE is a related uranium phosphate, but with baryta in place of lime. Yellowish-green; G 3-5. Copper-Uranite (Chalkolite, Torbernite) : CuO 843, U^O^ 61-19, PW 15 08, H'O 15-30. Tet., mostly tabular, passing into foliated micaceous examples. Emerald-green, paler in the streak, with metallic-pearly lustre ; H 2-25 ; G 3-5-36. BB, fusible and reducible to metallic copper. Forms in nitric acid a yellowish-green solution. Chalkosiderite ; CuO (8-15), Fe»0', APO», PO*, H'O 15 per cent. In small, light-green, anorthic crystals. G 3-1. 1 1 Water-percentage 8-11. Tagilite: CuO 61-85, P^0» 27-64, H»0 1051. Clino-Rh. ? but mostly fibi"ous, mammillatetl, &c. j emerald-green; H 3; G 4 4-1. BB, fusible and reducible.* . ; Ehlite • CuO 67, P'O"* 24, H'O 9. Rh. 1 but mostly in foliated and bladed examples, witli peai'ly lustre on cleavage surface; ''I 1-5-2; G 39-4-3. Decrepitates in bulb-tube. On charcoal, reduced.! •Tho reduced coi>per-globulo is surrounded by a black coating of unreduced phospliate' With parb. soda, perfect reduction onsues. f The re \\ ocd copper^globule is surronudud t)y a h'Mok ooatiitg of uareduccd phosphate With curb, aodu, perfect reductiou eusuea. MINERAL TABLES : — XVII. 167 Phosphorchalcitk : CuO 7088, P'0» 2M0, H«0 802. Clino- Rh., but mostly fibrous, mammillated, &c. ; gi-een, blackish-green ; H 4'5-5 ; G4*l-4"3; decrepitates and blackens on ignition; fuses to a dark bead with crystallized surface ; on charcoal, reduced.'* DiHYDaiTE is closely related, but consists of CuO 69, P'^0* 24*7, H^0 6-3. ,.,',-■, .-,-.■ ■:;'■-■ "f '\ f Water-percentage under i. Libethenite: CuO 66-5, P^O* 297, H'O 3-8. Rh., crystals veiy small ; dark-green, blackish-green ; H 4 ; G 3"6-3"9. Decrepitates and blackens in bulb-tube. In forceps, melts to a dark bead with crystallized surface. On charcoal, forms a black globule surrounding reduced copper. ^*^^ Some examples of Wavellite, Peganite, Fischerite, and Turquoise (se« under C, below), contain a small amount of CuO, and thus give a copper- reaction with borax, C».— IN POWDER. COLOURED BRIGHT-BLUE BY IGNITION WITH COBALT-SOLUTION. .-t t Water-percentage 20-40. Wavellite: A1'0» 3810, P^O* 3516, H'O 26-47, but traces of Fluorine often present. Rh. (crystals mostly small and indistinct), commonly in botryoidal radiated-fibrous examples of a pale green, greenish- white, or yellowish-white colour ; H 3'5-4 ; G 2*3-2'5, BB, swells up, separates into fibres and becomes opaque-white, but does not fuse. " • Fischerite — Peganite — Varisoite : Hj'^drateJ aluminous phos- phates closely related to Wavellite. Rhombic in crystallization, but commonly in radiated fibrous examples of a green or white colour. H 3-5 ; G about 2 5. BB, like Wavellite, Planerite, Striegisan, Richraondite, Evansite and Zepharovichite are probably altered examples. These minerals can only be distinguished by accurate chemical analysis. Many give a slight copper-reaction. The per- centage of wauer is as follows : Variscite 23, Peganite 24, Wavellite 265, Zephiu-ovichite 27, Fischerite 29, Richmondite 35, Evansite 40-42, Calaite or Turquoise : AfO' 47, P'O'' 32 5, H'O 20-5. In light- blue and bluish-green amorphous masses; H 6; G 2"6-2"8, BB, * The rodiiced cai)i">r-globule i« surrouiidutl by a black costing of unreduced phosphate. With c;irb. «uda, iierieet reductiuu eiisuca. 168 BLOWPIPE PRACTICB. decrepitates, and often blackens, but remains unfused. Many examples shew traces of copper. f f Water-percentage under 13. Lazulite : MgO, FeO, Al^Os, P2O*, H^O (5-7 per cent). Glino- Kh. (but scarcely differing from Rhombic in aspect and measure- ments). Blue, bluish-white; H 5-6 ; G 3-3'2. BB, exfoliates and crumbles, but does not fuse. . , Berlinite — Trolleite — Auoelite: Hydrated aluminous phos- phates of a blue or greenish-blue colour. Water ])ercentage : 4, 6, and 12*5 respectively. Obscurely known or doubtful species. G*.— IN POWDER. COLOURED PALE-RED, GREEN, OR DARR-OREY BY lONITION WITH COBALT-SOLUTIONw f With Co-sohition, pale-red. Lunebergite: MgO, P^0^ W0\ WO (3023 per cent.). In white, fib]X)US and earthy masses. Hl-1"5; 2*05. Easily fusible, with green coloration of the flame-border. "With sulphuric acid and alcohol, gives the gi-een flame chai-acteristic of B^O'. Struvite : a hydrous phosphate of ammonia and magnesia. Rh. (hemimorphic). Colourless, yellowish, pale brown ; H 1-5-2; G 1-6-1 "8. In peatbogs, guano-deposits, &c. Evolves ammoniacal fumes on ignition. tt With Co-solution, liyhl-green. (BB, on charcoal with carb. soda, a zinc nthlimatp). Hopeite: ZnO, P^0^ H^O] Rh. ; greyish-white; H 2-5-3, G 2-7-2 -8. BB, fusible into a white bead. Some examples shew presence of cadmium. . . 1 1 1 With Co-aohition, dark-grey. Brushite : CaO 32-6, P'O^^ 41-3, H'O 261. Cliuo-Rh. ; colotu-less, yellowisJi ; H 1-5; G 2'2. Metabi'ushite and Isoclase are related products. In all, the pi-esence of CaO is i>eadily determined by the spectroscope. Churchite: CaO, CeO, DiO, P'0», H'O (15 \^v oent.\ Clino- Rh. (1) radiated. Greyish-white, pale-red ] H2-5-3; G 3-i. Imper- fectly known. MINERAL TABLES: — XVII. 169 NOTE TO TABLE XVII. This Table is represented by Pliosphates, or by Pliosphates combined with Fluorides or Chlorides. Its more important species may be referred broadly to the following groups : (1) Apatites; (2) Triplites; (3) Alumina Phosphates ; (4) Iron and Copper Phosphates ; (5) Uranium Phosphates. The Apatite group is characterized by its Hexagonal crystallization, and by the common formula 3 (3 RO, P'06) + R (Fl, Cl)». It is re^jresented by Apatite and Pyromorphite, and also by the related arseniate and vanadiate, Mimetesite and Vana.— DISTINCTLY SOLUBLE AUD SAPID. Sassoline (Boracic Acid) : BW 5645, H^O 4355. Clino-Rh. or Anorthic (?), but essentially in small pearly-white scales and tabular examples sometimes stained by ferruginous matter. H 1 ; G 1 '4-1 "5 ; bitter-acid taste, soapy to the touch. BB tinges the flame green, and melts with intumescence into a hard clear glass. Larderellite (Hydrated Bomte of Ammonia) : In small rhombic or rectangular plates and scales of a white colour. Scarcely soluble, except in hot water, and thus almost tasteless. See below, under B*. Borax or Tinkal : Na'^O 16-2, B'O^" 36 7, ff^O 471. Clino-Rh. ; H 1 •5-2-5; G 1-7-1 -8; coloui-less, or stained brown, yellowish, &c., by impurities. Taste, slightly alcaline. BB, intumesces and melts easily, but (as regards natural or crude varieties) the glass is dark or more or less coloui'ed. Moistened with sulphuric acid, or with glycerine, it tinges the flame green. B».— practically insoluble and without TASTE; OR DECOMPOSED BY BOILING WATER ONLY. t iVo marked Mn or Fe reaction. Stassfurtite (Massive and slightly altcired Boracite V) : In fine- granular or fibre as masses of a white or yellowish- white co our. 172 BLOWPIPE PRACTICE. Yields 0"5-l por cent, water on ignition : composition otherwise as in Boracite. H 4 55 ; G 2-9-30. Readily fusible. SzAiLBBLYiTB : MgO, B»0', H*0 (7 12-5 per cent.). In small globular masses of radiated-fibrous structure and white colour; H 3-5 ; G 2-7. Easily fusible. Hydroboracite : CaO, MgO, B'0», H«0 (26 per cent.). In ci-ystalline, radiated-fibrous or leafy masses of a white or pale reddish tint. H 2 ; G 1 •9-2. Very easily fusible. Shews red and green Ca-lines in spectroscope if moistened with HG acid. BoROCALCiTE : CaO, B'0», H'O (35-5 per cent.). Clino-Rh. 1 Mostly in snow-white acicular crystals and incrustations. Very easily fusible. Becuilite is closely related, but yields less water (2')-75 per cent.). Both shew Ca-lines in spectroscope when moistened with HC acid. Priceite, a milk-white chalky borate of lime, with 203 i)er cent, waterj from Oregon, is probably identical, the amount of water in these earthy borates being very inconstant. Ulexite (BoronatrocalciTe): Na'O 680, CaO 12-21, B^O' 45-66, H'^O 35-33. In white, mamillated and fibrous masses. G 1-8. Very easily fusible with yellow coloration of the flame. Decomposed, in powder, by boiling water. Tinkalzite and Cryptomorphite are closely related substances. Larderellite : Ammonia 127, B^O* 68-6, H*0 187. In white shining scales or small crystalline plates resembling Sassoline. Solu- ble in hot water. Yielding ammoniacal fumes on ignition. Fusible with strong intumescence; t f BB, marked reaction of Iron or Manganese. SussEXiTE : MnO, MgO, B^O', H*0 (9 per cent,). In white, or pale-i-eddish, silky-fibrous masseSi H. 2 5-3; G 3-42. Very easily fusible, with green flame-coloration. Laqonitb : F'0», B'0», H'O (1273 per cent.). In yellow, ochreous masses from tlie boracic-acid lagoons of Tuscany. NOTE TO TABLE XVIII. This Table, apart from Boracic Acid, is composed exchisively of Borates, distinguished readily from other compounds by the peculiar yellowish-green coloration which they impart (when moistened with sulphuric acid) to the flame of alcohol. Many of these minerals are still imperfectly known, and are MINERAL TABLES : — XVIii. 173 apparently of somewhat inconstant composition, more espocially as regards the hydrous species. Boracite and Tinkal (crude Borax) are the principal repre- sentatives of the Table. Boracite [2 (MgO, B'O') + Mg Cl"] occurs essentially in small hemihedrally- moditied cryBtals of the Begular System, remarkable for their high degree of hardness, which ec^uals that of ordinary quartz. Hence they scratch glass very distinctly. They are generally colourless, but sometimes present a pale grey, greenish or yellowish tint, and arc always assoriated with anhydrite, gypsum, or rock salt. The most simple consist of the cu1)e truncated on the alternate angles, and thus presenting a combination of cube and tetrahedron. Very commonly the cube-edges are also truncated by the planes of the rhombic dodec aedron ; and the latter form predominates in some crystals. As in most other hemihedrally-modified minerals, Boracite is pyro-electric. The substance known (from its locality) as Stassfurtite appears to possess essentially the same composition, exoe2>t that it yields a small amount of water on ignition. This substance is thus commonly regarded as massive Boracite, but its hardness is comparatively low, usually under 5. It occurs mostly in granular or sub- fibrous masses of a chalky-white colour. Tinkal or crude Borax (Na'O, 2B*0' + 10 H^'O) is a product of certain salt lakes, and is mostly in the form of small granular or crystalline masses of a greyish or brownish-white colour. Mois- tened with sulphuric acid, or simply with glycerine, it imparts a distinct green coloration to the flame. Per ae, it colours the flume intensely yellow, and melts with great intumescence into a more or less cleai '>ead. In the bulb-tube it evolves 47 '2 per cent, water. Its crystallization ib Olino-Rhombic, and the ordinary borax crystals have a remarkable resemblance^ even in their angle values, to those of Augite. [174] . TABLE XIX. [ [^uatre non-metallic. Easily dissolved, BB, by borax or phosphor-salt. Giving with the latter reagent and CuO an intensely azure-blue or green flame (CI., Br., or I reaction)]. A.— Soluble in Water. Sapid. A'.— No Water (or meuely traogs> in bulb-tubbl t Entirely dissolved BB hy carb. soda. Rock Salt (Halite) : Sodium 39-31, Chlorine 60'69. Reg., with cubical cleavage; H 2 ; G 21-2-2; colourless, white, grey, greenish, red, violet, &o. ; streak white ; taste, strongly saline, sometimes bitterish from presence of chloride of magnesium and other im- purities. BB, generally decrep'tates, colours the flame strongly yellow, melts, and in prolonged heat sublimes. Sylvine : K 52-35, CI 47-65, but generally contains NaCl. Reg.; H 2; G 1-9-2; colon .''jss, greyish, reddif^ ;^ &c. ; taste, like that of rock salt. BB, easily fusible, colouring the flame violet if pure. In spectroscope, even if impure from NaCl, . Scarlet-i-ed ; Teti-agontd. Doubtful sub a naturaUy-oocurring species. MINERAL TABLES : — XIX. 177 NOTE ON TABLE XIX. This Table consists entirely of Chlorides and Oxy-Chlorides. Other chlorine compounds combined •with phosphates, &c., will be found in preceding Tables. The only important species, or those of tolerably frequent occurence, belonging to the present Table, consist of Rock Salt, Kerargyrite or Corneous Silver Ore, and Atacamild. Rock Salt or Chloride of Sodium is widely distributed in the form of beds, in strata of various geological periods, and, in solution, in sea-water and numerous mineral springs. It occurs also as a product of sublimation in many volcanic regions. Normally, it is colourless and transparent ; but is very generally of a red, greenish, grey, violet or other colour, from intermixed impurities. Its crystals belong to the Regular System, and consist chiefly of simple cubes, or of aggregations of small cubes presenting a hopper-shaped aspect. Other forms (the octahedron, &c.), are comparatively rare. The cleavage is cubical, and strongly marked. Lamellar, granular, and sub-fibrous examples are also abundant. These are very frequently associated with gypsum and gypsiferous clay. Although normally anhydrous, rock salt (more especially in its less pure varieties) absorbs moisture from the atmosphere, and runs gradually into deliquescence. It dissolves in somewhat less than 3 parts of water, and it possesses the p>tculiarity of being about equally soluble in hot and cold water. Most exampU i decrepitate very strctagly on ignition. From other chlorides it is readily distinguished by its saline taste and cubical crystallization and cleavage, combined with its intensely yellow flame-color- ation. Kerargyrite, often known as "Horn Silver" or "Corneous Silver Ore," is readily distinguished by the large globule of silver obtained from it by the blowpipe, and by its waxy aspect, sectility, and shining streak. It gives also reduced silver if moistened and placed in contact with a piece of zinc. It occurs mostly in compact masses or thin layers of a pearl-grey, greenish or blueish colour, turning brown oii 'Exposure. Unattacked by nitric acid, it dissolves more or less readily in ammo;iia. Atacamite is a hydrated compound of chloride and oxide of copper, but of somewhat unstable composition. In some examples the water equals 12-13 per cent., and in others it is as high as 22^ per cent. The mineral by its green colour . and general aspect resembles certain cupreous arseniates and phosphates, but from these it is distinguished by the azure-blue coloration which it commu- nicates to the blowpipe flame, as well as by the precipitate formed in its nitric acid solution by nitrate of silver. As seen in mineral collections, it is generally in the form of a blackish-green or deep emerald-green sand. Its crystals are small, vertically-striated prisms, and rectangular octahedrons, of the Rhombic Syat«m. V: V = 112^ 18'. Cleavage brachydiagonal. IB [178] TABLE XX. [Lustre non-metallic. Readily soluble BB in borax or phosphor-salt. Warmed, in powder, with sulphuric acid, evolve glaas-corroding fumes. ] A.— Fusible. + Anhydrous, or yielding merely traces of moisture on i.^ ' ^'tion in bulb-tube. Fluor Spar (Fluorite) : Ca 51-3, F 48-7. Reg., essentially cubi- cal (see Note at end of Table), cleavage octahedral ; H 4; G 3 •1-3-2; colourless, violet, yellow, pale-green, deep bluish-green, rose-red, &c., with white streak. In most cases phosphorejicent when heated. BB, generally decrepitates, fuses into a white enamel, which tinges the flame-border distinctly red, and reacts alkaline, after prolonged ignition. Ratofkite is a mixture of fluor spar and mai4, of a dull greyish-blue coloui". Cryolitk : Na 32-8, Al 13, F 54-2. Anorthic, but mostly in lamellar masses with nearly rectangular cleavage; H 2-5-3 ; G 2"9-3'0; white, or sometimes slightly yellowish or reddish; streak white; brittle. Melts in candle-flame into a white enamel. BB on charcoal, leaves a white crust which becomes blue on cooling after ignition with cobalt solution. Soluble in boiling solution of caustic potash. Shews strong Na-line in spectroscope. Chiolite (Tetragonal), Nip- holite, Arksutite, and Fluellite, are related compounds of similar aspect. In Arksutite pai-t of the Na is replaced by Ca. Sellaite: Mg 38-7, F 61-3. Tet.; colourless. H 5; G 297. Easily fusible into a white enamel. Becomes pale-red by ignition ' with cobalt solution. Very rare. Accompanies anhydrite at the Gerbulaz glacier in Savoy. Leucophane : CaO, BeO, SiC, NaF. Rh., but commonly in lamellar, cleavable masses. H 3 5-4, G 2 "9-3. Greenish-gi-ey, yellow. Phosphorescent when heated or broken. BB, very easily fusible. Melinophane (Meliphanite) is a closely related species of a yellow colour, but Tetragonal (?) in crystallization. + t Yielding water by ignition in bulb-tube. Pachnolite : Na 10-35, Ca 1799, Al 12-28, F 51-28, H-0 810. Clino-Rh. (?). In minute twin-crystals in cavities of Cryolite. Colourless, strongly shining. BB, crumbles and fuses into a white MINERAL TABLES : — XX. 179 piitimel. In bulb-tube falls into powder and yieUls 8 per cent, water. Ill si)ectroscope shews Na-line, and green and red Ca-lines. Thom- senolite is closely related or identical. Pkosopite: Ca, Al, Si, F, H^O. Anortliic ; colourless; H 4-4-5; (t 2 9. Often earthy from decomposition. Sometimes altered into riuor spar. An iaij)erfectly known species accompanying Iron Glance at Altenberj', Saxony. When transparent and crystalline, yields 14 84 per cent water. B— Infusible. Fluocerite : Ce, F. ; Hex, (crystals, small, ts bular), but mostly in granular examples of a i)ale-red or yellowish colo \v. H 4-5 ; G 4-7. Whitens or becomes yellow on ignition. BB, infusible. Hydro- iluocerite is clo.sely related (if not an altered fluocerite) but yields on ignition about 5 per cent, water. Yttrocerite : Ca, Ce, Y, La, Di, Er, F, H'^O. In crystalline- granular masses of a light greyish-violet or blue-grey coloui', with imi)erfect (tetragonal) cl -avage. BB, infusible. Pakisite; Harmatite; Fluorides combined with carbonates; hence eftervescing in acids. See Table XIII. NOTE ON TABLE XX. This Table consists essentially of Fluorides. Other Fluor-compounds com- bined with phosphates (Apatite, Triplite, &c, ) will be found in Table XVII. Fluo-silicates (apart from Leucophane, placed here on account of its ready solution, BB, in phosphor-salt and borax) belong to one of the succeeding Tables: XXIV-XXVII. Fluor Spar is the only commonly-occurring or generally distributed mineral belonging to the present Table. It occurs very commonly with ores of lead, ziuo, and silver, more especially in mineral veins ; but is also found in cavities and fissures in limestone and other stratified rocks. It usually forms groups of distinct crystals, but sometimes presents itself in columnar, sub-fibrous, limellar, and compact examples. The crystals as a rule consist of simple cubes, or of cubes slightly bevelled on the edges by the planes of a tetrakis- liexahedron (mostly OC 3). In many examples the cube-facey present a four- fold series of strise, meeting in a point at or near the centre of each face. 1'liese striae, lines of growth in the formation of the crystal, indicate the edges of a suppressed tetrakis-hexahedron, so to say. Fluor spar is often colourless, but more frequently it presents an amethystine, pale-green, yellow, or deep bltie-green colour, and occasionally a rose-red or pearl-grey tint. The cube edges by transmitted light often show a shade of colour more or less distinct. 180 BLOWPIPE PRACTICE. from that of the faces ; and columnar or fibrous examples are frequently zoned in different tints. In all varieties the streak is white. Hardness between that of calcite and apatite, or equal to 4 of the ordinary scale. Sp. gr. 3'15-3'2. Most examples when moderately heated exhibit a green or bluish phosphor- escence ; but, if a fragment be heated rapidly, decrepitation almost invariably ensues. By fusion, BB, a white enamel is produced. This tinges the flame red, and reacts alkaline after sufficient ignition. The red and green Ca-lines show prominently in the spectroscope, if a small splinter be held for a few minutes in the outer edge of a Bunsen-flame. [181] TABLE XXI. [Lustre non-metallic. Readily dissolved BB by boiax or phosphor-salt. Warmed in a test-tube with sulphuric acid, evolve orange-red or brownish nitrous fumes.] A.— Anhydrous Species. Entirely soluble BB in carb. soda. Nitre (Saltpetre); K*0 46-53, NW 53-47. Rh. (V : V 118° 49'); H2; G 1-9-2-1 ; normally colourless. Easily soluble in watei- ; taste, saltish, cooling. BB fusible with intumescence, colouring the flame-border clear-violet. On charcoal, deflagrates and is absorbed. NiTRATiNE (Chile Saltpetre, Soda Nitre): Na^O 36 47, N^O* 63-53. Herai-Hex. (R : R about 106") H 1-5-2 ; G 21-2-2 ; normally colour- less, but often brownish or reddish from impurities. Easily soluble ; taste, saltish, cooling. Deliquescent. Colours flame intensely yellow; otherwise like potash-nitre. B— Hydrated Species. In carb. soda, BB, only partially soluble. NiTROCALCiTE : CaO 30-76, N*0* 58-80, H'0. 10-44. In white or greyish earthy efflorescences on the walls of limestone caverns, cellars, < iTROMAGNESJ' 'B : Mg O 24-10, N^Qs 65-10, H*0 10-80. Occui-a with, and closely resembles, Nitrocalcite ; but the white crust, left BB on charcoal, exhibits a pink tinge after ignition with cobalt-solution. NOTE TO TABLE XXI. This short Table comprises the three or four representatives of the group of Nitrates hitherto recognized as minerals. All are soluble and sapid. By ignition with organic bodies, they detonate more or less violently ; and when warmed with sulphuric acid, or fused with bisulphate of potash, they evolve reddish or brownish nitrous fumes. The bases (magnesia excepted) are readily recognized by the spectroscope. Soda nitre (often erroneously called " cubical nitre") is distinguished also from ordinary or potash nitre hy its crystallization in small rhombohedrons, its deliquescence, and its property of communicating a deep yellcrw coloration to the Bunsen or blowpipe flame. In the spectroscope, many examples shew the red K-line as well as the Na-line, and the ^iresenco of lime is also sometimes revealed (see Part I., page 55). [182] TABLE XXII. [Lustre non-metallic. Easily tlissolvecl BB by borax or phosphor-salt. Fomiinc by fusion with carb. soda and nitre an alkaline salt partly soluble in water, the solution assuming a blue, brown, or green colour by boiling with hydrochloric acid and a piece of tin or zinc. A —Anhydrous Species. Yielding no water (or merely traces of moisture) by ifirnition in bulb-tube. A» -GIVING LEAD GLOBULES OR OTHER FUSIBLE METAL, BB, WITH CARB. SODA OR ALONE. t With Borax, BB, a hright-green glass. {Streak, strongly-coloured.) Crocoisite (Crocoite): PbO G9, CrO» 31. Clino-Rh. (see Note itt close of Table) . H 2-5-3; G 5-9-6 ; red; streak orange-yellow. BB. generally decrepitates ; fusible and reducible, under slight detonation, on chai'coal. Produces chlorine fumes with hydrochloric acid. Forms a brown or yellow solution with caustic potash. Phcenicite : PbO 77, CrO' 23. Rh. (crystals tabulai', indistinct), mostly bladed or fibrous, acconpanying Crocoisite. Red; streak. red; H 3-35 ; Gr 575. Fusible and reducible. Vauquelinite : PbO 61-48, CuO 10-95, CrO 27-57. Clino-Rli. (crystals very small, indistinct), commonly in coatings and botryoidal : H 2-5-3 ; G 5-5-5-8. Dark-green, greenish-black ; streak green. BB, intumesces slightly ; fusible and reducible. With borax in R. F. (especially on addition of tin) forms a brick-red opaque bead from presence of copper. Laxmannite is a variety in which both CrO* and P'^O* are present ; but this is probably the case in most varieties of Vauquelinite. Dechenite : PbO 54-95, VO^ 45-05. Mostly in small botryoidal masses or groups of minute indistinct crystals; H 3-5; G 5-82 ; reddish-yellow, brown; streak, yellow or omnge. Fusible and I'educible. Eusynchite : essentially a lead and zinc vanadate, resembling Dechenite in colour and general aspect. Descloizite : essentially a lead vanadate of a dark-green or gi'eenish-black colour, with bands of yellow or brown. Pucherite : Bi^Os 71-74, V^0° 28-26, but often showing traces of P'O" and As^Oft. Rh. (c?' atals very small); red, brown; H 4; MINERAL TABLES : — XXII. 183 G 625. BB, decrepitiites, and yields reduced metal, with yellow ring on charcoal. Soluble in hydrochloric acid, with development of ' chlorine fumes, the red or yellow solution yielding a precipitate on dihitioa. ; Streak white or indistinctli/ coloured. ) Vanadinite: Pl^ 70-83, V'OM9-35. PbCP 9-82. Hex. (iso- morphous with species of the Apatite group); H 3; G 6-8-7*2. Yellow, reddish, brownish. BB, decrepitates, throws oft' sparks, and gives reduced lead. With phos. salt and CuO, gives a^ure flame. 1 1 With Borax, BB, no green coloration; hut green or blue glass loith phosphor-salt in RF. Wulfenitij: PbO 61-4, MoO' 38-6 Tet.; H 3; G 6-7 ; yellow, yellowish-grey, red (the latter colour due apjiarently to presence of lead chromate), rarely colourless. BB, decrei)itates, melts and gives reduced lead. Stolzite: PbO 49, WO' 51. Tet. (see Note at end of Table); H 3; G 7'9-8-l ; grey, also green, reddish, and brown. BB, melts easily into a bead which crystallizes on cooling. On charcoal in RF, reduced. A— NO REDUCED LEAD BB ON CHARCOAL. t BB, no magnetic globule. Scheelite: CaO 19-45, W0» 8055. Tet. (see Note at end of Table); H 4-5-5 ; G 5-9-6-2; colourless, greyish, pale-yellow, some- times red, brown, or greenish ; streak white. BB, fusible on the edges, or in thin splinters only. TuNGSTic Ochre : W 79-3, O 207. In earthy coatings of a yellow or greenish colour. BC, infusible, blackens. Insoluble in acids ; soluble in ammonia. MoLYBDic Ochre : Mo 65-7, O 34-3 In earthy, yellow crusts and coatings. BB easily fusible. On charcoal, absorbed (if pure). Easily soluble in hydrochloric acid. f t BB, magnetic globule. Wolfram : MnO, FeO, WO'. Dark-brown, reddisli brown, with dark streak. In Clino-Rhombic crystals and lamellar masses, which present in most cases a sub-metallic lustre. H 5-5-5 ; G 7-1-7-55. BB fusible to a magnetic globule with crystalline surface. With cirb. soda, strong manganese-reaction. See Table IX. 184 BLOWPIPE PRACTICE. B— Hydrous Species. Yielding water by ignition in bulb-tube. (Cm reaction.) VoLBORTHiTE : CaO, CuO, V^O*, H^O (5 per cent.). Hex. ; green, greenish-yellow ; streak, yellow ; H 3 ; Cr 35. BB, blackens, and fuses on charcoal into a dark slag containing reduced copper. (Cm and Ph reactions.) MoTTRAMiTE : CuO, PbO, VW, H^O (3-7 per cent.). Tn dark crystalline coatings with yellow streak ; H 3 ; G 5*9. On sandstone from Cheshire. Psittacinite (from Montana) is a related compound in green sub-crystalline and botryoidal coatings, with 8| per cent H^O. NOTE TO TABLE XXII. This Table is composed essentially of Chromates, Vanadates, Tungstates, and Molybdates. The two first may generally be distinguished from other compounds by the clear emerald-green glass which they form BB with borax in a reducing Hame. The colour comes out in its fidl purity as the glass cools. If fused in a platinum spoon with carb. soda and nitre a partially-soluble salt results. This, in the case of Vanadates, becomes blue when warmed with a few drops of hydrochloric acid. Chromates, thus treated, give a green solution. See also the reactions of the latter described in Part I. of this work, page 49. Tungstates (m the absence of colouring oxides) form BB with phosphor-salt in the RF a fine blue glass, whUst with borax the glass is of a yellowish or 'brownish colour. Molybdates give with i)hosphor-salt in the RF a fine green glass. See also the distinctive reactions of these bodies with hydrochloric acid and zinc, as given in P .rt I, pages 46, 47, 62. With the exception of Wolfram (a species which commonly presents a sub- metallic aspect, and thus belongs more especially to Table IX. ) no mineral of this Table can be regarded as of common occurrence. Attention, however, may be directed to the following : the chromate Crocoisite, the molybdate Wulfenite, and the tungstates Wolfram, Stolzite, and Scheelite. Crocoisite is readily distinguished by its fine red colour and orange-yellow streak, and by the emerald-green glass which it forms BB with borax*. It occurs commonly in groups of small or acicular crystals, and in granular masses and coatings. The crystals are Clino-Rhombic combinations ; most commonly, vertically-striated prisms terminated by the two planes of an acute hemi-pyramid ; or the same prism terminated by a very acute front-polar or hemidome, thus closely resembling an acute rhombohedron. * Deceptive specimens are occasionally made by placing a piece of quartz in a crystallizing solution of bichromate of potash. MINERAL TABLES : — XXII. 185 Wulfenite (molybdate of lead) occurs in small Tetragonal cryjtals, mostly of a yellow or yellowish-grey colour, but orange-rod in some chromium or vanadium-containing varieties. The crystals are either tabular or more or less flattened parallel with the base, or are otherwise small pyramidal combinations. As pointed out by Von Kobell, a beautiful azure-blue coloration originates if the iinely-powdered mineral be warmed with concentrated sulphuric acid in a l)orcelain capsule, and some alcohol be th«n adJed. Stolzite (tungstate of lead) and Soheelite (tungatate of lime) crystallize also in the Tetragonal tSystem, but the latter often occurs in crystals of half an inch or more in length, usually a simple square-based pyranii*!, measuring 130" 33' over the base or middle edge. Stolzite has a very high sp. gr,, 7 '9-8*1, and is usually grey or brownish in colour, more rarely green or red. Scheelite has a sp. gr. of 5'9-6'2, and is commonly grey or greyish-yellow, though occasionally also brown, red, or green. Both, when warmed with nitric aoid, leave a yellow residuum of WO^, soluble in caustic alkalies. Wolfram is readily distinguished from the other minerals of the Table by its dark-brown or red-brown colour and streak ; and by the magnetic globule which it yields before the blowpipe. With carb. soda, also, it gives a strong reaction of mmganese. Its crystals, as a rule, are of comparatively laige size. Ai regards their g^narjkl char^ator, use Moid to TaUle IX. [186] TABLE XXIII. [Lustre non-metallic. Easily dissolved BB by borax or phosphor-salt, but not yielding any reaction of the preceding Tables.] A.— Streak or Powder distinctly coloured. A». -MAGNETIC, OR BECOMING SO AFTER STRONG IGNITION. t Anhydrous species. Magnetite (Magiietic Iron Ore): FeO 31, Fe^O' 69. Black, with black streak. In octahedrons and other crystals of the Regular System, and in lamellar and granular masses, rarely earthy. H 5 '5-6 "5 : G 4*9-5"2. Lustre, commonly sub-metallic. See Table IX. Magnoferrite : MgO^ Fe^O*. In small black octahedrons, as a product of sublimation of Vesuvian fumeroles. Streak, dark -brown ; strongly magnetic j G 4*65. Accompanies thin, tabular crystals of Iron Glance. Jacobsite : MgO, MnO, Mn'^Os, Fe^O*. Reg. ; granular ; black ; stieak, reddish-black ; H 5*5-60 ; G4-74-4-77; strongly magnetic: practically infusible. Strong Mn reaction BB with carb. soda. In crystalline limestone from Sweden. 1 .anklinite : ZnO, MnO, Fe'^0'. Reg., but commonly in small rounded masses. Black ; streak, brown or brownish-black. More or less magnetic in most examples. H 6-6-5; G 50-51. Lustre mostly sub-metallic : See Table IX. BB, in powder, with carb. soda and borax on charcoal gives a sublimate of ZuO. With carb. soda, also, strong Mn reaction. Chromite : FeO, MgO, APO^ Fe'^O', Cr^O'. Reg., but commonly in granular masses. Brownish-black; streak, dark -brown. Some- times magnetic. Infusible. With borax, BB, fine green glass. Lustre, commonly sub-metallic. See Table IX. Ilmenite (Titaniferous Iron Ore): Fe^O', Ti^Os, but FeO also present in some varieties. Hemi-Hex.; iron-black, mostly with sub- metallic lustre. H 5-6 ; G 4-3-5 -2, commonly about 4*9. The hydrochloric acid solution, diluted, and boiled with a piece of tin or zinc, becomes at first colourless and then violet. See Table IX. Red Iron Ore (Hsematite, Red Ochre, «fec.). Fe'^O', with 70 per cent, Fe. Herai-Hexagonal ; but when of non-metallic aspect, mostly in fibrous-botryoidal, lamellar, or earthy examples. Red, brownish or MINEKAL TABLES : — XXIII. 187 bluish-red, with cherry-red streak. H 5-6, or lower (1*5-3) in earthy and sub-earthy varieties ; G 4 8-5 '3. BB, blackens and becomes magnetic. Fusible only in fine splinters. See also Table IX. f f Hydrous species. Yield water by ignition in bulb-tube. Brown Iron Ore ( = Gcethite, Limonite, Stilpnosiderite, Lepi- dokrokite, Yellow Ochre, &c. These, although commonly ranked as distinct species, cannot properly be regarded otherwise than as varieties of Brown Iron Ore, only differing from one another by their percentage of water, a character by no means alisolutely constant) : Fe^O' -f- m H^O, with Fe 60-63, and H^O 10-15 per cent. Eh. (Gcethite), but mostly in fibrous-botryoidal, massive, and ochreous examples. Dark-brown, light-brown, brownish-yellow, with yel- lowish-brown or dull yellow streak ; H 3*5-5'5 (but lower in ochreous and earthy varieties) ; G 3-2-4-2, commonly about 3.8-40, BB, yields water, blackens, and becomes magnetic. Fusible in thinnest splinters only. TuRGiTE is a closely related compound, but has a red streak, and yields only 5-5*5 per cent, water. G 3*5-4 'S. OxALiTE (Humboldtine): FeO 42*10, Oxalic Acid 4210, H^O 15 80. In hair-like crystals, fibrous and earthy examples, of a yellow colour ; H 2 ; G 2*1-2*25. BB, blackens, becomes magnetic, and then becomes converted into red iron-oxide. If a particle be a fused into a bead of borax, coloured blue by copper oxide, the latter becomes rapidly reduced to Cu^O, and the glass becomes opaqvie red, or shews red streaks, on cooling. By this character, Oxalite is readily distinguished from yellow-ochre. A> .-YIELDING, BB, WITH CABB. SODA ON CHARCOAL, A DISTINCT SUBLIMATE AND METALLIC GLOBULES. Minium (Mennige, Red Lead) *, Pb 90*7, 9*3. Earthy; or pseudo- morphous after galena or cerussite ; red ; sti*eak, orange-yellow ; H 2 (or less); G 4*6-4*8. BB, darkens, and fuses easily; on charcoal reduced. In HCl acid becomes transformed into white PbCl'', with evolution of chlorine fumes. Partly soluble in dilute nitric acid, leaving residuum of puce-coloured PbO*. Insoluble in caustic potash. Massicot (Litharge; Bleiglatte): Normally, Pb 92*8, 7*2, but always impure from presence of Fe^O', &c. Fine scaly, earthy ; sulphur-yellow, omnge-yellow ; paler in the streak ; G 7-8-8 0. BB, easily fusible and reducible. Soluble in hot solution of caustic potash, and reprecipitating partly in crystalline scales. 188 . BLOWPIPE PRACTICE. Bismuth Ochre : Bi 89-7, O 10-3. In yellow, grey, or greenish crusts on Native Bismuth, «fec. ; G about 4-5. Fusible into a yellow crystalline bead ; on charcoal reducible. ZiNciTE (Spartalite) : Gives zinc sublimate with carb. soda, but no metallic globules. See below. A». -WITH CARB. SODA ON PLATINUM WIRE, DISTINCT MANGANESE REACTION. t Anhydrous Species. (BB, zinc sublimate on charcoal. Streak, orange-yellow. ) ZiNCiTE (Spartalite): Normally, Zn 80'3, O 19'7, bnt always con- tains a certain percentage of Mn*0'. Hex., but commonly in lamellar or granular examples, often partly coated by white zinc-carbonate ; red; streak yellow; H4; G 5 -5-5 "7. Infusible. Soluble in acids. {BB, no sublimate ; no copper reaction. Colour and streak, black or dark-brown. ) Braunite ; Hausmannite : In small crystals (mostly Tetragonal octahedrons) or granular examples of dark-brown or iron-black colour and sub-metallic lustre G iJ-i'd. See Table X. Pyrolusite : MnO*. Iron-black, very soft, mostly in fibrous masses of essentially sub-metallic lustre. ; infusible. See Table X. {BB, roith borax in RF, an opaque-red cupreous bead. ) Crednerite : CuO 43, Mn*0' 57. In iron-black, cleavable masses of essentiallv sub-metallic lustre. See Table X. t + Hydrous Species. Manganite : Mn^'O', H*0. In dark steel-grey or iron-black crystals and other examples of essentially sub-metallic (or metallic) lustre. H 35-4 ; G 44. See Table X. Psilomelawe : MnO, MnO*, HO^, in somewhat variable propor- tions, with part of MnO replaced by BaO, K^O, ur by treatment BB with cobalt solution). Brucite : MgO, H'O. Occasional examples : see above. Alkaline r.'action after ignition. {With carh. soda, BB, strong manganese-reaction). Pyrochroite : MnO 79-8, H^O 20-2. In white, foliated masses, forming strings in certain examples of magnetic iron ore, but weathering brownish-black from conversion of the MnO into higher degree of oxidation. BB, blackens ; infusible. (Ca-lines in spectroscope, and alkaline reaction, after ignition). Whewellite: CaO 38-36, C^O' 49-31, H^O 12-33. Clino-Rh. ; in small (commonly twinned) crystals on certain examples of Calcite. Colourless; lustre vitreo- adamantine; H 2-5-2-0; G 1-83; infusible; by gentle ignition converted into CaO, CO*. NOTE ON TABLE XXIII. This Table is composed essentially of Oxides. The more commonly occurring species, belonging to it, may be grouped in four series, as follows : — ( 1 ), Iron Ores and related compounds; (2), Manganese Oxides; (3), Red Zinc and ('opper Oxides ; and (4), the magnesia hydrate, Brucite. The Iron Ore group comprises, chiefly, (i) the anhydrous species of Regular crystiiilization. Magnetite, Franklinite, and Chromite (with common formula KO, R*0') ; (it) the anhydrous Hemi-Hexagonal species, Haematite and Ilmenite (with oominon formula RW) ; and (Hi) the hydrous species, conveniently ranked together under the common name of Brown Iron Ore (with common formula= 11^0'+ m H'J). All the species of this group become magnetic after ignition i)r semi-fusion, and several are magnetic in their normal condition. In most cases the finely powdered ore dissolves without much ditBculty in hot hydro- chloric acid, but Chromite, Ilmenite, and titaniferous-holding Magnetite are exceptions. The two latter in the form of very fine powder generally yield to slow digestion (in a small, covered beaker on a sand bath, the acid being kept just at the boiling point), but Chromite (unless mixed with magnetite) is very slightlj attacked. It may be decomposed however (sufficiently for determina< tive purposes) by gentle fusion, in fine powder, with a mixture of carb. soda, 192 BLOWPIPE PRACTICE. borax, and nitre. By this treatment an alkaline chromate, soluble in water, is formed. The solution, decanted from the insoluble residuum, may then be evaporated to dryness, and the resulting deposit fused with borax for the pro" duotion of a chrome-green glass. The presence of chromium may also be shewn by the deep green coloration produced by addition of sulphuric acid and alcohol : ^se Part I., page 49. Comparatively few examples of Magnetite are referrible to the present Table, as in most specimens of that mineral the lustre is unmistakably metallic or sub-metallic (s?e Tables VIII. and X.). Some examples, however, are obscurelj"- metallic in aspect. These are black in colour, with black streak, and strongly magnetic. Commonly in granular or lamellar masses, with G averaging 5'0. When crystallized, in octahedrons and rhombic dodecahedrons. Franklinite and Chromite much resemble examples of Magnetite with obscurely metallic lustre. They are mostly in black, granular masses, with normally dark brown or red brown streak, but the latter is often black from presence of magnetite, or greenish from intermixed chloritic or pyroxenic rock- matter. Franklinite is often strongly magnetic (probably from presence of Fe'O*). Chromite is only occasionally magnetic, and its specific gravity falls below 4*6, averaging usually 4 "3 or 4 '4. Franklinite with carb. soda, BB, forms a turquoise enamel (Mn reaction), and gives on charcoal (if treated in powder with carb. soda and borax) a sublimate of ZnO. Chromite with borax gives (on cooling) a fine green glass. See also its reactions described above. Ilmenite resembles the above minerals by its black colour and brownish or black streak, as well as by its frequent occurrence in granular or scaly granular masses ; but its crystals are rhombohedral combinations closely resembling those of Haematite (R : R 85°3r). It is most readily distinguished by the deep amethystine colour which results when its hydrochloric acid solution (somewhat diluted) is boiled for a few minutes with a piece of tin. Haematite occurs under several more or less distinct conditions ; but in most cases it presents a metallic or well-marked sub-metallic aspect, and is thus referred to in preceding Tables (see Notes to Tables VIII. and X.). The examples belonging more especially to the present Table commonly come under the designation of Red Iron Ore, of which Reddle or Red Ochre is an earthy variety. In these, the streak is always distinctly red, and the colour either brick-red, brownish-red, or bluish-red, the lustre in the latter case merging into sub-metallic. The harder examples are very frequently in fibro- botryoidal masses. BB, in the RF, all blacken and become magnetic. Brown Iron Ore includes several so-called species or snb-species, compounds of Fe'O* with variable amounts of water. All yield a yellow or yellovrish- brown streak ; and all become red by ignition with free access of air (especially ill powder), the water being driven off. Ordinary varieties assume a bright i^ colour on ignition, but varieties which contain much manganese give a dull-red or chocolate-red powder. Before the blowpipe in a reducing flame, all become black and magnetic, and fine splinters exhibit fusion. Practically, theie compounds may be referred to three series : — (t) a series, typified by GiBthite, in which the water averages 10 x>er cent., the formula being FeH)*; MINERAL TABLES : — XXIII, * 193 II'O ; {ii) a second series, typitiecl by Limonite, the formula of which may ])e written Fe*l)', [i H\), with 14 to 15 ver cent, water ; and (lit), a series of Hog ores and Ochres containing 20 • .■ cent, or more water, and having jjart (if the iron in the condition of FeO combined with lumiic or other organic acid. No very strict 'ines of demarcation can be drawn, however, between tliese varieties, (jtcthite, although frei|aently in fibrous and other examples, occurs occasionally in thin-scaly and acicular crystals of the Ehonibic "System. Tlie other lirown Ores are unknown in true crystals, although cubes and other pseudomorphs derived from Iron Pyrites are not unccmimon. They occur chicHy in rihro-botryoidal, granular, and earthy masses. Many of the fibrous examples present a silky lustre, and some are comparatively light in colour. Many brown ores, met with. Cuprite (Red Copper Ore or Ruby Cjpper) occurs commonly in octahedrona (often with sunk faces) and in rhombic dodecahedrons and other forms and combinations of the Regular System, frequently converted into gi-een carbonate 14 194 BLOWPIPE PRACTICE. on the surface. It is also found in acicular groups and in lamellar and < *'ior niaases ; and in a dull, sub-earthy condition (mixed with Fe'O', &c. ) formint' the so-called "Tile Ore." Its more distinctive characters are its red roloiir and streak, and its easy reduction, BB on charcoal, to metallic copper. It dissolves witli eH'ervesccnce and production i>f coloured nitrous fumes in uitrit- acid, forming (as in the case of copper compounds generally) a green solution which becomes intensely blue on addition of annnonia. Brucite, MgO, H*(), is easily distinguished from the other commonly occurring minerals of this 1'able by its white streak, softness, pearly aspict. and its magnesia-reaction, BB, with nitrate of cobalt. Ou ignition it evolvt-> 30 to 31 per cent, water, and reacts alkaline. [195] TABLE XXIV. [Lustre non-metallic. BB, slowly attacked or only in part disaolved by borax or phosphor-salt. Infusible, or fusible on thinnest edges only. Hardness sufBcient to scratch ordinary window-glass distinctly.*] A — Insoluble (in powder) in hydrochloric acid. A'.— SPECIFIC GRAVITY OVER 5 0. t With carb. soda and a little bm'ax, BB, yielding metallic tin. Cassiterite (Tinstone): — 8n 78-62, O 21-38, but .nost examples contain traces of Fe'^0*, Mn'''0^ &c. Tetragonal (c?-ystal8 often twinned), see Note at end of Table; also massive and in rolled pebbles ( = stream tin, wood-tin) often with sub-fibrous structure. Brown, black, grey, reddish, &c., rarely colourless ; H G-0-70 ; (I 6-7-7-0. Infusible, but reducible on charcoal (especially if f»iseic crystalli'-ation) in the meteoric iron of Breitenbach in Bohemia. (JVb obtcrvahle cleavar/e plancx). Quartz (Rock crystal, Amethyst, Calcedony, Agate, &c.): Normally, pure silica; Si 46-67, O 53-33, but often coloured by traces of Fe'^0\ Mn'03, &c. Hexagonal or Hemi-Hexagonal {see Note at end of Table) ; crystals, commonly six-sided prisms striated transversely and terminated by a six-sided pyramid ; often massive, botryoidal, granular; H 7-0 ; G 2 -5-2 -8 (clear examples and crystals commonly about 2-65); colourless, white, violet, smoky-brown, pink, red, gi-een. grey, black, &c., the colours of massive examples often in stripes or spots : see Note at close of Table. BB unchanged. With carb. soda fusible with effervescence (due to expulsion of CO'*) into a clear glass. Opal (Hyalite, kc): SiO^ with from 2 to 20 per cent. H'O : the latter usually 3-10 per cent. Opaque and strongly coloured varieties also contain intermixed Ee'^O' and other impurities. Uncrystalline,and thus normally without action on polarized light. In nodular, botry- oidal, and other massive examples ; H (normally) 5-5-6-5 ; G 1-5-2-5, commonly 1-9-2-2; colourless, bluish- white, yellowish-red, with m- ternal play of colours or iridescence (Noble Oj»al, Girasol, Fire-Opal) ; also colourless, forming vitreous coatings or botryoidal masses on lava (Hyalite) ; or white, yellow, brown, red, bluish-gi-ey, &c., often in stripes or patches in the same specimen, and with more or less waxy or sub-resinous lustre (Common Opal, Semi-Opal, Wood Opal, tfec). BB usually decrepitates ; in the bulb-tube yields a little water; otherwise like quai'tz. In powder, soluble in hot solution of Cf us^ic potash. Jasper Opal is an opaque red, dull-yellow or brown variety, mixed with a considerable amount of Fe''0* or Fe^'O'', H^'O. Menilite is a light-brown or bluish-grey variety in flat noduhu- i)ieces. Pearl- sinter, Siliceous Sinter, Geyserite, «fec., are stalactitic, enciusting or porous varieties, deposited by many hot springs. Tri[)oli, Polishing Earth, Randanite, are forms of amorphous silica, made up of minute tests or coverings of diatoms. MINERAL TABLES : XXIV. 203 B. -Readily decomposed or dissolved (in powder) by hot hydrochloric acid* B'.- YIELDING NO WATER (OR TRACES ONLY) BY IGNITION IN BULB-TUBE. t Decontjwsed, ivUhout yelatinization, by hydrochloric acid. Leucite: K^O 21-53, APO^ 2350, SiO^ 5497, but part of the K.^0 couinionly replaced by Na'^0. Tetrag., but crystals closely resembling a trapezohedron of the Regular System. H 5"5-6'0 ; G 2 -45- 2 "50; white, light-grey, yellowish or reddish-white. Only found in crystals or small rounded masses in certain lavas. lufus^'ble ; Avith ( )o-soluTiion, BB, assumes a bright blue colour. In fine powder, decomposed by hydrochloric acid, with separation of gramdar silica. Shews red K-line distinctly in spectroscope when ignited and fused with carb. soda or moistened with hydrochloric acid. Pollux : Cs^O, Na^O, APO», SiO^ with about 2| per cent. H'^0, the latter easily escaping detection in the examination of small fragments. Reg. (crystals very minute combinations of cube and trapezohedron 2-2). ' Commonly in small camphor-like colourless masses. H 5-5-6-5 ; G 2-8-2-9. Fusible only on thin edges. The powder heated with fluoride of ammonium and then moistened with hydrochloric acid shows in the spectroscope the two characteristic ^(jiisium lines. These are bright blue and close together, one being almost in the position of the blue Sr-line. A rare species, hitherto Didy found in the Island of Elba. 1 1 Decomposed, loith separation of gelatinous silica, by hydrochloric acid. (Zn reaction: characteristic ring-deposit on charcoal by fusion of test-substance ivith carb. soda). Willemite : ZnO 73, SiO'* 27. Hemi-Hex. (crystals commonly six-sided prisms terminated by an obtuse rhombohedron of 128^ 30', but very small, and often with rounded edges) ; H 5 5 ; G 3-9-4-2 ; white, brownish, red, green, »kc. Infusible, or attacked, BB, on thinnest edges only. (Zn and Mn reactions). Teoostite : Like Willemite in composition but with part of the * Reduce a small fragment (5 or 6 grains, or less) of the test-substance to powd.u-; place this (by means of a folded slip of glazed paper) at tlie bottom of a clean test-tube ; twist a rolled- up piece of soft paper round the top of the tube to serve as a handle, the ends of the paper bi-liig twisted together; cover the powder to the depth of about half-an-inch with strong hydroclilorie acid, and boil gently (letting tlie flame touch the side of the tube neai- tUe toy of tlie acid) for two or three minutes. 204 BLOWPIPE PRACTICE. ^iiO replaced by MuO and FeO. Hemi-Hex. (crystals comparatively large, mostly six-sided prisms with rhombohedral terminations). Commonly opaque or semi-opaque, yellowish-grey, greenish or brown, BB with carb. soda forms a turquoise-enanrel. Otherwise like Willemite. Properly, a manganese variety of the latter species. {Fl reaction with sulphuric acid). Chondrouite: MgO, FeO, SiO* (33-37 per cent.), MgFP. CHnu- Rh., but commonly in small granular masses of a yellow, yellowisli- white, reddish, brown, or green colour imbedded in cryst. limestone ; H 6-0-6-5 ; G 30-3*25. BB infusible, or rounded only on thinnest «dges. Clino-Humite is closely related. HuMiTE : a Chondrodite of Rhombic crystallization. In small crystals with numerous pyramidal planes, and generally a well- developed basal plane, chiefly from Monte Somma, but recognized also by E. Dana (with Chondrodite and Clino-Humi >) from Brewster, N.Y. {No Zn or Fl reaction. O 30 to 3-5). Chrysolite or Olivine (Peridot): Average composition, MgO 49, FeO 10, SiO'^ 41 ; but in some vai'ieties the FeO is higher, and MnO and TiO^ are occasionally pi'esent. Rhombic, but often in small granular masses in basalt, &c. H 6'5-7'0; G 3'2-3*5. Green of various shades, yellow, brownish, rarely yellowish-red. BB, infusible, except as regards some very ferruginous varieties (Hyalosiderite, &c.) which yield a magnetic slag or globule : see Table XXVI. Forsterite (Boltonite) is identical in composition, crystallization and other charac- ters. Hortonolite and Glingite are ferruginous varieties. MoNTiCELLiTE (Batrachite) : Average composition, CaO 35, MgO 22, FeO 5-5, SiO' 37-5. Rh. ; H 55; G 3-12 ; colourless, greyish, pale greenish or yellowish-grey. BB, rounded on thinnest edges only. Ignited and then moistened with HCl acid, shews in spectro- scope momentary red and green Ca-lines. Gehlenite : Essential composition, CaO, Al^O*, SiO" with small amounts of MgO, FeO, FeW, and H'O; Tetrag. (crystals chiefly simple square prisms) ; H5 5-6'0; G 2-98-3*10; pale greenish-grey, green, brownish. BB, rounded on thin edges. In spectroscoi)e (after ignition and moistening with HCl) shews Ca-lines very distinctly. {G 4 or higher ; colour, black). Gadolinite : YO, CeO, BeO, FeO, SiOS with traces of H'O, and occasionally small amounts of ErO, CaO, &c. Rliombic or Clino-Rh., MINERAL TABLES : — XXIV. 205' I)ut chiefly in small granular masses without distinct cleavage. Black, i,fieenish-black ; streak greenish-gi-ey ; H 6-5-7 0; G 40-4-3, BB, iriany varieties emit a peculiar glow, and most exami>les swell up slightly and become greenish-grey, but none exhibit fusion, properly Ko-called. B«.— YIELDING WATER ON IGNITION.* {BB, strong Cu-reaction icith borax, or v^hen moistened with hydrochloric acid) ^ DioPTASE : CuO 50-44, SiO^ 38-12, H'O 11-44. Hemi-Hexagonal (crystals chiefly combinations of hexag. prism and rhombohedron, with angle of 95° 28' over polar edges of the latter) ; cleavage rhom- hohedral, with R-.R 125° 54'; bright emei-ald-green, with paler streak; H 5 0-5-5; G 3-27-3-35. BB, generally decrepitates, blackens, but remains unfused. With carb. soda, on charcoal, gives metallic copper.. (Gelatinizes in hydrochloric acid. A rare species. The amorphous copper silicate, Chrysocolla, has normally a low degree of hardness, and is decomposed by hydrochloric acid without gelatinization. ISee Table XXV. (BB, with carb. soda on charcoal, zinc reaction). Calamine : ZnO 67-5, SiO* 25, H^O 7'5. Rhombic (crystals hemi- iiior{)hic, i.e., with different terminations, but generally small, and somewhat indistinct) ; H 5-0 ; G 3-3-3-5 ; colourless, or variously tinted. The crystals pyro-electric. Frequently in botryoidal and other massive examples. BB, infusible ; commonly decrepitates. Decomposed with gelatinization by hydrochloric acid. {N'o reactions of Cu or Zn. G 4'9 to 5-0). Cerite: CeO, SiO*, ffO (6- 12 per cent.), but -with part of the t'eO constantly replaced by LaO, DiO, CaO, &c. Hexag. (?); mostly in massive examples of a red, reddish-grey, or brownish colour ; H 5-5 ; G 4-9-5-0. Gelatinizes in hydrochloric acid. The solution (if not too acid) gives with oxalic acid a white precipitate which becomes converted into tile-red Ce^O* by ignition in the platinum spoon (Von Kobell). [G under 3-0). Pollux : Yields on ignition a very small amount of water. Mostly in small colourless camphor-like masses. See under B*, above. •The minerals of this section belong properlj to Table XXV., as they scratch glass more or leas indistinctly, but to avoid risk of error in their determination they are referred to alio here. 206 BLOWPIPE PRACTICE. NOTE ON TABLE XXIV. This Table inclndes a series of hard, infusible or very difficultly fusiMc minerals of vitreous or other non-metallic lustre ; with, in addition, a few species in which the lu3tre is occasionally sub-metallic. These latter are comparatively rare,' and they belong normally to Table X. The following are the only species of importance, or of ordinary occurrence, which possess sufficient hardness to scratch glass distinctly: — (1) The Dia- mond ; (2) a group of closely allied Tetragonal species, comprising: Cassiterite. Rutile, Anatase, Zircon ; (3) the purely or essentially aluminous species. Corundum, Chrysoberyl, Spinel, Gahnite ; (4) the purely siliceous species. Quartz and Opal ; and, (5), the silicates, Topaz, Beryl, Cyanite, Andalusite, Staurolite, Chrysolite, Chondrodite, Tourmaline, lolite, Leucite, Orthoclase, Albite. The Diamond is distinguished essentially by its extreme hardness, its peculiar adamantine lustre, and, in ordinary examples, by its crystallization. The latter is Regular, but the crystals have almost invariably curved planes. The principal forms comprise the tetrahedron and octahedron, and the jwlamantoid 3 1"f, the last often distorted both by curvature of faces and by elongation. The cleavage is octahedral. In the Bunsen Hame on platinum foil, diamond dust bums slowly away, but small splinters remain unchanged. The Tetragonal species, Cassiterite,. Rutile and Anatase, have the common formula RO* ; and with these, from its close correspondence in crystallization with Rutile, the Zircon may be placed. Cassiterite, SuO'*, is readily distin- guished by its high sp. gr. (67-7'0), and by yielding reduced tin, BB, with carb. soda or other reducing flux on charcoal. The crystals are commonly short eight-sided prisms, terminated by the planes of the two corresponding square pyramids (without basal plane) ; and they are very frequently in geniculated twins. P : P over polar edge = 121° 40' ; P : P = 133° 30'. In mineral veins, Cassiterite is very generally associated with Wolfran* and Quartz, the latter forming the ganguc or veinstone. The variety known as "stream tin" occurs in small rolled pebbles and grains in alluvial deposits. "Wood tin" is also an uucrystallized variety of light or dark brown colour and concentric-radiated structure. Rutile^ TiO', distinguished in ordinary examples by its red or brown colour and adamantine lustre, closely resembles Cassiterite in crystallization, and especially in its geniculated twin-forms ; P : P = 123° 8' ; vertical planes, in general, longitudinally rtriated. Rutile occurs also occasionally in acicular radiating crystals, traversing quartz ; and in small dark pebbles (Nigrine). Anatase or Octahedrite, another form of TiO', is mostly in awW pyramidal crystals of a greyish-brown or peculiar blue colour, with adamantine, more or less sub-metallic lustre. The crystals com- monly shew a consecutive series of several pyramids, but are sometimes tabular from extension of the basal plane. The angle over middle edge in P = 136° 36' (over polar edge 97° 51') ; in J P, 79° 54' ; in i P, 53° 22' ; in f P, 39° 30 . Both Anatase and Rutile, and the Rhombic species Brook ite, after fusion in file powder with carb. soda, are dissolved by hydrochloric acid. The solution assumes a deep violet colour if slightly diluted and boiled with metallic tin. MINERAL TABLES '. — XXIV. 207 Zircon, ZrO', SiO^ ocours occasionally in small granular masses, but most coinriionly in simple crystals of the Tetragonal System. Those aru frec^uently small square prisms terminated by a square pyramid measuring 123° 20* over polar edges, and 84" 20' over middle edges. The basal plane is always absent. Other common crystals are eight-sided, from combination of the two square prisms, and in many a socond pyramid is subordinately present. Some crystals, again, shew the planes of one or more octagonal pyramids, 3 P 3, 4 P 4, 5 P 5, but these planes are usually quite narrow or of small size. Zircon is mostly red or red-brown in colour, but sometimes pale yellowish-grey, orange-yellow, greenish, or colourless. Its hardness (7'o), and its high sp. gr. which averages 4"4or4"5, and always exceeds 4"0, are salient characters. BB loses colour, but is quite infusible. The powder is slowly taken up by borax, the saturated glass becoming opaque when flamed. Corundum, Al^O^, is distinguished by its great hardness (9'0), its high sp. gr. (38-4'2), hexagonal or hemi-hexagonal crystallization, and complete infusi- bility ; and by the fine blue colour imparted to it by treatment, BB, with cobalt solution. It occurs under three more or less distinct conditions : (1) in small transparent or sub-transparent crystals of a blue, pink, red, or othtr colour, or sometimes colourless, forming the sapphire, ruby, &c., of jewellers, according to the colour ; (2) in coarser translucent or opaque crystals and cleavable masses of a greyish-green, red, brown or other tint, forming the variety known as Adamantine Spar ; and (3) in fine-granular masses of a grey or dark bluish-grey or black colour, commercially known as Emery. The latter variety is sometimes mixed with grains of magnetic iron ore. The Corundum crystals are mostly small, pyramidal combinations, or six-sided prisms with narrow j^yramidal planes and large basal face, and are frequently ill-formed. The cleavage is basal, and also rhombohedral, with R : R 86° 4'. Many crystals are parti -coloured, blue and white, &c,; and in some (asteria sapphire), a six- rayed opalescence is visible. The cleavage faces often shew a delicate striation. For blowpipe reactions, see the Table, Chrysoberyl, BeO, Al'O' (or perhaps Be*0', A1*0'), is a comparatively rare species of a green or greenish-white colour, sometimes reddish by transmitted light, and often shewing a pale-bluish opalescence — whence the name Oymo- phane, by which this species is also known. The crystals are Rhombic com- binations, and are frequently in pseudo-hexagonal stellate groups* — both simple and compound crystals being generally more or less tabular from extension of the front vertical form or macro-pinakoid V, The hardness of chrysoberyl (8"5) nearly equals that of corundum ; and its comparatively high sp. gr. (37-3"8) is also distinctive. * Compound stellate and hexagonal groupings are comnioii among crystals of the Rhomliir System (Chiysoberyl, Marcasite, Discrasite, Aragonite, Cerusite, kc,.), and are occasioiiallv seen in C'lino Rhombic and Regular crystals (the latter in Camphor, &c.), but are appanntly unknown among minerals and chemical products of recognized Hexagonal crystalliziition. The beautiflil snow-crystals so common in Canadian winters are thus most probably not truly hexagonal, but compound Rhombic forms. See a brief communication by the writer in the Canadian Journal, 1800. 208 BLOWPIPE PRACTKJR. Spinel, normally iMgO, Al^'O', is readily (listinguished, in most examples, by its oceurrence in small oetahedrons, commonly twinned, as well as by its great hardness (80), and its high specific gravity (3r)-4'l), The colour is usually some shade of red, but colourless and other-coloured varieties arc also known. After fusi(m in line powder with bisulphate of potash it is partially soluble in water. Ammonia throws down (locculent Al'O* from tlie solution. )le only on the thinnest edges. Some crystals are red internally and green externally, or present different colours at the extremities ; and nearly all the clear examples are transparent when viewed across the prism, and opaque longitudinally. All, moreover, exhibit electrical polarity when heated. * lolite, known also as Dichroite and Cordierite, is commonly in the form of small, granular, vitreous or resino- vitreous masses, imbedded in granitic and crystalline metamorphic rocks ; but is found at some localities in distinct crystals, and occasionally in the form of small rolled pebbles in alluvial deposits. The colour is mostly dark-blue or pale-blue by reflected light, and brownish or yellowish by transmitted light, whence the name Dichroite. Some varieties, however, are colourless, grey, or blueish-brown. The crystals belong to the Rhombic System, but have in general a pseudo-hexagonal aspect : a common combination consisting of the forms V, V, P, P, and B ; with V : V 119" IC; B : P 160^ 49'. Fine splinters melt at the extreme point, but practically the * This may be shewn l)y suspending a crystal front the ring of the blowpipe-lamp, or other iviiivenient support, by means of a piece of thin silk-thread tied round the centre of the crystal. Tlie latter is heated carefully In a small platinum or porcelain capsule, care being taken not to bum the thread, over a spirit-flame or Bunsen-bunier. On the capsule being removed, one (ind of the prism will be attracted, and the other end repelled, by a glass stirring-rod or stick of sealing-wax rubbed previously for a few seconds on the ooat-sleeve. 212 BLOWPIPE PRACTICK. Hpecica may l)C placed among the infusiblo silicates. From Mvie Coruiidiim (Sapphire), and from Sappliirinc and blue Spinel, it is readily diatinguished by its low sp. gr. (2 '6). From l)lue Tourmaline (Indigolite), also, by lowir sp. gr., and by not becoming electric when heated ; and from Quartz, hy forming, BIJ with carb. soda, a slaggy semi-fused mass in place of a clear glass. Many examples of lolite are partially altered or decomposed, and the.sc give traces of wator in the bulb-tubo. Leucite is readily distinguished, as a rule, by its occurence in small rounded grains or crystals of a white, gr«^> , or pale-yellowish tint, in lava. The crystal* closely resemble the trapezohedron 2-2 of the Ilcgular System, but have binn shewn by Von liath to he .eally Tetragonal — at least as regards uiotit examples, if not all. Many crystals contain minute needles and scales of augite, magnetite, &c. , scattered through their substance. In powder, leucite is slowly decomposed by hot hydrochloric acid. The solution, rendered pasty by partial evaporation, shews the red K-line in the spectroscope if held (ui a clean platinum wire for a few seconds in the outer edge of a Bunsen-ilame. The K-line is rendered visible also by igniting some of the powder on a Iddp of platinum wire, and then dipping it into some carbonate of soda or powdered fluor-spar, and again ciposirg to the flame. The glare from the sodium spectrum may be entirely cut ofl" by the intervention of a piece of deep-blue glass. Orthoclase ; Albite. These species belong properly to Table XXVI, and their crystallographic and other characters are there described. In general, they form cleavable masses of a white, flesh-red, bright-red, grey, pale-yellowish or clear-green colour ; or occur in crystals of a more or less flattened aspuct, often twinned (see Note to Table XXVI.). In Orthoclase the principal clea- vage planes meet at light angles ; in Albite, at angles of 93* 36' and 86" 24 . and one of the cleavage planes in the latter species generally shews a delicate striation, best seen under the magnifying glass. Orthoclase, treated in powder with carb. soda (as described under Leucite, above) shews very distinctly the red K-line in the spectroscope.* • This test for the presence of potash in Orthoclase, so far at least as regards the use of tart soda, WP-s first described by Bunsen. If the mineral, in powder, be fused with fluor-spar Uu red K-lino comes out, I find, still more distinctly ; and many examples, when thus trcateo shew the Li-liue as well. By the intervention of a piece of blue glass the Ca-lines (from tl.t fluor-spar) and tlie Li-line become obliterated, and only the K-line remains visible. Tlie hitttt is also brouglit out in most if not in all cases by simply moistening the test-matter, alttt ignition, with liydrochlorio acid [213] TABLE XXV. f Lustre non-motallic (in some casea pseudo-nietallic). Slowly f>r incomjiletely (liisolved BB by phoaphor-salt. Infusible, or fusible on thin edges only. Hardness insulBcient to acratch ordinary wiinlow-glaas. ] A. -Occurring in micaceous or foliated masses or crystals, the foliae elastic or flexible, and easily separable by the finger-nail. A».-FOLIiE DISTINCTLY ELASTIC. Muscovite (Potash Mica) : Essentially K'O 9, Al'O' 35, SiO« 4(), with small amounts of Fe'O*, H^'O, Fluorine, &c. Rhombic or Clino- Rhombic (T), but crystals hexagonal in aspect. Optically biaxial, with large angle of divergence. Structure thin-foliated or scaly, thi; folife easily separable. White, brown, black, green, (fee, with metaUic pearly lustre on cleavage-plane ; flexible and elastic in thin pieces ; H 20-30; G 2-7-31. BB, exfoliates, and melts readily on the ndges (if in the form of a thin scale) into a greyish- white enamel.* In acids, insoluble. Fuchsite is a more or less deej- green chrorai- toious variety, in fine-scaly aggregations. Damourite and Margarodite are hydrated micaceous minerals, apparently derived from Muscovite. See Table XXVII. Roscoelite is a Vanadium-mica (in small greenish- brown or green, radiately arranged folia? of metallic- jiearly lustre) from Eldoi-ado Co., California. Phlogopite (Potassic-Magnesian Mica) : K*0 12 75, MgO 32*55, APO" 13-95, SiO^ 4075, with small amounts of IPO, F, &c. Rhombic (optically biaxial), but essentially hexagonal in aspect ; thin-foliated, or scaly ; chiefly yellowish-brown, with golden, metallic-pearly lustre on cleavage-face; H 2-5-30; G 2-75-2-90; BB, whitens, and melts on thin edges into a greyish-white enamel. In powder decomposed by sulphuric acid, the silica separating in colourless scales. Common in crystalline limestones, t Biotite (Potassic-Ferromagnesian Mica) : Closely resembles Phlo- gopite in composition and general characters, but usually of dark colour — green, black, or brown ; optically uniaxial, and of assumed * Tlie Micas (Muscovite, Plilogopite, Biotite and other reprcHentatives, Lepidolite excepted), are always placed among the infusible sptcies, in works on Determinative Mlneralogj'. As a lulc, however, all melt more or less readily on the edges when tested in the form of a thin scale. In the spectroscope, all shew the red K-line, and many the Li-line also, either per se, or when moistened, after ignition, with HCl acid. t Thia species is present iu great abundance iu most of the apatite deposits of Canada. 214 BLOWPIPE PRACTICE. Hexagonal crystallization. Fusible on edges into a black or dark enamel. Decomposed by sulphuric acid. Commonly ibund in vol- canic and trappean rocks, but many volcanic micas are optically biaxial. A».— FOLTiE FLEXIBLE BUT NOT ELASTIC. t Yield water by ignition in bulb-tube. Chlorite (Pennine) : MgO 13 to 27, FeO 15 to 30, APO' 19 to 23, SiO* 25 to 28, H'O 9 to 12. Hexag. or Hemi-Hex. (crystals mostly tabular), but commonly in foliated and scaly examples of a dark or rich green colour ; flexible in thin pieces ; H 1 '0-1 "5 ; G 2-65-2*95. Fusible on thin edges into a yellowish-grey or dark and often magnetic glass. Decomposed by sulphuric acid. Metachlorite, Prochlorite, Aphrosiderite and Tabergite, are closely related chloritic substances. The latter occurs in coarse, bluish-green, foliated masses. KiGMMERERiTE : A chromifei'ous chlorite of a red or violet-red colour, or green by i-eflected, and red by transmitted light. Mostly in hexagonal pyramids and prisms of foliated structure. RiPiDOLiTE (Clinochlore) : Clino-Rhombic in crystallization, but identical in general characters and composition with Chlorite proper. Epichlorite, Korundophyllite, Helminthite, are varieties or closely related. Pyrosclerite is a chromiferous variety from Elba. Delessite is an essentially ferruginous chlorite, allied to this or the preceding species, of frequent occurrence in amygdaloidal traps. Pyrophyllite (Foliated Kaolin) : APO', SiO^ H*0, with traces of MgO, &c. Essentially in radio-foliated examples of a clear green or greenish-white colour, and somewhat pearly lustre; flexible in thin pieces; H I'O; G 2-75-2-95. BB, exfoliates and curls up, but remains unfused, or vitrifies slightly on thinnest edges only. With Co-solution assumes a fine blue colour. Talcosite, from Victoria, is a closely related substance, passing into Kaolin proper. 1 1 ^0 looter y or traces only, in bulb-tube. Talc : Essential composition, MgO 31-7, SiO' 63 5, H'O 4-8, but the H*0 is not driven ofi" by moderate ignition, and is thus regarded as basic. Occurs commonly in six-sided tabular crystals and foliated masses of a peai'ly-white, greenish- white, clear-green, or greenish- grey colour. H 1*0; G 2-67-2-80. BB, exfoliates, becomes opaque- white, and melts on thin edges, but less easily than mica. With Co-solution, becomes pale-red. Insoluble in acids. MINERAL tables: — XXT. 215 B.— Occurring in distinctly schistose or foliated examples, but the component folise more or less brittle, not flexible. Bi.— YIELD WATER BV IGNITION IN BULB-TUBE.* Margarite (Pearl Mica): CaO, APO», SiO*, H^'O, with small amounts of K^O, Na'O, Li^O, MgO, F, &c. Rhombic (1) ; mostly in six-sided tables and lamellar masses of a pearly-white, pale-gi-een, reddish or greyish colour; the lamella} more or less brittle. H 3-5-4'0; G 2-95-3-10. BB, melts on the edges, often with slight intumescence. Scarcely attacked by acids. In spectroscope, after ignition and moistening with HCl acid, shews momentary red and green Ca-lines, and, in most examples, red K and Li lines, also. Emeryllite, Euphyllite, Diphanite and Gilbertite, are identical or closely I'elated. Euphyllite, however, is decomposed by sulphuric acid. Antigorite (A slaty Serpentine) : MgO 36 to 37, FeO 6 to 7, SiO* 41 to 43, H»0 11-5 to 12-5, with traces of APO», &c. In schistose masses of a dark green or greenish-brown colour; H 2-5 ; G 2*62. Fusible on thin edges. Slowly decomposed by sulphuric acid. Schiller Spar (Bastite). Probably an altered Bronzite : Con- tains MgO, FeO, SiO'^ with about 12 por cent. H^O, and small amounts of K^O, CaO, Cr'^O', APO*, &c. In schistose or foliated masses of a dark-green colour, with yellowish-brown reflections on the cleavage surfaces. H 3 •5-4-0 ; G 2-6-28 ; BB, melts on the edges only ; becomes brown and sometimes magnetic after ignition. Decomposed by sulphuric acid. PiCROPHYLL : A hydrated magnesian silicate occurring in sub- foliated or coarse-fibrous examples of a greenish-grey colour ; H 2*5 ; G 2-73. Fusible on thin edges. Regarded as an altered Pyroxene. Chlorophyllite : Contains MgO, MnO, APO', Fe'0», SiO», H^O. In foliated masses or coarse indistinctly formed crystals of a green or brownish colour. H about 3*0 ; G about 2*7. Fusible on thin edges only. Scarcely attacked by acids. Probably, in part, an altered lolite. Groppitb: Contains K»0, CaO, MgO, APO», Fe'O", SiO», H^'O ^7 per cent.). In foliated or scaly masses of a rose- red or brownish- * Pew, if any, of the minerals belonging to this section can be regarded as true species. An a rule, they consist of altered products of more or less unstable composition, and their deter- iniuative characters are commonly ill-defined. Tills remark apx>lie8, with few exceptions, to the representatives of the present Table, generally. 216 BLOWPIpJi PRACTICE. red colour, the folise brittle; H 2-5-'J0; G 2-73. BB, whitens, and vitrifies on thin edges. B«.— ANHYDROUS SPECIES : NO WATER, OR TRACES ONLY, EVOLVED IN BULB-TUBE. Bronzite (Foliated Enstatite) : Contains MgO, FeO, SiOl Com- monly in schistose or foliated masses of a dark-brown or dark-green colour, with pseudo-metallic bronze-like lustre, and very {»erfett cleavage in one direction. H 4-0-50 ; G 2 '9-3-5. Fusible on tliinnest edges only. Not attacked by acids. Anthophyllite : MgO 27-8, FeO 16-7, SiO^ 55-5. Rhombic, but essentially in thin-lamellar and fibrous masses, with tolerably easy cleavage in three directions ; yellowish -brown, greenish-grey, bronze-green, with somewhat metallic-pearly lustre. H 5-0; G 3-2. BB, vitrifies only on thinnest edges into a black magnetic enamel : practically, infusible. Very slightly attacked by acids.* Clintonite : Composed essentially of CaO, MgO, APO', SiO*, with traces of H^O. Chiefly in hexagonal tables of a brown or yellow colour, with metallic-pearly lustre; H 5-0; G 30-3-2. Practically infusible. Decomposed by hydrochloric acid. Xanthophyllite (in yellow radiating lamellfe on certain talcose schists), and Brandisite (in dark-^een tabular crystals, weathering brownish), are apparently related compounds, but are only partially attacked by hydrochloric acid. In Clintonite and in these related silicates the silica is under 20 or 21 per cent. Ignited and moistened with HCl acid, all shew in the spectroscope red and green Ca-lines in momentary flashes. C— GcciirilQg in crystals or in granular, fibrous, compact, or other non-micaceous examples. Streak-powder colour- , less, pale-green, or lightly- tinted, —not black, ci.— yielding water by ignition in bulb-tube. t Form with borax, BB, a deeply coloured glass, (Cu reaction). Dioptase : CuO 5044, SiO' 38-12, H^O 11-44, In emerald-green crystals — hexagonal prisms with rhombohedral summit-planes — suffi- • In ordinary examples, Bronzite and Anthophyllite can rarely be separately distinguished. The first is regarded as a Rhombic represento cive of the Pyroxene series, and the latter as a Riiombic Ainphibole ; but the characteristic pj roxene and amphibole ingles (87° 6' and 124° 30'X or angles approaching theae, are rarely determinable. Hypersthene 's a very ferruginous and comparatively hard Bronzite, distinctly fii^ible. See Table XXVL. MINERAL tables: — XXV. 217 ciently hard (5 0-5-5) to scratch glass slightly : See Table XXIV. 33. BB, decrepitates and blackens, but does not fuse. With carb. soda, easily reduced. Gelatinizes in heated hydrochloric acid. A rf»re species, in crystsJline limestone from the Kirghis Steppes of Western Siberia. Chrysocolla (including Kupferblau, (fee.) : Composition somewhat variable, but essentially CuO 4527, SiO' 3421, H'^O 20-52. In • ori>hous and botryoidal masses, coatings on copper ores, and 'x;casionally in pseudomoi^phs. Colour, green, greenish-blue, bright- blue; brownish or black from presence of Fe^'O*, MnC^^ kc; H 2*0-6*0; G 2-0-2*6. BB, blackens, but does not fuse. On charcoal with carb. soda, reduced to metallic Cu. Decomposed with separation of silica (but as a rule without perfect gelatinization) by hydrochloric acid. Demidowite is a Chrysocolla mixed with copper phosphate. Asperolite a variety with 27 per cent. H'^O. Other varieties are mixed with copper carbonate, opalized silica, &c. Allophane (Cupreous vai'ieties) : Al^O^ SiO*, H^'O (35 to 3G per cent.), mixed with copper silicate. In- amorphous, stalactitic and botryoidal examples, coatings, &c., of a light-blue, green, red, or brownish-yellow colour. H about 3-0; G about 2-0. BB, blackens, and often swells up slightly, but does not fuse. In HCl acid, gelatinizes. {Ni reaction : page 43). RiETTisiTE : NiO, Si02, H'O (11 per cent.), mixed with Fe^O>, copper-phosphate, cobalt-arseniate, &c. Amorphous, incrusting; green of various shades ; H 2*0-2-5 ; G 2*3-2-4. Genthite (Nickel-Gymnite): NiO, MgO, SiO^ H^O (19 per cent.). In green and greenish-yellow coatings on some examples of Chromic Iron Ore, and occasionally in soft sub-earthy masses. H 2 •0-4-0 ; G about 2-4. BB, infusible, blackens. Pimblite: MgO, NiO, APO', SiO^ H^O (21 per cent.). In earthy masses, coatings, &c., oi an apple-green colour. H 10-2-5; G 2-3 (to 2*7 ?). BB, blackens, and vitrifies on thin edges. Alipito and Chrysoprase-Earth are identical or closely related compounds. {Fe reaction). Anthophyllite : In yellowish-brown, or greenish metallic-pearly examples of lamellar or fibrous structure. Some examples only yield traces of water on ignition. iSee B", above. 218 BLOWPIPE PRACTICE. HisiNOERiTE (Thraulite) : FeO, Fe*0', SiO^ H»0 (10 to 20 or 22 per cent.), with small amounts of MgO, Al^O', &c. In earthy and nodular masses of a pitch-black or brownish-black colour, with brownish streak. H 3-0-4-0 ; G 2-6-3 -1. BB, becomes magnetic, and vitrifies on the edges, or in some examples melts into a steel-grey magnetic globule* («ee Table XXVII.). Decomposed by HCl acid with separation of slimy silica. NoNTRONiTE : Essential components Fe»0», SiO», H»0 (21 to 25 per cent.), but small amounts of APO', CaO, &c., are also generally present. In earthy and nodular masses of a yellow, green, greenish- white or brownish colour; H 1-0-1 '6; G 2-0-2-4. BB, infusible, or fusible on the edges only, but becomes magnetic. Pinguite and Gramenite are identical or closely related. Chloropal (XJnghwarite) is also very similar in general characters and composition, but is somewhat harder, probably from admixture with opalized SiO*. {Cr reaction : see page 48). WoLCHONSKOiTE : Cr'0», Fe^O , SiO^ H'O (about 20 or 21 per cent.), with small amounts of MgO, MnO, APO*, &c. In earthy and nodular masses of a grass-green or blackish-green colour; H 1-5-2-5; G 2-2-2-3. BB, practically infusible; gelatinizing in HCI acid. MiLOSCHiN (Serbian) : APO», Cr^O' (under 4 per cent.), SiO^ H^O (about 23 per cent.). In blue or blue-green, earthy and amorphous masses; H 1-0-2 0; G 2-1-2-2; adheres to the tongue. BB, infusible. Partially decomposed by hydrochloric acid. 1 1 J^orm BB with horax an uncolou/red or lightly-tinted glass. (The saturated boraae-glasa beeomea opaque-white on cooling or when flamed). Cerite : CeO (LaO, PiO) 73-5, SiO" 20-4, H'O 6-1. Chiefly in fine-granular masses of a red, brownish, or reddish-grey colour. H 5-0-5 5 (scratches glass feebly) ; G 4-9-5-0. BB, becomes dull yellow, but remains unfused. Gelatinizes in hydrochloric acid. Thorite : ThO», SiO». H'O. Keg. 1 Mostly in small black masses, often fissured, and sometimes with reddish coating ; streak, brownish or reddish ; H about 4-5 ; G 4-4-4*7. BB, becomes yellow, but * L. H. Fischer : Clavis der Silicate : 1804. This work, a Determinative Grouping of the Silicat«s (containing many original observations), should have been referred to among the list of works on Determinative Mineralogy at page 21. MINERAL TABLES : — XXV. 219 remains unfused. Gelatinizes in HCl acid. Veiy rare : commonly regarded as altered Orangite. Orangite: ThO», SiO«, ffO. Tetragonal? Mostly in small granular or sub-foliated examples of a reddish-yellow or oi-ange-red colour; H 4*5 ; Gr 5'2-5-4. Gelatinizes in HCl acid. Very rare; accompanies Thorite in the micaceous zircon-holding syenite of Brevig in Norway. [Note, — Moat examples of Cerite, Thorite, and Orangite, when ignited and moistened with hydrochloric acid, shew a momentary Ca-spectrum. ] {A ziTic-aubUmate formed on charcoal by fimon with carb. aoda and borax). Calamine : ZnO 67-5, SiO^ 25, H'O 7-5. Crystallization Rhombic ; crystals mostly hemimorphic (with B plane at one extremity only), arranged in drusy or fan-shaped aggregations, and generally flattened from extension of the side vertical or brachy-pinakoid faces "V. The species occurs also very commonly in botryoidal, cavernous, and other examples ; colourless, white, yellowish, brown, green, light- blue; H 50 (scratches glass feebly); G 3*3-35 ; crystals, pyro- electric. Infusible, BB, or vitrified slightly on thinnest edges, only, only. Gelatinizes with hydrochloric acid. Ignited with Co-solution, becomes green (or partly blue and partly green) on cooling. (Slowly attached BB by^ borax ; the glass not rendered opaque by flaming. With Co-solution, assume a distinct blue colour). Kaolin : APO» 397, SiO* 46-4, H^O 13-9. Chiefly in earthy or fine-granular masses made up in part of microscopic scales. White, pale-red, greenish-white; H I'O or less; G 2'l-2"3 (or in some varieties slightly higher : 2*3-2*6). Infusible ; decomposed by hot sulphuric acid. Cimolite, Anauxite, Pelicanite, Hunterite, &c., are related aluminous compounds, but contain a somewhat higher per- centage of silica. Nacrite or Pholerite : A crystalline or sub-foliated Kaolin, in peai'ly-white scaly masses or six-sided tables, often in fan-shaped groups. Composition and other characters as in Kaolin propei*. Agalmatolite (Figure Stone * in part) : K'O, A1'0», SiO^ H*0 (about 5 per cent.). White, pale-grey, yellowish, pale-red, green, • Although many of the smaller Chinese images are carved out of this stone, a great number (perhaps tlie greater number) consist of steatite or of serpentine. In these, the substance blackens in the bulb-tube, and assumes a Uesh-red colour aftqr ignition with Co-solution. 220 BLOWPIPE PRACTICE. gi-eenish-wliite ; mostly in fiue-granular almost compact masses, but these consist frequently of microscopic scales; H 20-30 ; G 2-8-2-9. BB, whitens, and vitrifies on thin edges. Decomposed by sulphuric acid. Shews the red K-line- very distinctly in spectroscope, when ignited and moistened with HCl acid. Finite : K^O, MgO, FeO, FeHY, APO', SiOS H^O (4 to 8 per cent.). In six-sided and twelve-sided, more or less opaque crystals, of a greyish- white, grey, brown, greenish or bluish colour ; H 2 '0-3 -5 ; G 2*5-2"9. BB, vitrifies on thin edges only. In spectroscope shews distinctly the red K-line when ignited and moistened with hydro- chloric acid. Apparently an altered lolite. The following sub- stances, all of which give a K-spectrum, are more or less closely related : Pyrargillite from Finland (brown, brownish-red, H'^0 15*5 per cent.) ; Fahlunite (dark-brown, dark-green, greyish, H^O 8 to 9 per cent.); Weissite (grey, brown, H^O 3 to 5 per cent.); Iberite from the vicinity of Toledo (greyish-green, in coarse six-sided prisms, aq. 5 to 6 per cent.); Gieseckite (gi-eenish-grey, aq. about 6 per cent.); Liehenerite (green, greyish, aq. about 5 per cent.). The tv/o latter are regarded as altered nepheline ; the others as altered iolite. In all, the hardness is below 4-0, and the sp. gr. below 2-9. G'lgan- tolite belongs to the same series, but is readily fusible {see Table XXVII). Esmarkite: MgO, MnO, FeO, Fe'0», APO', SiOS H^O (£-5 per cent.). This mineral, like those placed under Finite, above, is also apparently an altered lolite ; but it is placed here, apart, as the representative of a non-potassic series. Occurs mostly in coarse twelve-sided prisms of more or less scaly texture; grey, brown, greenish, &c., in colour; and dull and opaque, or practically so. H 3'0-4'0; G 2'6-2'8 ; fusible on thin edges only. Praseolite, Aspasio- lite, and Bonsdorjffite, are identical or closely related substaiices of a green or greenish-brown colour, occurring mostly in six-sided, eight- sided, or twelve-sided ])ri8ms, with dull surface and rounded edges. Halloysite: APO' 35, SiO'^ 41, H^O 24. Nodular, earthy; greenish or greyish-white, pale dingy blue; H 1-0-2 -5; G 1 •9-2-1 ; feels somewhat greasy, and adheres to the tongue. Infusible. Decom- posed by hot sulphuric acid. Lenzinite and Glagerite are identical or closely related. Kollyrite is also very similar in general characters, but contains 40 per cent. H'^O, with 46 Al'^0', and only 14 SiO'. MINERAL TABLES ; — XXV. 221 {Aasume a paUred colour after ignition with Co-nohition, or do not become hlvf' In the bidh-tuhe, yenerally blacken). Steatite (compact or fine-granular Talc) : White, greenish, «fec., often mottled. More or less soapy-feeling and very sectile. On ignition, yields traces of water only. See C, below. Serpentine: MgO 43-48, SiO^ 43-48, H^O 13-04; but part of the MgO very generally replaced by FeO, and small amounts of NiO, A1*0*, and Cr'^O', are occasionally present. In fine-granular or compact masses, or occasionally slaty or fibrous. Sometimes, also, in p.seudomorphs after Olivine, Pyroxene, Spinel, and other species. Of various colours, but chiefly some shade of green, greenish- or greyish-yellow, brown, or red, two or more colours in irregulai- patches being olten present in the same specimen ; translucent or opaque; H 3'0-4-0; sectile; G 2-5-2-7. BB, whitens, and fuses on thin edges. Deeply-coloured (ferruginous) varieties do not redden distinctly with Co-solution. X)ecomposed by sulphuric, and also, though less easily, by hydrochloric acid. Picrolite, Picrosmine. Bowenite, Retinalite, Marmolite, Antigorite (see fibove, B^), Chrysotilc (see below), and many so-called Soapstones, are varieties, (Jhkysotile (Serpentine- Asbestus) : Properly, a fibrous asbestifonn serpentine, in silky, easily separable fibres, of a yellowish, greenish- white, or oil-green colour. BB, a fine fibre melts at the extreme l)oint. Baltimorite is a bluish, coarsely fibrous variety, often con- taining APO' and Cr^O'. Metaxite is also a fibrous serpentine. Meerschaum (Sepiolite) : MgO, SiO^ H^O (the hitter somewhat variable, but usually 11 or 12 per cent.). In fine-granular, more or less compact and very sectile masses of a white, pale-yellow or greyish colour. •Sometimes in pseudomorphs after Calcite, &c. H 1-5-2-5; Gr about 1-0-1-3. BB, hardens, and melts on thin edges. Decomposed by HCl acid, with separation of slimy silica. Deweyltte (Gymnite) : MgO 37, SiO'' 41, H'O 22. In more or less compact masses of a dingy yellow or yellowish-white colour and somewhat waxy lustre ; H 2-0-3-0; G 1-9-2-22. BB, fuses only on the thiimest edges. Decomposed, without gelatinization, by hydro- chloric acid. Kerolite is closely related in general charactei-s and composition. Villarsite : MgO, FeO, MnO, SiO", H^O. In pyramidal or thick tabular crystals (apparently rhombic, and pi'obably pseudomorphous 222 BLOWPIPE PRACTICE. after Olivine), arranged generally in compound groups; also in rounded granular masses ; green, dingy-yellow, or greyish ; H 3 0; G 2-9-30. Infusible. Decomposed by acids. Pyrallolite: MgO, CaO, APO», SiO^ H'O. Commonly in j)rismatic, coarse-fibrous, or granular masses, rarely in Clino-Rliombic crystals with basal cleavage ; green, greenish-white, pale yellowish- grey ; H 3-0-40; G 2-53-2-73. Fusible on thin edges only. Gener- ally regarded as an altered Pyroxene. C».— YIELD NO WATER (OR TRACES ONLY) BY IGNITION IN BULB-TUBE. t Sectile. ( With Co-solution assume a flesh-red colour). Steatite (compact or fine-granular Talc): MgO 31-7, SiO^ 63-5, H*0 4-8 — but the latter is only evolved on intense ignition. Massive ; tine-granular or compact; also in pseudomorphs after Scapolite, Oi'thoclase, Andalusite, Spinel, Pyroxene, and other species ; white, grey, greenish, reddish, y Rose. These species closely resemble one another, arnl in ordinary, iin- crystallized exanijilt'S th(!y can scarcely he distinguished. As a rule, however, (Mdorite is a more ferruginoii.! jpecies, and thus generally becomes magnetic after fusion or strong ignition, nnd its sp. gr. is in some examples as high as '2V ; whilst that of Ki[)id()lite rarely exceeds 2'7. This distinctifm, however, only applies in special cases, and is practically of little vabif. The Talcs and Steatites are exclusively or essentially magnesian silicates, (uintaining 4 or 5 p. e. of apparently basic water, only expelled by intense ignition. Hence, hy ordinary ignition in the Itulb-tube, these minerals yiehl. as a rule, merely traces of moisture, and they are thus generally placed among anhydrous species in determinative gif)upiugs. The formula may be written (H'^O, .3 MgO), 4 SiO^. Tale projier is easily recognized by its oeeurrenco in soft, Hexiblc, more or less pearly scales and foliated masses of a white, clear- green or otiicr light colour, cond)ined with its soa})y feel, and its property of assuming a flesh-red tint l)y ignition with cobalt-solution, the latter character serving to distinguish it from pyroi)liyllite and other foliated minerals of the ahiminous Kaolin group. Altliough very soft and llexilde, tlie folite are inelastic. Steatite is a more or less compact Talc, usually white, grey, greenish, reddish, or mottled in colour, and very sectile. It usually gives distinct traces of water livine, Pyroxene, Spinel, and other magnesian species. The Kaolins present a remarkable resemblance in outward characters to many Talcs and Steatites, some representatives of the group (Fyrophyllite, itc.) being made up of soft, flexible, pearly, and foliated masses, whilst others 16 226 BLOWPIPE PRACTICE, are fine-granular (fir microscopically scaly) in stnioturc, and more or less 8oaii>' to the toiicli. But the Kaolins are essentially aluminous, antl thus assume a distinct blue colour after ignition with cobalt-solution. The principal repre- sentatives of tlie group comprise Kaolin proper, Nacrite or Pholerite, Pyro- phyllite, Agalmatolite, Halloysite, and KoUyrite. These are sufficiently tleseribcd in the Table. All are essentially decomposition products. The Finite group consists of crystallized pseudoniorphous products d^srived from the alteration of lolite, or apparently in some cases from tliat of J'ephe- lii\e or other species. Tluise substances are chietly in six-sided or twelve- side. SiO^ 37'40, with traces of H-'O, &c. In hexagonal tables and scaly masses of a black colour with greenish streak, the scales somewhiit brittle; H 2'5-3'0; G 30-3-2. BB forms a black magnetic gla.ss or enamel. AsTROPiiYLLiTE : K'-'O, Na^O, CaO, MgO, MnO, FeO, Fe^O^, A\H)\ ^\(y, with 7 66 per cent. TiO'^ and a little H^O, according to Pisani's analysis. In six-sided tables and micaceous prisms of a bronze-yellow colour and metallic-pearly lustre. Folia? slightly elastic. BB easily fusible with some bubbling into a black, more or less magnetic bead. The HCl solution, slightly diluted and boiled with a piece of tin, assumes an amethystine colour. ,*^^ In the spectroscope both Lepidomelane and Astrophyllite, when moist- tened, after ignition, with HCl acid, shew the red K-line. t t Readily decomposed hy sulphuric acid. Structure micaceous. BiOTiTE (Potassic Ferro-magnesian Mica): Mostly in dark-gi-een or black micaceous examples, with flexible foliaj. Fusible on the edges only : See Table XXV. 1 1 t Fibrous. Insoluble in acids. Byssolite (Ferruginous, asbestiform Amphibole) : In fibrous masses of a green or greenish-brown colour. BB, fuses into a black and often magnetic bead. A5._0CCURHING IN CRYSTALLIZED, LAMELLAR, GRANULAR. OR OTHER NON- MICACEC'JS EXAMPLES. t Easily decomposed, with gelatinization, by hydrochloric acid, {Fusion-bead magnetic. ) Fayalite: FeO 706, SiO^ 29-4, but part of the Fe in some examples replaced by Mn ; intermixed FeS or FeS^* also frequently * The silicates of this Division form also in most cases a black glass by fusion with carb. suda. 228 BLOWPIPE PRACTTCU. present. In Llack or greenish-black masses, commonly magnetic from interniixed pyrrhotine or magnetite; H 6 0-6-5; G 4-0-4"2. BB, easily fusible into a black magnetic bead. Hyalosideuite (Ferruginons Chrysolite): MgO, FeO, SiO^ In small i)rismatie crystals of the Rhombic System, yellowish-brown in eolonr ; H 6-0-6-5 ; G 3-4-3-5 ; BB, fusible only in fine splinters into ■■\ black mo.i"e or less magnetic slag. Ilvaite or Lievrite: CaO 13-7, FeO 35-2, Fe^O^* 196, SiO- 29-3 (with 2-2 basic water 1). Rhombic; crystals essentially i)rismatic, with V:V 112^^ 38', and V2 : V2 106° 15', the V planes in most trrystals longitudinally striated ; also in coarsely fibrous, columnar, and gnxnular masses ; black, brownish-black, with dark streak ; H 1-5-6 -0 ; G 3-8-4-1. Easily fusible into a black magnetic bead. ^Moistened with HOI acid, shews red and green Ca-lines in spectro- scope very distinctly. Orthite or Allanite (Cerine): CaO, CeO, LaO, FeO, Fe^O', Al-'O^ SiO% with, in some examples, YO, MgO, WO, &c. Clino- Rhombic : crystals in general transversely elongated, but sometimes tubular ; occurs also in columnar and fine granular examples, mostly of a pitch-black colour- and somewhat sub-metallic aspect; but also lirown or dull greyish yellow, and then more or less resinous in lustre ; H 5-5-6-0; G 2-8-3-8 or 4-0. BB melty easily, with bubbling, into :t dark, generally magnetic, bead. Bodenito, Bagrationite, Erdman- iiite, and Muromontite, are probably varieties. Allochroite (Ferro-calcai'eous Garnet) : CaO, FeO, SiO'-'. Chiefly in rhombic dodecahedrons of a dark -red, dark-green, or brown colour. Kasily fusible. Decomposed, with gelatinization, by hydrochloric acid in some examples, only. See under Garnet, lielow, page 230. SiDEROMELANE : CaO, Fe-O^, APO'*, SiO', with small amounts of MgO, MnO, K^O, NaO. In black amorphoxis masses resembling black Obsidian; H 6-0; G 2-55-2-60. Easily fusible into a black magnetic slag. Practically identical with Tachylite, but distinguished by its larger amount of iron, and by dissolving somewhat less readily ill hydrochloric acid. (Fusion-globule not mcujnetic. No sulphur-reaction.) Tachylite : CaO, FeO, APO^ SiO^ with, in genei-al, small amounts of K'O and Na*0, MnO, MgO, and sometimes TiOl In black or \irownish-black amorphous masses of vitreous lustre, much resembling MINERAL TABLES : — XXVI. 229 some Obsidians. H 6-0-6r>; G 2-51-2-60. BB, easily fusible with bubbling into a black (noa-magnetic) glass or enamel. In spec- troscope, shews Ca-lines, and in many examples the red K-line aJso. An essentially volcanic or trappean product. Tephroite : MnO 703, SiO- 29-7, In granular, cleav.nblb masses of a reddish-grey or dull reddish-brown colour, weathering brownish - black: the cleavage rectangular. H 5"5-C0; G 40-4-12. Easily fusible to a black slag. With carb. soda gives strong maiiganest^- reaction. Knebelite is probably identical, although said to be in- fusible.* Tephroite differs essentially from the more common man- ganese silicate Rhodonite, by its ready gelatinization in HCl acid. Rhodonite being practically insoluble. (Fimon-product not magnetic. St. nng sulphiir-rendionA) Helmne : BeO, MnO, FeO, SiO- with Mn, Fe, S. Reg. ; crystals chiefly tetrahedral ; occurs also, though rarely, in botryoidal masses , H 5-5-6-5; G 3-2-3-4 ; yellow, brownish, yellowish-green. BB, in O.F. a dark bead, dull yellow in R.F. In hydrochloric acid, evolves odour of suljih. hydrogen, and is decomposed with gelatinization. Danalite : A flesh-reci or yellowish-grey Helvine, with MnO largely rejdaced by ZnO. Crystallizes iii regular octahcjdrons, some- times with truncated edges, and occurs also in small, disseminated grains. Blowpipe and acid reactions like those of Helvine proper, bub a zinc-sublimate foj-med (with carb. soda and borax) on charcoal. 1 1 Decomposed imperfectlij by hj/drochloric acid, hut completely by sulphuric acid. Sphene (Titanite): CaO Tpartly rei)laced by FeO and MnO) 28-57, TiO^ 40-82, SiO^ 3061. Uliuo-Rh.; crystals mostly small, with more or less ortho-rhombic as])ect, often tabular and frcipiently twinned : see Note at end of Table ; })rown, grey, yellow, green, &c. ; occurs also in cleavable and fine-granular masses; dark-brown, light-bi-own, grey, yellow, green, tfec. ; H 5-0-5-5 ; G 3-4-3-f> ; lustre vitreo-resinous. BB, commonly becomes yellow and melts with Inibbling to a dark enamel. The sul[)huric acid solution (or the a(i|ueou8 solution obtained by fusing the finely ground mineral with bisulphate of ]iotash) ♦Judging from its stated characters and composition, its infnsibility is most iiuprol)nliU'. I have tried without succoss to procure a Rpocinien for comparison. ^ See page 01, Kxperinicnt 1. Tlie carl), soda should be used Boinewhat in excess. Tlicse rjiinorals give also a strung Mn-reactiou. 230 BLOWPIPE PRACTICE. assumes a violet colour if boiled with a few drops of hydrochloric ■Acid and a piece of tin*. In spectroscope, shews red and green Ca-line.s if moistened with HCl acid after strong ignition. Keilhauite (7ttro-titanite): CaO, YO, AFO^ Fe-Q^, TiO^ SiOl Commonly in dark reddish-brown twin-crystals resembling those of Sphene, but often of comparatively large size ; H 6-0-7"0 ; G 3-5-3-72. BB, like Sphene. 8CHORLAMITE (Ferro^titanite) : CaO 29-38, Fe^O^' 20- 11, TiO'^ 21-34, SiO'^ 26-09, with small amounts of MgO, FeO, and alkalies. Reg. ; crystals rare, commonly the Rhombic Dodecahedron, or that form with the trapezohedron 2-2, hcnr.e much resembling garnet crystals. Occurs mostly in small granular masses of a pitch-black colour ; H 7-0-7-5; G 3-78-3-86. BB, fuses on the edges, or entirely, into a black slag or bead ; other reactions like those given under Sphere, t 1 1 Partially or slightly attacked in normal condition by hydrochloric acid, but readily decomposed by that acid after fusion, f (During fusion, impart a red colour to tlie flame.) Ferruginous Lepidolite : In brown, grey, or greyish-red scaly aggregations; H2-5; G 2-9-3-0. BB, fusible with great bubbling into, a dark magnetic bead, See Lepidolite proper, under B'^., page 234. {During fusion, impart a green colour to tlie point of the flame.) AxiNiTE : CaO 20-2, MnO 2-6, FeO 2-8, Fe^O' 6-8, APO' 16-3. B'^O^ 5-61, SiO"^ 43-5, with small amounts of MgO, K'^O, and basic H^O. Anorthic ; crystals essentially flat or very thin rhomboidal ])risms, replaced only on single edges and angles ; brown, violet-brown, green, pearl-grey, amethystine, different tints often shewing in dif- ferent directions; H 6-5-7-0; G 327-333. BB, easily fusible, with gi-een coloi-ation of the flame-point, to a black bead, which generally becomes green and translucent in the inner flame. (No green or red coloration of flame during fusion. Never in fibrous, acicular, or prismatic examples. ) Garnet: Dark suh-species (Ahnfindine, Aplomc, Andradite, Pyrope, Melanite, Spessai'tine, &c.): Average composition, RO 33 to 43, R'O* ♦ In fine powder, Si>liene is also sufflciently decomposed by hydrochloric acid to give this ctiaractcristio reaction when the solution is boiled witli a piece of metallic tin. t Tlu! fused bead or sl.'ig nuiat bo cruslied under paper oatlie anvil, or lu a small steel mortar, md then ground, to a Qae powder. MINERAL TABLES: — XXVL • 231 21 to 32, SiO* 35 to 40 (RO = CaO, MgO, FeO, Mu< ) ; R^O^' - APO', PVO^). Reg.; principal foi-nis, tlio rhombic doileoaliodrou and the trapezohedron 2-2 (see Note at end of Table). Frequently in rounded grains and indistinct crystals ; red, brown, black, dark-green, &c. ; H 6-5-7'5 ; G 3-6-4'3 (in dark varieties). BB, fusil)le more or less readily into a dark and general -y magnetic bead. The Bohemian giirnet, Pyrope, which occurs chiefly in small grains of a deep-red (;olour, contains a small amount of chromium (CrO I), and becomes black and opaque on gentle ignition, but recovers its red colour and translucency on cooling. As shewn by Dr. L. H. Fischer, it is only decomposed to a slight extent, after fusion, by hydrochloric acid. {Essentially in fibrous, aricular, o)' jmsinatic exampks.) Ei'iDOTE (Pistacite, Thallite, Bucklandite, Piedmontite, Withamite, &c.): CaO 36 to 40, APO^' 18 to 30, Fe^O^ 7 to 20 or Mn'O^ 10 to 25, SiO'^ 36 to 40, with traces of MgO, ifec, and about 2 per cent, basics water. Clino-Rh. ; crystals in general elongated parallel to the ortho-axis, with cleavage pi .nes meeting at angle of 115" 24': see Note at end of Table ; occurs also in acicular, fibrous, and other examples; green of various\shades, greenish-yellow, black. (In inanr ganese varieties, blackish-red or dull cherry-red.) H C0-7"0; G 3'3-3'5. BB, swells up, and forms a dark cauliflower-like slag, or in some oases a black glass, generally magnetic. In phosphor-salt, somewhat easily decomposed, dift'ering remarkably in this respect from examples . of Pyroxene and Amphibole of similar as})ect. t 1 1 1 Very slightly attacked hy hydrochloric acid, both he/ore and after fusion. {In triangular or nine-sided j)ri..sms ; or in acicnlar, columnar, or fibrous ex- amples, triamjidnr on cross -fracture.) Sciioul; Black or Daiuc-Brown Tourmaline: Approximate composition : MgO 7 or 8, FeO 5 to 10, APO'' 30, B^O^ 9 or 10, SiO^ 38, witli small amounts of K'^O, Na^O, Li^O, KaO, MnO, F, and basic water. Hemi-Hexagonal (see Note at end of Table) ; also very commonly in columnar and fibrous masses, the com[)onent fil)res shewing under the magnifying glass a triangular cross section ; Black, dark-brown, with vitreous external lustre ; H 7'0-7"5 ; G 3-03-3-20 ; pyro-electric. BB, melts more or less easily to a bhick slag or glass, which often attracts the magnet. The fused beail reduced to fine powder is decomposed by strong sulphuric acid. Alcohol added to 232 BLOWPIPE PRACTICE. the solution, and ignited, burns with the green flame characteristic of B'"0\ The crushed bead made into a paste with sidphuric acid, imi)arts this colour to the blowpipe-flame. A drop of glycerine in- tensities the reaction : see page 28. (EaseMially in lamellar or foliated masses with strongly pronounced cleavage in one direction.) Hypersthenk (Ferruginous Bronzite) : MgO, FeO, SiO^ Rhoml)ic, but crystals of (piite exceptional occurrence ; essentially in bronze- brown, gi-een, or greenish-black, lamellar masses, with metallic-pearly lustre on cleavage plane; H 5'0-60 ; G 3'3-3-4. BB, fusible more or less easily into a black magnetic bead or slag. See under Bronzite in Table XXV. {In lamellar or fibrous masses or distinct crystals, with cleavage-angle and prin- cipal prism-angle near 87°. ) AuGiTE (Dark Pyroxene): Average composition, MgO 12 to 18, CaO 18 to 20, FeO 10 to 13, APO^ 4 to 8, SiO" 47 to 50, with small amounts of MnO, &c. Clino-Eh. ; the more common crystals are eight-sided prisms, composed of the forms V, V, and V, with two inclined summit-i)lanes, or large basal plane*. Often twinned parallel to V {see Note at end of Table). V : V 87° 6'; V on V 90°; angle over summit-planes 120° 48'. Commonly, in cleavable, fibrous, or granular masses. Black, greenish-black, dark-green, dark-brown ; FI 5'0-G"0; G 30-3-4. BB, fusible more or less easily into a black, generally magnetic bead. Hedenbergite is a uou-magnesian augite, consisting of CaO 22-18, FeO 29-43, SiOU8-39: black, black ish- gi'een, in cleavable masses. Coccolite is a dark -green augite, occuiing in granular masses or small crystals with rounded edges and angles. Breislakite is an acicular variety from Italian lavas. Fassaite (Pyrgqm), and some Sahlites also belong to the present sub species. Acmite: Na^O 13-88, FeO 6-45, Fe^O^* 28-641, 810^51-03, with small amounts of K^O, MnO, TiO^ .— IMPART A DISTINCT RED OR GREEN COLOUR TO THE ULOWPIPE-FLAME. t BB, Jlame coloured red. (Soft ; scaly or foliated. ) Lepidolite (Lithionito, Lithia Mica): K^O 4 to 11, Na'O 1 to 3, J.i^'O 1-5-5; MuO 2 to 5, APO'^ 14 to 29, Fe»0'^ to 28, HiO'^ 40 to 52, with from 4 to 8 per cent. Fluorine. Essentially in scaly aggi-e- gations or micaceous masses of a rose-red, pale-reil, peai-1-grey, or greyish-white colour; H 2-0-4-0 (commonly 2-5); G 2-8-30. BB, very easily fusible with great bubbling into a coloiu-less blebby gla.ss " Very thin siiliuters fuse without the aid of tUu blowiiiiie, as first pointed out by Dr. L. II. Fischer ; Clavis der Silicate, p. 11, MINERAL TABLES : — XXVI. 235 (or, as regards forrugiiious examples, into a dark metallic bead), with crimson coloration of the flame. In the spectroscope, the red Li-line and yellow Na-line come out very prominently, the red Kline sub- ordinately*. After fusion, completely decomposed by hydrochloric acid. Cryophyllite : K^O, Li^O, MgO, MnO, FeO, Fe20^ AFO\ SiO" (53'46) with 2 to 3 Fluorine. Essentially in dark-green, six-sided, micaceous prisms and scaly masses j G 2'9. BB, colours the lian\e red, and fuses with great bubbling. (Hard. Not micaceous in structure. ) Petalite : Li-0 (with small amount of Na^O) 442, APO'' 17-80, SiO"'* 77 "96. Essentially in lamellar masses (Clino-Rh.) with cleavage- angles of 117°, 141° 23' and 101° 30', but the two latter often indis- tinct ; colour, pale-red, reddish- white, or nearly colourless ; H 6 '0-6 "5 ; G 2 '4-2 '6. ]>B, colours flame pale-red, and melts to a colourless glass. In the spectroscope, especially if the test-matter be moistened with hydrochloric acid, the red Li-line comes out very distinctly. Insoluble in acids. Kastor is a variety in coarse Clino-rhombic crystals from Elba : Y on V 86° 20'. SpOx)UMENe (Triphane): Li^O 6-73, AlW 29-21, SiO^ 64-06; but part of the Li'-'O commonly replaced by small auiounts of Na^O and K^O and traces of CaO. Clino-Rhombic, with V : V 87°, but crystals comparatively i*are. Commonly in cleavable masses with cleavage- angles of 87° = V : V, and 133° 30' = V : V. Pale-green, greenish- white, or greenish-grey; H 6-0-7-0; G 312-3-20. BB, colours flame distinctly red, and melts easily, with much expansion and bubbling, into a colourless glass. Insoluble in acids. In s],)ectroscope,, shews red Li-line and yellow Na-line distinctly. 1 1 Flame coloured green. ( Very easily fusible. ) AxiNiTE : Essentially in groups of thin sharp-edged crystals, brown, green, brownish violet, pearl-grey, or amethystine in colour. BB, melts in the oviter flame into a black glass, and with carb. soda gives manganese reaction. See above, page 230. * The K-line is scarcely visible unless the Na and Li liuea bo cut oil' by tliu intervention of a jiiece of deep-blue glass. 236 BLOWPIPE PRACTICE. Danburite : CaO 22-75, B-0» 2845, SiO- 4880. Anorthic ; but mostly in lamellar massess with cleavage-angles of 110^, 12G° and 93', the two lattnr more or less indistinct. Yellowish-white, pale-yellow ; H 7*0 ; G 29r)-2-96. BB, easily fusible, with green coloration of the flame. The powder moistened after ignition with hydrochloric acid, shews in the spectroscope gi-een B-lines with transitory flaslies of the red C'a-line. {Fusible with dijjicuHy or on the edges only.) Hyalophane (Barytic Feldspar) : K?0 782, Na^O 214, BaO 1505, APO" 21-12, SiO"'' 52-67, with traces of CaO, MgO, &c., but the com- position, more especially as regards the amount of baryta, appears to be somewhat variable. Clim-Rhombic ; crystals practically identical with those of Orthoclase ; cleavage very perfect parallel with basal plane; white, pale-reddish; H 6-0-6-5; G 2-80. BB, fusible on edges only, unless in thin splinters. Distinguished from the feldspars, generally, by the green oolour imj)arted to the point of the flame. In acids scarcely attacked. B1.-YIELD STRONG REACTION OF SULPHUR OR CHLORINE* t Give sulphur reaction, BB, with carb. soda. Helvine ; Danalite : Essentially in small tetrahedrons or octahe- drons, or in sniiill grains, of a yellow, brownish, yellowish-green, or reddish-grey colour. H 5-5-6-5 ; G 3-2-34. Gelatinize and evolve odour of sidph. hydrogen in hydrochloric acid. BB, in outer flame give a black or dark fusion-})roduct. iSee under A'', page 229. Hauyne: K-'O 4-96, Na'O 11-79, CaO 10-60, APO^* 27-64, SiO" 34-06, SO' 11-25. Reg.; chief crystal form, the rhombic dodecahe- dron ; occurs also in small grains. Essentially blue or bluish-green, rarely colourless (Berzeline); H 5-0-5-6; G 2-4-2-5. BB, decrepitates, and melts slowly into a pale-blue or colourless glass. Gelatinizes in liydrochloric acid. NosiNE (Nosean) : NaO, APO', SiO^ SO'. Closely resembles Hauyne in crystallization, and in its blowpipe and acid reactions, but commoidy ash-grey, greyish-blue, or greenish-white in colour, and with larger percentage of soda (24-89). • See page 61, Experiments 1 aurl 3. In testing for sulphur, tlie reagent, carb. soda, should be used somewliat iu excess. MINERAL TABLES : — XXVI. 23T Lapis-Lazuli : ISTaO, CaO, SiO'-, SO', &c. Essentially in granular masses of a rich l)lue colour, frequently internuxed with calcito, grains of iron i)yrites, and other siil)stances. WIkui crystallized, in rhombic dodecahedrons. H 5-5 ; G 2-38-2-4r) ; BB, melts easily to a colourless glass. Gelatinizes in hydrochloric acid, most examj)les. •evolving sulph. hydrogen during decomposition. Mu.MiosoMMiTK : GivBS feeble S-reaction, but strong reaction of <;ldorine : see below. + t Give Cl-reaction with cupreous phosphor-salt bead. Sodalite : Na'^O, A^'0^ SiO^ NaCl. Reg. ; chiefly crystallizetl iu rhombic dodecahedrons, or in combinations of that form and the- cube ; occurs also in granular exami)les ; mostly colourless or green- ish-white, less commonly blue or bluish-green. H 5-5 ; G 2-13-2'30. HB, a colourless glass. In hydrochloric acid, gelatinizes. Microsommite: K'^0, Na'^0, CaO, A1'^0^ S10^ NaCl, with small percentage of SO^ in most examples. Hexagonal ; chiefly iu minute six-sided prisms on certain Vesuvian lavas; H G"0; G 2*6. BB, according to Sacchi, difficulty fusible. Gelatinizes in hydrochloric acid. The spectroscope should shew Na, K, and Ca lines, but the wi'itei- has not been able to procure a specimen for examination. EuDiALYTE : Na^O, CaO, FeO, ZrO^ SiO^, with small amounts of GaO, MnO, Sic, and about 2 per cent. NaCl. Hemi-Hexagonal ; crys- tals, acute rhombohedrons with extended basal plane ; 11 ; li 73° 30', H:R 112° 18' and 67° 42'. Dark purplish-red, brownish-red, H 5 -0-5 -5 ; G 2-8-3-0. Melts easily to a greyish-green glass or enamel. Gelatinizes in hydrochloric acid. Eucolite from Norway is closely related. Both are rare species. B».-NO DISTINCT (RED OR GREEN) PLVME-COLORATION. NO REACTION OP SULPHUR OR CHLORINE. t Decomposed loith gelatinization hi) hydrochloric acid. (BB, with carb. soda on charcoal, a distinct sublimate). EuLYTiNE (Bismuth Blende): Bi'^O^* 83-75, SiOMG -25, but gen- erally intermixed with Fe'O*, Mn'''0', PH)', Fl, &c. Keg. : crystals essentially tetrahedral, very small, in drusy aggregations ; occurs also in botryoidal masses; H 4-5-.5-0; G about 6*1. Fusible into a xaiiii>|i's of the Pavyne and Cancrinite v.irioties. t In some oases, the deeoniposition, alttioiigh snfflciently marked, is more or less in'^din- plete. If decomposition ensue at all, the supernatant liquid, diluted slij^litly and filtered from the undissolved residuum, will yield a distinct precipitate with amuiciiiia, or with oxalate of ammonia.addcd subsequently. 240 BLOWPIPE PRACTFOE. Weill LiciUTF.: Na-0, CaO, FoO, Zl•0^ NlrO», SiO^ Ithonihio or (.'lino IMioniliic, but crystals mostly indistinct ; cuinnioiily in small an;^iilar j^rains, or in sub-columnar masses and indistinct tabular forms. Yellow of various shades, yellowish-brown; H H-O-G-O ; iJ 3*41. J)|} melts easily into a yellowish bead. Jlitherto only found in the Zircon-syenite of Norway. (Oieinij BB tv'Uh fused phoHphor-aalt in open glcuts tube a strong Fluorine-reaction). Lkucophane : CaO, BeO, SiO'', NaF. Essentially in cleaval)le lamellar masses of a palo yellow or greenish-grey colour. H 3'5-40; (r 2"'J-3. Strongly phosphorescent, and very easily fusil)le. Slowly decomposed by hydrochloric acid. See under the Fluorides, in Table XX, page 178. A rare species. Mkmnopiiaxe (Melii)hanite) : CaO, BoO, SiO', NaF', Occasion- .'\iiy in Tetragonal crystals, but commonly in hunellar masses and di.sseminated grains of a yellow colour; H 5-0; G 3.02. BB, easily fusible (but is said not to phosphoresce!). Very rare, and still im- ]>erfectly known. {Funihle on charcoal into a 30'), and 93^ 50' (or 93=" 30'). Principal cleavage-plane (B), delicately striated ; twin-crystals, very frequent. Occux's also in lamellar and fine-granular masses. H 6-0 ; G 2 6-2 66 ; white, pale-red, greenish-grey, etc., with somewhat waxy lustre ; ♦ Of Dos-Cloizeaux, not Breithaupt. Tlie Microcliue of the latter is the iridescent Orthoclase from the ziruon-syenite of Norway, MINERAL tables: — XXVI. 247 occasionally iridescent. BB, fuses, in thin splinters, into a colourless glass. Apart from its more ready fusibility, tliis species cau scarcely be distinguished from Albite, except by actual analysis. {f^p. gr. under 2'5. Compact stnicture. Veri/ easifi/ fii-4hle). Obsidian :. K'Q, Na-'O, Al^O^ SiO'S with small amounts of CaO, Fe^O^, etc. In amor[)hous masses, breaking with conchoidal fracture into glassy sharp-edged fragments. H G-0-7"0; G 2'2-2"4. Black, brown, grey, greenish, &c., sometimes striped or zoned in different tihades ; translucent to opaque. Easily fusible with bubbling into a white glass or enamel. Pitchstone is a less vit/3ons, coarser variety. Pearlstone is a closely related substance, made np essentially of small pearly concretions, or containing these in a vitreous obsidian-like paste. All are volcanic products : rather rocks than minerals proper. NOTE ON TABLE XXVI. This Table consists entirely of silicates, distinguishefl from other compoimds of that class by being distinctly fusible, anil by yielding no water (or merely traces) when ignited in the bullj-tube. All give the characteristic reaction of silicates by fusion with phosphor-salt — a silica-skeleton separating, whilst the bases dissolve iu the tlux. In some cases, a portion of the silica is dissolved also, but this precipitates on cooling, and the bead becomes more or less opalescent or clouded. The more commonly occurring minerals of the Table comprise representatives of the following series : ISIicas, Boro-Silicates, Garnets, Epidotes, Iron Chrysolites, Pyroxenes and Ampliiboles, Scapolites, Felds])ars. The Mica Group, as regards the present Ta])le, is chiehy represented by Lcpitlolite — the ordinary micab, Muscovite, Phlogopite, and Biotite, being as a rule fusible only when in very thin scales, and often on the edges only. Hence, these latter species are descril)ed in Table XXV. , and in the N^te to that Talde. Lepidolite is easily recognized (in ordinary examples) by its deli- cate red or reddish-grey colour, and its occurrence iu aggregations of soft, pearly scales. Also by its inturaescenco and ready fusion in the blowpipe - tlame, or even in the llame of the Bunsen burner, and by the crimson coloration which it imparts to this. In the spectroscope, the crimson Li-line and yellow Na-line come out at once with groat brilliancy, but the red K-line is generally overpowered by the intensity of the lithium spectrum, unless this be cut off by the interventiou of a blue ghiss between the spectroscope and the llame. The Boro-silicates of this Table include the dark, fusible Tourmalines, represented essenti.ally by Schorl, and the anorthic species, Axiinte. These, liowever, have no very close I'elations as minerals, beyt)nd the presence in both ui boracio acid, an exceptional compuneut. The silica percentage is com- 248 ' BLOWPIPE PRACTICE. paratively low, averaging 88 or 39 in Tourmaline, anil about 41 in Axinite. Tlie boraeic acid apparent]}' replaces alumina. Schorl may generally be distinguished by its jet-black colour and triangular cross fracture. The crystals are sometimes simple three-sided prisms ; but these are bevelled, in general, on their vertical edges — a combination of — and V2 l)f:ing thus formed— and tl are usually terminated by the jjlanes of a rhombohedron (R) with polar angle, i.e., angle over a polar edge, of about 13.3° 30'. Frequently also the planes of a second rhombohedron ( -2R) with polar aingle of about 103" or 103° 20', alternate with the latter ; and crystals often shew dissimilar forms at their extremities: see the Note to Tablk XXIV. Axinite is readily distinguislied by its liattened, sharp-edged, anorthic crystals (brown, violet, pinkish-grey, in colour, or sometimes green from inter- mixed chlorite), and by the green coloration which it communicates to the blowpipe-Hame during fusion. The crystals are essentially oblicpie rhomboidal prisms with only the diagonally-opposite edges and angles replaced. The prism-angle equals 135° 31' ; B on one prism-plane, 134° 45' ; and on the other prism-face, 115° 38'.* The two prism planes are vertically striated. I.e., parallel with tlieir combination edges, whilst the B plane is striated trans- versely. The Garnet group is rejiresented in tliis Table by the different varieties or sub-species of (}arnet (the infusible chrome-garnet Uwarowite [Table XXIV.] excepted), and by the related species \'eiiuvian. The specific name of ( larnct inoludes a great number of related silicates of legular crystallization and common formula — the latter, empirically, 3 RO, RK)3, 3 SiO'''. The 110 represents CaO, MgO, MnO, FeO ; and the R'^O^ equals APO''', Fe'^U^, &c. The varieties which result from the preponderance of one or the other of these isomorphous bases necessarily present different colours, and, within certain limits, different degrees of si)eciiic gravity. t The colour thus varies, as a rule, from light tints of red, yellow, and green, through deep- red and olive-green into brown and black ; and, occasionally, colourless examples are met with. Tlie more common garnets are dark-red or red- brown, and nearly or quite opaque. The average sp. gr. is about 3 '5 for tlie lighter coloured varieties, and 3 '9 or 4'0 for the dark garnets, the limits lying between 3"1 5 and 425 or 4"3. The crystallization is comparatively uniform,- consisting essentially of the rhombic dodecahedron or of the trapezohedron 2-2, or of the two combined. In the trapezohedron, the angle over a long or axial edge equals 131"^ 49'. In combination, the trapezohedron replaces the edges of the dodecahedron, and thus presents a cruciform four-planed point- *By most German crystallographcM B is made tlie face of a tetarto-iiyrainid, P. Tlie angles given aliove are those of Von Hath, Init they lluetnate within 30 or 40 minutes m crystals fruiii different localities. t This latter eharaetcr, however, does not depend absolutely on coniposiWon, as regards minerals geniTally. A striking instance is afforded by ordinary Iron Pyrites and Copper Pyrites. The former, eoasistiug of Fe 4t5'(57, 8 5:i-:!ri, has an average ,sp. gr. of 5 0; whilst \\w jatter, witl> less sulplmr (:i4!t , and with the heavier metal copper forming part of the base (Cu 34 0, Fe 30 S), shews a luaxiinum density of only 4"3, MINERAL TABLES : — XXVI. 249 ment jvt each pole of the crystal. Occasionally also, the edges of the rhombic do locivheilron are bevelled by the planes of the adamantoid 8-;j or 4-g. Vesuvian or Idccrase closely resembles Giarnet in general composition, and until recently the two were thought to present the same atomic constitution. This is probably not the case, although the formula of Vesuvian is still doubtful. But the two minerals apart from crystallization are evidently nearly allied. The more common crystals of Vesuvian are composed of the two square prisms V and V, striated longitudinally, and terminated by a square pyramid, P, more or less deeply truncated at the apex by the basal form B. Frequently the vertical edges of V are bevelled by the planes of an octagonal prism V2 or V3 ; and the polar edges of the pyramid are replaced by a front-polar or front- pyramid P. Angular measurements are slightly variable, but average as follows : P : P over polar edge 129° 29', over middle edge 74° 14' ; B : P 142° 5.3' ; P : P over polar edge 141° 1', over middle edge 5G° 8' ; B : P 151' 56'. For other characters, see the Table. The Epidote (Iroui) is represented in the Table by Epidote, Zoizite, and AUanite or Orthite. Tlie latter in most examples is decomposed with gelati- nization by hydrochloric acid, and is black and almost sub-metallic in aspect. Commonly in columnar and fine-granular masses ; more rarely in olino-rhombic crystals, with V: V 70' 48' and 109° 12' ; V: V 125° 24' ; and B:V ll.^r. Tliis latter is also the cleavage-angle, but the cleavage is verj-^ indistinct. Zoizite and Epidote are not decomposed by hydrochloric acid until after fusion, when they also gelatinize. Zoizite is light-colourod, mostly grey or frreyish-white, and chielly in columnar masses. Its crj-stallization, lung con- sidered identical with that of Epiilote, is now regarded as lllumibic, but crystals are rare and more or less indistinctly formed. Ei)idote is usually dis- tinctly coloured, the tints ranging from ligiit yellowisli-giecn to dark green, brown, and black. Many examples are lilirous and acicular, and closely resemble examples of pyroxene and ampliibole, and also schorl. From these, however, Epidote is readily distinguished by its peculiar reaction under the blowpipe. In place of forming a single bead or fused globule, it swells up into a cauliflower-like mass, the separate portions of which become rounded, but cannot with 'ordinary blowing be brought into a bead, properly so called. Crystals are of frequent occurrence. They are clino-rhombic, and practically identical with those of Orthite, but arc not easily nuide ou+. by the unpractised eye. In their conventional position, they form transversely elongated prisms. the extension being in the direction of the ortho-diagonal or right-and-left axis, with usually two (or several) inclined planes at the side. Tlie horizon- tally extended planes usually comprise the basal plane B, and the front-vertical V, witli interfacial angle (which is also the cleavage angle) of 115^ 24'. In the same zone with these planes, several intermediate planes (the faces of front or ortho-polars) also frequently occur ; and in most cases the jdanes of this zone are striated parallel with their combination-edges. The more comnum forms of the zone are B (tlje chief cleavage-plane), V (the second cleavage-plane), and P ; with consecutive interfacial angles of 115° 24' as stated above, 128° 18', and 116° 18'. The two predominating planes at the lateral ends of the crystal 250 BLOWPIPE PRACTICE. are sometimes the prism-planes V, with angles of 1 10° on adjacent faces, and 70' in front or over V, and 125° on V. In other crystals, these end planes are those of the hemi-pyramid P, and tiiey Tneet at an angle c 109" 85'. Both V and V are also sometimes present together, meeting at angles of 150° 57' and 1 17" 40'. Twin combinations, with twin-face parallel to V, are of frecjuent occurrence. The so-called Iron Chrysolites are represented by Fayalite, Hyalosiderite, and Lievrite or Ilvaite, the latter, only, of general occurrence. This S2)ecie8, by its black colour and general aspect somewhat resembles Orthite. Like Orthite also, it melts readily into a black magnetic glass, and is decomposed with separation of gelatinous silica by hydrochloric acid. The crystallization however is Khombic, and the crystals are elongated vertically. In most cases they are eight-sided prisms, composed of the two rhom])ic prisms V and V2, terminated by the four planes of a rliombic pyramid P, the front p^lav edges of which are replaced by a plane of the form P. The chief angles are as follows : V : V 112° 38' ; V2 : V2 106° 15' ; P : P, over front cdge_or over P, 1 17' 30' ; over side edge 139" 30' ; over middle edge 77° 12' ; P : P, over sum- mit, 112" 49'. The prisms, in general, shew strong vertical stritv, imlicating additional prismatic forms, V^, &c. ; and crystals thus affected often become more or less cylindrical, and pass into columnar masses. The Pyroxene series comprises a group of species and sub-species (essentially bisilicates of RO, typically MgO, FeO, CaO) in which the crystallization is either Clino-llhombic or Rhombic, with the chief prism-angle and cleavage- augle approximating to 87° (or its su])plement 93°). Tlie Rhombic species com2)ri3e Enstatite, with Bronzifce and Hyperstheue. The typical Clino- Rhonibic forms, in which, as in the Rhombic group, alumina is either absent or only subordiuately present, include Pyroxene proper, with Acmite and other rarer species (Jeffersonite, &c.) ; and also the manganese species, Pthodouite, and the more or less aberrant WoUastonite, the latter a purely calcareous species differing essentially from the ordinary pyroxenes by being readily decomposed, with separation of gelatinous silica, in hydrochloric acid. The lithia-holding and aluminous Spodumene or Triphane ft also commonly- referred to the Pyroxene group from its cleavage-angle and lately determined crystallization ; but its composition (Li^O 4*5 to 6 "5, APO' 25 3 to 29, SiO" 03 to 0(5) and its general aspect, are more feldspathic than augitic. The prism- angle (and corresponding cleavage-angle) V ; V, scarcely diflers from the principal cleavage-angle in Albite. Its distinctive characters, and those of the other minerals of the group, are given sufficiently in the Table, but some additional remarks on the commonly occurring species Pyroxene are here appended. This species is commonly subdivided into Non-aluminous and Aluminous Pyroxene. The non-aluminous pyroxenes (apart from the ferrugi- nous sub-species Hedenbergite) are chiefly of a light colour, and the aluminous varieties, mostly (though not exclusively) deep-green 9r black, and more or leas ferruginous ; but even in these, the alumina is always under 10, and generally uuder 7, per cent. The old name of JJiopdde may serve couvenieutly MINERAL tables: — XXVI. 251 to include all the light-cnlourod nnn-almniTions pyroxenes (MaLaoolitc, Alalite, &c.), ami tliat of Auijita to denote .lie dark and generally aluminous varieties. In both diopHide and augite the crystals are prismatic and essentially eight- sided, or (as regards these prismatic planes) made up of the four planes of the rhombic prism V, truncated on its obtuse vertical edges by the two planes of the Front- Vertical V, and on its acute e to 3*4), and by its partial dcccmi- position in hydrochloric acid. From the Feldspars it difi'ers essentially by ita want of sharply-detiued, smooth and lustrous cleavage-planes, and by its ready fusion, The more tj'pical feldspars, moreover, Urthoclasc and Albite, are not attacked I)y hydrochloric acid. The JY'ldspars are essentially aluminous silicates of potash, soda, or lime, characterized by the general absence of iron oxides and magnesia, by their light coloration, their non-librous, cleavable structure, the latter an e8))ecially salient character, and by their clino-rhombic or triclinic (anortliic) crystalli- zation. As a rule, they are difficultly fusible, and the lime species only are decomposed l)y acid. In the more typical or alcaline feldspars, the amount of silica exceeds (50 per cent. It is now very generally thouglit that three species only of feldspar sliould be admitted, viz.: the potassic species Orthoclase, the soda species Albite, and the lime species Anorthite, tlie other so-called species being regarded as isomorjjhous mixtures or combinations of these. This view is probably correct, but in the present state of our knowledge it seems neces- sary to recognize (as in the Table) the following compounds as constituting distinct feldspathic types: The potash feldsptars Ort/iwlwie. and Microclive ; the barj'to-potassic feldspar /f//afo^>/(o/if' ; the soda feldspar ^1 //>(7'' ; the soda- iime feldspar Ol'moclam (including Andesine) ; the lime-soda fehlspar I,>ihra- (lorUe ; and the lime feldspar Anorthite. The more distinctive characters of these are given fully in the Table ; but some additional remarks on the crystallization of the two more important species Orthoclase and Albite are here appended. Orthoclase crystals fall under three comparatively distinct types. The crystals of the first or simplest type are short rhombic-prisms terminated by two sloping planes. The latter are frequently of nearly similar size and shape, but consist of the base, B, and a hemi-orthodome or ortho-polar P, of course in alternate positions. V : V 118M7' ; B : P 129° 43' ; B : V 112" 1.3' ; P : V 110° 41'. P is often transversely striated, and is sometimos much larger than B, in which case its planes resemble the V planes in shape, and the crystal has much the aspect of a truncated rhombohedron. Occasionally, the side- vertical V is also present. This type frequently occurs in twin forms, with twin-face,* a face of B. It might be termed the Adularia or St. Gothard type. Its crystals are in general more or less translucent, and are always in druses or attached to the sides of clefts and cavities of the rocks in which thej occur. In the second or Baveno type, the crystals are usually six-sided prisms, composed of four V planes and the two planes of the side or clino-vertical V, terminated by the basal plane and a second ortho-dome or ortho-polar 2P. • Throughout these notea, the term " twin-fnce " always denotes the face or plane of junction of the united crjstals. • 254 BLOWPIPE PIIACTK'E, These cryHtals, aa a rule, are greatly elongatetl in the direction of the clino- (liagonal, and thus the two \\ planes .ind the two V planca become drawn out Uackwivrda and tipwards, so as to mask the true symmetry of the crystal to an UJipractised eye. V : V J^nd B : V, as above ; V : 2P 134° 20' ; B : 2P 99° 38' ; B : V 90'. The cleavage is i)arallel to the latter planes. Very fre- quently tlio otlges between B and V are replaced by the side-polar or clino- / ... ^ dome 2P, the planes of the latter inclining on B and V at angles respectively of 135" 4' and 134° 56'. Occasionally also, the vertical edges between V and V are replaced by tlie planes of the prism V3. Crystals of this type occur very commonly in twins, with the twin-face a plane of the side-polar or clino-dome 2P. In these crystals, conseiiuently, two long B planes, and two long V planes, como togotlier, and the crystals arc rectangular in aspect. In other twins— witli marked re-entering angle- -the basal plane is the twin-fac ; or plane of junction. These crystals are sometimes translucent, but are com- monly opatiue, and are often rough or dull on their external surfaces. Crys- tals of the third or Carlsl>ad type possess the same forms as those of the pre- ceding type, but present a very different aspect from the predominance of the side-vertical planes V, and the apparent Hattening of the crystals parallel with these. The elongation moreover is essentially vertical. Simple crystals are much less common than interpenetrating twins, with twin-face parallel with V. These crystals are always imbedded, and thoy are commonly (^ lite opaque and more or less rough and dull. Very often, they are partiaJy altered into Kaolin, and eoiuctimcs into impure Calcite, without change of form ; and in Cornwall, tin-stone psoudomorphs have assumed their shape. A fourth type is presented, according to Gustav Rose, by the orthoclase twins from the syenite of southern Norway, in which the form V fails, and the crystals are united parallel to the ortho-vertical V. In Albite, simple crystals are of rare occurrence. Crystals which appear to be simple, are in most cases really compound, as shewn by the striation of the basal plane. One of the more common combinations consists of q. six-sided prism composed of the three forms V, (V), and V, terminated by three other forms, the base B, a front ^wlar (P), an I a tetarto-pyramid (P) : e.ach of these six forms, of course, consisting of a pair of opposite planes only. When the crystal is in position, B appears at the top in front, and (P) and (P) at the back ; these positions being necessarily reversed as regards the bottom of the crystal. V : (V) 120° 47"; B : (P) 52° 17' and 127° 43' ; B : V 86° 24' and 93° 36' (= the cleavage angles) ; B : V 1 10° 50' ; B : (V) 114' 42'. . The side- vertical planes V commonly preponderate and impart a flattened appearance to most crystals. In the more common twins, two B planes, two V planes, and two (P) planes come together. The re-entering angle between B and B MINERAL TABI.KS : — XXVI. 255 equals 172" 48', and these planes are delicatcily or strongly striated. Doublo or multiple twins of th.s character, with two B planes and two (P) plauti alternating at both extremities of the crystal, are not uncommon. In the variety of Albite known as Pericline the crystals are more or lest elongated in a transverse or right-and-left direction, but the interfaoial angles are practically identical with those given above. The forms B and (F) pre- dominate, and the short, side-vertical planes V are strongly striated ; but the stricu arise, here, from an oscillation between the latter form and another ver- tical prism V3, the planes of which occasionally replace the combination edges of V and V, or V and (V). In the twinned Periclinea, the plane of junction is parallel to the base. [256] TABLE XXVII. . [Lustre non-int+^^allie. Slowly attacked or only in part dissolved, BB, by ][.>ho8phor-salt. Fusible. Yielding water on ignition]. A.— Fusion-product, magnetic* ' Ai.— DECOMPOSED WITH GELATINIZATION BY HYDIlOCnLOUIC ACID. t In masses of essentiallij leafy or scalij structure^ or in crystals icith marked basal cleavage. Hardness less than that of caltite. Cronstedite: MgO, MnO, FeO, Fe^O^ SiO^ IPO (10 to 12 per ocut.). Ifemi-Hex. ; crystals very small, often acicubir, mostly very iicnto rhombohedrons and scalenchedrous with ba.sal plane ; cleavage parallel to the latter ; in thin leaves somewhat flexible ; also in radi- ated-fibrous examples. H 2 5 ; G 3'3-3"3 ; black ; streak, dark-green. Fusible with intumescence into a black magnetic bead. Sideroschi- zolite is identical or closely related. In both, the crystal-planes shew a strong tendency to curvature, and in Cronstedite the R planes are longitudinally striated. Voigtite (Altered Biotite 1) : CaO, MgO, FeO, Fe*0\ APO^ SiO-, H^O (9 per cent.). In green or dark-brown scaly and foliat<>^ ex- amples, resembling an ordinary dark-coloured mica. Fusible uito a black, more or less magnetic bead. TiiuRiNGiTE : MgO, MuO, FeO, Fe'0^ APO', SiO^ IPO (10 to 12 pel' cent.). In dark-green, sculy-granular and micaceous masses, with greyish-green streak and pearly lustre. H 20-25 ; G 3"l-32. Fusible into a black, magnetic bead. Owenite is identical or closely related. IViETACHLOBiTE : FeO, APO', SiO^ H'^O. In dark-green, radiated, leafy masses, resembling ordinary Chlorite, birt diftering by its larger percentage of FeO, and by gelatinizing in hydrochloric acid. t t Gccurring in earthy or uncrystaUme masses. Chamoisite (Chamosite): FeO, AX'0\ SiO^ H'O, often mixed wnth calcite, &c. In dark-green or greenish-black, fine-gi\antilar, ♦The minerals of this subaivisiou are for the greaiei jiart of inoro or Us» iiulBflnite compo- niticii Vt;i'y U'w can be riinki' streak, dull yellow; H 3-0-5-0; G 2-4-2-G. Easily fusible with in- tumescence into a more or less magnetic bead. Rapidly decomposed by hydrochloric acid, with separation of gelatinous silica, as regards, most examples. j f f In distinct crystals or in fibrous and columnar mass s lohich scratch glass readily. Ilvaite ; Orthite : See Table XXVI. Some examples, only,, evolve traces of water on ignition. a«.-decomposed bt hydrochloric acid, with separation of scaly or granular silica. t In leafy or scaly masses, or in tabular or prismatic crystals with marked basal cleavage. Chlorite (Aphrosiderite and other essentially ferruginous vari- eties) : MgO, FeO, Fe'0\ Al\')^ !SiO^ H^O (about 9 to 12 per cent.). In tal)ular (Hexagonal) crystals, and in foliated and fine-scaly masses, of a dark or bright-green colour ; H 1-1-5 ; G 2-75-2-95. BB, melts as a rule on the edges and surface, only, into a dark magnetic slag. Strigovite is closel}-^ similar in general characters ; but its sp. gr. is slightly lower, 2-59, and its water percentage equals 14-80 according to Websky's analysis. Delessite is another dark -green chloritic min- eral, occurring in scaly and fine-fibrous masses and coatings in amyg- daloidal traps. - AsTROPiiYLLlTE (Titaniferous Mica): In golden or bronze-yellow foliated masses, often radiately grouped, and in tabular Clino-Khom- bic crystals; H 35. Most examples yield only traces of water on moderate ignition. See Table XXVT., page 228. PvROSMALiTE : Essential components — MnO, FeO, SIO^, IlH) (about 8 percent.), CI. Hexagonal : cj-ystals mostly six-sided prisuL^^ or tables with strongly-uiarked basal cleavage ; occurs also in granu- 18 258 BLOWPIPE PRACTICE. lar masses ; brown, dark-green, with metallic-pearly lustre on cleav- age plane; H 4'0-4"5 ; G 3-0-3*2. In bulb-tube yields water, and on stronger ignition, yellow drops of ferrous chloride. BB, fuses easily into a steel-grey or black magnetic globule. i \ In gramdar, Jihrotis, or earthy masses. ^ Palagonite : In gi-anular, vitreo-resinous masses, of a yellow or brown colour with dull-yellow streak. Commonly gelatinizes in hydrochloric acid, but some examples are decomposed without gela- tinization. i^ee above, page 257. Delessite : In dai-k-green scaly and short-fibrous masses and coat- ings in amygdaloidal trap. See above, under Chlorite. Anthosiderite : FeW, SiO^, H'^0 (about 36 per cent.). In tough, fibrous masses of ochre-yellow or brown colour, associated with magnetic iron ore. H 6*5 ; O about 3'0. BB fuses with difla^- culty to a grey magnetic slag. Xylotile (Mountain Wood, &c.): MgO, Fe'Qs, SiO^ H^O (about 10 per cent.). In light-brown or dark-brown fibrous or ligniform masses ; H l-5-2"5 ; G 1 •5-2-6, commonly about 2"2. Some examples melt, BB, quite easily, others with difficulty, to a more or less mag- netic bead. Mountain Cork is a related substance ; also Xylite ; but, in all, the composition is indefinite. Some varieties do not give BB, a magnetic product. Others are scarcely attacked by hydro- chloric acid. Hisingerite (Thraulite): Essential components — FeO, Fe'^O^ SiO'', H^O (19 to 22 per cent.), with small amounts of MgO, Al'O*, kc. In rounded masses with rough surfiuje an 1 compact structure, con- choidal in fracture, and pitch-black colon i, with brown or greenish streak; H 3'0-4-0 ; brittle; G 2-6-3-1 ; BB melts difiicultly (in some cases on the edges only) into a grey or dark magnetic slag. Melanolite : Na^O, FeO, APO', Fe'^O', SiO^ H^O (about 10 per cent.). In black, sub-fibrous coatings of waxy lustre and somewhat greasy feel; H r5-20; G 2*7-2-9. Easily fusible into a black mag- netic globule. Seladonite (Green Earth) : K*0, MgO, FeO, A1^0^ SiO^ WO, mixed with CaOCO', &c. In earthy or compact masses and coatings in amygdaloidal tra;js, and also frequently in pseudomorphs after augite. Green of various shades ; somewhat shining in the streak ; H 1*0-2 ; MINERAL TABLES : — XXVII. 259 G 2-8-2-9. BB, melts into a black magnetic bead. In hydrochloric acid loses its colour, and is slowly decomposed with separation of fine-granular silica. Glauconite or Green-Sand, in disseminated par- ticles and grains in cretaceous and other strata, is of genei-ally similar character. Both substances, when ignited in the Buusen-flame, shew the red K-line, in the spectroscope, very distinctly. a».-insoijUble in hydrochloric acid, or scarcely attacked by that reagent. t In masses or crystals of leafy or scaly structure with strongly-marhed cleavage in one direction. {Futsihh in thin pieces). Ferruginous Micas (Biotite, &c. ) : Yield traces of water in some examples, only; as a rule, fuse merely on the edges. See Table XXV. [More or less brittle. Hardness insufficient to scratch glass). Stilpnomelane : Essential components — MgO, FeO, APO', SiO», H'^O (about 9 per cent.). In dark-green or greenish-black radio- foliated masses or small sca-ly particles. H 3'0-3"5 ; G 2'8-3*4. Fusible (in some cases readily, in others slowly) into a magnetic slag or globule. Scarcely attacked by acids. (Hardness sufficient to scratch glass slightly). Chloritoid : Average composition — MgO 3-0, FeO 27*0, APO' 390, SiO' 26, H'O 7-0. In dark or blackish-green, foliated and scaly-granxilar masses, the folise more or less curved and brittle. H 5-5; G 3-5-36. BB, slowly fusible (often on the edges only) into a black magnetic slag. Slightly attacked by hydrochloric, but readily decomposed by sulphuric acid. Sismondine (blackish-green), and Masonite (dark greenish-grey) are apparently identical. Ottre- lite (greenish -grey to greenish-black, in small six-sided tables with rounded angles, in certain clay slates) is also closely related. It gives, BB, with carb. soda a strong manganese-reaction. t t //I fibrous masses. (Easily, futiihlc), Krokydolite (Crocidolite) : Na'^O, MgO, FeO, SiO^, H^O (2-5 to 5 per cent.). In deep-blue or lavender-blue fibrous masses, the fibres tough and flexible. H 3 0-4 ; G 32-33. Easily fusible into a black magnetic globule. 260 BLOWPIPE PRACTICE, Kirwanite; CaO, FeO, APO^ SiO^ H2O (about 4 per cent.). In opaque davk-green nodular masses of radiated-fibrous structure. H 2-0; G 2-9. BB blackens, and melts. • * . {Fusible on edges only. ) ^ Xylite : CaO, MgO, Fe'0\ SiO'^ H'^0 (4-7 per cent.), with small (accidental i) amount of CuO. In opaque nut-brown, fibrous or ligniform masses. H 3'0 ; G 2'93. Fusible on the edges only. Dis- tinguished from Xylotile or Mountain Wood, proper, by its resist- ance to acids. It differs also from the latter mineral by containing (according to Hermann's analysis) a certain amount of lime. t t t /n more or less earth)/ or comimct masses. SoRDAWALiTE : MgO, FeO (or Fe^O'), APO», SiO», H'^O, with inter- mixed ferrous phosphate, &c. In black or dark -green coatings and earthy masses, weathering brown. H 4*0-4*5 (I); G 2G; fusible into a black magnetic globule. Partially decomposed by hydro- chloric acid. Hitherto, from Finland only. Chloroph.eIte : MgO, FeO, SiO^ H'O (about 42 per cent.). In gi'cen or brownish-green amygdaloidal masse^ in trappean rocks. Weathers brown and black. H l"0-2"0; G about 2*0. BB, forms a black magnetic slag or globule. Distinguished from Delessite, Lillite, Chamoisite, &c., by its resistance to hydrochloric acid, and by the large amount of water which it yields on ignition. Nigrescite, a green amygdaloidal mineral, blackening on exposure, is identical or closely related. B.— Fusion-product, non-magnetic. Bi.— fusible on the edges or in fine scales or splinters ONLY; BUT EXFOLIATING AND CURLING UP, IN SOME CASF:S, ON IGNITION. t Micaceous or scaly minerals. { Water under 55 jyer cent. In bulh-tubc little more than traces evoloed. ) Muscovite (Ordinary or Potash Mica): Ehistic in thin leaves. Not decomposed by sulphuric acid. See Table XXV., page 213. Damourite 100 11-20, APO^ 37-85, SiO^ 4522, H'O 5-25. In yellowish-white pearly scales and foliated masses, associated (as regards known localities) with tSt"vuro]ite and Cyauite, or with Corundum. H 1-5-2 -5; G 2 8. BB exfoliates, and molts on edges. Decomposed, with separation of silica scales, by sulphuric acid. MINERAL TABLES : — XXVII. 261 Margai'odite and Sericite are closely allied micaceous substances, ap- parently altered Muscovite, with variable amounts of water. All shew the red K-line in the spectroscope very distinctly. Paragonite (Hydrous Soda-Mica): Na»0, K^, A1'0^ SiO^ H'O (2'5 to 4*5 per cent.). In scaly or schistose masses of a yellowish- white, pale-grey, or light-green colour, and pearly lustre. H 20- 3'0 ; G 2"79. Fusible on the edges into a white enamel 5 decom- posed by sulphuric acid. Pregrattite, distinguished by marked ex- foliation BB, is closely related. Oellacherite (Hydrous Barium-Mica) ; K'^O, Na*0, SrO, BaO, CaO, MgO, APO, SiO*, H'^O (about 4 or 4-5 per cent.). In white or pale-green scaly masses of peai'ly lusti«. H l-5-3'0 (?); G 2'8 2'9. Fusible into a white enamel. Should be readily distinguished by its spectroscopic reactions, but the author has not been able to procure a specimen for examination. Phlogopite (Potassic-Magnesian Mica) : In golden-brown, mica- ceous crystals and masses. Decomposed by sulphuric acid. Ses Table XXV., page 213. CooKEiTE : A hydrous mica, giving marked lithium reaction BB, or in spectroscope. Forms red or reddish-grey scaly aggregations. Probably altered Lepidolite. RuBELLANE : Na*0, K^O, MgO, F&'O', AFO', SiO^ H'O. In red or brownish-red hexagonal tables with pearly lustre on cleavage plane. H about 2-5 ; somewhat brittle. BB, melts (in some cases on edges only) into a dark ferruginous glass. Regarded as an altered Mica. Occurs in certain ti*achytes and other volcanic rocks. Hel- vetane (coppei--red, yellow, green) is closely related. Mabgarite (Pearl Mica) : In white or lighi^coloured scaly and foliated masses with strong pearly lustre. Fusible on edges, only, but in some cases with slight bubbling. Moistened with hydro- chloric acid, shews momentary red and green Ca-lines in spectroscope. See Table XXV., page 215, Talc : MgO, SiO'', with small amount of basic water. In white, light-green or other foliated or scaly examples, with pearly lustre. H 1 ; very sectile, flexible, and soapy to the touch. BB, exfoliates, but melts on tliin edges only. Evolves merely traces of water in the bulb-tube. With Co-solution becomes flesh-red. See Table XXV., page 214. 262 BLOWPIPE PRACTICE. ( Water, 5 6 to 14 per cent. : evolved in marked quantity in bulb-tube.) Pyrophyllitb : APO», SiO^ H*0, with traces of MgO, &c. In light-green or greenish-white radio-foliated and scaly masses. H I'O. BB, exfoliates and curls up, but remains pi'actically unfused. Be- comes blue by ignition with Co-solution. Belongs properly to Table XXV.; see page 214. See also Nacrite or Pholerite, page 219. Vermiculite : MgO, FeO, APO», SiO^ H^O, with traces of CaO, K*0, &c. In scaly and coarsely-foliated examples and six-sided micaceous tables of a yellowish -brown, yellow or green colour. HI •0- l•5 ; G 2 -2-2 -4; slightly flexible in thin leaves. BB, expands and curls up greatly, and melts subsequently to a white or greyish en- amel. According to Prof. Cooke, should form three species : Jef- ferisite, Culsageeite, Hallite. Chlorite (Pennine); and Ripidolite or Clinochlore : In green, scaly or foliated masses and micaceous crystals. As a rule, fusible on the edges only, in many cases into a black, slightly magnetic en- amel. Belong properly to Table XXV. : see page 213. 1 1 Minerals of compact, Jihrous, or other non-micaceous structure. More or less distinctly sectile.* (Assume a blue colour after ignition with Co-solution.) Agalmatolite : Massive, fine-granular, or compact in structure ; white, greyish, gi- '^nish, &c. The substance of many Chinese " Figure- stones." Fusible uu th i edges, only. See page 219, Table X''! . . PiNITE, FaHLUNITE, i*YRARGILLITE J WeISSITE J IbERITE ; ESMARK- ITE ; BoNSDORFFiTE : In more or less dull and opaque crystals — essentially six-sided, eight-sided or twelve-sided prisms — of a greyish- white, grey, brown, green or dull-bluish colour. Fusible on the edges only. See page 220, Table XXV. KiLLiNiTE : K^O, FeO, A1»0', SiO', H»0 (about 9 or 10 per cent., or less in some cases). Chiefly in greenish-grey or brownish-yellow columnar or broad-prismatic aggregations, translucent in thin pieces. H 3 ■0-40; G about 2*7. BB, expands somewhat, and melts slowly (in some cases on the edges and surface only) into a white or greyish enamel. Decomposed, in powder, by sulphuric acid. ScHR^TTERiTE (Hydrargillite (1) mixed with a lime or other sili- • The minerals of this section are fusible, as a rule, upon the edges only. Tliey belong pro- perly, therefore, to Table XXV. See pages 219-222. MINERAL TABLES : XXVII. 263 cate, traces of copper sulphate, &c. Yields on ignition from 36 to 41 per cent, water). In earthy and botryoidal masses, coatings, e. all blacken ou evolviug water. 264 BiiOWPIPE PRACTICE. B«.-FU3IBLE WITHOUT MARKED BUBBLING OB PREVIOUS INTUMESCENCE. t Insohcble in hydrochloric acid. DiALLAGE (Schistose and "more or less altered Pyroxene) : In foliated O)' sub-foliated masses of a greyish-green or greenish-bi-own colour and metallic pearly lustre. Yields often merely traces of water : in no case more than 3 or 4 per cent. See page 242, Table XXVI. 1 1 Decomposed, by hydrochloric acid, toith production of chlorine fumes. (BB, with carh. soda, strong M ii-reaction.) Klipsteinite : MgO, MnO, MnH)', Fe^O', SiO^ H^'O (9 per cent.). In amorphous masses of a brown or brownish-grey coloui', with reddish-brown streak; H 5-0; G 3-5. Fusible into a dark slag. 1 1 t Decomposed, ivith or without gelatinization, hy hydrochloric acid. {BB, with borax, a chrome-green glass. ) Pyrosclerite : MgO, FeO, KVO\ Cr'O" (143 per cent.), SiO^ H'^0 (11 per cent.), von Kobell. In cleavable masses, indicating Rhombic crystallization ; in thin pieces somewhat flexible ; H 3*0 ; G 2 •7-2 -8 ; green of various shades, with pearly lustre on cleavage- planes Fusible quietly, or with slight bubbling only, into a greenish- gi'ey enamel. Hitherto, from Elba oidy. {In spectroscope, marked Ba-reaction when moistened with hydrochloric acid.) Harmotome: K^O 3-3, BaO 20, APO» 15-7, SiO^ 46, H^O 15. Rhombic (?) : commonly in groups of small, cruciform crystals, with calcite, &c., in trap amygdaloids. Generally colourless, otherwise white, grey, reddish, brown, &c.; IT 45 j G 24-2-5. Fuses quietly, with pale-green colomtion of the flame-boi-der. Decomposed by hydrochloric acid, with separation of fine-gi-anular silica. See Note at end of Table. Edingtonite: BaO 26-84, ArO" 22-63, SiO' 36-98, H'O 12-46, Heddle. Tetragonal; crystals, mostly, small square pi-isras with hemihedral polar planes; greyish-white, pale-red; H 4-0-4-5 ; G 2-7. Gelatinizes in hydrochloric acid. Hitherto, from Scotland only, accompanying harmotome, anakimCj calcite, &c. MINERAL TABLES : — XXVII. 265 (In spectroscope, marked Ca-reactlon lohen moUtenei, after Ujnition, with hydro- chloric acid.*) Pectolite : Na^O, CaO, Al^O', SiO^ H»0. Clino-Rh. ; but com- monly in cleavable fibrous or sub fibrous masses, witli cleavage angle of 95" 23' ( = B : V). Colourless, or greyish or pale greenish-white, often opaque and more or less earthy from alteration. IT (in un- weathered examples) 5-0; G 274-2-88. Fuses quietly. Yields as a rule only 2 or 3 jier cent, water on ignition. Decomposed without gelatinization by hydrochloric acid, but gelatinizes after fusion. Chalilite : Na'^0, CaO, MgO, APO», ¥q'0\ BiO^, H^O (about 16 per cent.). Reddish-brown, massive; H 4-5 ; G 2"25. An imperfectly- known mineral, hitherto from Antrim only. Analcime ; Natrolite : Normally lime free, but some examples of exceptional occurrence shew momentary Ca-lines in spectroscope, see below. (/« spectroscope, no Ca-lines, hut strong Na-reaction.) Analcime : Na'^0 140, APO» 23-3, SiO'^ 545, H^O 82 ; but a small percentage of CaO present in some varieties and K^O in others. Hegular ; crystals either small cubes with angles i'ej)laced by the planes of the irapezohedron 2-2, or the latter form alone. Colourless, white, light-gi-ey, flesh-red ; H 5 5 ; G 2-1-1 -3. Fusible without intumescence into a more or less clear glass. Decomposed by hydi-ochloric acid with separation of slimy silica. See Note at end of Table. Cuboite is a green or gi'eenish-grey variety. Eudnophite is regarded as a Rhombic Analcime. Cluthalite is a somewhat decomposed vaiiety. Natrolite (Mesotype in part) : Na20 16-30, APO» 26-9G, SiO» 47-29, H'O 9-45, but traces of CaO, &c., occasionally present. Rhombic ; crystals veiy small, often acicular ; essentially Rhombic (almost rectangular) prisms, tei-minated by the planes of a rhombic octahedron. V : V 91° ; P : P, over polar edges, 1 43° 20' and 1 42° 40'. Occurs also, and more commonly, in radio-fibrous masses, often with crystalline botryoidal surface. Colourless, white, /ellow, light-brown, * If a zeolitic mineral do not shew these spectroscopic, reactions very distinctly wlicn simply moistened by hydrochloric acid, a jiortion in fine powder should be dissolved in the acid m a ■mall porcelain capsule with attached handle (like that figured on imgo 20) over the apirit-lamp or Bunsen-flame. A drop of the solution may then betivkoti up by a platinum wire (bent at the extremity into a small loop or ear) and held within the edge of the flame, caro being taken to test the wire previously for negative results. By this treatment, distinct although more or less transitory spectra are always obtained when lime, barj ta, potash, &c., are present in the mineral. 266 BLOWPIPE PRACTICE. red ; two or more tints frequently present in concentric zones in the Hame example. H 5-0-5-5; A 2'l7-2-27. Very easily fusible in the simple candle or Bunsen-flame, without intumescence, into a colourless glass. Decomposed, with gelatinization, by hydrochloric acid, Radiolite or Bergemanite, Lehuntite, Galactite, Brevicito, Fargite, are varieties. Mesolite (Antrimolite, Harringtonite) is a closely related zeolitic mineral, but contains both lime and soda, and is thus intermediate between Natrolite and Scolecite. It occurs essentially in radio-librous masses and acicular crystals. Yields 12 to 14 percent, water ; gelatinizes in hydrochloric acid, and fuses quietly or with very slight intumescence. B'.-FUSIULE WITH MUCH BUnBLING OR WITH PREVIOUS INTUMESCENCE. + Undissolved or scarcely attacked by hydrochloric acid. (Inyellow,Jihrom examples. DB, atronrj Mn-re.artion.) Carpiiolite : MnO, FeO, Fe»0», APO', SiO^ H*0 (10 to 11 per cent.), with small amounts of MgO, F, »kc. Acicular, or in radio- fibrous aggregates of a straw-yellow or greenish-yellow colour and silky lustre; H 4-5-50; G 2-9-30. The water evolved by strong ignition dfiposits Hj)ots of silica on the sides of the bulb-tube, and attacks the glass. BB, intumesces and forms a dull-brownish bead» (In opaque, prismatic cryntals.) GiOANTOLiTE : Na^O 1-2, K'O 27, MgO 3-8, MnO 09, APO»250, Fe^O^ 1 5-G, SiO* 46-3, H^O, 60. Rhombic ; crystals (probably pseudo- morphous after lolite), thick, twelve-sided prisniB, more or less dull ; green, greenish-grey ; H 3*5 ; G 2'8-2'9, Fusible with bubbling into a. greenish slag. When ignited and moistened with hydrochloric acid, shews red K-line distinctly in sj)ectroscoj>e. (Fn pale-red deavahle, masses.) WiLSONiTE : K'O, CaO, MnO, FeO, APO', SiO^ H'^O. In rose-red or pale purplish-red cleavablo masses ; slightly tibroi s and pearly in the cleavage directions, lustreless and more deeply-coloured trans- versely ; cleavage rectangular; H 3 0-3 '5 on cleavage surfaces, other- wise 5-0-5'5 ; G 2'75-2-8, BB, expands or increases in volume, and fuse^ii with slight bubbling into a very blebby glass or white enamel. MINERAL tables: — xxvu. 267 Moistened with hytlrocliloric acid, shews Ca-liuea in flashes, and red K-line persistently.* ^ .-. ' 1 1 I^ecomposea hy hydrochloric acid, with sejmration of yranular or slimy silica. . ^ , (IlardneMn 6 or 7 0. Scrdtrh ijIuhh alront/li/.) . - , Prehnite: CaO 27-14, Al^O' 2487, SiO' 43G3, IPO 436. Rhombic ; crystals tabular or short-prismatic, in aggregatt^d groups (»Cfl Note at end of Table). Occui-s also, and more commonly, in radio-fibrous masses with l»otryoidal and crystalline surface ; grfienish- white i>assing into distinct shades of green; II fiO-T-O; G 2-8-3-0. Fusible with continued bubbling. In sp*;ctrosco[if), when moistened with hydrochloric acid, espexjially after fusion, shews red and g7'(^en Ca-lines in flashes. The fused bead gelatinizes in the acid, but in its normal state Phrenite is more or less slowly and incm I^ile Koyair, Lake Superior, in small nodular masses of green colour and nidi(!- fibrous structure, is also a variety or related substance, intermixed with grains of magn(;tic ii-on ore, itc. Faujasite: K'^O 4 30, Na'O 484, CaO 436, APOMOOO, SiO> 46*77, H^O 28 '03. Regtdar ; crysttils, small octahedi-ons (or accoi-d- ing to Knop, very flat^planeistilbite agrees in composition and general charactei"s, but its crystals are small I'hombic prisms terminated by the front and side polars P and P, the latter predominating. V : V 135° 10'; P ■ P over sunnnit 109° 46', P:P147"40'. Colourless or bluish-white. In hydrochloric acid, decomposed with separation of fine granular silica-. Hrulandite (Stilbite of most German syst(^nis) : CaO (with small amount of Na^O and KH)) 9-34, AFO^ 1683, SiO' 59-06, HH) 1477. Clino-Khombic ; crystals mostly tabular parallel to the side or clino- vortical j)lane ; commonly n^aile up of the front and side verticals / V and V (the latter predominating) with a front polar P, and narrow Base. Wli(;n lying cousefjuently with V upwards, the crystals present a psc3udo-hexagonal aspect. P: V 129° 40' ; B : V 116" 20' and 63^' 40'. Cleavage very perfect parallel to V, the jdanc^s, as in Still)itt*, strongly pearly. Coloui-, hjrdness, and otlirr cliaract(!rs, physical and cluMnical, like those of Stilbite. Euzeolite, Lincolnite, Beaumoutite (/) are varieties. (//( aiHO)'i)lioiis t'jut tuples vitfiout dialinct cleavage.) Chomkuite: CaO, MgO, Al'O^ SiO^ IPO (9 per cent.). In Buow-white or pale-yt^llowisli, disseminated masses; II - 5-3, more or less seotile ; G 29. BI*, fusible with bubbling into a greyish- 270 BLOWPIPE PRACTICE. white glass or enamel. Decomposed by hydrochloric acid, with separation of granular silica. Hitherto, from Elba only. Related to Pyrosclerite, page 265 above. t t t Decomposed, with perfect gelatinization, hy hydrochloric add. (BB, sulphur-reaction with carb. soda.) Ittneuite : K^O, Na'^0, CaO, Al^O', SiOS H^O (9-8 per cent.) In small, granular masses, with dodecahedral cleavage, of a grey or blue- grey colour. H .5 -0-5 "5 : G 2 '3-2 -4. Fusible with strong bubbling into a blebby semi-opaque glass or enamel. Yields gypsum to boiling water, as recognized by the precipitates formed in the solution by oxalate of ammonia and chloride of barium, respectively (Fischer). Decomposed by hydrochloric acid, with emission of sulphuretted hydrogen and separation of gelatinous silica. An altered Hauyne or Nosean, see page 236. (BB, flame-horder coloured distinctly green.) Datolite: CaO 350, BW 21-9, SiO' 375, H'O 56. Clino- Rhombic (or Ortho-Rhombic V) ; occurs commonly in groups of small vitreous crystals, rich in planes (see Note at end of Table), or in coarsely granular masses. Greenish-white, colourless, green, reddish- white. H 5 -0-5 -5 ;' G 2-8-3"0. Fuses very easily, with much brbbling, and green coloration of the flame, to a colourless or veiy lightly- tinted glass. Gelatinizes in hydrochloric acid. In spectroscope, shews per se two vivid green lines with one pale-green and a faint blue line, from presence of B*0'. When moistened with hydrochloric acid, a test-fragment shews also J"ed and green Ca-lines in flashes ; but the i)resence of lime is best shewn by a drop of the solution, taken up in a double-loop of clean platinum wire and held against the edge of the Bunseu-flame. Humboldtite is a variety in small crystals, associated with 'amellar Apophyllite, from the Tyrol. BoTKYOLiTE : Contains 1064 per cent, water, and occurs in fibro- botryoidal examples of a greenish, pale-grey, or reddish colour; otherwise like Datolite. {Mol'plyiiig to an older "-^delforslte," since shewn to be an impure WoUastonito containing Interndxcd quart)!. MINERAL TABLES :- -XXVII. 273 {In vitreous, amorphous masses). HyoROTACHYLiTE : K^O, Na^O, CaO, MgO, FeO, Fe^O', APO», TiO^ SiOS H^O (12-90 per cent.), according to Peterson and Senfter. Forms nodular and other masses of iincrystalline structure in basalt. Dark-green or blauk. H 3'5; G 2-13. Fusible with more or less bubbling. Decomposed, with gelatiiiization, by hydrochloric acid. See Tachylite, page 228. NOTE ON TABLE ::XVII. Many of the minerals ijlaced (to avoid risk oi error in their determin.ation) in the present Table, belong ijropcrly — on account of their difficult fusibility or slight percentage of water— to preceding Tables, and are described more fully in these latter. The various Micas, Talc and Steatite, Agalmatolite, the Pinites, &c. , are examples. See more especially the Note to Table XXV. The minerals which belong essentially to the present Talile consist for the greater part of zeolites — hydrated silicates of very characteristic occurrence in trapjjean or basaltic rocks. With these, in a Determinative grouping, the boro-silicate Datolite may be conveniently placed, as it resembles many zeolites in general characters, and is also frequently present in amygdaloidal traps. The zeolites, as the name implies, either swell ujj or intumesce on the fir it application of the blowpipe-flame, or otherwise meit very easily, and generally with bubbling. All, when reduced to powder, are readily decom- posed by boiling hydrochloric acid, the silica separating in many cases in a gelatinous form. The presence of CaO, BaO, or K'''0, is easily ascertained by the pocket-spectroscope, if a drop of the solution be taken wp in a small loop of platinum wire and held within the edge of a Bunsen-flame, As a rule, when lime and potash are present together, the red and green Ca-lines come out first, and then, as these fade away, the red K-line comes into view. in the present Note, onlj' the more common of these minerals are referred to, the crystallographic and other characters of the less important species being given in sutficient detail in the Table. The commonly occurring species, as regards their blowpipe reactions, fall into three series, as follows : §1. Fusible quietly: (a) soda-species: Analcime, Natrolito ; {h) barytic species : Harmotome, § 2, Fusible with much bubbling, but without (or without marked) intu- mescence* on first application of the flame ; Patolito ; Prehnite, §3. Oni'ng up or intumescing on first application of the flame: (a) lime- potash species : Apophyllite, Phillipsite ; (/*) gelaiiniziag lime-species: Thom- • By " intumescenee " is meant, luTe, not a mere expansion of tlie substance, but a throwing out of excrescences or curling up after the manner of borax. Minerals which intumesce in this manner on the drat application of the llame, fuse afterwards in general without bubbling, aud, as a rule, somewhat slowly, 19 274 BLowTPiPE pRAcrrcEr. Bonite, Scolecite, Laumontite ; (c) non-gelatinizing lime-species : Cha.ha.site, Stilbite, Heulandite. The leading characters of .these species are given in the Table, but neces- sarily in brief form only ; a few additional references to their crystallization are therefore appended. Analcime, in most examples, is at once recognized by its crystals, as these are generally well-formed and easily made out. They belong to the Regular System, and consist either of the trapezohedron 2-2 (measuring 131°48'3{>" over long or axial edges, and 146° 26' 33" over intermediate edges), or of a combination of this form with the cube, the latter commonly predominating and thus having each angle replaced by three triangular planes (with inclin- ation of cube-face on abutting 2-2 face measuring 144° 44'). The cleavage is cubical, but very indistinct. In the sj>ectroscope, as a rule, no other line than a strong Na-line is observable if the test-matter be careiuUy freed from accompanying calcite. Crystallized Natrolite was formerly and is still often known as Mesotype, the term Natrolite having been originally limited to the yellowish-brown, concentric-fibrons variety, then regarded as distinct. The crystals belong to the Rhombic System, but are frequently acicular, or are only partially formed (as polar planes) at the extremities of the filjres of which ordinary examples are so commonly composed. When distinctly formed, they consist of a nea»'ly rectangular prism with front angle ( = V : V) of about 91°, terminated by tl.e planes of a somewhat low pyramid or octahedron measuring 143° 20' and 142° 40' f er polar edges, and 53° 20' over middle edge. P on V, conse- quently, measures 116° 40'. The prism-planes in most examples are striated vertically (sometimes very coarsely), and occasionally either the front or side edges are replaced by V or V, in the spectroscope, pure examples as a rule shew only a strong Na-line, but transitory flashes of red and green Ca-lines sometimes appear. Harmotome, a barytic zeolite, is in general readily recognized by its small, symmetrically formetl cruciform crystals, altliough, occasionally, re-entering angles m these are more or less inconspicuous or are indicated only by stria*. The crystallization is apparently Rhombic, but the Tystals have to some extent a Tetragonal aspect. They consist commonly of a rectangular prism (composed of the forms V and V), terminated by the planes of an octahedron or pyramid, P, or occasionally by those of a side-polar or brachydoir.e P. In some crystals, tlie polar plants are simplj' striated ; in otliers, tlie V planes shew a lozenge-shaped striation.* Two (or four) of these crystals form inter- IMjnetrating twins, with vertical axis in common. P : P, over polar edges, 120' 1' and 120° 42' ; P : P 110° 20'. Cleavage, V distinct, V somewhat less apparent. A drop of the hydrochloric ncid solution, taken up in a loop of • Some cryHtnllograiihers (iift<^r Des Cloizeanx) make tlie System Cliuo-Rlioinbic, and regard this frnnt-vertioiil fonii mh tlie basiil form. Ou that view, most of the crystals ■will be elongated in the direction of the eliiid-axis. MINERAL TABLES : — XXVIL 275 platinum wire, shews the green Ba-lines in the spectroscoi)e very distinctly. The diluted solution gives also a marked precipitate with a drop of sulphuric acid. Datolite — a hydrated boro-silicate of lime — is described fully, as legards its more distinctive characters, apart from crystallization, in the Table. Its crystals belong to the Clino-flhombic system, but many (the Arendal crystals especially) are strikingly Ortho-Rhombic in aspect. These latter are chiefly in the form of rhombic or six-sided taliular crystals, composed of the forms V and V, with broadly-extended basal jjlane, and commonly with a front-polar or orthodome ( - '2P) and other polar planes subordinately developed. In many crystals these polar plane.s appear ecjually at corresponding extremities, with but little if any difference in their angle values, and thus imjjart an Ortho-Rhombic character to the crystal. In crystals from other localities, however, and in some of the Arendal crystals, they are developed only at one extremity. In the Andreasberg and most other crystals, the liasal plane is also well-developed as a rule, but the prism-planes (V, V^, and V) and certain polar ijlanes (especially - 2P, - P, and the side-polars or brachydomes 2 P (I and 4P) are also well formed, and the crystals are thus more sliort-prismatic than tabular. In some crystals, again, the basal form is entirely absent. The principal angles are as follows: V: V 76' 38'; V^: V^ US'' 22'; V: Vi 160° 38' ; B : V 90° 0' (and 89° 54') ; B : - 2P 135° 4'. The marked green color- ation (from the presence of B'^U^) which datolite imparts to the flame of the blowpipe or Bunsen burner serves at once to distinguish it from other minerals, of similar aspect. T?rehnite is distinguished from other Zeolites by its high degree of hardness, ( = 6 to 7), and its small percentage of water. It occurs most commonly in.' botryoidal masses with crystalline surface and radio-fibrous structure, the colour varying from pale greenish-white to deep api)le-green. Distinct crys- tals are comparatively rare. Tliey belong to the Rhombic System, and i)re- sent four types : (1), The symmetrically tabular type — in which the crystals are thin rhombic tables composed of the forms V and B ; or six-sided tables composed of V V and B ; or eight-sided tables made up of V, V, V, and B, the basal form in each case greatly preponderating. (2), The tabular type with brachydiagonal elongation — in which the thin crystals contain the fonns V, V and B, and are greatly extended alimg the two latter, thus passing at times into fibrous aggregations with the two front planes of V at the free end of the lil)rcs. (3), The short-prismatic type with ectroscope a vivid calcium spectrum, and as this fades out a transitory red K-line generally comes into view. Stilbite and Heulandite may in general be distinguished easily from other zeolites by tlieir almost constant occurrence in bladed or narrow-foliated examples, with very perfect cleavage in one direction and strong jjearly lustre \> on the cleavage surface. The latter is parallel to a side-vertical, V, or (in Heulandite) V. The hardness, also, is lower than in most other zeolites, viz.: 3'5-4'0. The free ends of the foli;© generally shew crystalline facets. The colour is commonly either white, red, or light-brown. In Stilbite, the crystal- system is Rhombic, and the more common crystals consist of a rectangular prism (V, V, usually flattened parallel to V, the cleavage plane), with the planes of a rhombic octahedron, P, at each extremity. Occasionally, the vertical edges of the rectangular prism are slightly replaced by tlie rhombic prism V, and the point of the octahedron is truncated by the basal ferm B, The prism-angle, V : V, equals 94° IG' ; P : P over front polai" edge, IIU' 16' ; over side polar edge, 114° ; over middle edge, OC^. In Heulandite, the system is Clino-Rhombic. The more cammonlj'-occurring . crystals are made up of the front- vertical form S^, the side or clino- vertical V, the front-polar or hemi-orthodome P* and the basal form B. The side- vertical V (the cleavage plane) generally predominates, the crystals being usually much flattened in that direction ; but occasionally, crystals are elongated transversely, i.e., in the direction of the ortho-diagonal or right-and-left axis, in which case the frontal forma V and P prepouderata The hemi-pyramids 2P and §P, and the clinodome or side-polar 2P, also occasionally occur as sub- ordinate forms. P:V equals 129*40'; BiV, UG" 20' ; 2P:2P, in front, 136° 4' ; §P : §P, 146° 52' ; 2P : 2P, over summit, 98" 44'. Although both Stilbite and Heulandite are essentially lime species, they usually containi .^mall amounts of soda and jwtash. When, a, droji of th*' hydrochloric-acid solution (taken up in a loop of clean platinum wire) is exairined by tlio spectroscope, the red K-liue, therefore, almost always app3^r§ for *n iystant, ^s the vivid red and gteeu Ca-Uues fade out of view* INDEX TO THE MINERALS IN PART '11. Abichite, 144. Abrazite (v. Gismondine), Acadialite, 268. Acanthite, 107. Acanticone (v. Epidote). Acmite, 232. Acttnolite, 233. Adamaatine iSpar, }96, 207. Adamite, 145. Adularia Feldspar^ 245, 253. .^delforsite, 272. ^girine, 233. jEschynite, 126. Agaliuatolite, 219. Agaric Mineral (v. Calcite), Agate, 208. Aikinite, 107. Alabandine, 108, 124, 152. Alulite, 243. Albertite, 132, Albin, 268. Albite, 246, 254. Alexandrite (v. Caii-ywsberyl). Algodonite, 101. Alipite, 217. Alisonite, 107. AUauite, 22a Allemontite, 101. AUochroite, 228. AUoclase, 103. AUophane, 217. Almandine, 230. Alstonite, 137. Altaite, 113. Alum, 154. Alumatone, 155. Aluminite, 155, 162. Alunite, 155. Alunogene, 154. Amalgam, 115. Amazou-stone, 246. Amber, 132, 133. Amblygonite, 164, Amethyst, 202, 208. Amianthus, 243. Ammonia-alum, 154. Amphibole, 233, 243, 251. Amphigene (Leueite), 203. Analcime, 265, 274. Anatase, 127, 129, 196, 206. Anauxite, 219. Andalusite, 199, ?ia Andesine, 253. Andradite, 230, Anglarite (v. Viviariite). Anglesite, 151, 160. Anhydrite, 152, 16L Ankerite, 136. Annabergite, 145. Anorthite, 241, Anthophyllite, 216. Aiithosiderite, 257. Anthracite, 128, 223. Antliraconite (v. Calcitei). Antigorite, 215. Antimony, 113. Antimony Blende, 149. Antimony Glance, 110, 112. Antimonial Silver (v. Dyscra- site). Antimonial Nickel Glance, 110. A utimemal Nickel Ore, 114. Antimony Ckire, 149. Antimonito, 149. Antriniolite, 266. Apatelite, 158. Apatite, 163. 169. Aphanese, 144. Aphrodite (Meerschaixm^ Aphrosiderite, 257. Apht'ialose, 153. Apthonite (Tetrahedrite ?) Apjolmite, 158. Aplome, 230, ApophyUite, 267, 276. Aquamarine (Beryl), 200. Arffioxcne, 144. Aragouite, 138, 141. Arcanite, 153. A rfvedsonite, 234 Argentite, 107. 109. Arkansite, 127. Arksutite, 178. Arijuerite, 115. 280 INDEX. Arragonite, 138, 141. Arsenic, 101. Arsenical Iron, 101. Arsenical Pyrites, 103, 104. Arsenioxis Acid, | ijo • Arsenolite, j ^*^- Arseniosiderite, 146. Asbestus, 243. Asbolan, 189. Asmanite, 201, Asparagus stone v. Apatite). Aspasiolite, 220. Asperolite, 217. Asphalt, 132. Aspidolite (Magnesia Mica). Astrakanite, 154. Astrophyllite, 227. Atacamite, 176, 177. Atelesite, 145. Atelite, 176. Atheria&tite. Atlasite, 176. Auerbachite, 198. Augelite, 168. Augite, 232. Aurichalcite, 136. Auripigment (v. Orpiment). Automolite, 197. Autunite, 166, jftvanturine ( = Quartz with in- spersed scales of mica, iron-glance, &c.). Axinite, 230, 248. Azurite, 135, 142. Babingtonite, 233. Bagratiouite, 228. Baikalite (Amphibole). Baltimorite, 'J 21. Bamlite (var. Sillimanite), 200. Barnhardtite, 105. Barrandite (Strengite ?), 165. Barytine, 152, 160. Barium Mica, 261. Baryto-calcito, 137, 153. Baryto-celestine, 152. Bastite, 215. Batrachite, 204. Baudiaaeritc, 139. Beaumontite, 269. Bechilite, 172. Beraunite, 165. Bergemannitc, 26C. Berlinite, 168. Berthierite, 1 1 0. Beryl, 200, 209. Berzelite, 146. Borzeliae, 106, 236. Beudantite, 144, Beyrichite, 105. Bieberite, 157. Bindheimite, 150. Bhmite, 103, 104. Biotite, 213. Bismuth, 115. Bismuthine, I ia? ma Bismuth Glance, \ ^"'' ^""' Bismuth Ochre, 188. Bismutite, 136. Bitter Salt (Epaomite), 154. Bitter Spar, 1:^8. Bitumen, 132. Bituminous Coal, 132, 134. Black Band, 141. Black Oxide of Copper 116. Black Jack, 109. Blende, 108, 109, 151, 159. Blcedite, 154. Bloodstone (v. Quartz). Blue carb. copper, 135. Blue Vitriol, 156. Bodenite, 228. Bog Iron Ore, 193. Bog Manganese Ore (Wa-'.), 188. Bolognese Spar (Barytiuo), 152. Boltonite, 204. Bombiccite, 133. Bonsdorffite, 220. Boracite, 171, 173. Borax, 171, 173. Bornite, 105, 108. Borocalcite, 172. Boronatrocalcite, 172. Boracic Acid, 171. Botryogene, 157. Botryolite, 270. Boulangerif«, 111. Bournonito, 111, 112. Bowenite, 221. Bragite, 127. Brandisite, 216. Braunite, 125. Breislakito, 232. Breithauptite, 114. Breunnerite (Mesitine), 136. Brevicite, 266. Brewsterite, 268. Brittle Silver Ore, 110. Brochantite, 158. Bromargyrite, 175. Bromlite, 137. Brongniardite, 111. Brongniartine (v. (jlauberite). Bronzite, 216. Brookite, 127, 199. Brown Coal, 132. INDEX. 281 Brown Iron Ore, 125, 128, 187, 192. Brucite, 190, 194. Brushite, 168. Bucholzite, 200. Bucklaiulite, 231. Bunsenite, 190. Buratite, 136. Buntkupfererz, 105. Bustamite, 233. Byssolite, 227. Bytownite (var. Anorthite). Oabrerite, 145. Gacholong (var. Opal). Cacoxene, 165. Cairngorm, 208. Oalaite, 167, 170. Calamine, 205, 219. Calamite (Tremolite), 243. Calaverite, 113. Calceilony, 208. 8S^r, I '"•»»■ Caleilonite, 135, 151. Calomel, 176. Canaanite (var. Pyroxene). Cancrinite, 239. Cantouite (Covelline ?). Caporcianite, 272. Carbonado, 196. Carmiiiite, 144. Carnallite, 174. Carnelian, 208. Carpholite, 266. Cassiterite, 127, 195, 206. Castor, 236. Cat's-IIye, 208. Celeatine, 152, 160. Cerargyrite, 175, 177. Cerine, 228. Cerite, 205, 218. • Cerussite, 135, 142. f'ervantite, 149. Ceylanitc, 197. Chabasite, 268, 277. Chalcanthite, 156. Chalcetlony, 208. Chalkosiue, 106. Chalilite. 265. Chalcanthite, 156. Chaleoi)hanite, 126. Chalcophyllite, 144. Chalcoi yrite, 105, 108. Chalc(.lite, 166. Chaleotrichite (— Aoicular Cu- prite). Chalcoaiderite, 160. Chalcosine, ) i^/. ino Chalkosine, \ ^^^' ^^^' Chalcostibite, 111. Chalibite, 265. Chalybite (Siderite), 13'^. Chatamite, 101. Chamosite, 256. Chessylite, 135. Chesterlite (Orthoclasc). Chiastolite, 199, 223. Childrenite, 165. Chile Saltpetre, 181. Chiolite, 178. Chlatlnite (Meteoric Enstatite). Chlnanthite, 101. Chlor- Apatite, 163. Chlorastrolite, 207. Chlorides (v. Table XIX.). Chlorite, 314, 224, 257. Chloritoid, 259. Chlorocalcite, 174. Chloromelane (Croustedite), 266. Chlor opal, 218. Chloroph-ieitc, 260. Chlorophane Fluor Sj)ar). Chlorophvllite, 215. Chlorotile, 144. Choudro-arscuit©, HA. Chondrmlite, 2(V4, 211. Chonikrite, 269. Christophite, 131. Chromic Iron Ore, 118, 124, 12S. Chromite, 118, 124, 1:^8, 186, 192. Chrome Garnet, 198. .Chrome Mica, 213. Chrysoberyl, 197, 207. Chrysocolla, 217. Chrysolite, 204, 210. Chrysoprase, 208. Chrysotile, 221. Churchite, 168. Cimolite, 219. Cinnabar, 121. 122, 130, 131. Cinnamon-stone (Uainet). Clarite, 103. Claudutite, 148. Claiisthalitu, 106. Clay Inmstoue, 136, 141. Cleavelandite, 246. Clinoclase, 144, 147. Clinochlore, 214. Clino-Humite, 204. Clintonite, 216. Cluthrtlite, 265. Coals. 1:^2, 1.34. Cubalt Bloom, 143. 282 INI^EX. Cobalt Spar, 137. Cobalt Vitriol, 157. Cobaltine, 103, 104, Ooccinite, 170. Coccolite, 232, CoUyrite, 220, Colophonite, 245, Columbite, 126, Comptonite, 271, 276. Cookeite, 261, Copiapite, 158. Copper, 116. Copper Binnite, 103, Copper Glance, 106, 109. Copper Mica, 144. Copper Nickel (Nickeline), 101, 102. Copper Pyrites, 105, 108. Copper Uranite, 166, 170. Copper Vitriol, 156. Copperas (Green Vitriol), 156. Coquimbite, 157. Coracite, 190. Corilierite, 200, 211. Corneous Lead Ore, 176. Cornwallitt (a co})per arseniate). Corundum, 196, 2^. Corynite, 103. CJoaalite, 107. C^otuunifce, 176. Couacranite, 241. Covelline, 130. Crednerite, 126. Crichtonite (Ilmenite), 118. Crocidolite, 259. Crocoisite, 182, 184. Cronstedite, 256. Crookesite, 106. Cryolite, 178. Cryophyllite, 235. Cryptolite, 164, (!ryptoinori)hite, 172. Cubanite, 105. (hibo Ore, 145. Cuboite, 265, Culsageeite, 362. ('Unuuingtonite, 2.34. Cuprite, 116, 122, 123, 189, 193. (^upropluml)ite, 107. Cyanite, 197, 210. ( 'ymophane, 197. Cyprine, 245. Daniourito, 260. Danaitc, 103. Diuialito, 229. Dauburitti, 236. Dark Red SUver Ore, 110, 112, 121. Datolite, 270, 275. Daubreite, 176. Davyne, 239. Davidsouite (Beryl). Dawsonite, 139. Dechenite, 182. Delessite, 214, 257. Delvauxite (a lime-iron phos- phate). Demidowite, 217. Descloizite, 1S2. Desmine, 209, Deweylite, 221, s Diadochite, 159. Diallage, 242. Diallogite, 137. Diamagnetite, 124. Diamond, 196, 206. Dianite, 196. Diaphorite, 111. Diaspore, 196. Dichroite, 200, 211. Dihydrite, 167. Diopside, 243. Dioptase, 205, 216. Diphanite, 215. Dipyrc, 241. Disterrite ( Brandisite), 216. Diathene, 197, 210. Dolomite, 138, 140. Domeykite, 101. Donacargyrite, 111. Dopplerite, 132. Dufrenite (Green Iron Ore, an iron phosphate). Dufrenoysite, 103, 104. Durangite, 147. Dyscrasite, 113. Dysluite (Gahnite), 197. Edingtonite, 264. Egeraae, 244. Ehlito, 166. Ekebergite (Warnerite), 240. Eh-eolite. 239. Elastic Bitumen, 132. Elaterite, 232. Electrum (.Amalgam), 115. Eliasite, 190. Enibolite, 175. Emerald, 200, 209. Emeral. Eucolite, 237. Eudialyte, 237. Eudnophite, 265. Eukainte, 106. Eulytine, 237. Euphyllite, 215. Eupychroito, 1 0.3. Eusynchite, 182. Euxeiiite, 127. Ev zeolite, 269. Evaiisite, 167. Fahlerz, 110. Fahluuito, 220. Fargite, 266. Farcolite, 272. i.<'assaitc, 232. Faujasite, 267. Fauserite, 158. Fayalite, 227. Feather Alum, 157. Feldspar (lime), 241. Feldspar (potash), 245. Feldspar (soda), 24P. Feldsi)ar Group, 2u3. Felsobanyite, 155. Fergusonite, 127. Fibro-Ferrite, 158. Fibroli*j, 200. Fichteiite, 133. Figure Stone, 219. Fire Blende, 149. Fire Opal, 202. Fischerite, 167. Flint, 208 Flos Ferri, 138. Fluellite, 178. Fluocerite, 179. Fluor-Apatite, 163, 169. Fluorite, 178. Fluor Spar, 178, 179. Foresite (near Stilbite), 269. ' Forsterite, 204. Fowlerite, 233. Francolite, 163. Franklinite, 118, 124, 128, 186, 192. Freislebenite, 111. Frenzelite (Guanajuatite), 106. Frugardite, 245. Fuchsite, 213. Gadolinite, 204. Gahnite, 197, 208. Galactite, 266. Galena, 107, 109. Galmei (Calamine), 205. Garnet, 2.30, 141. Garnet Group, 248. Gaylussite, 1.38. Gehlenite, 204. Geierite, 103. Genthite, 217. Geocerite, 133. Geocronite, 1 12, Gersdorffite, 103. Gibbsite* (see Note, below). Giesseckite, 220. Gigant(»lite, 266. Giil>ertite, 215. Gillingite (Hisingerite), 218. Giobertite, 138. Girasol, 202, Gismondine, 271. Glagerite, 220. Glaserite, 153. Glauberite, 153. Glauber's Salt, 153. Glaucodot, 103. Glauconite, 259. Glaucophaue, 244. Glingite, 204. Glockerite, 158. Gmelinite, 271. Gtt'thite, 125. Gold, 116. Gold- Amalgam, 115. Goschenite (v. Beryl). • Acciflentiilly omitlniil from foot of page 220, wl^ro it ghouhl follow Kollyiite : QiBBSiTR (Hyrtnirgillitu) : — A1«0» efi'u, li*u 34'6. In miiall liexiifjniiul ciystuls with basnl cleavage, or in mamillary or stftlac^litli'. px.imples of a wliit«, Kr(!fnisli-y(.llow, or o|1kt Hj^lit colour. H 2-.')-3 0; O 2-;)-2 4 UB, inrnsible, but commonly cxfoliutea. In powder, (lisBclvttl by cauatic potash ; ahu by sulphm !u acid. 284 INDEX. Cjoslarite, 155. Grahamite, 122. Gramenite, 218. Gramrriatite, 243. Graphic Tellurium, 113. Graphite, 117. Green Garb. Cooper, 135. Green Earth, 258. Green Vitriol, 156. Grey Antimony Ore, 110, 112. Grey Copper Ore (Tetrahedrite), 110. Greenockite, 151. Greenovite Sphene), 229. Grengesite (near Delessite), 257. Grophite, 215. Groroilite, 188. Grossular, 241. Guadalcazarite, 106, 107. Guanajuatite, 106. Guarinite, 239. Gummite, 190. GurhoKan, 1.38. Gymnite, 221. Gypsum, 155, 161. Gyrolite (Apophyllite?), 267. Haarkies (Millerite), 105. Hrematite, 118, 120, 114, 128. Haidingerite, 146. Halite (Rock Salt), 174, 177. Hallite, 262. Halloysite, 220. Halotrichite, 157. Harmatite, 179. Harmatome, 264, 274. Harringtonite, 266. Hartite, 133. Hatchettine, 133. Hauerite, 108, 124, 152. Ilausmannite, 125. Hauyne, 246. Haydenite, 268. Haytorite (Quartz in pseudo- raorphs after Datolite). Heavy Spar, 152, 160. Hebronite, 164. Hedenbergite, 232. Hedyphane, 144. Heliotrope (Bloodstone), 208. Helmiuthite, 214. Hclvine, 229. Helvetane, 261. Hematite, 118, 120, 124, 128, Hercynite, 198. Herderite, 164. Herrerite, 137. Herschelite, 268. Hessite, 113. Hessonite (Garnet). Heterogenite, 189. Heterosite, 166. Heulandite, 269, 278. Hjelmite, 127. Hisingerite, 218, 258. Hcernisite, 146. Homichline, 105. Hopeite, 168. Horbaohite, 105. Hornblende, 233. Horn Silver Ore, 175, 177. Horseflesh Ore, 108. Hortonolite, 284. Hovite, 1,39. Hubnerite (Wolfram). Humboldtilite, 238. Humboldtine, 187. Humboldtite, 270. Humite, 204 Hunterite, 219. Hureaulite, 166. Hyacinth, 198. Hyalite, 209. Hyalophane, 236, 246. Hyalosiderite, 228. Hydrargillite (see Foot-note to Gibbsite). Hydroboracite, 172. Hydrocuprite, 189. Hydrodolomite, 139. Hydrofluocerite, 1,39. Hydrohematite, 125. Hydromagnesite, 138. Hydrophane (var. Opal). Hydrotachylite, 273. Hydrozincite, 139. Hypersthene, 232. Iberite, 220. Ice-spar (var. Orthoclase), Iceland Spar (var. (Jalcite). Idocrase, 244, 249, Idrialine, 130. Iglesito, 1.35. Ilmenite, 118, 120, 125, 128, 186, 192. Ilvaite, 228, 250. — Indicolite, 199. lodargyrite, 175. lolite, 200, 211. Iridium, 117. Iridosmine, 117. Iridosmium, 117, Iron, 117. Iron Alum, 157. Iron Chrysolites, 260. INDEX. 285 Iron Glance, 118, 120. Iron Pyrites, 105, 108. Ironstone, 140. Isoclase, 168. Ittnerite, 270. Ixolyte, 132. Jacobsite, 118. 186. Jamesonite, 111, 112. Jargon (Zircon), 198. Jarosite, 159. Jasper, 208. Jefterisite, 362. Jeffersonite, 233. Jenite (Lievrite), 228, 250. Jet, 132. Johannite, 157. Jordanite, 104. Kammercrite, 214. Kalaite (Turquoise). Koinite, 154. Kakoxene, 165. Kalinite, 154. Kampylite, 144. Kaolin, 219, 225. Karminspath, 144. Karstenite (Anhydrite), 152. Kastor, 215. Keilhauite, 230. Kenngottite (var. Miargyrite). Keragyrite, 175, 177. Kerasine, 1.35, 176. Kermesite, 121, 123, 149. Kerolite, 221. Kibdelophane (Ilmenite), 118. Kieserite, 155. Kilbrickenite, 112. KiUinite, 262. Kirwanite, 260. Kjerultine, 163. Klaprotliine (Lazulite), 168. Klipsteiiiite, 264, Knebelite, 229. Kobellite, 112. Kcettigite, 145. Kollyrite, 220. Konite, 130. Kottigite, 145. Kongsbcrgite, 116. Konleinite, 133. Koruudophyllite, 214. Koupbolite, 267. Krantzite, 132. Kraurite ((jreen Iron Ore, an iron i)liosphate). Kreittonite, 197. Kremereite, 175. Krisuvigite, 158. Krokidolite, 259. Kuhnite, 146. Kyauite, 197. Labradorite, 241. Labrador feldspar, 241. Lagonite, 172. Lampadite, 189. Lanarkite, 151. Lancasterite, 139. Langite, 158. Lanthanite, 139. Lapis Lazuli, 237. Larderellite, 172. Latrobite (var. Anorthite). Lauuiontite, 272, 277. Laxmannite, 182. Lazulite, 168. Lead, 115. Lead Binnite, 104. Lead Glance, 107, 109. Leadhillite, 135. Leafy Tellurium Ore, 111. Lehrbftchite, 106. Lehuntite, 266. Lenzinite, 220. Leouhardite, 272. Lepidoclirocite, 125, 187. Lepidokrokite, 125, 187. Lepidolite, 230, 234, 247. Lepidomelane, 227. Lettsomite, 158. Leuchtenbergite (Ripidolite), 214. Leucite, 203, 212. Leucophane, 178, 240. Leucopyrite, lOl. I^evyne, 268. Libethenite, 167, 170. Liebenerite, 220. Liebigite, 139. Lievrite, 228, 250. Lignite, 132. Ligurite (Sphene), 229. Lillite, 257. Lime Uranite, 166. Limonite, 125, 128. Linarite, 158. Lincolnite, 269. .^liudakeritc, 139. Linnceite, 105. Liroconite, 144, 147. Litharge, 187. Lithia Mica, 234. Liver Ore, 131. Lobolite, 245. LoUingite, 101. 286 INDEX. Loewite, 154. Loxocla.se (var. Orthoclase). , Ludlamite, 165. Ludwigite, 171. Luuebergite, 168. Luiinite (Phosphorchaloit«), 167. Luzonite, 103. Magnesia AIutti, 154. Magnesite, 1.38, 140. Magnetic Iron Ore, 118, 120, 124, 128, 186. Mpgnetic Pyrites, 105, 108. Magnetite, 118, 120, 124, 128, 186. Magnoferrite. 186. Malachite, 135, 142. Malacolite, 243. Malakon, 198. MaUlonite (=:Bismuthic Gold). Mangau Blende (Alabandine, 124). Manganite, 119, 120, 125. Manganese Alum, 158. Manganese Spar, 137. Manganese Vitriol, 168. Marble, 140. Marcasite, 105, 108. Margarite, 215. Margarodite, 261. Marmatite, 151. Marmolite, 221. Martite, 118. Mascagnine, 153. Maskelynite ( = Meteoric Labra- dorite). Masonite, 259. Massicot, 187. Matlockite, 176. Maxite, 135. Medjidite, 157. Meerschaum, 221. Megabromite, 175. Meionite, 240. Melaconite, 189. MeLanglance, 110. Melanite (Black (jarnet). Melanolite, 258. Melanochroite (Phoenicite), 182. Melanterite, 166. Melilite, 238. Melinophane, 178, 240. Meliphanite, 178, 240. Meionite, 114. Melopsite (near Deweylite), 221. Menaccanite, 118. Mendipite, 176. Meneghnite, 111. Mengite, 126. Menilite, 202. Mennige, 187. Mercnry, 115. Mesitine, 1,36. Mesolite, 266. Mesotype, 265. Mctabrnshite, 168. Metachh)rite, 214, 2.56. Metacinnabarite, 107. Metaxite, 221. Meteoi'ic Iron, 117. Miargyrite, 110, 121. Micas, 213, 224. Microbromito, 176. Microcline, 246. Microlite (Pyrochlore), 126. Microsommite, 237. Millerite, 105. Miloschin, 218. Mimetesite, 144, 148. Minium, 187. Mirabilite, 153. Mispickel, 103, 104. Mizz(mite, 241. Molybdenite, 107, 109. Molybdic Ochre, 183. Monazite, 165. Monrolite, 200. Montebrasite, 164. Monticellite, 204. Moonstone ( = Opalescent Feld- spar). Morenosite, 157. Moroxite (var. Apatite), 163. Mosandrite* Mottramitc, 184. Mountain (york, 258. Mountain Wood, 258. MilUerine, 113. Mundic, 105. • Aorideiitally omitted from Table XXVII., immediately following Heulandite, a.s annexed: (//■ 40 ; streak distinctly yellow or brovmish ; decomposed by hydrochloric acid with jtroduction of chlorine fumes). MosANDRiTK :- EsRcntinl components: Na«0, CaO, MnO, Gc«OS with Di*!)a and La«()8. TjOU, SiOS, II20. llli(inibi(H?), but mostly in broad-fibrous or lamellar masses of a redilish-biDwn colour; Q 2'9-3 0. BB irituuioscos and fuses readily into a yellowish-brown bead. The liyilro- chlorlc-aold solution is reddish-yullow, butbocoutes paler, and evolves chluriue, on heating. A very rare 8i>ecles. INDEX. 287 Muromontite, 228. Muscovite, 213, 224. Nacrite, 219, Nadorite, 150. Nagyagite, 111. Nantokite, 175. Nasturane, 127. Native Antimony, 113. N. Arsenic, 101, 102. N. Bismuth, 101, 115. N. Oopjjer, 110. N. Goia, 116. N. Iridium, 117. N. Iron, 117. N. Lead, 115. N. Mercury, 115. N. Palladium, 117. N. Platinum, 117. N. Silver, 110. N. Sulphur, 130. N. Tellurium, 113. Natrolite, 2o5, 274. Natron, 138. Naumaunite, 106. Needle Ore, 107. Neftgil, 133. Nemalite, 190. Nepheline, 239. Nephrite, 243. Newjanskite, 117. Nickel Glance, 110. Nickel <;rreen, 145. Nickel (iymnite, 217. Nickel Vitriol, 157. Nickeline, 101, 102. Nigrescite, 260. Nigrine, 127. Niobite (Columbite), 126. Nipholite, 178. Nitratine, 181. Nitre, 181. Nitrocalcite, 181. Nitromagnesite, 181. Nontronite, 218. Nosean, 236. Nosine, 236. Nuttalite, 241. Obsidian, 247. Ochres : Bismutli O., 188. Manganese O. (Wad), 188. Molybdic, O., 183. BedO., 186, 192. Tungatic O., 183. Uran 0., 190. Yellow O., 187. Octahedrito, 127, 199. (Ellacherite, 261. Oerstedite, 198. Okenite, 268. Olatite, 240. Oligoclase, 246. Olignn Spar, 1.36. Olivenito, 143, 147. Olivine, 204, 210. Ompliazite (Var. Pyroxene). Onkosine (compact ma<;ne.sian mica? Kelated to Phlogo- pite or Biotite, as Steatite to Talc). Onofrite, 106. Onyx (Agate), 208. Opal, 202, 208. Ophiolite, 225. Orangite, 218. Orpiment, 130, 131. Orthite, 228. Orthoclase, 245, 2,5,3. Osnielite (Pectolite?), 265. Osmium-Iridiura, 117. Oateolite, 163. Ostranite, 198. Ottrelite, 259. Ouvarovite, 198. Owenite, 256. Oxalite, 187. Oxhaverite, 268. Ozarkite, 272. Ozokerite, 133. Pachnolite, 178. Paisl)ermte, ) t,, , .. PajsberSite; ( ^- Rl^odonite, Palagouite, 257. Palladium, 117. Paper Coal, 132, Paraffine, 133. Paragon ite, 261. Paranthine, 240. Pargasite, 233. Parisite, 179. Passauite, 241. Patrinite (Aikinite), 107. Paulite (v. HyiKjrstheue), 232. Pearl Mica, 215. Pearl Spar (Dolomite). Pearlstone, 247. Pectolite, 265. Peganito, 167. Pegmatolite, 245. Pelip-^uite, 219. Pelokonite, 189. Pennine, 214. Percy lite, 176. 288 INDEX. Periclase, 190. Pericline, 24(3, 255. Perirlot, 2()t. Peristeritc, 246. Perowskito, 126. Perthite, 245. Petalite, 235. Petroleum. 132. Petzite, 113. Phacolite, 208, 278. Phiestiue (Altered Bronzite). Phannacolite, 146, 148. Pharmacosiderite, 145, 148. Phenakite, 200. Phengite (Muscovite). Phillipsite, 270, 276. Phlogopite, 213, 224. Phoeiiicite, 182. Pholerite, 219. Phosgeuite, 135, 176. Phosphocerite, 164. Phosphorchaloite, 167, 170. Phosphorite, 163 Phyllite (OttreUte ?), 259. Physalite, 197. Piauzite, 132. Pickeringite, 154. Picotite (Chroiniferous Spinel). Picrolite, 221. Picrophyll, 215. Picrosmine, 221. Piedmontite, 231. Pilinite (asbeatiformamphibole?) Pimelite, 217. Pinguite, 218. Pinite, 220. Pinite group, 226. Pisanite, 157. Pissophane, 158. Pistacite, 231. Pistomesite, 136. Pitchblende, 127, 190. Pitchstoue, 247. Pittizite, 146. Plagionite, 111. Plauerite, 167. Plasma (Green Calcedony). Platinum, 117. Platinum-Iridium, 117. Platitium-Irou, 117. Plattnerite, 122. Pleonaste, 197. Plinian, 103. Plumbago, 117. Plumbo-Oalcite, 135. Plumosite (Jamesonite). Poliauite, 119. Pollux, 203. Polyadelphite (var. Garnet). Polyargyrite, 110. Polybasite, 104, 110, 121, 143. Polycrase, 126. Polydymite, 105. Polyhalite, 156, 161. Polymignite, 126. Polyxene (N. Platinum). Poonahlite, 272. Porcelain Earth (Kaolin), 219. Prase, 208. Prascolite, 220, Prasine (Ehlite), 166. Pregrattite, 261. Prehnite, 267- Prochlorite, 214. Prosojiite, 179. Proustite, 121, 123, 143. 147. , Przibramite, 129. Pseudomalachite (Phosphor- chaloite), 167. Pseudophite (Compact Chlorite). Psilomelane, 119, 125, 193. Psittacinite, 184. Pucherite, 182. Purple Copper Pyrites, 105, 108. Puschkinite (Epidote). Pycnite, 197. Pycnotrope, 263. Pyrallolite, 222. Pyrargillite, 220. Pyrargyrite, 110, 112, 121, 123. Pyreneite (Black Garnet). Pyrgom, 232. Pyrites : Arsenical Pyrites. Capillary Pyrites (Millerite), 105. Cockscomb Pyrites, 108. Copper Pyrites, 105. Iron Pyrites, 105, 108. Magnetic Pyrites, 105, 108. Purple Copper Pyrites, 105. Radiated Pyrites (Marca- site), 105. Spear Pyrites, 108. White Iron Pyrites (Mar- casite), 105, 108. Pyrochlore, 126. Pyrochroite, 189, 191. Pyrolusite, 119, 120, 125, 193, Pyromorphite, 163, 169. Pyrope, 231. Pyrophyllite, 214. Pyrophysalite (Pycnite), 197. Pyropissite, 132. Pyrosclerite, 264. Pyrosmalite, 257. INDEX. 289 Pyrost'/ite, 149. Pyrostilpnite, 149. Pyroxene, 232, 243, 250. Pyrrliite (Pyrochlor?). Pyrrhosideritc (Goethite), 187. Pyrrhotine, 105, 108. Quartz, 202, 208. Quicksilver, 115. RabdionJte, 189. Radiated Pjrrites (Marcaaite), 105. Eadiolite, 266. Rammelsbergite, 101. Randanite, 202. Raphilite (var. Amphibole). Ratofkite, 178. Realgar, 130, 131. Red Antimony Ore, 121, 123, 149. Red Copper Ore, 116, 189. Red Hematite, 186, 192. Red Iron Ore, 186, 192. Red Lead, 187. Red Ochre, 186, 192. Red Silver Ores, 121, 123, 147. Red Zinc Ore (Zincite), 188, 193. Reddle, 192. Redruthrite (Copper Glance), 106. Remingtouite, 139. Renaselaerite (Pseudon. Orpheus Steatite). Retinalite, 221. Retinite, 132. Reussin, 154. Rhoetizite (Kyanite), 197. Rhagite, 145. Rhodizite, 171. Rhodochrosite. 137, 141. Rhodonite, 233. Richmondite, 167. Rionite, 112. Ripidolite, 214, Rittingerite, 102, 104, 121, 143. Rivotite, 150. Rock Crystal, 202, 208. Rock Salt, 174, 177. Romerite, 157. Ropperite, 137. Rottistite, 217. Romanzovite (var. Garnet). Romeite, 150. Roscoelite, 213. ^ Rose Quartz, 208. Roselite, 145. Rubellane, 261. - 1 20 Rubellite, 199. Ruby, 196, 207. Ruby Blende (Red Silver Ores), 147. Ruby Copper (Red Copper Ore), 189. Ruby Silver (Red Silver Ores), 121, 123, 147. Rutile, 127, 129, 198, 206. Ryacolite, 245. Sagenite (var, Rutile). Sahlite, 232, 243. Salammoniac, 174. Salamstone (var. Corundum). Salmiac, 1V4. Saltpetre, 181. Salt, 174. Saniarskite, 126, 196. Sanidine, 245. Sapphire, 196, 297. Sapphirine, 197. Sarcolite, 239. Sardianite, 151. Sartorite, 104. Sassoline, 171. Saynite, 105. Scapolite, 240, 252. Scheelite, 183, 185. Scheererite, 133. Schiller-spar, 215. Schorl, 231, 248. Schorlomite. Schrffitterite, 262. Schreibersite (Meteoric Iron Phosphide). Schwartzembergite, 176. Scleroclase, 104. Scolecite, 272, 277. Scorodite, 146. Scoulerite, 272. Seebachite, 268. Seladonite, 258. Selenite, 155, 161. Sellaite, 178. Senarmontite, 159. Sepiolite, 221. Serbian, 218. Sericite, 261. Serpentine, 221, 225. Serpentine Group, 225. Seybertite (Clintonite) 219. Siderite, 136, 140, Sideromelane, 228. Sideroplesite, 136. Sideroschisolite (Cron8*;edtite), 256. Sieburgite, 132. 290 INDEX. Siegenite, 105. Silaonite, 106. ' Sillimanite, 200. Silver, 116. Simonyite (Blodite), 154. Sismondine, 259. Sisserskite, 117. Skutterudite, 101. Smaltine, 101, 102. Smaragdite, 243. Smithsonite, 137, 141. Soapstone, 242. Soda Alum, 154. Soda Nitre, 181. Sodalite, 237. Sommite (Nepheline), 239. Sommervillite, Sordawalite, 260. Spartalite, 188. Spathic Iron Ore, 136, 140. Spear Pyritea (Marcaaite), 108. Specular Iron Ore, 118, 120. Sphoerocobaltite, 137. Sphcerosiderite, 136. Sphalerite, 108, 109, 124, 151, 160. Sphene, 229. Spinel, 197, 208. Spodumene, 235. Stannine, 105, 100. Stassfurtite, 171, 173. Staurolite, 198, 210. Steatite, 222, 225, 242. Stellarite, 132. Stellite(Pectolite?). Steppanite, 110. Sterlingite (Damourite). Stern bergite*. Stiblite, 149. Stibnite, 110, 112. Stilbite, 269, 278. Stilpnomelane, 250. Stilpnosiderite, 187. Stolzite, 183, 185. Strengite, 165. Striegisan, 167. Stiigovite, 257. Strogonowite (Altered Seapo- Ute). Stromeyerine, 106. Strontianite, 137, 142. Struvite, 168. iStypticite, 158. Succinite, 132. Sulphur, 130. Susannite, 135. Su3sexite. 172. Svanbergite, 155. Sylvanite, 113. Sylvine, 174. Symplesite, 146. Sj'^ngenite, 156. Sysserskite, 117. . Szaibelyite, 172. Tabergite, 214. Talnilar Spar, 238. Tachydrite, 174. Tachyaphalite, 198. Taohylite, 228. Tagilite, 166. Talc, 214, 225. Tolcosite, 214. Talc-Apatite, 163. Tallingiue, 176. Tantalite, 127. Tapiolite, 127. Tarmowitzite, 135. Tauriscite, 157. Tekoretine, 133. Tellurium, 113. Tengerite, 139. Tennautite, 103, 104. Tenorite, 116, 122. Tephroite, 229. Tetartin (Albite), 246. Tetradymite. 113. Tetrahedrite, 110, 112. Texasite, 139. Thallite, 231. Thenardite, 153. Thermonatrite, 138. Thomaenolite, 179. Thomsonite, 271, 276. Thorite, 218. Thraulite, 218, 258. Thulite, 244. Thuringite, 256. Tiemannite, 106. Tile Ore, 122, 189. Tinkal, 171. Tinkalzite, 172. Tinstone, 127, 129. Tirolite, 144. * Omitted from Table III., page 105 : (Ag and Fe rtaetions). Sternberoite : Ag, Pe, S, In somewhat variable proportions. Hex., but commonly in leafy, flexible examples; tombac brown with blue tarnisti; 11 10-1 '5; Q 4'2. BB, fusible into a ailver-coated magnetic globule. INDEX. 291 Titaniferous Iron Ore, 118, 120, 125, 128, 18G, 192. Titanite, 220. Tecornalite, 175. Topaz, 107, 200. Topazolite (Yellow Garnet). Torbarnite, 1,32. Torbeinite, 1G6. Touniuilinu, 199, 211, 231, 244. Traversellite (var. Asbestus). Tremolite, 24.S. Tridymite, 201. Triphane, 235. Triphylline, 104, 170. Triplite, 1G3, 100. Tripoli, 202. Tra'gerite, 140. Troilite, 105. Trollcite, 108. Trona, 138. Troostite, 203, 222. Tschermigito, 1 54. Tschewkiuito, 238. Tuugstic (.)chre, 183. ' • Turgite, 125, 187. Tunierite, 105. Turquoise, 107, 170. Tyritc, 127. Tyrolite, 144, 147. Ulexite, 172. Ulluicuinite, 103, 110. Unghwarite, 218. Unionite, 244. Uraconise (Uran Ochre), 190. Uraninite (Pitch Blende), 127, 190. Uranite, 100. Uran Mica (Copper-Uranite), 100. Uran Ochre, 190. Uranospinnite, 140. Uran Pitch Ore, 127. Urao (Theruionatrite), 138. Urpethite, 133. Uwarowite, 198. Valentinite, 149. Vanadinite, 183. Variscite, 107. Varvicite (Warwickite), 120. Vauquelinite. 182. Velvet Copper Ore, 158. Verde Antique Marble, 225. Vermiculite, 262. Vesuvian, 244, 249. Villarsite, 221. Vitreous Copper Ore (Copper Glance), 100. Vitreous Silver Ore (Silver Glance), 107. Vitriol, blue, 150. Vitriol, col)alt, 157. Vitriol, green, 150. Vitriol, manganese, 158. Vitriol, nickel, 157. Vitriol-Ochre, 1 58. Vivianite, 1()5, 170. Voglianite, 157. Va'lknerite, 101, Voglite, 139. Voigtite, 250. Volborthite, 184. Voltaite, 157. Voltzine, 151. Vulpinite (Heavy Spar), 152. Wad, 188, 103. Wagnerite, 103. Walpurginite, 145. Wapplerite, 140. Warringtonite, 158. Warwickite, 120. Wavellite, 107, 170. Wel)sterite, 155, 102. Wehrlite, 112. Weissite, 220. Wernerite, 240, 252. Whewellite, 191. Whitneyite. 101. Wichtisite, 2.34. Wichtyne, 234. Willemite, 203, 222. Williamsite (var. Serpentine). Wilsonite, 200. Wiluite, 245. Wiserite, 139. Wthamite, 231. Witherite, 137, 142. Wittichenite, 107. Woehlerite, 240. Woelchite (var. Bournonite). Wcerthite, 200. Wolfachite, 103. Wol£mite,!ll«'122.123.1S3. Wolfsbergite, 111. Wolchonskoite, 218. WoUastonite, 238. Wolnyn (Heavy Spar), 152. Wood Opal, 202, 209. Wood Tin, 200. Woodwardite, 158. Wulfenite, 183, 185. Wurtzite (Hexagonal Blende). 202 md %.f mJ INDEX. Xantliito, 245. Xiuitliacoiu), 143. Xauthophyllite, 216. Xauthoaidorito (var. Brown Iron Ore). Xenolite, 200. Xeuotime, 164. Xylite, 260. Xylotile, 258. Yellow-Ochre, 187. Yttrocerite, 179. Yttrotantalite, 127. Yttrotitauite, 230. Zalpaite, 107. Zaratite, 139. v Zeagonite, 271. Zeolites, 2T.\ to 278. Zepharovichite, 107. Zeuuerite, 144. Ziegenite, 105. Zinc Bieu.le, 108, 109, 124, 129, 151, 159. Zinc Bloom, 1.39. Zincite, 188, 193. Zinc Spar, 137. Zinc Vitriol (Goslarito), 155. Zinkenite, 111. Zii)peite, 157. Zircon, 198, 207. Zoisite, 244, 249. Zorgite, 106. Zwieselite, 164. Zygadite, 246. OOPF, ULAUK