IMAGE EVALUATBON TEST TARGET (MT-S) A 1^ ^ 4 $P^ /A Photographic Sciences Corporation 33 WEST MAIN STRUT WIBSTIR.N.Y, MS80 (716) e73-4S03 CIHM/ICMH Microfiche Series. CIHIVI/ICMH Collection de microfiches. Canadian Institute for Historical Microreproductions / Institut Canadian de mirroreproductions historiques ;V Technical and Bibliographic Notes/Notes techniques et bibliographiques Th« tot The Institute has attempted to obtain the best original copy available for filming. Features of this copy which may be bibliographically unique, which may alter any of the images in the reproduction, or which may significantly change the usual method of filming, are checked below. □ n n □ D D n Coloured covers/ Couverture de couleur Covers damaged/ Couverture endommagee Covers restored and/or laminated/ Couverture restaurde et/ou pellicul6e Cover title missing/ Le titre de couverture manque Coloured maps/ Cartes gdographiques en couleur Coloured ink (i.e. other than blue or black)/ Encre de couleur (i.e. autre que bleue ou noire) I I Coloured plates and/or illustrations/ D Planches et/ou illustrations en couleur Bound with other material/ Reli6 avec d'autres documents Tight binding may cause shadovs or distortion along interior margin/ La reliure serr^e peut causer de I'ombre ou de la distortion le long de la marge intdrieure Blank leaves added during restoration may appear within the text. Whenever possible, these have been omitted from filming/ II se pect que certaines pages blanches ajouties lors dune restauration apparaissent dans le texte, mais, lorsque cela dtait possible, ces pages n'ont pas 6t6 filmies. Additional comments:/ Commetitaires suppl^mentaires, L'Institut a microfilm^ W' meilleur exemplaire qu'il lui a dt6 possible de se procurer. Les details de cet exemplaire qui sont peut-dtre uniques du point de vue bibliographique, qui peuvent modifier une image reproduite, ou qui peuvent exiger une modification dans la m^thode normale de filmage sont indiqu6s ci-dessous. I I Coloured pages/ D Pages de couleur Pages damaged/ Pages endommag6es Pages restored and/oi Pages restaurdes et/ou peilicul^es Pages discoloured, stained or foxec Pages d6color6es, tachetdes ou piqu^es Pnges detached/ Pages d6tach6es Showthrough/ Transparence Quality of prir Qualitd in6gale de limpression Includas supplementary materit Comprend du materiel supplementaire Only edition available/ Seule Edition disponible I I Pages damaged/ I I Pages restored and/or laminated; I ~V Pages discoloured, stained or foxed/ I I Pnges detached/ r~~l Showthrough/ I I Quality of print varies/ I I Includas supplementary material/ I I Only edition available/ Pages wholly or partially obscured by errata slips, tissues, etc., have been refilmed to ensure the best possible image/ Les pages totalement ou partiellement obscurcies par un feuillet d'errata, une pelure, etc., ont 6t6 film^es A nouveau de fapon d obtenir la meilleure ima^i possible. Thj PO! Of 1 filn Ori be{ the sioi oth firs sioi or! The sha TIN whi Ma| diff enti beg righ reqi mel This item is filmed at the reduction ratio checked below/ Ce document est film* au taux de reduction indiquA ci-dessous. IPX 14X 18X ^X "1 I n I \ \ m \ \ \ ' 26X 30X 12X 16X 20X 24X 28X 32X The copy filmed here has been reproduced thanks to the generosity of: National Library of Canada L'exemplaire filmd fut reproduit grSce d la gdndrositd de: Bibliothdque nationale du Canada The images appearing here are the best quality possible considering the condition and legibility of the original copy and in keeping with the filming contract specifications. Original copies in printed paper covers are filmed beginning with the front cover and ending on the last page with a printed or illustrated impres- sion, or the back cover when appropriate. All other original copies are filmed beginning on the first page with a printed or illustrated impres- sion, and ending on the last page with a printed or illustrated impression. The last recorded frame on each microfiche shall contain the symbol — ^> (meaning "CON- TINUED"), or the symbol V (meaning "END"), whichever applies. Maps, plates, charts, etc., may be filmed at different reduction ratios. Those too large to be entirely included in one exposure are filmed beginning in the upper left hand corner, left to right and top to bottom, as many frames as required. The following diagrams illustrate the method: Les images suivantes ont 6t6 reproduites avec le plus grand soin, compte tenu de la condition et de ia nettetd de I'exemplairs filmd, et en conformity avec les conditions du contrat de filmage. Les exemplaires originaux dont la couverture en papier est imprim^e sont film^s en commenpant par le premier plat et en terminant soit par la dernidre page qui comporte une empreinte d'impression ou d'illustration, soit par le second plat, selon le cas. Tous les autres exemplaires originaux sont filmds en commenpant par la premidre page qui comporte una empreinte d'impression ou d'illustration et en terminant par la dernidre page qui comporte une telle empreinte. Un des symboles suivants apparaitra sur la dernidre image de cheque microfiche, selon le cas: le symbole — ^>signifie "A SUIVRE", le symbols V signifie "FIN". Les cartes, planches, tableaux, etc., peuvent dtre filmds A des taux de rdductioi diff^rents. Lorsque le document est trop grand pour dtre reproduit en un seul cliche, 11 est filmd A partir de Tangle supirieur gauche, de gauche d droite, et de haut en bas, en prenant le nombre d'images n^cessaire. Les diagrammes suivants illustrent la m6thode. 1 2 3 1 2 3 4 5 6 MINE c ! - U si' M i\ OHAPMAISI'S MINERAL INDICATOR. 1 1 J ,\ tr- WORKS BY PROFESSOR E. J. CHAPMAN. ■- , •• I... , MINERALS x\NI) (GEOLOGY OF CENTRAL CANADA, COMPRISISCI THE PROVINCES OF ONTARIO AND QUEBEC. Third Edition, With 250 Wnod-rnU and a ropioim Index. 11. AN OUTLINE OF THE (lEOLOClY OF CANADA. INCLUDING AT;i. THE PROVINCES OF THE DOMINION. With six .Hketch-maps and six platen of eharactfiridic fossils. A New Edition in Pr<'i^s. in. BLOWPIPK PRACTICE. WITH ORIOINAf. TABLES FOR THE DETERMINATION OF MINERALS. Second Edition. Tliis work has been favora1)ly noticed in the Uth and I2th editions of Von Kobell's celebrated Tafe.ln ziir Bestinimunp der Mineralien. IV. PRACTICAL INSTRUCTIONS FOR THE DETERMINxVnON BY FURN.\CE ASSAY OF GOLD AND SILVER IN ROCKS AND ORES. Second Edifit^. ■ ■ V. ■ THE MINERAL INDICATOR. A PRACTICAL (U'lDU TO THE OETERMINA'l'ION OF IJRNRRALLY- OCCURRlN(J MINERALS. Second Edition. THE COPP, CLARK COMPANY LIMITED, 9 Front Street West, Toronto, M \j i THE '. . * MINERAL INDICATOR: A PRACTICAL GUIDE «1 ■ h .1 f 1 TO THE DBTEBMISATION OF GENERALLY - OCCURRING MINERALS. W K J. CHAPMAN, Ph.D., LL.D., Profrsnor in the University of Toronto. SECOND EDITION. TORONTO: THE COPP, CLARK COMPANY (Limited). 9 Fkont Stri?rt West, 1893. in3 '4 7 Entered according to the Act of the Parliament of Canada, in the year one thousand eight hundred and ninety-three, by The Copp, Clark Company, Limited, in the Office of the Minister of Agriculture. . - 1 1 i. \i I:-' ii PREFACE. ¥ r I : In his work on Blowpipe Practice, the author has given a y / series of original tables for the determination of minerals, in which, as distinguished from other determinative tables of this kind, an attempt is made to include under the same table min- erals of related composition only. In the interval that has elapsed since the publication of the first edition of this work, the advantages of the plan referred to have been fully proved in the author's laboratory by students of sufficiently advanced standing to determine readily the characters, and work out the reactions, on which the tables are based. But experience has also shown that something of a less elaborate description would be better adapted to meet the requirements of students just entering on the study of minerals. Hence the publication of the present simplified tables, by which the name and nature of any mineral of ordinary occurrence may be easily and rapidjy ascertained. All that is required, for this purpose, is a slight acquaintance with mineral terminology, and a few hours' pra- liminary practice in the use of the blowpipe. As regards their frequency of occurrrnce or their relative interest and importance, minerals may be referred to four more or loss distinct series. To the first belong all minerals of com- mon occurrence ; to the second, minerals of comparatively rare occurrence but of economic value, or otherwise of importance ; -'wm VI PREFACE. to the third, exceptionally occurring and comparatively unim- portant minerals ; and to the fourth, obscurely known and ill defined or doubtful species. The present tables include all representatives of the first and second series, and consequently all minerals that are likely to come under the observation of the general student or practical explorer. In this new issue of the Mineral Indicator a few additions have been made to the text, and the subordinate subdivisions of two or three of the tables have been re-arranged. Otherwise, the little book remains unaltered. E. J. 0. University of Toronto, July, 1893. ! ! J I PRELIMINARY NOTICE INCLUDING GENERAL INSTRUCTIONS TO BE OBSERVED IN USING THE TABLES. f 1 1 \. The aspect (or lustre) and the colour of a mineral must be determined, as a rule, on a perfectly unaltered or newly-fractured surface. Minerals of metallic lustre, more especially, frequently present a deceptive surface character from the assumption of a dark or other tarnish. 2. When a mineral presents a sub-metallic aspect it will probably be found in both divisions of the Tables ; but in doubtful cases it should be sought for more especially in the second division. A ready test, with regard to lustre in these doubtful cases, is as follows : — Let the student ask himself the question, " would this substance, from its appearance, be taken by an observer, ignorant of mineralogy, for a piece of gold, or brass, or copper, or bronze, silver, lead, tin, steel, or iron ? " If the answer be in the negative, the name of the substance should be sought for under Division II. 3. Minerals of metallic lustre, proper, are always opaque, even in thin splinters, and their streak or powder is always distinctly coloured. Minerals of pseudo-metallic or metallic-pearly lustre (as the various micas), on the other hand, are commonly translucent or transparent in thin pieces, and their streak is either white or lightly tinted. Substances of this latter description, therefore, must be sought for under Division II. of the Tables. 4. When a mineral scratches glass (i.e., ordinary window-glass) very feebly or doubtfully, it should be sought for principally under § 2 of the Division (metallic or non-metallic) to which it belongs. In 7 •■^^i ,''■1;! ^! 8 PRELIMINARY NOTICE. trying the hardness of a mineral, the operator should place a piece of glass flat upon a table, and then draw the mineral sharply across it — taking care to see previously that particles of quartz oj: pyrites are not present in the substance. Minerals which are not sufficiently hard to scratch glass, are more or less readily scratched by the knife. Minerals, on the other hand, which scratch glass, remain unmarked by the knife. 5. Minerals which fuse with, extreme difficulty, or only become vitrified and rounded on the thinnest edges, are placed in these Tables {in order to avoid risk of error) under both the fusible and infusible groups of the section to which they belong. In trying the fusibility of a mineral, beginners should be careful to operate only on thin jmd sharply -pointed splinters ; not on comparatively broad and thick- edged fragments. ;: 6. As an additional guide to determination, the essential com- ponents of the various minerals included in the Tables are briefty indicated ; but where percentages are given, these, for simplicity, are stated as a rule in whole numbers only. , 7. The Tables, with one or two exceptions, are subdivided for greater facility of reference into smaller divisions or Groups. At the head of each group a list of the minerals belonging to the group is given, and the determinative characters of these minerals are described in the succeeding observations. The student is advised cu add to the species in each list its more important determinative characters. This has been omitted expressly in the book, in order that the observations in question should be read and studied — maay students being inclined to save themselves trouble, to their awu detriment, in this respect. When, alsoy. th^ ittuos is made out, tho determination should be confirmed by the detection of the charaoter- istic componeats of the sub&taiuje, so far as this can be douA by Hxs blowpipe or by a few simple tests. Much, greater, and, in. the ead, more rapid progress will be luiuibs b.y a thovougltL examioation of these or four n inerals (or fewer) at a sitting, than by attempting to deter- mine the names only of half-a-score of examples. 8. As this litttljB hamUxKtk i& iatendedi to> be 'used by students aim gra] exd tera att« Pr^ min 9 be c mui (121 Kol Bru Dr. qui the «l i ■^1 < PRRLIMINARY NOTICE. almost at the beginning of their mineralogical studies, all crystallo- graphi'' references (beyond a few bare indications) have been purposely excluded from the Tables. A synopsis of the crystallization charac- ters of the more important mineral species will be found in the Notes attached to the Determinative Tables of the author's Blowpipe Practice. In these Notes also, the spectroscopic characters of minerals are fully given — a feature not found in other works. 9. The foUowiiig works on Determinative Mineralogy should also be consulted by more advanced students: — (I) Tafeln zur Beatim* mung der Minoralien, by the late Professor von Kobell, of Munich, <12th ed. by K. Oebbeke, 1884). (2) The American edition of von Kobell's " Tafeln," re-arranged and amplified by Professor George J. Brush. And (3) the Anleitung zum Bestimmen der Mineralien, by Dr. Fuchs, of Heidelberg. The Tables given in the present book are quite distinct from those of the above named works, as well as from the Determinative Tables of the author's Blowpipe Practice. 1 1 i 1 I ■JJli p DI §1. §3. DI I INDEX TO THE TABLES. DIVISION I.— Minerals of Metallic or Sub-Metallic Aspect. § 1. Hardness sufficient to scratch ordinary window-glass distinctly. Not scratched by the knife. Colour, brass- yellow .... Table I. Colour, tin-white or silver- white Table II. Colour, iron-black, steel-grey, or dark- brown Table III. § 2. Hardness insufficient to scratch window-glass distinctly. More or less readily scratched by the knife. Distinctly malleable or ductile Table IV. Not distinctly malleable : Colour, silver-white or tin- white ....Hkv Colour, brass-yellow, bronze-yellow, or reddish Table VI. Colour, metallic-grey, black, or dark- brown : . (i) Readily fusible or volatilizable Table VII. (u; Infusible, or fusible on thin- nest edges only Table VIII. DIVISION II.-Minerals of Vitreous, Stony, Earthy,, or other Non-Metallic Aspect. § 1. Hardness sufficient to scratch window-glass ^.^'Minctly. Streak or iwwder distinctly coloured . . .Tablb IX. 11 I ■ 'I; :| ■ ■ ' ■ ''■'f' U 12 W i .§2. IXDEX TO THE TABLES. . Streak uncoloui-ed, or indistinctly coloured (i. e., greyish, tfec.) Fusible: '''''' ' Black, brown, daik-red, or dark- , ; green in colour, and essentially op«que Table X. Colourless, or clear-green, greyish, pink, red, yellow, or blue in ^ ^ ►- colour Table XI. InfusibU^ (or fusible on thinnest edges only Table Xfl. IlardnesH insufficient to scratch window-glass. Easily scratched by the knife. ^'^P^^ Table XIII. Combustible : taking fire and burning when held in the form of a thin . »' splinter against the edge of a candle if V. flame or Bunsen-flame .TabLB XIV. Effervescing in dilute acid Tablb XV. Yielding l>ef<)re the blowpipe-flame, on charcoal, a garlic-like odour Table XVI. The preceding characters not manifested : Fttaible :— or otherwise reducible on clmi'coul : Btreak-powder coloured Table XVII. Streak-powder uncoloured Table XVIII. Infusible (or fusible on thinnest edges only): Streak-powder coloured Tablk XIX. Streak-powder uncolouifetl Tabli: XX. THE MINERAL INDICATOR. ^11 m TABLE I. [Lustre metallic. Hardness sufficient to scratch glass strongly. Colour, brass-yellow.] Iron Pyrites (Fe 47, S 53 = FeS^); Marcasite (Fe 47, S 53). These minerals are chemically identical, but differ in crystallization, and to some extent in other physical charac- ters. Iron Pyrites belongs to the Regular or Isopolur System, and when crystallized, is conmionly in cubes, penta- gonal dodecahedrons, or combinations of these forms. Its sp. gr = 4*9 to 51. Marcasite is Rhombic in crystalli^tition,. and occurs commonly in groups of prismatic crystals often arranged in crested rows ( = " Cockscomb Pyrites," " Spear Pyrites," &c.). Its sp. gr. ■■4'7 to 4*1), and its colour i* usually somewhat paler than that of Iron Pyrites, proper. It has, moreover, a great tendency to fall into decomposition. Massive and radio-fibrous varieties of both 8[)ecios are also common. BB, both emit a sulphurous odour, and melt readily into a dark magnetic globule. Ignited in a narrow test tube or bulb-tube, both yield a subliumte of suiphur. 13 fe 14 THE MINERAL INDICATOR. TABLE II. [Lustre metallic. Hardness sufficient to scratch glass more or less distinctly. Colour, tin- white or silver- white.] •Cobaltine (CoFe 35, As 45, S 20); Smihine (CoNi 28, As 72). Arsenical Pyrites or Mispickel (Fe 34, As io, S 20). These minerals fuse on charcoal with emission of copious arsenical fumes, easily recognized by their garlic-like odour. The resulting dark globule is magnetic. Ignited gently in a piece of open tubing, they yield a crystalline sublimate of As^O'. Cohaltine, and Smaltine, after roasting, colour borax BB deep-blue ; but only the smallest particle must be used, otherwise the glass will be so intensely coloured as to appear black and opaque. Both occur commonly in small crystals of the Regular or Isopolar System : Cohaltine chiefly in com- binations of cube and pentagonal dodecahedron ; Smaltine chiefly in octahedrons. Both, also, occur massive, dendritic, kc. Cohaltine is bright silver-white in colour ; Smaltine, greyish tin-white, and the latter (if quite pure) yields no sulphur-reaction BB with sodium carbonate. In both, the sp. gr. exceeds 6-2. Mispickel or Arsenical Pyrites is silver- white in colour, but rapidly tarnishes dull-grey. It occurs massive, and in rhombic prisms, mostly terminated by two lliit summit-planes, transversely .striated. Sp. gr. 6 to 6*3. Some varieties are cobaltiferous, and most examples contain small but workable amounts of gold. TABLE III. 15 TABLE III. [Luatre metallic or sub-metallie. Hardness snfficent to scratch glass distinctly. Colour, iron-black, steel-grey, or metallic-brown. ] In most of their examples, the minerals of this Table (those of steel-grey colour excepted) present merely a sub- metallic aspect. None emit fumes or odour when ignited BB on charcoal. First Group : Anhydrous species. No mater produced hy their ignition in a bulb-tube or test-tube. Magnetite (Fe 72-4, O 27-6). Frankli7iite ([ZnO, MnO, FeO] Fe^O^). Chromite (FeO 32, Cr-0'' 68). Hematite (Fe 70, O 30). Ilmenite (Fe-0'\ Ti'O^). Untile (TiO-). Anatase (TiO''). Wolfram yFeO, MnO, WO^*). Magnetite ( = Magnetic Iron Ore), Franklinite, and Chro- mite ( = Chromic Iron Ore), are the principal representatives of a group of oxides of the common formula [RO, R'-O^'] and of Regular or Isopolar crystallization — their connnon forms being the octahedron and rhombic dodecahedron. Massive and granular varieties are also common. Iri some of the rarer representatives of the group {Ferro-magnesite, &c.) part of the FeO is replaced by MgO. Magnetite is always strongly magnetic, often shewing polarity ; and Franklinite is very commonly magnetic also. In Magnetite the powder is black ; in Franklinite (when free f;om magnetite) it is usually dark-brown ; and the latter si)ecies gives a strong Mn-reaction by fusion with sodium carbonate. It is gener- ally in small roinided grains or crystals, with red zinc ore or H |. i I ^ 16 THE MINERAL INDICATOR. pale red troostite or willemite, in crystalline limestone. In both, the average sp. gr. =5*0. Chromite is much like granular varieties of magnetite, but is feebly or not at all magnetic, and its sp. gr. averages 4*5 only. With borax, BB, it forms a fine green glass. Hematite ( = Specular Iron Ore, Red Iron Ore) and Ilmenite ( = Titaniferous Iron Ore) are Rhombohedral in crystallisation, the crystals being usually fla< or thin-tabular; but lamellar, granular, scaly, and other varieties are also common. Hematite (as regards examples of metallic lustre) is steel-grey in colour, often with iridescent tarnish, and the streak is normally dull-red. BB, thin splinters fuse in the RF, at the extreme point, and become magnetic. In Ilmenite the streak is black or brownish. When in fine powder, the latter species is slowly dissolved if boiled gently in hydro- chloric acid, and the slightly diluted solution w^hen boiled with a piece of metallic tin becomes first colourless and then assumes an amethystine tint. Titaniferous examples of magnetite and hematite, however, shew the same reaction. Kutile and Anatase are metallic adamantine in lustre, and only certain varieties can be referred to this Table. They are chiefly distinguished from the other minerals of the Table by their lower sp. gr. (3-9 to 4-3), and by the amethys- tine or blood-red glass which they form BB with phosphor- salt in a reducing flame. Rutile (when the lustre approaches sub-metallic) is dark-red, brown, or black, with light-brown streak, and is either in square-prismatic crystals (often geniculated), or in rolled pebbles. Sp. gr. 4-2 to 4 3; nearly as hard as quartz. Anatase is brown or indigo-blue in colour, and is commonly in small acute octahedrons ; sp. gr. 3-9 to 4. ■i TABLE III. 17 Wolfram (a tungstate of iron and manganese) is black or bronze-brown, and sub metallic, only, in lustre. It is readily distinguished from the other minerals of this Table by its high sp. gr. (over 7*0), and its comparatively easy fusion. It melts BB into a magnetic globule with crystalline sur- face, and gives a strong Mn-reaction with sodium carbonate. Mixed in fine powder, with sodium carbonate and nitre, and fused in a platinum spoon, it forms an alkaline tungstate, soluble in hot water. The solution (which is of a green colour from presence of manganate of soda) when filtered or decanted from the insoluble residuum, aciditied with a few drops of hydrochloric acid, and boiled with a j)iece of tin or zinc, becomes rapidly colourless and then assumes a dee[) in- digo blue colour. Second Gkodp : Hydrous species; yielding water by igni- tion in the bulb tube. LimonUe : some varieties (Fe'-O^ 85 -G, H'-O 14*4). Psilomelam (Mn^Ol MnO, BaO, K'-'O, H'"0). Llmonite ( = Brown Iron Ore) presents as a rule, a non- metallic aspect, but some varieties are sub-metallic. On ignition, it becomes first red and then black and magnetic — the latter in the RF., or by ignition in the bulb tube. Black or brown in colour, with brownish-yellow streak. Massive, fibro-botryoidal, tkc. Sp. gr. 3'5 to 4 0. A thin splinter fuses BB at the extreme point. Psilojnelane occu's in iron black or dark steel-grc^y amor- phous masses with dark-brown or brownish-black streak. Non-magnetic after ignition. With sodium carbonate BB, it gives a strong Mn-reactiou. 18 THE MINERAL INDICATOR. . TABLE IV; [Lustre metallic. Hardness not sufficient to scratch window-glass. Malleable or Ductile.] The representatives of this Table comprise a small num- ber of native metals, and one malleable sulphide. Those bend before breaking, and when broken shew a " hackly " fracture. On the anvil, they flatten under the hammer. First Group: Readily fusible, BB, on charcoal Native Gold. Native Silver. Silver Glance (Ag 87, S 13). Native Copper. These minerals are readily distinguished from other mineruis of ordinary occurrence by tlieir malleability ; and, individually, by their resj)ective coioui'S : — gold-yellow silver-white with dark surface-tarnish —iron-black — copper- red. The metallic globule obtained by tusion on charcoal, in the case of N. Gold, N. Silver, and Sf.ver Glance (=: Ar on charcoal a yellow or white and yellow sublimate or ring-deposit. Antimony Glance and Pyrargyrite^ if pure, form a white sublimate, only. Galena is at once recognized by its high specific gravity, which exceeds 7, and by its rectangular cleavage. It occurs both massive and crystallized, commonly in cubes and **cubo- octahedron.s," and it breaks reidily into cubical fragments. BB generally decrepitates, volatilizes in great part, and then I TABLE VII. 27 melts intA a malleable lead-globule. H 2*5 ; sn. gv. 7-3 to 7 '6. Lead-grey in colour. Bismuth Glance occurs mostly in fibrous or acicular examples of a lead-grey colour. H 2 to 2*5 ; sp. gr. 6*4 to 6*7. BB yields a more or less brittle globule, and a dark- yellow ring-deposit. When fused in powder with potassium iodide, a ring-deposit af a vivid scarlet colour is obtained. Antimony Glance fuses in the flame of a candle, and volatilizes BB in dense white fumes, tinging the flame-point distinctly green. It occurs chiefly in fibious, lamellar, and granular masses of a light lead-grey colour : more rarely in elongated rhombic prisms with pyramidal summits. H 2 ; sp. gr. 4*5 to 4 '7. The powder rapidly becomes orange red in a hot solution of caustic potash. Jamesonite, and Zmk^nite form BB on charcoal a white and yellow ring-deposit from the presence of antimony and lead. Both are between lead-grey and steel-grey in colour, iind occur in fibrous, lamellar and acicular examples, and in small, rhombic crystals. In a hot solution of caustic potash, their powder is i-eadily decomposed, Sb'"S'' is dissolved out, and black PbS remains. A few drops of hydrochloric acid precipitaf^3 the Sb'''S^ in orange-red flocks. Jamesonite nve- sents a marked cleavage in one direction, and is too soft to scratch crystalline calcite ; its sp. gr. equals 5*5 to 505. Zinkenite is hard enough to scratch calcite, and its sp. gr. rismatic crystals, longitudinally striated, and terminated by the planes of a rhombic pyramid. Orthite much re- seml)]es Ilvaite, but the crystals are Clino-Rhombic and the streak is but lightly coloured. Both are easily decomposed, with gelatinization, by hydrochloric acid. ^*:^ See also Jchorl and other dark minerals in Table X. Second Group : Magnetic be/ore or after ignition. Infu- sible, or fusible only on thinnest edges. Magnetic Iron Ore (Fe 72-4, O 27-6). Franhlinite (FeO, MnO, ZnO, Fe'^O'). Chromic Iron Ore {FeO ?>1, Qv^(y^ Q9,). Ilmenite {¥e-0\ TvO% ,/-. Hematite (Fe^O^=Fe 70, O :iO). ^ Limonite (Fe-0^ 85, H^O 15). .; i ,, ,. 1^ t TABLE IX. 33 For more complete reference to these niinemls consult Table III. Briefly, their more distinctive characters are as follows : — Streak, black : — Magnetic Iron Ore = Magnetite (strongly magnetic ; sp. gr. 40 to 5*2 ). Franklinite (strong Mn-reaction with sodium carbonate BB ; sp. gr. b to 5*2). Chromic Iron Ore (Emerald-green glass with borax BB ; sp. gr. 4'{")). Ilmenite (Hydrochloric acid solution becomes violet- coloured by boiling with metallic tin or zinc ; sp. gr. 4 6 to 5 3). Streak, dull-red : — Hematite (=Red Iron Ore, com- monly in fibro-botryoidal masses ; sp. gr. 49 to 5*2). Streak, hrownish-yellow : Limunite (=Brown Iron Ore). Yields water on ignition. In the outer flame, BB, becomes I'ed ; in the inner ^lame, becomes black and magnetic. Occurs commonly in fibro-botryoidal masses, often with silky lustre. i.i Third Group : Injusihle. Not magnetic after ignition. Psilomelane (Mn^O^, MnO, BaO, K^O, H'-'O). Pitchblende (UO, U^O^, but rarely pure). !;, TABLE XI. [Lustre non-nu!tallic. Hardness sufficient to scratch glass. Streak uncolouroil. Fusible. Colourless, or of light, clear tint ; never o{)ai[ue-black or brown]. FiKST Gkoup : Imparting a green or red colour to the jmnt or margin of the blowpipe-jlame. Axinite (CaO, Mn(\ Fe'0'«, Al-'0'\ B-'O'', SiO''). Jioracite (MgC), B'O'', MtrCl'). Datolite (CaO, H'^0, W0\ SiO-). Jiotryolite (CaO, B'O'', SiO"-, H'O). JSpoifutnene (Li'-'O, Al-'O", SiO-'). 'lii .1 m m a*- Mf ^« 40 THE MINERAL INDICATOR. i Petalite (WO, Am\ SiO^). ^m6%om1 «s TABLE XI. 41 H 6-5 to 7 ; sp. gr. 31 to 3*2. In Petalite, the cleavage angles equal chiefly 117° and 14l°23'; H 6 to 6-5 ; sp. gr. 2-4 to 2 6. Spodumene, BB, swells up and fuses with mucli bubbling ; Petalite, fuses without intumescence. Both give silica-reaction by fusion with phosphor-salt. Amhlygonite does not give this reaction. It occurs in white or light- coloured cleavable masses, H 6; sp. gr. 3 to 3*1. Easily fusible into a white, opaque bead. Second Group : — Yielding water on ignition in the bulb-tube. Prehnite (CaO, APO^, SiO-, H^O 4 A7ialcime (Na'^0, AFO^ SiO^ H-'O 8 %). Natrolite (Na'^0, Al'O^ SiO-, H'-O 9| %). Thomsoiiite (Na'O, CaO, Al-O^ SiO^ H'^0 13 %). Scolezlte (CaO, Al'-^O^ SiO-', H'-'O 14 %). , Chnbazite (K'-'O, CaO, AFO'\ SiO^, H'O 21 %). ApophylUte (KF, CaO, SiO-', H'-'O 16 %). The minerals of this Group occur essentially in association with trappean or basaltic rocks, tilling amygdaloidal cavities in these, or occasionally forming small strings or veins. Prehnite scratches glass strongly, and yields as a rule little more than traces of water on ignition, il. 6 to 8 ; sp. gr. 2 8 to 3. Fusible with intumescence or continuous bubbling. See under Group 4, below. The other species of this group scratch glass very slightly, and in some examples not at all : hence they belong properly to Table XVIII., but to pievetit risk of error in their deter minatioii, they are leferred to, also, here. \' -f^ftc;: 42 THE MINERAL INDICATOR. n ill Analcime and NatroUte, fuse without intumescence, ajid colour the flame strongly yellow. Their ignition-loss is below 10 per cent. Analchne is mostly in trapezohedroiis and trapezohed rally moditied cubes i.e., with three small planes at each angle. Colourless, opaque-white, pale reddislj, lire. H 5*5; sp. gr. 2-1 to ^'S. Decomposed, without gelatinizing, by hydrochloric acid. NatroUte (=Mesotype in pait) occurs in :>cicular groups and small rhombic crystals, but more commonly in light brownish-yellow radio-fibrous masses. H 5 to 5*5 ; sp. gr. 2-17 to 2'27. Gelatinizes in hvdrocliloiic acid. IVionisonite, ScoU'^Ate, Chabazite, and Apophyllite, fuse with more or less strongly marked intumescence, and their igni- tionloss alwiiys exceeds 12 per cent. — varying from 13 per cent, in 71i07nsonite, to 21 per cent, in Chabazite. Thom- sonite {=^Compfonite) occurs in rhombic (nearly square) prisms, and in acicular and fibrous examples. H 5 to b-5 ; sj). gr. 2-3 to 2-4. iScolezite (although Clino-Rliombic in crystallization) much resembles ThomsotiitA in general charac- ters, but is distinguished (at least in typical examples) by its more marked intumescence on ignition, — the test-fragment expanding and throwing out worm-like excrescences on the first application of the Hame. Both gelatinize in hydro- chloric acid. Chabazite is readily distinguished by its occurrence in small, colourless or pale-red, obtuse rhombo- hedrons, — or, exce[)tionally (Phacolite), in twelve-aided, flat pyramids, frequently lenticular from distortion. H 4 to 5 ; s)), gr. 2 to 2 '2. Decomposed, without gelatinizing, by hydrochloric acid. Apophyllite or Ichthyoptlialmite diflejs from the other species of this group in not containing ■91 TABLE XI. 43 alumina. Hence, its hydiocliloric acid solution — after separation of the silica by evaporation, moistening the dry residuum with hydrochloric acid, and redissolving soluble matters in water -does not yield a precipitate with ammonia. It occurs chiefly in modified square-prisms and acute pyra- mids with strongly marked basal, cleavage, — the basal plane and cleavage plane being always j)early, and genei-ally mr-e or less iridescent, whilst the other planes are vitreous in lustre. Sp. gr. 2*3 to 2-4. BB, exfoliates and melts with bubbling. ^*^,. The following species may olso be referred to this group : — Fauj'inite, OiHmondiue, Znnjonite, Okenite, Brewectively, a connecting link to Aug He and Hornblende. In Diopside crystals, the prism-angle e(]uals SJ'^ 6' ; and in Tremolite a)id Aclynolite, the same angle equals 124° .'30'. In lamellar examples, the cleavage angles are identical with these.'* H 5 5 to 6; sp. gr., in Diopside, 3 to 3*4; in Treuiolite 2 "9 to 33. Both fuse, in thin splinters, with jsliijlit-bubbling. Enstatite is a rhombic, non calcareous pyroxene. In ordinary examples it cannot properly be distinguished from the latter, except by its diflicult fusibility. It presents a green or gi<'enish-grey colour, and occurs in cleavable masses iind occasionally in rhombic crystals. H nearly 6 ; sp. gr. 31 to 33. Fusible only when in very fine splinters. Orthodase, commonly known as '• Potash Feldspar." and * A synopsis of the crystal (3 pes of Piiroxi'iii' and Ainiiliihvle will be found in the Mineral Tables (Note to Table XXVI.) foiniin<< Part II. of the author's "Blowpipe Practice." I 1 M m : 14 ■^i| 50 THE MINERAL INDICATOR. Albite or " Soda Feldspar," occur chiefly in crystals (often large and rough) and in cleavable, lamellar masses, ot a white, red, giey, or light-green colour, easily distinguished from cleavable light-coloured Pyroxenes and Amphiboles by their lower sp, gr., which is always under 27. Orthoclase is Clino-Ilhombic in crystallization, and its cleavage planes (which are generally somewhat pearly) meet at right angles. Sp. gr. 'lb to 2-6, Albite is Triclinic or Anorthic in crys- tallization, and its cleavage planes meet at angles of 86 "24' and 93^36'.* Sj). gr. 26 to 2-65. Both Orthoclase and Albite are difficultly fusible unless in tine splinters, and they are tluis constantly regarded as infusible by students who have had but little practice in ))lowpi[)e work, or who per- sist in using fragments of unsuitable size;. Both scratch glass strongly (H = 6). Microliue or "Amazon stone" is practically a green Orthoclase. Its crysta^ in as})ect and angles aijree closely with those of Ortho but are re- garded as Triclinic. • Obsidian is easily recognized by its occurrence in amor- phous sharp-edged masses, somewhat resembling bottle-glass, of a grey, greenish, brown, black, or other colour. H 6 to 7 ; sp. gr. 2-2 to 2 4:. Shews conchoidal fracture, and is readily fusible. * See conspectus of the crystal types of Orthoclase, Microcline, aud Albite, ux the author's " Blowpipe Practice and Mineral Tables." I* TABLE XII. 51 TABLE XII. [Minerals of non-metallic lustre and iincoloured streak. Hard enough to scratch glass. Infusible, or fusible on thinnest edges only.] First Gkoup : Yiddhtg water on iynition in the h}dh-tube. rurquoise or Kalaite {k\-0\ P-0\ H-0). Laznlite (MgO, Al-^0'', P-^0^ H-'O). Dlaspore (A 1-0=', H-0). Chloritoid (AfgO, FeO, Al-'O^ 8iO-, H-0). (7^W(5e (CeO, SiO--i, H^O). Calamine (ZnO, SiO', H-0). Turquoise, Lazullte, Diaxpore, aiul Ch/oritoid, scratch glass distinctly ; Cerite i'ud Calamine, move or less feebly or indistinctly. Turquoise and Luzulite are |thospliates ; their solution in nitric acid gives consequently a canary-yellow precipitate with amni. molyV)date. Turquoise occurs in light-l>lue and blueish-green, opaque, uncleavable examples. H 6 ; sp. gr. 2() to 2-8. Blackens on ignition, and yields 20 to 21 per cent, water in the bulb-tube. Many specimens give copper- reactions with borax. Lazidite occurs essentially in small^ l)yraniidal crystals of a light-blue colour. H 5*5 to 6; sp. gr. .'i to 3'2. BB, crumbles, and tinges the flame-point pale- green, but does not fuse. In the bulb-tube, yields aV)out 6 per cent, water. Diaspore occurs mostly in white or lightly-tinted ex- amples, of a foliated, sctdy, or broad-fibrous structure : more rarely in rhombic crystals. H 6 ; sp. gr. .3 '3 to 3 5. m THE MINERAL INDICATOU. I •i!!' 'P i fi' ■iH! Decrepitiites (as a rule) on ignition, and yields alvout 15 per cent, water. Assumes a tine blue colour after ignition with cobalt nitrate. Insoluble in acids. Chlorito'ul is distinguished by its occunence in dark-green, foliated and scaly-granular masses, rescunbling ordinary chloriO' (Table XX), but differing by its much greater hard- ness (5'0 to G). Sp. gr. 3"5 to 3'6. Fusible on thin edges into a black magnetic slag. Decomposed, in j)Owder, by auli)huric acid, but scarcely attacked by hydrochloric acid. Oerite ami Calamine are deconiposed with gelatinization by hydrochloric acid. Both are scratched by the knife. Cerlt>', a comparatively rare species, occurs chieHy iu liue- gramdar masses of a red, brownish, or red-grey colour. H 5 to T)-;") ; sp. gr. 49 to 50. BB becomes yellow but does not fuse. Tn +he bulb-tube gives G per cent, water. The saturated borax-glass becomes opaipie on cooling or when flamed. Calamiwi occuis mostly in aggregations of small, vitreous crystals, and in botryoidal and cavernous masses, white, yellowish, or brownish in colour, and sometimes light-blue from picstiu'Ci of a rsnnill amount of cop|H!r oxide. iScratchcs glass ver) fi^ebly, in some cases not at all ; hence iielongs propei'iy to Table XX., which see. The saturated boiax- glass Ixicomes o[)a4ue on cooling or when flamed ; and when crushed and riixcid with sodium carbonate, it gives on char- coal, in a good reducing flame, a zinc hublimatt,- -lemon- yellow whilst hot, white when cold, and light-green afti'r ignition with cobalt solution. In the bnlb-tulie, Cahviiiine yields 7") per cent, water. Sp. gr. ',V'i to 3'5. Pyroelectric. '^ TAIILK XII. 63 Second Gkoup : — An/iydrous {or practlcalh/ anfri/drons) sppcies. Drcomposeil in pou'der by hijdrochlorlc aclcly the silica separating {(-n partial evaporation of the so/it- tion) in a nelatinoas slate. Willemite{VA\0,'^iO-). Troostite (ZnO, AFiiO, bVO, SiO'). Chrysolite ov Olir'^ne (Al-O, FtiO, SiO-'). (V/oWm/yV^ (MgFl-, x\[g(), FoO. SiO-). Uehlenite (CaO, M<,'(), Al-()'', SiO'). ' W}llemite and Troostite \\\\v\\ fused witli a niixturo of soilimu carbonate and borax ir a ijood reduciajj; llanic on eliurcoal, (U'|)osit on tln^ su|)|>ort a sul)lin»at(' of zim* oxide, lemon-yellow whilst liot, and white wiien cold. JMoistened with a dro|> of cobalt nitrate, and again ignited, tlit; subli- nuite on eoolinj; becomes li«>ht-y:i'et'n. Fused with borax on platinum wiio, both form a glass which on sntuiation Ite- comes opiujue by flaming or when cold. Wilhinlte is mostly in small ifianular masses or iu very small ihombohediid crystals with i^nnuh'd edges ; whilst Troostlfr (projK'rly a manganese-holding variety of Wil/emifi) is generally in o|ta- (jue or senn-o]»a(|U(^ crystals (hexagonal |>risms with rhond)0- liedral teruiiuations) of medium si/.e. I'oth are white, yellowish-grey, pale-red, bi-ownish, iVc, >! 5 A ; sp. gr. [id to 4'2 ; infusibh^ »tr vitrifying on thin edges only. Chrt/so/ife ( hondroilite i{]\^\ (iehleiiite scratch glass strongly. The common variety of C/tri/so/ite — the oidy one lil<(>ly to como under ordinary observation — is known as Olirine. This occurs chiefly in small, vitreous, griuiular t'xam|)les of a l)ottle-green or yellowish-brown colotir, in basaltic rocks. l! H m •1} u " i fi Pt THE MINKRAI, INDICATOR. Chri/solite proper V6 in small prismatic crystals of a pale- yellow or greenish-yellow colour. H 6*5 to 7 ; sp. gr. 3'2 to 3'5. Chomfrodite occurs mostly in small yellow, greenish, or yellowish-brown, granular masses, in crystalline limestone. H 6 to 6'j ; sp. gr. 3 to 33. Practically, infusible. In powJer, with concentrated sul|)huric acid, gives fluorine reaction — /. e., it emits fumes, on lieating, which corrode glass. GeJih'.nite. occurs chiefly in square prisms of small si-^e, greenish-grej, green or brownish in colour. H 5*5 to G; sp. gr. 3*1. BB, rounded on thin edges, TiiiHD Gkoitp : — Dissolved or decomposed in powder, with- ont yekUiiiizing, htj hydroctdoric acid. Zinc Spar (ZnO, CO'). Apatite (OaO, P\>', Ca [CI, F'']). Leucite {K\\ \\'0\ my). Zinc Spar and Apatite scratch glass very feebly or indis- tinctly, Jind ill many examples do not scratdi glass at all. Hence these minorfils belong i)roperly to other Tables. Zinc Spar is essoitially distinguished by efllervoscing in acids and by giving a snl)limate of ZnO (Icmon-ycllow whilst hot, and white when cokl) by fusion in a reducing flame on charc<»al with a mixture of sodium carbonate and borax : See Table KV.— Apatite occurs chiefly in hexagonal crystals and in granular and cleavable masses of m green, greenish-white, or brownish-i ed colour. Practically infusible, but, flne splinters vitrify at the extreme jwint in a well-sustained fliime. The solution in nitric acid yields a en nury -yellow preci|ntate with amm. molybdate. See Table XX., Group 2. 9 > TABLE XII. 55 Leucite, as h rule, is readily distinguished l»y its occurrence in trapezoijedrons (or pseudo-tiapcz^liedrons), or in small granular masses, in lava. Its colour is white, pale-yeliowisli or light-grey. H 5-5 to G ; sp. gr. 2'45 to 25. Infu.sihle. Fourth Gi?oup : — Forming BB vjlth borax in the li. F. a dark violet-brown glass ichich [irhen saturated) becomes coated bi/ff anting with a light-blue Jilm.^^ Ruiile (TiO-). Anatase or Ocfahedrite (TiO'). Brookite (TiO-). (Arka)isite=^Fervuff'\no\\H Brookite). These minerals can only ]»e distinguished individually by crystallization and general aspect. In all, the lustre is adamantine, ai)proacliing sub-metallic, liutile is commonly dark-red with indistinctly light-brown streak ; and is usually in stjuare-j)risniatic crystals, longitudinally striated, and very fVecjuently twinned so as to present a geuiculated aspect. It occurs also in the form of opaque, dark pebbles, a variety known as yigriiie, and in light-brown acicular examples. H G to Gf) ; sp. gr. 4-1' to 4-3. Anatase or Octahedrite is indigo-blue, brown, or yellowish- grey in colour ; and it occurs only in crystals : chiefly acute js(|uare based pyramids, of small size, but very distinctly foimed. H 55 to 0; sp. gr. 3*8 to 4. IJ rooki fe occwvs in rhombic crystals, connuonly more or less tabular, of a li<.ht- brown or light 3'ellowish-red colour; but is sometimes black and opaque, as in the variety Arkansite. W 5 5 to G : sp. gr. 4 to 4-3. Sfi' foot-note to (h'oup 3, Tahi,k IX. i '?•* M w' m ■ f m THE MINERAL INDICATOR. I I ff Fifth Group : Yielding metallic globules, BB, with * reducing flux on charcoal. Cassiterite or l'insto7ie (SnO-). This mineral, the common ore of tin, is the only represen- tative of this group. It is easily recognized by its high sp. gr. (6 "7 to 7), combined with its stony aspect and great hard- ness (6 to 7); as well as by the malleable metallic globules obtained from it by blowpipe treatment with reduciiii^ flux, on oliarcoal. It may be reduced indeed jjer se (althougli quite infusible) ; but a well-sustained blast is required for the j>urpose. With a mixture of sodium carbonate and <> little borax, or sodium carbonate and cyanide of potassium (tiie latter reagent it must be remembered is a highly poisonous substance), or with neutral ))otassium oxalate, the reduction is very easily ettected. (J asei), Al-0-'). ' Spinel (MgO, APO'). . - TABLE XII. ' o7 Gohnite (ZnO, APO^^. Pleonaste (MgO, FeO, Al'O'^). Diamond (C). Topaz {Al-0'\ SiO^ Fl). StauroUte (FeO, MgO, i\l'-0"', SiO'-). Cyanite (Al-'O' 8iO-'). Andalusite (Al-'O^ SiO'-). Uwaroicite {Chrome Garmt : OaO, Al-'O', Ci--0\ SiO-). Tourmaline {MgO, Al-0'', B'-'O'', SiO-). These miiienil.s nuiy be subdivided into lessei' groups in iiccoidiuice vvitli their .specitic gmvity. In Zircon, t'onm- (Inm, (jlahnite, and Pleonaste (the two hitter conunonly re- garded as varieties or sub-species of S[)inel), the s}). gi. e(jua!s or exceeds .i'O or 4. /ir<-o)h occurs in Tetragonal crystals (and occasionally in rounded grains; of a dai'k i»i light red, brown, yellow, yellowish-grey uv other colour, rarely colourlt^ss. The crystals are couinionly sijuare piisnis combined with a stpiart^ pyramid or with sev -d pyramids. H 7'5 ; sp. gr. nsnally al)out 4-4:. BB, in powder, slowly dissolved by borax, the saturated glass becoming opaipic when flamed. C'orundnm is the hardest of all known nnnerals, the diamond excej)ted. It represents thiee moic of less distinct varieties : Xoble Corundum, Admna iitun' Spar and Emeri/. 'J'he first occurs in small tranHi)arent or translucent crystals and rolled i)ebl,les of a blue, red, white, or otlier tint — two colours, as blue and white, i»eing often pi-esent together in the same exauiple. The crystals are chiefly acnite hexagonal pyramids, sometimes with o^fuleficent basal plane or shewing opalescence in that diiec li n ■ll 'wm\ ■ : ^Hf >^: j U r '1 ^B t' : i'S n ! 1 i i. ''■' »s J' mi "i 4: L: iiin ■ , zinc spinel, Gahiitp, \)\ its lower sj). gr. (which does not exceed 4), and also by not vielding a sublimate with reducing: ar Japiiiit'si', Saxon and Mexican in the Author'^ Miskkai, Tuii.Ks, forniintc l*»il II. of " BUOWfll'K I'RACTICK." b m m ■Hi 60 THE MINERAL INDICATOK. = '^:l S- i, !!, I ; a dark red or opacpie-browu colour, sonietinjes coated with glistening mica or intimately associated with crystals of hlue and wliite cyanite. H 7 to 7"5 ; sip. gr. 35 to 38. The rhombic crystals are commonly six-sided from ths re- placement of the acute edges. In other respects the s[)ecies is in general easily distinguished by the remarkable cruciform crystals in which it so commonly occurs. Cyanite or Kyanite (also known as Disthene) occurs chiefly in bladed or fihious masses, or in long imperfectly formed crystals, of a blueish-white, pale-blue, light-grey, greenish or reddish colour, and somewhat pearly or pearly-vitreous lustre. H, on ed^es, 7 ; on flat surface 5 to 5-55. Sp. gi'. 3-5 to 3*7. BB, (jiiite infusible. . A third sub-group, with specitic gravity below 3*3. com- ])rises Andalnsite and TournuiUne, the black, fusil)le variety of the latter, known as Hchorl, excepted. These givf^j, BB, with phosphor-salt, a silica skeleton. Andalusite is com- monly in granular masses and in somewhat coai'se prisms — apparently sipiare, but actually rhombic, with angles of about 01" and 89' — dull-red, grey, itc, in colour. H (in unaltered exam[)les) 7 to 7 '5 ; sp. gr. 3-1 to 3'2. BB, quite infusible. By ignition in powder with cobalt-solution, V)e- comes l)lue, but this character is connnon to all the aluniin- ous minerals of this group (Corumlum, Chrysoberi//, Cyanite, «fec.). The curious mineral Chiastolitf. is commonly regard- ed as a variety of Andalnsite. it is at once recognized by its peculiar occurrence in slender straw-like prisms scattered through certain clay slates and micaceous schists, or occa- sionally in thicker crucifoiinly-arranged prisms, shewing in both cases on the transverse section, a dark cross, or dark TABLE XII. 01 lozeng; at the centre and angles, composed of intervening rock-matter. Tourmaline, here considered apart from the bhick, fusible variety, Schorl, is usually in triangular or nine-sided prisms of a green, brown, blue, or rod colour ; sometimes red inter- nally, and green on the outside, in the same specimen. Red, lithia-containing varieties, are known as Ruhpllite. The prisms are more or less translucent when viewed trans- versely, and opaque (even in short jneces) longitudinally. 11 7 to 7 '5 ; sp. gr. 2'0 to .■i'2, Pyro-electric ; BB, i)ractically infusible ; but some examples become slightly blistered on thin edges, and most examples lose their colour. The pre- sence of B'-O'* is levealed by treating in fine powder with sulphuric acid, evaporating nearly to diyness, and testing on a loop of i)hitinum wire, or in a platinum spoon, in the Bunsen or ulowpipe flame ; or by adding alcohol, and inflam- ing the mixture. The point or border of the flame becomes coloured distinctly green. Seventh Group : — Specific gravity under 3. Reactions of preceiling groups not inanifested. The minerals referred to this group comprise the infusible species Quartz and Opal, in which there is no visible cleavage ; the practically infusible lolite and Beryl, with more or less distinct cleavage ; and the difficultly fusible feldspars Orthoclase and Albite, with strongly pronounced, spathoidal cleavage-planes. Quartz (HiU'-). Opal (colloidal SiO", usually hydrated). lolite (essentially, MgO, FeO, Al'-'O-', 8iO-). i. i m ii \%^^ I *' 62 THK MINERAL INDICATOR. m i' 1:1^ Be n/l oi.t merald {BeO, A\-0-\ i!^[0-). Orthoclase (essentially, K'O, Al-'O^ SiO-). • MicrocUne (like Orthoclase). Albite (essentiiilly, Na-0, Al^O^ SiO-). Quartz unci Opal break with conchoitlal fracture, and are quite int"usiV)le. Quartz occurs in vitreous masses, and abundantly in hexagonal prisms and pyramids, either colour- less, or tinted l)ro\vn, yellow, violet, rose-red, &c., forming, among others, the varieties known as Roch-crystal, Smoki/ Quartz, Cairmjorm, Aiaethi/st, and Rohe- quartz. Also in uncrystalline, subvitreous, calcedonic varieties, forming Calcedoiiy (white, yellowish, blueish, &c.). Carnelian (red, Chrysoprase (a])ple .^reen, the colour due to NiO), CaCs eye (yellowish, colourless, green, &c., with floating opalescence), Heliotrope or Bloodstone (dark -green, often with red-spots), Agate and Onyx (with baiuled colours), Jasper (o[)aque red, brown, ifec. ), Flint, Hornstone, Chert, d:c. — the latter varieties often forming the petrifying substance of organic remains. In the crystalline examples, H=7. All varieties of (puii tz thus resist the knife, and scratch glass very strongly. Sp. gr. 2*5 to 28, mostly about 2'G6. Opal occwv^ only in amor- phous masses, commonly in cavities of certain amygdaloidal trap-rocks. H 5*5 to 65 ; sp. gr. I '5 to 2*5. The leading varieties comprise Xohle Opal, Girasjl, Fire Opal (colourless, pale-blueish, yellowish : with green, blue, red, and other coloured iridescence) ; Hyalite (in colourless botiyoidal n) asses and coatings on lava) ; Common Opal, iSemi-Opalr Wood-Opal, (jt'c. (white, brown, blueish, red, yellow, &c., with more or less waxy or sub-resinous aspect). These varieties almost invariably yield a little water by ignition in the bidb- TABLE XII. «3 tube ; and tliey are attackeil, and wliolly or in great part dissolved, wlien boiled in fine powder with a strong solution of caustic potash. loll te (aho named Di> hroitf and Cordierite) is not veiv oominon. It occurs chieHy in small granular examples ot a dull-blue, blue-bhick, or brownish colour, and occasionall\' in short thick pi-isms of pseudo-hexagonal aspect. Transi)arent specimens are dichroic or projjerly trichroic, shewing difl'er ent tints (blue, pale brown, yellowish) in diti'erent directions. H 6-5 to 7-5 ; sp. gr, 2') to L*-7. Infusil)le, or fusible only on thinnest (Mlges. Beryl occurs most commonly in simple or slightly moditied hexagonal prisms, and also in masses of columnar and granular structure, greenish-white, ])ale-gveen, greenish-blue, emei-ald-green, or yellow, in colour. The bright green varieties, coloured by a small amount of Cr-'0\ form the Emerald. H 7 to 7'r) ; s])ecitic gravity 2-G(') to 2 '75, Thin splinters become o[)aque- white in the blow[)i|ie flame, and frit or fuse slightly at the extreme point ; but tndess the test-fragment be very sharj)ly [)ointed, and the blast be well sustained, very little sign of fusion is j ro- duced. Hence the mineral is cominonlv legMided as in- fusible. The feldspars, Orthodase and Allilto, and the green Mi- crocline or Amazon IStone fuse reailily on the edges if tested in the form of thin s|)linters, and a shar^jly pointed frag- ment becomes quickly rounded ; but comparatively thick and square-edg* le, — all risk of error in their determination being thus avoided. They are easily recognized by their broad, smooth cleaA'age planes. ' These, in Ortlwdase meet at 90" and in Albite at 93''36' and 8fi^24'. Orfhodase is Clino-Rhombic, and Albite Trielinic in crystallization, twinned lorms in both being common* Wliite, red, reddish-white, light-green, in colour. H <» : s[». gr. 2-5 — 2-05. Microcline is a green feklspar, regarded as Trielinic, bnt closely resembling Ortho- rlase in the configuration of its crystals and in other chai'acters. TABLE xnr. [Lustre iKtn-inetallic. Hardness insiifticient to scratch wii.dow- glass. Sapid.] The minerals of this Table are soluble in water, and all possess a distinctly saline, bitter, or other taste. With the exception of Rock Suit, they occur, as a rule, in more or less earth V crusts, or in minutely crystalline efflorescences. First Gkoup : — ''.inng chlorine reacfion (i.e. azure colora- tion ofjlame) hj/ fusion ivAth j^hosphor-salt mid coj)per oxide. Rock ^alt (Na 3U-31, CI. GO'69). • Siilvine (K, CI). ' • S(d Ammoniac (Am, CI). • * Rock Salt occurs chieHy in lamellar masses -with strongly ^ See synojwis of their leadinjf crystal t3pes in the Mineral Tables attached to Uu' author's " Blowpipe Practice." , . , , «1 ill i TABLE XIII. 65 marked cubical cleavaijo, and occasionally in sub-fil)rous ex- amples an«l crystallized in cubes. Commonly colourless, but often shewing pale tints of brown, green, violet, S:c., and sometimes deeply coloured, as bright red or brownish-purple. H 2 ; sp. gr. 21. BB, generally deci-e]»itates, colours the flame strongly yellow, melts, and in prolonged heat suldimes. Sylvine (comparatively restricted in its occurrence) closely resembles Rock Salt, but colours the blowpipe-flame, or Buiisen flaine, violet. Sal Ammoniac occurs in colourless greyish or brown crusts, or at times in trapezohedrons and other related forms (usually much distorted), on lava and other volcanic rocks. Also in small quantities in many coal-pits. BB, volatilizes without fusing, the evolvetl fumes giving out a strong am moniacal odour. ^^*^^ See also the carbonates of Group 4, below, these being often mixed M'ith sodium chloride. i" ' w m irJECOND Group : — Colouring the blow pipe Jlame (or Bunsen- Jlaine) distinctly green^ i/ moistened with a drop of sulplinric acid or glycerine. SassoUne (Boracic Acid, B'-'O'', H'''0). Borax or Tinkal (Na'-'O, B-'O^, H'^0). Sassoline colours the flame green, ;jer se. It occurs in small pearly scales, normally white, but often brownish tkc. from presence of ferruginous matter. Fuses with intu- mescence into a hard clear glass. Borax in its crude state ( Tinkid) occurs in small Clino- Rhombic crystals and granular masses of a gi'ey or brownish-white colour. BB, colours the flame intensely yellow, and luelta with strong intumescence. 5 II Gii THE MINERAL INDICATOR. Moi tened with sulphuric acid, or simply with glycerine, it imparts a yellowish-^reen colour to the flame-border. Third Group : — Dfjiwjrathig when ignited on charcoaL Xitre (K-0, N-0^). Soda Nitre (Na-'O, Na'-Q-'). Xitrocalcite (CaO, W0% H-0). Xitromagnes'ite (MgO, N'O^ H-0). These compounds evolve orange-red or brownish nitrous fumes when warmed, in powder, with a few drops of sul- plmric acid. The two first are anhydrous. H I 5 to "J. XitTt' or Saltpetre crystallizes in long [)rism-pyramids of the Rhombic System, and imparts a violet colour to the flame- border. Commonly fouuvi in white or Vjrownish incrusta- tions. Soda Nitre, also known as Nitratine and Chili-S'i/t- petre, crysbulizes in small, obtuse rhombohedrons, but oc- curs generally in crystalline granular examples of a white or greyish tint. It colours the flame-border intensely yellow. Whilst Nitre and Soda Nitre dissolve entirely by fusion with sodium carbonate, Nitrocalcite and Xitromagnesite leave in that reagent an undissolved earthy mass. These latter sulL-'tances also yield 10 to 11 per cent, of water on ignition. Both occur in j»i'fiyish-white crusts and efllorescences on the walls of limestone' caverns, cellars, &c. The white crust 'eft aftor ignition on charcoal, assumes a pink tingfe in the case of Nitromagnesite afttr treatment with cobalt solution. Fourth Group : — Ejferoescing vig^oroudif with dilute acid. Natron (Na-'O, 00-, H'-'O). i l! TABLE XIII. (37 Trona (Na^O, C0^ H'-'O). ' - fkiylussite (Na-'O, CaO, 00', H^O). Natron and Trona, are entirely absorbed by fusion on charcoal; Gaylnssite {w\\\c\\ is only partially solulde in water) leaves on the charcoal an earthy crust. 'Hiey occur mostly in etHorescent coatings and small crystalline-granular masses of a white or greyish coloui', nioio rarely in distinct crystals of the Clino-Rhombic System. Xatron gives 63 per cent, water on iguition ; Trona, 22 per cent. ; and Oaylnssite, 30 to 31 per cent. They are freijucntly mixed with sodium chloride. Fifth Group ; Fonniny liTi njith soisteaed a dark stain to Uad test-paper or to a silver coin,* Anhydrous sub-groiip : — Mascagnine (Amm. SO''). r/ZrwenVe (K-0. SO-'*). Thenardife (Na'O, S0«). 6-7rta6my a laitii> or pandli'-lliiiiic, as gUM fn'- • lut'iitly contains sulphur, ami tluH hi'foiiitH coinniunii'atoil, to the lest matter. Lead test-puiter 1m made by steeping some flltcrinK or^white blottMi); ]mper In a Holiitiou of acetate of lead and drying for uhc. ti J 18 THE MINERAL INDICATOR. • it. ;■• I- [ft . IIwl'' : il I; iff' t:i BotrAjoyrue (MgO, FoO, Fe'O-', «0-'', H-0, 29 p.c) /)VMe Vitriol 01- Chalcanthite (CuO, SO'^ H^O 36 p.c.) ^Zwy>^. (K-C) [often replaced by Na-'O, MgO, MnO, FeO, iirc.,] AFO'', SO^ H-'O 45-5 p.c.) Aliinoyene {X\'0\ SO'', li'O :t8 p.c.) Masccujniru', (Hdserite, TJieitardite, and G'lauberite, do not yield water when ignited in a test-tube. The three tii'st dissolve entirely or leave no residue when fused with sodium carbonate. Masi-agnine volatilizes with strong aunnoniacal odour. It occurs in white or yellowish ciusts or maunnil- lated niass»-s on c(ntain lavas, (jllaserite and Tltenardite occur also in crusts auil earthy coatings of a white or greyish colour. Tilt' first colours the flame violet ; the second, yel- low. Hoth melt i-(!adily, and are absorbed on charcoal, but sometimes decrepitate on Hrst application of thy flame. (ihi/uherite is only jiartially solul)le in water, but has like tlw other alkaline sul})hates a l)itter, saltish taste. Occurs in whitti, grey, reddish and other coloured ci'usts, and in small, Clino-llhombic crystals. In sodium carbonate it is only in part dissolved ; and on charcoal it leaves a white earthy mass uualtsoibed. Chiefly found in association with rock-salt. The sulphates of the second sub-gi-oup yield water on ignition in a test-tube oi- bulb-tube. Mirahilife (Olauber's Salt) dissoivi^s entirely by fusion with sodium caibonate. J'i'r ae it colours the flame infcenstjiy yellow, anr('Hence of Fe'-()"'. It passes into I/alotrichife or Feather Alum. Green Vitriol and Jiotri/ogene leave Bl> a magnetic sIh- tnd their solution gives a deep blue precipitat(; with ferrit yanich^ of potassium. Giecn Vitriol is tisually ])ale- green in colour ; liotn/ocfene is red or brownish-yellow, with yellow streak ; and it is only in pait soluble in water. JJlue Vitriol occurs in blue or greenish-l)lu(^ coatings, and occa- sionally in crystalline examples on copper ores. Moisteiu^l and rul>l)ed on a steel knife-blade, it coats the blade with a Him of metallic co[)per. ' » #■ # See Pofi/lial/ife ('ruble Wllf) which is i)artially siduble and lias a slightly bitter luit very feeble taste. ( 'hietly in pale-red, grey, and yellowish, colunuiar and lil)rous masses. Igiiition-loBa = G per cent. • Note : — ^b•uly other soluble or ])artially soluble sulphates of natural oecurrcnee have been reeogni/cd, h\it most of these are com- jiaratively r;i and many are iiulistinetly characterized. See the author's " lib.. v pipe Practice," 'Jable XV'l. * t ', , w w^ THE MINERAL INDICATOR. !*■■.. til TABLE XIV. [Lustre non-metallic. Hardness insutiicient to scratch glass. Com- bustible]. The minerals of this Table when held in the form of a thin fragmei.t against the flame of a Biinsen burner or com- mon candle immediately take fire, and continue to burn for n short tiiiK, after removal irom tlie flame. Tlie test frag- ment sliould be taken up by a pair of steel forceps (without platinum tips) and held just within or against the flame- border. - ,' ' . ■ "' , FiKST Gkoup : — Einiftlnij a (pn'lic-odonr during comfmstion. JiWihjar (As 70, 8 30). Orpiment (As 01, S 3'J). Realgar has a red colour and orange-yellow streak, and is commonly in snuill granuhir masses or Clino-Rhombic crystals, the hitter as a rule more or less indistinct. Orpi- ment is goldon-yt^llow with ])early and sub-resinons lustre, and liglit-yt'.iow streak ; and it occurs in foliated, scnly, and granuliir masses ; more rar«*ly in small prismatic crystals of the Rhombic system. H, in both, If) to 2. Both sj>ecies molt very easily, and volatilize in dense fumes. Skcond Gkoup : — Emitting a sniphitrous odour during combustion. * Satire Snlphur. Cinual ■8). Xativr Sufphnr is yellow or reddish, with pale-y<'llo^v streak and r»>sinous lustre. It is commonly in granular TABLE XIV. n masses antl occasionaily in small crystals — mostly acute rhombic pyramids. Its sp. gr. does not exceed 2*1 and is generally 19 or 2. It melts into red-brown drops which become pale yellow on cooling; and it readily volatilizes. Cinnabar is commonlv red in colour, but is sometimes red- dish lead-grey, and occasionally almost black from admixture with bituminous matters. The s^^veak is always red, and the sp. gr. usually about 8, although somewhat lower in impure carbonaceous varieties (6 7 to 7 5). BB, it rapidly volatil- izes. By ignition with sodium carbonate, iron filings, or other reducing agents in a small flask or bulb-tube, it yields a giey su})limate, which runs into fluid globules when rubbed by an iron wire or thin "ilass rod. Third Group : — Brnitthig during combustion a hitwninoua or aromttic odour. Bituminous Coal (H, C, O). Jirown Cool, or Lignite (H, C, O). AspJialt or liilvmen (H, C, O). Amber (IT, C, O). Bitamlnous Coal, Brown Coal, and Asphalt, burn with yellow, smoky flauie and bituminous odour. Bitumlnons or ordinary cual is more or less distinctly laminaied in struc- ture, with alternate thick layers of solid, lustrovis coal, and thin layers of soft black carbonaceous matter— known as " mineral charcoal " — in which a distinctly woody structure is observable. Streak black; sp. gr. 12 to If). Scai'cely or not at all attacked by boiling Holutio\i of caustic pot- ash. Brotrn Coal in typical examples has a more or less mi THE MINERAL INDICATOR. S; ■ '* il'l- t *■ ; IK II' I f(l .' i- distinctly ligneous ai)ijeaiance, with brown colour and l>iown streak ; but many examjdes are laminated, and coni- ])aratively dense and dark in colour, and thus pass into ordinary coal, from which they differ chiefly by occurring at a higher geological horizon. As a rule, however, they aie less dense; and they yield a lighter coke, which never presents the fused a<;glutinated character of- the coke vielded Wv most exiimi)les of ordinary coal. They generally contiun, also more water, and frequently a larger amount of " ash," or mineral matter. True brown-coals or lignites impart a brown colour to a boiling solution of caustic potash. Cannel ooiils and Jet are intermediate varieties. Asphalt or Bitu 'mt'H occurs in solid, viscous, and licpiid examples, the latter passing into Petroleum. The solid varieties show a con- choidal fracture. Elaterite is a soft, s[»ongy variety, re- seml)liiig caoutohoue. Albertite, a black, brittle, comi»act liiyhlv lustrous and inflanmiable substance, is closelv related. Amber occurs in nodular masses of a deep or pale-yellow colour [lassing into yellowish-brown, H 2 to 2*5 ; sp. gr. 1(> to ri. Strongly electric by friction. Burns with velhnv llame and aiomatic odour. ^* :^ \'ariuiis so-callt'(l " mineral resiiis " (Ozokerite, Hartitc, Hatdultine, Schterei'itf, d-c.) lielong also to this group, but are comparatively rare and of little interest as minerals. They occur mostly ill soft wax-like masses of a yellow or brownish colour, or in white pearly laminse. See the author's " Blowptpe pRArriCF, " Also the Appendix to Part I of the same work, for a method of assayiuy coals by the blowpipe. , s TABLE XV. TABLPJ XV. [Lustre non-metallic. Hardness insufficient to scratch glass. vescing in dilute acid]. 7-\ Etfer- The minerals of this Table consist entirely of carbonates. The effervescence is most readily |)ro(lucecl by inserting some of the substance (in a coar.sely powdered state) into a test- tube, and then covering it with hj'drochloric acid dilutetl with about an equal volume of water. If the efteive.scenoe be feeble, the acid must be gently warmed over a spirit-lauij) or Biuisen-burner. Fused with borax or phos|)lior-salt. a vigorous effervescence is also produce*!, from the eseaj>e of 00-. First (tRoup : — Ent'irelji solnhle /jIJ la sodium carhonatt^. Per se, colouriwj thi'jiame f/reen or red. The test may be uiade i)y fusion with sodium carbonate on ))latinum wire oi' on charcoal. In the latter case, the whole of the test-matter is absorbed ; l)ut the complete solution of tlie substance is [)erhaps better seen in a loop of platinum wire, before the fused bead solidities. If any lime be present in the bead, it remains undissolved. Witherite (BaO, CO-). Stront'umite (BaO, CO'-f. With Witherite, the point and border of the blowpipe- flame is coloured apple-green ; with Strontianite, carmine-red — tiie coloration coming out most vividly after prolongeil ignition of the test-fragment. Withrrite fus«'S readily into u clear glass which becomes opacpie on cooling : if it contain |ii )■■% < 1 J 4 I M! >t >t if ■1 4" <4 THE MINERAL INDICATOR. MnO, the glass is pale blueisb -green. Strontianite forms BB a caulitlower-like mass, tlie separate ends of which fuse upon the edges. Both species occur in crystals of the Rhombic System, but more commonly in fibrous, columnar, granular, and other imcrystallized examples. In Witherite, "the sp. gr. equals 4-2 to 4*4 ; in Strontianite, 3"6 to 3'8. ^*^Ahtonite (=BroniUU) and Baryto-calcite, are compounds of BaO, CO-, and CaO, CO^. They colour the blowpipe- Hame pale- green, but are only partially soluble by fusion in sodium carbonate. Average sp. gr. 3 7. Some examples of Strontianite, also contain a small percentage of CaO. Seond Group Yielding, BB, on charcoal, metallic glohiles of Copper or Lead. Malachite (CuO, CO^, H-0). Azurite (CuO, CO^, H'-O). Cerussite (PbO, CO'-). These minerals are easily reduced ^;e>* se, but the reduction is rendered still more easy by mixing the test-matter, in ))Owder, with some sodium carbonate. Malachite and A ::u7'itc are copper carbonates —green and blue, respective!}'', in colour. Both yield water on ignition. The hydrochloric acid solution is rendered deep blue by ammonia, used in sufficient quantity. Malachite is commonly in botryoidal anil fibrous masses, and is often zoned in deej) and light-green tints. Azurite is chiefly in groups of rich blue (Clino-Rhombic) crystals. Both occur also in earthy coatings or '* blooms " on copper ores and copper-holding locks. Malachite yields 8'15 p. c. water on ignition, and TABLE XV 76 I Azurite 5-2 p.c. The s|). gr. of MnlacMte=2>-l to 4 ; of AzuritH, 3-7 to 3-8. Cn'ussite is a lead carbonate, either colourless, or greyish, &c., and sometimes nearly black from incipient conversion into PbS. It presents a peculiar vitreo-adamantine lustre, and occtirs in massive and crystallized examples. The crystals belong o the Rhombic System, and are frequently in cruciform and stellate groups. Sp. gr. 6*5. Exceedingly brittle. Anhydrous. - ^ Thusd Group : Jiecoming magnetic after ignition, or form- ing a tnrquoise-enamel }>y fusion with sodium carbonate. Siderite or Sjmthic Iron (FeO, CO- but part of the FeO often replaced by MnO, tkc.) Ankerite (CaO, MgO, MnO, FeO, CO'-'). lihodochrosite or Afanganese Spar (INtnO, CO'-). These carbonates are placed together because, frou) the A icarions relations of Lie monoxides FeO, MnO, MgO, CaO, 'i t', als.> known as Di'iJloi/ite and }fanganetie Spur, is connected witili Solerlte l)y varieties of passage, more especially by the variety of the latter known as Oligoii Spar. Typically. Rhodocl'rosite is of a pale-red or ro.se-pink colour, and is commonly found in botryoidal anrecipitate, and ♦^est witii sodium phosphate. Care must of course be taken to see in eacii case that the i)re('ipitation is complete, Lime is also easily detected by a small ape<'trosco])e. See Blowi'ifk Fhaotiob ; Paiit I. TABI-K XV. FoL'KTii (tRovp : Assmnin;/ a lufht-ijrppn colour uflpf vjoU'ioa with cobalt solution. 1 ^ i J. •1 111 SinUlisonite or Zinc Spar (ZuO, CO"-). This mineral is tlie only repres* ntative of the present group. It occurs chiefly in l)otryoitla] and incrustinf^ niass< s, and in a;,'gi ogations of snjidi rhoniljoiiedrons, either colourh'ss and vitreous, or yellowish-gi'cy, l>rownish, «fec., aiid opaque. It readily scratches other carhonates and <'ven tiuor spar. H=5 ; sp.gr. 4 to 4'4. Yields 151] wi li a mixture of sodium carbonate and horax, a sublimate of ZnO — lenion-vellow whilst hot. white when cold, and l)ecomini' light-green after ignition with cobalt nitrate. The satm-ated borax .)ead becomes opaque on cooling or wiien tlameil. Fifth Group : Shevnny alkaline reaction, after iynition, hut without (/iviraj reactions of piecediny (jruuits. A small fragment must be sti'ongly ignited on charcoal or in the j)Iatinum-ti|)ped forceps; placeil when cold on a slip of red litnms-paper ; and moistened with a drop of distilled water : a blue spot will apj»ear beneath and around the test-matter The satunted l)orax bead becomes opaque on cooling or by flaming — /. '., by sulyection to an intermittent flame Calcite (CaO 56, CO" 44). Dolomib' (CaO. MgO, CO'"). Magmnlfe (MgO, CO'^). Arragonite (CaO, CO'^). I -li i!- !' ii ,1 i I; ■1 mamgammm ■ _ •f^ 11'-!' w P' i Jjra if 11 i.' 78 THE MINERAL INDICATOR. ii: i « IS t* i I V ■ I ■J., Calcite, Dolomite, aii pure examples) becomes distinctly reddened after ignition with cobalt solution. Arragoiiite lias the same comjiosition as Calcite, but crystallizes in Rhombic forms (often in twins of marked pseudo-hexagonal aspect), and ditters also slightly by its greater hardness (3"5 to 4 in place of 3), and by its some- what higher sj). gr. (2-7 to 3). Occurs fiecpiently crystal- lized, and also in fibrous and coralloidal examples. Colour, chiefly white, j>ale-yellow, or brownish-violet. Infusible, but generally falls into powder on ignition. Effervesce .s^ strongly in cold acids. * » See also Baryto-Calcite and AlstoniU;, infusible carbonates, colouring the Hame pale-green, and possessing an average sp. ^v. of 3-7. TABLE XVI. [Lustre non-metallic. Hardness inauliicient to scratch glass. Yielding BB on charcoal a garlic-like odour]. Gkoup 1 ; — Yielding BB on charcoal a silver globule. Colour and streak, deep-red. Froustite or Light-Red Silver Ore (Ag 66, As 15, S 19). This mineral has a strong, adamantine lustre, and is commonly more or less transjtarent. H 2-5; sp. gr. 5-4 to 5-6. Fusible per se, if held at the side of a Bunsen or candle-flame, without the aid of the blowpipe. The reduced globule, as obtained BB on charcoal, retains its bright i'l' riJ I ! i I Ml m THE MINERAL INDK'ATOK. ,^ pi' suiface in an oxidating flame. As an a blue solution. TiroHle, however, leaves a residuum of CaO, CO" ; and white Hecl.s of Al'-'O'' sepaiate from Lirvcunite. Apart from tlu-sci distinctions, the separate species are not always of easy determination without com})lete analysis, but the following is a comparative summary of their more sali- ent charaeteis : Oliveitite and Cli)iocht<(' are dark-green, often blackish- green ; the fii'st, Khombic ; tlo s(^cond, Clino-Rliombic, in crystallization; l>ut whilst O/ic-nite is commonly in small crystals (roseml»ling in general shajte those of the common l)asaltic augitcs), Cliuochisn is most frecjuently in radio- riljrous (^xamph's, whence its (leiinan name of "Htrahlerz." A'rinif'i, A'nc/n'oife, and C'h(i/coj)hi/l/itc, are mostly of a bright, cnuMald-green colour. The latter occuis essentially in tabular, micaceous examples (whence its poj)ular name of •' copper mica "), and it is thus easily n^cognized. Kvinite is chieily in small ronnded masses of concentric-scaly stru(!ture, and is harder than other cupreous arseniates, being equal in hardness to Huor-spar, or eviMi slightly harder than that mineral. /'JiichroUe is commonly in small, thick, vertically- 8ti iated crystals of the Ithombic System. Tiro/i'f.f. and Liroconite are light-green or light-bUu! in colour. The fii'st occurs mostly in mamillary radio-hbrous oxam|iles, au belong'.ng to the present gi'oup, [t occurs chiefly in acicular, (iltrous, and efflorescent examples ; sometim(»s in small peai'ly crys- tals of the Clino-Hhond)ic System. Easily fusible Yields about 24 per i-ent. water on igtiition. Sometimes pah^-pink in colour, from pait of the CaO being replaced i-y CoO. I! J''- nr 84 THE MINBHAL IXDRATOR. I 4-1 '^-.ifi • . ' TABLE XVTI. [Fusible or roctucihle on charcoal. .Streak- j)()W(ler, coloured], F1EI8T Group: Pitrthf or irholhj iiolalUhuihh', unth emission of a)ifimoni(U fiim.f'i'. Streak, red. Pifrargyrite or Dark Red Silrer Ore ( Ag, SI), S). Kermesite {'i^\yi^\ ^hH)^). These minerals exhibit in many examples a sub-metallic lustre. Both melt without the aid of tl e blowpipe if held in the form of a small fragment against the edge of a candle or Bunsen flame. On charcoal, they give a dens(^-white antimonial sublimate or i-ing-deposit : Kerniesite volatili- zing entirely, and Purargyrite yielding a large globule of silve:-. Kenne.^ite occurs in gi-ouj>s of acicular crystals or in small radio-{il)rous tufts, mostly accompanying Antinioni/ (/lajtce. Pi/rargijrite is chiefly in cleavable masses, and in Hexagonal or llhoml)ohedial crystals, of a dark or l)luish-red colour j)assing into dark lead-grey. 8p. gr. 5 '7 to 5'9. It often emits an arsenical odour on ignition, from tlie presence of As'-'S'', the hitter j)artly replacing Sb'-S''. • See also, (7i/ot«/>ar (Table XIV). Hecond Group: Non i.-'ohuife on ignitioti.. Colour, dark or bright-red with red or orange streak. (Jvprite or Ped Copper Ore ^Cu'^O). Crocoisite or Lead Chromate (PbO, CrO"'). Cuprite is dark-red or bluiHh-red in colour, with red streak, l)ut the colour is often obscured by a coating of green car- bonate. It occurs in cleavable masses, and very cunimonly I TABLE XVII. 85 in small octaliedrons and rhoiobic dodecaliedrons. Sp. gr. 5'7 to 6. Easily reduced BB to metallic copj»ei-, colouring the tiame deep-green. Crocoisife lias a bright-i-ed colour and orange-yellow streak. It occur.s in groups of more or U^ss acicular (Clino-Hhom- bie) crystals, and in small flaky masses and coatings. S|). gr. 5'9 to G. BB, dcci-epitates, blackens, and becomes ve- duced to ni<;tallic lead. With l)orax, forms an emerald-green glass. With hydrocldorie acid, causes the evolution of chlorine fumes. j^*^j See also J*/i(hiilcif( (a red chroinatu «'th reil streak, ofti'ii iu lihrous masses acoeinpaiiying Croeoisitf) ; n»i;l .'/iiiiuin or linl oi'hkof lidtl (mostly in earthy crusts with (irangt'-yellow streak). Uoth cause the evolution of ciilorinc wla'ji warmed witli hydrorhloric acid, and both are eai'ly reducible Rli on cliarcoal ; Imt Minium gives no Ureen glass by fusion with l)orax or phosplior-salt. See also red coloured varieties of W'ulfenito, Table Will. Also (Table XIX) Hal Ircii On and Jiroini Jrun On-, which fuse on thin edj^es in a reducing tlame, and hecoine magnetic. TniHi) (IxouP: Colour a, i>i/ drudk, black or broivninh-blnck, Wolj'rani (FeO, MnO, WO").' Mehicoulte (CUiO). Wolfrani^ wbich in some (examples scratches glass very feebly, gives BP) with sodium carbonate a strong mauganeso reaction — i.e. a blae-gre(Mi enamel. Mt^/acouitf becomes reduced to metallic copper. Wol/'ram is also readily dis- tinguished by its liigh sp. gr., which e([uals 7"1 to 1'^). It occurs mostly in lamellar masses or in clinorhoml)ic crystals. H, 5"0 to ').;"), Very easdy fusible into a magnetic globule. 1; 1 ■' li ^i ;i 'k\ I !■ mmm THK IMINKIIAL INI ATOR. Meloxonite occurs generally in earthy masses or in pseudo- iuoij)lis after cuprite. Tenorite lias the same composition (CuO) but is distinctly metallic or sub-metallic in lustre. See Table VII. Fourth (jROUP : Colour green, jHtler in the streak. Yielding water on ignition, and giving BB, ivith sodium carbon- ate on cJiarcoal, a copper globule. Atacaniite (CuCl-, OuO, H'O). Brochantite (CuO, SO', ll-'O 12 to lo %). Lihethenite (CuO, P-'0\ H-'O 4 %). PhoHphorchahite (CuO, P'-'O'', H'O 8 %). FJdite (CuO, P-O', H-0 9 %). Tagilite (CuO, P'O'' H-0 10 o %). Chalcolite oi- Copper-Uranite (CuO, U'O"', P'^0'', H'-O 15 to IG %). Atacamite is a c\ipreous oxy- chloride, and, as such, it colours the blowpipe-llame bright azure-blue. Occui's in small I'hombic crystals, and in grains, of a rich green colour. Atlasite is this substance partly converted into carbonate. lirochnyitiU' is a c()j)per sulphate, and thus forms by fusion with sodium carbonate on cliarcoal an alkaline sul j)hide, which 1)roduces a dark-Uiown or black stain wIkmi moistened and laid on a silver coin.* All the other mintu'als of the group are phosphates. Their nitric-acid solution when warmed with a * The trinl nhouM lie made with an oil or candle flame, as roul-^fOH oi'ten contains ulphur, and imjuirlH this to the test -mutter when the (\iHion is elTedloil by ii modi - fled Thinsoniiiuiior. ir^ TABLE XVII. m few particles of amni. molybclate gives a canary-yellow pre- cipitate. Lihethenite is dark olive-green or blackish-green, and occurs coninionly in groups of small rhombic crystals, isomori)hous with the cupreous aiseniate Olivenife. Its ignition loss does not exceed 4 per cent. PJiOspJiorchalcite, Ehlite and Tagilite ai-e of an emerald-green or clear-green colour. They occur mostly in groups of very small and more or lef;s indistinct crystals (Hhombic or Clino-llhombic), and in radio-fibrous, mammillated, and earthy examples. Ehlite is especially distingui.nhed by its easy cleavage in ono diiection, nnd its more or less bladed structure. C/ialcolite, the copper-uranium phosi)hate, is also easily cleavable in one direction, and it piesonts a rich emerald-green colour, with pearly lustre on the cleavage ])lane. As a rule, it is readily distinguished from the copper phosphates })ropor, by the square, tabular crystals and broad ieafy masses in which it commonly occurs ; as well as by its high ignition-loss, amounting to over 15 per cent. Fifth Ghoup: Colour yellow or i/flloir/sh-green, loith jyalc- yellow streak. Yielding water oti ignition. Uranife or Antunite (C'aO, U'O'', ll-'O 15 to 19 /). This is the only mineral of ordinary occurrence referable to the present group. It occurs in snudl tabular crystals (of Tetragonal aspect), and in leafy UKtsses, very easily cleavable in one direction — the cleavage-plane shewing a pearly lustre, as in the copper uranium phosphnte. Chalcolite. Easily fusible into a dark luwl. Fovins with phosphor-salt, BB, a yellowish-green glass in the O.F., and a bright chrome- green glass in the 11. F. i J f'i \M' > I mm u THE MINERAL INDICATOR. Sixth Group : Colour indigo-blue or bluish-green. Fusible on charcoal into a magnetic globule. Vivianite (FeO, Fe'O', ¥'(¥', H'-O 28;/). The above is the only mineral of common occurrence belonging to this group. (For related iron phosphates, mostly yellow or brown in colour, see the author's Blowpipe Practice, Table XVII.) Vivia7iUe is normally colourless, l>ut always presic crystals occur at some localities. In the bulb-tube it swells, up, red- dens, and yields a large amount of water. Fuses BB into a magnetic globule. ^*^ See, also, Chlorite (Table XVI IT), which fuses on the edges, ill some examples, into a dark, magnetic slag. Coiiunonly in dark- green, soft, foliated, scaly, or scaly-compact masses, witii in some cases a distinctly greenish streak. i w w W^ 'K|'>< Kj:' m *\ la ! t TAItLE XVIII. 89 TABLE XVIII. [Re are compariitively uniinpoittint. Tlu'V occur niostlv tia wliiu^ or vellowish incrustations on ^ k. » JutiiHony Glance and other antiiiionial sulpliidcs. Valen- tinite, wliich contains 83^ pt'r cent, antimony, occurs also in acicular or small tabular crystals of tlie Rhombic System ; sji. gr. oS to ")•(). BB, becomes yellow, melts very easily, iUivl volatilizes. Senarnionite has the same composition and general aspect, but crystallizes in regular octahedrons, often with curved faces. Both sul)linie rt ily i>y in the bulb-tube Cervuntite is a combination of antimonious and antinionic acids, and although i-educible (and then volatilizable) on charcoal, especially if mixed with sodium carbonate, it does not fuse per Sf, and is not volatilizaljle in the bulb-tube. Yell ow y -11 eJU)Wisli-\v hite n>- « r. 4. Antimony Ochre and Stihlite nnich resiMuble the above, but yield water on ignition. Occur essentially in earthy incrusting exam[)les of a yellow or yellowish-white colour* m 90 THE "MINERAL INDICATOR. '' 'ft*' li VH! ^^1) ' i 1 r i and occasionally in pseudomorplious crystals derived from Antimony Glance. Antimony Ochre fuses easily ; Stihlite is infusible, but becomes reduced on charcoal. Skcoxd Group: Yielding per se or with sodium carbonate on charcoal, metallic globules, and depositing ( Kerargyrite excepted ) a yellow coating on the support. Kerargyrite (AgCl). ryromorphite (PbO, P'O^ PbCl^). Vanadinite (PbO, V-0\ PbCl"). Amjlesite (PbO, S0»). Wnlfenite (PbO, MO'). Stolzlte (PbO, WO'^). Euhjtine (Bi'-O'^ SiO-). Kerargyrite, Pyromorphite, and Vanadinite produce a strongly-marked chlorine reaction, i.e., an azure-blue colora- tion of the flame-point, when fused with phos[)hor-salt and cop[)er oxide, or with phos[)hor-salt, alone, in a loop of copper wire. Kerargyrite, commonly known as '* Horn Silver Ore," is easily distinguished by the large globule of silver which it yields JjB on charcoal. It occurs commonly in waxy -looking, very sectile examples of a violet-brown, grey or greenish colour. H 1 to 15 ; sp. gi'. 5'6. Sometimes mixed with AgBr and Agl, when the flame-point is coloured more or less green. Pyromorphite occurs chiefly in hexagonal prisms (sometimes acicular and often barrel -shaped) and in mammillated and granular examples of a dark-green, light-green, brown, grey, or yellow colour. H 3i) to 4 ; sp. gr. 6-9 to 7. Fused on charcoal, per se, it forms a white or light-coloured globule a TABLE XVIIl. n which crystiillizes witli broail facets on cooling. Witli soiliiini carbonate, easily reduced to iiK^tallic lead. Va>in- dinitc occurs in small, sharply defined hexagonal ])risms of a pale or deep red colour, either hollow, or indented at the base. Sp. gr. 6*8 to 7-2. AnglesUe with sodium carbonate, on charcoal, gives strong sulphur-reaction — i.e., the slag around the reduced leatl pro- duces a dark stain when placed with a drop of water on a silver coin.* Commonly in colourless or greyish (Rhombic) crystals and crystalline masses of marked adamai' tine lustre, and in mammillated and other examples. Sp. gr. G-1 to 64. W u/ fen ite and Stoh'Ue form deeply coloured git^en or green- ish-blue glasses by fusion in a reducing llame with phosphor- salt. WulJhiUe is mostly in small, tabular crystals of the Tetragonal System, yellow or yellowish-grey in colour, (or sometimes red from intermixture of lead chromate or vana- diate.) 8p. gr. 6-7. As pointed out by voit Kobell, a beautiful blue coloration ensues when the powdered mineral is warmed with concentrated sulphuric acid in a ixn-colain capsule, and some alcohol is added to the mixture. Stohite is especially distinguished by its high specific gravity, 7 '9 to 8'1, and by the fine blue or greenish-l)lue glass which it forms by fusion with phosphoi-salt in a icducing Hame. It occurs connnonly in very small, often fusiform, square-based pyramids and other Teti-agonal crystals, and also in nuim- millated examples, grey or brown (more rarely red or gieen) in colour. Nitric acid dissolves out the PbO, and leaves a yellow residuum of WO''. " As stated in a preoertinjr footnote, the fusion sHould be eflfeoted by the Hiune of a candle or that of an oil lamp. There is always risk of sulphur lieing com- municated to the test-matter by a gas flame. Hii V I ! '■ iWlii mt m IMAGE EVALUATION TEST TARGET (MT-3) A %^ 4^ 1.0 I.I 11.25 •• I. ill— U IIIIII.6 V] 0%i ^m'^^^ > ^."^J^ *> c*^ 7: V /A Photographic Sciences Corporation 33 WIST MAIN STRUT WIBSTIR.N.Y. M980 (■;\6) 872-4503 hosplioi'escence. Cryolite occurs in white, lamelhir masses with nearly rectangular cleavage. Sm;dl fragments melt easily if held airainst the ed^e of a candle flame. BB on charcoal, runs into liquid fusion, and is in great part absorbed, leaving a white, earthy residuum which becomes bright-blue when moistentd with cobalt nitrate and again ignited. H 2"f) to 3; sp, gr, 2 "OS. ChioUte and Pachnolite are closely related. Barytine, Celestine, and Anhydrite, ai-e sulphates, and thus form by fusion with sodium carbonate on charcoal, a so-callod *' hepar," or reddish mass which imparts when moistened a dark stain to the surface of a silver coin or piece of lead test- pa[)er ; but the fusion should be made by the flame of a candle or oil-lamp, as ordinary gas frequently contains sul- phur. Ignited per se iii the blowpipe forceps, Barytine co- lours the flame-point j>ale-green, and Celestine imparts to it a oarmiiie-red colour, the colour becoming veiy intense oil r pi' I f n mh P n : f- ■ 04 THK MINERAL INDICATOR. prolonged .subjection of tli^ test-fragment to the action of the flame. Both dissolve entirely BB, in sodium carbonate, whilst Anhyd7''ite leaves undissolved a white earthy mass. The sp. gr. of Barythie equals 4".3 to 4*7 ; that of Celesthie, 3"9 to 4 ; and that of Anhydrite, only 2-8 to 3. Barytine occurs in rhombic crystals (often tabular) ;* and in lamellar, fibrous, and other exam[)les, either colourless, or opaque- white, yellow, pale-red, brown, etc., in colour. Ce/esfhie occurs also in colourless rhombic-crystals (often associated with native sulphur), and very commonly in fibrous and lamellar examples of a lir.-ht or deej)-blue color, and occasional- ly also in red examples. Anltydrite is rarely in distinct crystals, but commonly in lamellar, granular, and other masses, mostly of an opaque-white or greyish colour, or variously tinted. TriphyUine occurs in cleavable, lamellar masses of a grey- ish-green or greyish-blue colot.r. H 4 to 5 ; sp. gr. 3o to 3'G. Easily fusible, generally colouring the flame both green and red. The latter colour comes out very strongly if the test-matter be moistened with iiydrochloric acid or fused with barium chlorid(^ The solution iii nitric acid gives a canary-yellow pi'eci})itate with amm. molybdate. Fourth Group : Characters like those of the prrcedln:/ Group, but yielding water on ignitiov. Gypsum or Selenite (CaO, SO'', II'-'O). Polyhallite (K'O, CaO, MgO, SO', H'O). ** See syiioi)Hin of itw crystiil typuH in the Tahli's which accimijiaTiy tli of an aggregation of minute pearly scales, and is readily distinguished by the vivid crimson colour which it imparts to the blowpipe-flame. It melts very easily, with continued bubbling. It occurs also occasionally in foliated or micaceous examples. H commonly about 2*0 ; sp. g»\ 2-8 to 3. Muscovite and Phlogopite are conmion species of mica. They occur essentially in foliated or finely-laminated masses, which admit of separation into the tliinnest leaves, and present a metallic-i)early lu8ti*e. Also in detached scaly particles, and in Jiexagonal and rhombic plates and crystals * Many examples of Crocidolite are intimately intermixed witli quartz or calce- dony, by which the normal character of the mineral is obscured or destroyed. ' i"i TABLE XVIII. 9T with strongly-pronounced basal cleavage. Thin leaves are flexible and elastic. BB, fine scales become opaque and fuse more or less readily on the edges. Muscovite is com- monly of a white, brown, black, or greenish colour, and is insoluble in acids. Phlogopite is commonly brownisb-yeilow or golden-brown in colour; and is decomposed in powder by strong sulphuric acid, the silica separating in colourless scales. Biotite is a related, ferro-magnesian mica, mostly of a dark-green, black or dark-brown colour, and like Phlogopite is decomposed by sulphuric acid. As a rule (though not exclusiv^l}/), Muscovite, forms an essential component cf granites, gneissoid rocks and mica slates; whilst Phlogopite occurs in connection with crystalline limestones; and Biotite, with lavas, trachytes, and basalts. Margarite or Pearl Mica is distinguit-hed from the micas proper, by the comparative brittleness of its component folia). It occurs in six-sided tables and lamellar masses of a pearly- white, pale green or pale-reddish colour. H 3 -5 to 4 ; sp. gr. 3. Fusible on the edges 'with slight intumescence. Contains about ') per cent, water, but yields little more than traces by ignition in the bulb-tube. Talc contains from 4 to 5 per cent, of water, but this is only driven off by intense ignition, and thus no water is obtained by ordinary treatment in the bulb-tube — or, at the most, a mere trace only appears upon the glass, Talc oc- curs under two leading conditions : in soft, ibliated and scaly examples of a pearly-white, light ^^vqqw or other light colour ( = Talc proper) ] and in compact or crypto-scaly masses, white, grey, greenish, (fee, or mottled, in colour (=z Steatite). Both are more or less soapy to the touch, and 7 i i ' 1*. i. t" ft iiF 98 THE MINERAL INDICATOR. very sectile. Thin folije are flexiVde but not elastic. Sp. gr. 2-67 to 2 '8. H, in Talc proper,^^\ ; in Steatite lo to 2-5. BB, both harden considerably, but fuse only on the thinnest edges. See Table XX. Sixth Group : Bloiopips characters like those of the Fifth Gi'oup, but water evolved (in distinctly visible quantity) on ignition in the bulb-tube. Sub-Group a : Fusible with strong intumescence. Stllbiteor Desniine {Oix,0 , Al-O'', SiO-, H-0 17 %). Heulandite (CaO, Al^O^ SiO'-, H-0 15 %). Chabnsite (K'-'O, CaO, Al'-^O^ SiO''', WO 21 %). Apophyllite (KF, CaO, SiO', H-O 16 %). Thomsoiiite (Na-'O, CaO, Al'O, SiO', H'O 13 %). Scolezite (CaO, Al-'O^ SiO', H-O, 13 to 14 %). Laumontite (CaO, Al'O'', SiO', H-'O 16 %). Phillipsite (K-0, CaO, ArO', H'-O, 17 %). SuB-Giioup B : fusible without intumescence. Haruwtome ^ K'-'O, BaO, APO^ SiO-, H'-'O 15 %). AvMlcime (Na-0, Al'O^ SiO", H-0 8 %). Natrolite (Na'-'O, A1'0'\ SiO', H-0 9^ ^). Sub-Group C : Fusible only in fine splinters, and then,, as a rule, upon the edges merely. Chlorite (MgO, FeO, Fe-0'', M'0\ SiO'^ H'-'O, D to 12%). Ripidolite (A feebly terruginous chlorite). Serpentine (MgO, Sio'-', H'-'O 13%). Chrysotile (Asbestiform Serpentine). • TABLE XVIII. 99 as a, Tlif^ re[)resentatives of sub groups A and B belong to the natural group of "Zeolites" — a series of hydrated silicates occurring especially in amygdaloidal cavities of ti'ap})ean or basaltic rocks. All are very easily fusible (in thin frag- ments melting in the Bunsen-flame without the aid of the blowpipe), and those of the first sub-grou}» intuniesce or foam up on the first application of the fianio, whence the name " Zeolite." All are readily decomposed by hydio- chloric acid, the silica (in all but Stilbite, I/euldudite, Chaha- site, Analc'ime and llarmotome) se[)arating in a gelatinous state on partial evaporation of the solution. Some of the species scratch glass faintly, and are thus referred to in Table XI. ; but to avoid risk of error in their determination, it has been thought advisable to place them also in the present Table. Stilhite and Heiihindite mucli resemble each other and Ciui only be distinguished properly by their crystallization, which is Rhombic in Stilbife, and Clino-BhomMc in Ileulandite. Both occur commonly in white, brown, nv rod, foliated and radio-fibrous nuisses and grouped crystals, with very perfect cleavage in one direction, and strong ))eavly lustre on the cleavage plane. H 3'5 to 4 ; sp. gr. 2-1 to 2-2. (Jhabasite })roper, is easily distinguished by its occurrence in small rhombohedrons, uiostly colourless, or whi.e, red, &c. H, 4 to 5 ; 8\\ gr. 2 to 2 '2. A variety known as PhacoUte occurs in very fiat twelve-sided pyramid', and allied forms, often lenticular from distortion. Th:ise species are decom- posed without gelatinization by hydrochloric acid. Apophyllite or Ichthyopthahnite occurs in Tetragonal crys- tals or lamellar masses, colourless or opaque-white, pale- reddish, (fee. The crystals are either square prisms with li II if,' 100 THE MINERAL INDICATOR. ' 1(1 :, 4#.i h Hi replaced angles, oi" acute pyramids, mostly with basal plane? the latter shewing a pearly and often iridescent lustre, whilst the other planes are vitreous. The cleavage is parallel with this basal plane, and the cleavage surface is also irides- cent-pearly. H 4*5 to 5 ; sp. gr. 2 3 to 2 -4. BB, ex- foliates and melts with bubbling. Thomsonite occurs in rectangular prisms (often ncicular), and in fibrous masses, mostly colourless, H 5 to 5 5 ; sp. gr. 2-3 to 2*4. Fusible, with more or less intumescence. Scolezite is much like Thomsonite in general characters, although Clino-Rhombic in crystallization, but its salient character (at least in typical examples) is the expansion and pronounced intumes. cence which it exhibits on ignition. Laumontlte is also Clino-Rhombic in crystallization, but is commonly in opaque-white efflorescent exann>les, from loss of water by weathering. H (in unaltered examples) 3 to 4 ; sj). gr. 2*2 to 2-36. Fusible with intumescence. Phillipsite or Lime- Harniotoine is mostly in small colourless, cruciform-crystals (but also Mt times in simple crystals) of the Rhombic System. H 4-5 to 5 ; sp. gr. 2?>. Fusible with intumes- cence. Har7iioto'nie, Analcime, and Natrolite, fuse quietly before the blowpipe — i. e. , without preliminary intumescence. Harmotome is readily distinguished by its occurrence in small cruciform-crystals of vitreous lustre. Its partial solution in hydrochloric acid, diluted and tested with a drop of sulphuric acid, becomes immediately milky from precipi- tation of BaSO^. Analcime may generally be recognized by its occurrence in small trapezohedrons, or in combinations of cube and trajjezohedron — the cube shewing three small in TABLE XVIII. Wl planes on each angle. Colourless, light-grey, pale-red, &,c. H 5-5 (scratches glass feebly in most examples) ; sp. gr. 2-1 to 2-3. Colours the blowpipe-flame strongly yellow. De- cora])osecl by hydiochloric acid, with gelatinization. Natrolite is commonly in radio- fibrous, botryoidil masses, of a brown- ish-yellow colour, but it occurs also in acicular or very small crystals of the Rhombic System, either colourless or lightly tinted. H 5 to d'-f) (scratches glass slightly) ; sp. gr. 2-17 to 2-27. Tinges the blowpipe-flame strongly yellow. Gelati- nizes very readily in hydrochloric acid. The ignition-loss in both Analcime and Natrolite is under 10 per cent. ; in other commonly occurring Zeolites, it varies from 13 or 1 4, to about 20 per cent. The minerals of sub-group C, are at once distinguished from those of the preceding sub-groups by theii- diflicult fusibility. As a rule, they exhibit signs of fusion before the blowpipe only on their thinnest edges, or at the point of tine fibres, only. They comprise : the foliated, scaly or crypto-scaly species, Chlorite and JNpidolite ; the compact or slaty Serpentine ; and the silky fibrous Chrysotile — the latter, properly, an asbestiform variety of Serpentine. Chlorite {=Pennine) is normally dark-green in colour ; foliated, scaly, or earthy, in structure, and very soft and sectile. Sp. gr. 2*75 to 2 95. Thin scales melt on the edges and surface into a dark, magnetic slag. Some ex- ceptional, chromiferous varieties are dark-red. Kividolite (=Clmochlore) is a non- ferruginous or slightly -ferruginous Chlorite. It melts on the edges into a yellowish-grey enamel. Serpentine occurs normally in compact or fine-granular ■!i iir ■ '■; J ) 1 l^K 1 ^^■ff ( fW Zi n f0 102 THE MINERAL INDK ATOR. masses of a green, yellow, red, brown, or greyish colour — two or more colours being often present together in veins and irregular patciies. More rarely it occin\s in slaty masses {Antigorite, (fee.,) and in fibrous examples, strongly silky in lustrf {Chrysotile). The latter is usually greenish or yellow- ish ./hite in colour, or sometimes i)ale blueish- white. Average sp. gr. of Serpentine proper, 2*5 to 2-7. ^*^ Mcerscha iim (in white or yellowish, compact, sectile masses ; sp. gr. l"0 to 1*3; yielding 11 or 12 p. c. water on ignition) ; Dexveij- lite or Gfjmnite (in yellowish, waxy-looking masses, yielding 22 p. c. water); Villarsite, Pi/raUofile, Sec, also belong to this sub-group. !See " Blowpipe Practice," Table XXV. ■ TABLE XIX. [Lustre non-metallic. Hardness insufficient to scratch glass. In- fusible, or vitrifying on thinnest edges only. Streak, coloured.] First Group ; Magnetic in natural condition. Magnetite (Exceptional exam]>les, only). Black ; streak black. See Tables III. and IX. Second Group : Magnetic after strong ignition in a reducing Jiame. Red Iron Ore (Fe^O^^). Red Ochre (Earthy Red Iron Ore). Brown Iron Ore {Fb'O'^^WO). Yellow Ochre (Earthy Brown Iron Ore). This group includes only the soft and ochreous varieties of Hematite and Linionite, distinguished respectively by I'll 11; ., « TABLE XIX. 103 their streak — red in one case, and brownisli-yellow in the other. In a reducing flame, these varieties blacken, and become slightly vitrified on their edges, \)ut piactically they may be regarded as infusible. After ignition, they readily attract the magnet. Red Iron Ore is generally in granular, fibrous or slaty masses, lied Ochre or Reddle is merely an earthy variety, sufficiently soft to mark and soil. Brown Iron Ore occurs in lamellar, granular, and radio- fibrous botryoidal masses of a dark or light-brown colour and ochre-yellow streak. It frequently j)resents a smooth, glazed surface, and is often iridescent. Bog Ore is a sub- earthy variety, commonly containing a certain amount of FeO combined with liumic or other organic acid. Yellow Ochre is simply the Brown Ore in an earthy condition, soft enough to mark and soil. These varieties give off water in the bulb-tube, and become red when ignited in the free air. Some contain a considerable amount of Mu'-'O'', in which case the powder after ignition assumes a chocolate-red colour, and gives a greenish-blue turquoise-enamel by fusion with sodium carbonate mixed with a little borax. l!' Third Group : Not magnetic after ignition. Streak, yale- broiV7t, reddish-brown, or yellow. . Zinc Blende (ZnS ; or [Zn, Cd, Fe] S). Zincite or Red Zinc Ore (ZnO + ZnO, MnO^). Greenochite (CdS). «*•* Hauerite (MnS^). Zinc Blende, Hauerite, and Greenockite give strong sal- plmr reaction with sodium carbonate : see below. I l5 I I r mm ■HI m I*' < h ♦ f I 104 THE MINEKAL INDICATOR. Zinc Blende and Zincite^ fused witli a mixture of sodium carbonate and borax in a reducing flame on charcoal, give a sublimate of zinc oxide. This is lemon-yellow whilst hot, and white when cold. Moistened with a drop of cobalt nitrate, and again ignited, it becomes bright-green on cooling. hauerite and Zincite fused with sodium carbonate give Mn reaction in the form of a turquoise enamel. Zinc Blende is distinguished by its pale-brown streak, and by the formation of an alkaline sulphide by fusion with sodium carbonate and a little borax in a reducing: flame on charcoal. The fused mass, removed from the charcoal, and placed with a droj) of water on a silver coin, imparts a dark stain to the surface of the latter. The fusion, hov^ever, should be efl'ected by the flame of a candle or oil-lamp, as sulpluir is often communicated to test matters by the flame of gas. Zi)ic Blende also gives off" an odour of sulphuretted hydrogen when tested in powder by hydrochloric acid. Many examples of this mineral [>oss«>8s a sub-metallic lustre (see Table VIII.) ; and some of the dark, ferruginous varieties become slightly vitrified on thin edges before the blowpipe-flame. The ujore common colours are dark-brown or black, with pale-brown streak ; and some of these examples are blood-ied, by transmitted light. Other examples are dark-green, yellow, etc. ; but the streak in light-coloured examples is almost colourless. Most yellow varieties, when scratched strongly in the dark, shew phosphorescence. Zinc Blende occurs commonly in cleavable lamellar masses, tetra- hedrons and other crystals of the Regular System, and occa- sionally in sub-tibrous examples. H 3*5 to 4 ; sp. gr. 3 9 to 4-2. TABLE XIX. 105 Hmierite occurs ciiietiy in dark-brown, opaque octahedrons, mucli resembling crystals of Magnetite or Galinite, and also in combinations of cube and pentagonal dodecahedron, ^vitli reddish-brown streak. H := 4 -0-4 -5 ; sp. gr. 0-4-3-5. Piac- tically infusible, but gives BB strong Mn-reaction. Zincite or Bed Zinc Ore occurs usually in laiiiellar and granular masses of a blood-red colour with orange yellow streak. It is commonly associated with Franklinite, and is often coated in places with white zinc-carbonate. H 4 ; sp. gr. ")-5 to 5-7. BB, infusible; with sodium carbonate mixed with a little borax, gives a greenish-blue turtpioise-enamel. Greenockite or Cadmium Sulphide is comparatively rare. It occurs in small pyramidal crystiUs (acute, hexagonal pyramids with lower half entirely replaced by basal plane) of a yellow or yellowish-brown colour, and yellow streak. H 3 to 35; sp. gr. 485. BB generally decrepitates, and becomes deep-red whilst hot. Infusible. With sodium carbonate, gives a red-brown sublimate of ca*. n oxide. This is best- seen by rubbing the surface of t u loal support, [)revious to the trial, with some powdered cuaik or bone-ash. FouKTH Group : Colour green or greenish-blue, paler m t/te streak. Chrysocolla (CuO, SiO'-, H-'O). Pimelite (MgO, NiO, Al-'O^ SiO'-, H-'O). Chrysocolla occurs in amorphous botryoidal masses, and in coatings on coi)j)er ores. Also, occasionally in pseudo- morphs. Green or blue, vdtli very pale streak. H (in solid examples) 2 to 5 ; sp. gr. i, to 2 6. BB, blackens, but does not fuse. With sodium carbonate on charcoal gives Vi,.: V I warn. 106 THE MINERAL INDICATOR. ■I it' a globule of metallic copper ; and with pliosplior-salt, a silica- skeleton. In the bulb-tube yields over 20 p. c. water. The rare Bioptase, a liydrated copper-silicate from Siberia, also belongs to this group, but is hardly liktly to come under the student's*] observation. It occurs in hexagonal prisms, with rhombohedral summit-planes, of a beautiful emerald- gieea colour. Scratches glass slightly, yields 11 4 p. c. water on ignition, and gelatinizes with hydrochloric acid. Sp. gr. 3-3. Pimelite occurs in apple-green coatings and earthy masses. BB, blackens, and generally vitrifies on thin edges. With boiax in an oxidating flame, forms as amethystine glass which becomes brown on cooling. In the bulb-tube yields about 21 })er cent, water. Nickel-Gymnite in green or greenish-yellow coatings on certain examples of Chromic Iron Ore, is a closely-related substance. * * See, also, Chlorite (Tables XVIII. and XX.), some examples of which present a greenish streak. Commonly in dark-green, foliated, scaly, or compact-scaly masses, sufficiently soft to be scratched by the finger-nail. Infusible, or fusible on thin edges only. Fifth Group : Not exhibiting the distinctive characters of preceding groups. Colour black or brownish black. In soft, earthy masses. BB, colourinr/ borax strongly. Manganese Ochre or Wad (MnO, BaO, MnO', H-'O, &e.). Cobalt Ochre or Asbolan (CuO, MnO', CuO, Fe'-O'', H^O, &c.). These Ochres are mixtures of more or less inconstant composition. They occur in biack or dark-brown, earthy, M TABLE XX. 107 f I ' stalactitic and other amorphous misses. Both, form a tur- quoise-enamel by fusion with sodium carbona te : and the cobalt ochre gives a blue glass, more or less pure, with borax, especially in a reducing flame, when the amethystine colour (imparted to the glass by manganese oxide) become destroy- ed. Both yield water on ignition, and cause the emission of chlorine fumes when warmed with hydrochloric acid. Sixth Group : Black, lustrous, compact. BB, insoluble in borax. Anthracite (carbon more or less pure). This variety of coal is distinguished from other coals by its comparative hardness and uninflammable character. Black, with con- choidal fracture. Sp. gr 1-3 to 1-8. BB, infusible, but burns slowly away without flame. TABLE XX.* [Lmtre non-metallic. Hardens insufficient to scratch glass distinctltf. Insoluble, or fusible on thin edges, only. Streak, nncoloured]. Oroup 1. — Yielding water in manifest quantity by ignition in the bulb-tube. Sub-Group a : Assu?ning a blue {or green) colour after ignition with cobalt- solution. * Many of the minerals placed fn this Table will he found also in preoedinK' 'Tables. This arises from the fact, that, in some fe«v, the hardness is just sutticit nt to scratch soft varieties of >j:las8. And ag-ain, although oonunonly stated to be infusible, many of the minerals referred to the present Table shew si,s,'ns of fusion on the e ^:f TABLE XX. 109 r hlue\ 0). Dre or ion of Alunite and Aluminite are sulphates, and, as such, they form by fusion on charcoal with sodium carbonate a so-called ■** hepar " or reddish slag, which imparts when moistened a dark stain to the surface of a silver coin. Alunite scratches oalcite, and yields on ignition 13 p. c. water. Commonly in granular masses of a white or pale-reddish or yellowish -colour, more rarely in small rhombohedral crystals. Alv^ minite yields to the finger-nail, and gives off on ignition about 47 p. c. water. Occurs commonly in white or greyish^ porous, earthy masses, which adhere to the tongue. Both give off SO- by strong ignition; the evolved water thus red- dens litmus paper. Wavellite is readily recognized by its almost constant occurrence in green, greenish-white, or ijale-yellowish, radio- fibrous and botryoidal examples on clay-slate or sandstone. H 3-5 to 4 j sp. gr. 2-3 to 2-r). BB, tinges the flume pale- green, and separates into fibres which become opaque-white but do not fuse. The solution in nitric acid Cor in caustic potash diluted and rendered acid by nitric acid) yields- a canary-yellow j^recipitate on warming with amm. molybdate. In the bulb-tube gives oft* 25 to 26 p. c. water. Various related species of closely similar character, but differing more or less in their water jjercentage, are named Peyanite, Fischer Ite, &c. Gihhsite or Ilydrargillite is comparatively rare. Occurs mostly in white or pale greenish-yellow mamillary and stalactitic examples, and in small hexagonal prisms with ])asal cleavage. K ?5 to 3; sp. gr, 2 35. BB infusible, but commonly exfoliates. Water percentage, 34*5. Bauxite is a related substance, variable as regards amount of water. m m n 11 m \ \\ 110 THE IMINERAL INDICATOK. Calamine, AUophane, Kollyrite, and Ilalloysite, are decom- posed with gelatiriization by hydrochloric acid. The first scratches calcite very strongly, and some examples scratch glass slightly. The others are softer than calcite. ^ Calamine or Zinc Silicate occurs chiefly in aggregations of small, vitreous crystals, and in botryoidal and cavernous masses, either colourless, or brownish, yellowif^h, &c., and sometimes light-blue from presence of a small amount of copper oxide. But it is chiefly distinguished by yielding a sublimate of ZnO, when fused with a mixture of sodium carbonate and borax in a good reducing flame on charcoal. The sublimate is lemon yellow whilst hot, and white when cold ; and it becomes light-green when moistened with a drop of cobalt nitrate and again ignited. Another distinctive character (as regards the minerals associated with it in this group) is its pro})erty of forming BB with borax a glass which on saturation becomes oi)aque-wliite by flaming or when cold. H 5 ; sp. gr, 3 "3 to 3*5. Pyro-electric. The powder ignited with cobalt solution, becomes partly green and partly blue on cooling. In the bulb-tube yields 7 "5 per cent, water. Allophane occurs in amorphous, botryoidal and similar examples. H 3 : sp. gr. about 2. Sometimes mixed with copi)er silicate and then light-blue or green in colour, other- wise red, brownish, &c. H alloy site and Kollyrite are essentially in white, grey, greenish or other coloured nodular and earthy examples, sufliciently soft, in general, to be scratched by the finger-nail, and somewliat soa})y to the touch. The first yields about 24 and the latter about 40 per cent, water. Like other related substances, Lenzinite, TABLi; ;cx. Ill Glaegerite, &c., they are decomposition products of somewhat variable composition. Kaolin, Nacrite or Pholerite, and Pinite, do not gelatinize in hydrochloric acid, and as a rule are only slightly attacked by that reagent. Kaoi.in (including Cimolite, ifec, is essen- tially in very soft, more or less earthy masses, of a white- reddish or other light colour , Xacritc, in pearly-white, soft, scaly masses and six-sided tables ; and Pinite (commonly regarded as a decomposed lolite), in six and twelve-sided prisms, of dull-grey, white, brown, and other coloui-, and usually opaque. The latter commonly vitrifies on thin edges before the blowpipe flame. Fahhmite, Gieseckite, Esmarkite, &c., are closely related (see the author's " Blow- pipe Practice," Table XXV.) ^*^ See AgahnatoUte and PyroplijiUUe in Group 2, below. These, ill the bulb-tube, yield as a, rule, merely traces of water. The minerals of Sub-Group B, do not assume a blue colour after ignition with cobalt nitrate. All are essentially magnesian silicates. Colourless examples thus become flesh- red after treatment with the Co-solution, but coloured varie- ties, as a rule, become dark-gvey or dingy-black under this treati lent. Meerschamn, Dev^eylite, and Serpentine proper, occur in fine-granulaf or compact masses of great sectility. Thin splinters, BB, fuse, as a rule, on the extreme edges, and harden considerably. Meerschaum is white or pale-yellow in colour, and of very low siiecific gravity (1-2 to 1'3). In hydrochloric acid it gelatinizes. Deweylite is also white or yellowish, and .omewhat waxy in lustre. H 2 to 3 ; sp. gr. 1'9 to 2*2. Decomposed, without gelatinization, by hydro- H Ih i n 4 m 112 THE MINERAL INDICATOR. . .. ' »■" } 1' L^ 1 1 i i 1 L chloric acid. Serpentine is chiefly green, brown, yellow, red, or greyish — two or more colours often occurring together in veins and patches. H 3 to 4 ; sp. gr. 2 5 to 2'7. Decom- posed by hydrochloric acid, and more readily by sulphuric acid. Meerschaum yields about 11 or 12 p. c. water when previously dried at 212° ; otherwise, from 12 to over 20 p. c. ; Deweylite yields about 22 p. c. ; and Serpentine about 13 per cent. Most of these magnesian silicates blacken at first in the bulb-tube. Chrysotile is a fibrous or asbestiform Serpentine, occurring in soft, silky-looking, parallel -fibrous masses of a yellowish- white or greenish-yellow colour. Fine fibres melt at their extreme point. Baltimorite is also a fibrous Serpentine of a bluish colour. Picrolite, Picrosmine, Metaxite, are other varieties of fibrous or bladed Serpentine, usually pale green- ish or greenish- white in colour. / Antigorite, Bastite, and Chlorite, are distinguished from the above by their occurrence in slaty or foliated examples. Antigorite is properly a slaty Serpentine, usuall;^ deep-green in colour and often translucent. H 2 5 to 3. Bastite or Schiller Spar occurs in laminated examples of a green or brown colour, with somewhat metallic-pearly lustre, and is^ probably an altered Bronzite. Yields generally about 12 per cent, water. Decomposed by hydrochloric, and more readily by sulphuric acid. H about 3 or 3 5 Chlorite occurs in foliated and scaly-compact masses and hexagonal tabular crystals, and also in detached scaly parr tides, mostly of a dark-green colour. Some rare chromif- erous examples, however, are dark-red. These form the sub-species Kcemmererite. All varieties are sufficiently soft TABLE XX. 113 n to yield to the finger-nail, and thin i)ieces are flexible but not elastic. The essentially ferruginous chlorites fuse on thin edges into a black magnetic slag. Other varieties or species {BipUolite, &,c.,) vitrify on the edges into a yellow- ish-grey slag or enamel. In the bulb-tube, all yield from 9 to 12 per cent, watei" ; and all are decomposed (in powder) by sulphuric acid. H I to 1-5 ; average sp. gr. 285. Very commonly associated with magnetic iron ore. VermicuvUe is a hydrous, magnesian mica, occurring in coarse hexagon a Irtables and foliated nuisses of a brownish- yellow, or green colour. BB, exfoliates and expands into a vermiform mass of difficult fusibility. Yields about 14 per cent, water. Brucite is chiefly distinguished by its occurrence in white or greenish- white, scaly or sub-fibrous, pearly examples ; by the large amount of water (normally 31 j^er cent.) which it yields on ignition ; and, if pure, by the absence of a silica reaction with phosphor-salt H 2 ; sp. gr. 2*3 to 2*4. In- fusible. Becomes flesh-red after ignition with cobalt-nitrate. Nemalite is a white or pale-blue asbestiform variety *^* See, also, I'alc and Steatite in Group 2, below. Second Group : Not yielding water (or yielding traces of moisture only) by ignition in the bulb-tube. Sub-Group a : Rapidly and entirely dissolved BB by phosphor-salt. Apatite (CaO, P-^O^, CaF-', CaCP). Scheelite (CaO, WO"). Barite, some examples (BaO, SO'). ^inc Blende, light-coloured varieties (ZnS). 8 ■ iii I 5 IIP ! j 114 THE MINEKAL INDICATOR. Sub-Gkoup B ; Slowly attacked BB, by jiJiosjj/n.r-saif. a silica skeleton remaining in the head. Agalmatolite (K-'O, Al-'O^ 8iO-, H-'O). PyrophyUite{A\^0\^iO-^,WO). Talc (MgO, H-0, SiO-). .S7ert^i7e (MgO, H-0, SiO-). i,Vo>/;5<7e (MgO, FeO, SiO-). Muscovite (K'-'O, Al-0'', SiO-). Fhlogopite (K-'O, MgO, APO^ SiO'). Biotite (K-0, MgO, FeO, Fe'-'O"'', ..^I'-'O^ SiO-;. Ajmtite, in veiy line splinters, is fusible at the extreme point, but may practically be regarded as infusible. Mois- tened with sulphuric acid, it tinges the flame-] )oint pale- green. Scheelite is also practically infusiVjle, although very thin splinters vitrify on the edges in a w ell-sustaiued fl:'.me. Both species are dissolved readily by fusion with borax, the saturated glass becoming milk-white and opaque on cooling or when flamed. A2xUiie is commonly green or greenish- white, or more rarely reddish-brown, in colour ; and when crystallized, is usually in hexagonal prisms (often of lajge size), frequently terminated by the planes of a six-sided pyramid. H 5 ; sp. gr. 2-9 to Ji*3. The solution in nitric acid gives a canary-yellow precipitate with amm. molyV)date, especially on warming. Scheelite is at once distinguished by its high specific gravity, 59 to 6"2. Also, by giving a blue-glass by fusion in a reducing flame with phosphor-salt ; and by leaving in nitric acid a yellow or greenish-yellow residuum (WO''). It occurs commonly is small, acute, TABLE XX. 115 sqnare-Vtased nyraniids of a light-grey, yellowisli, nnl or brownish colour, but is sometimes colourless or "reenish. Barite is projierly a fusible species, and thus belongs to Table XVIII. ; but the fusion is not always readily effected by students intx})erienced in the use of the blowpipe, especi- ally when thick-edged fj-agments are tested. Colours the flame-point j)ale-green ; and with sodium carbonate gives sulphur-reaction. Sp. gr. 4-3 to 4-7. Colourless, yellow, ttc. See Table XVI IT., Group 3. Zinc Blende, which also gives sulphur reaction, BB with sodium carbonate, and evolves odour of sulph. hvdrogen in hydrochloric acid, belongs to Table XIX., as the streak in all ordinary varieties is distinctly bi-own, although conin)on- ly more or less pale. See Table XIX., Group 3. As regards Sub-Group B, AyalmatoUte and P}jroj)hijIlite become bright blue, on cooling, when m oistened with cobalt nitrate, and ignited. Talc and Steatite, under lIus treatment, assume on cooling a pale-reddish tint. The other minerals of the sub-group become dark-grey or blackish. Agalmatolite occurs in fine-granulai-, almost compact (or ci-ypto-scaly), very sectile masses ; white, yellowish, reddish- white, (fee, in colour, and sufficiently soft to be scratclied by the finger-nail. Many of tlie small, Chinese images, seen in collections, consist of this mineral — hence, its pojudar name of " Figure Stone ;" but some of these images (pei-haps the greater number) consist of steatite or serpentine. Pyro- phyllite occurs in very soft, pearl y-white^ scaly and foliated examples, much resembling Nacrite or Talc, but distin- guished by expanding and exfoliating very strikingly under i; ' I . . . i! / 11 I ;t!i 116 THE MINERAL INDICATOR. 6'i 31^ \i> »: V, \.] the first action of the blowpipe flame. It does not f»ise, however, beyond exhibiting signs of vitrification on the extreme edges. Both Agalniatolite and Pyrophyllite, on intense ignition, yield about 5 p. c. water, but when tested in the ordinary manner in the bulb-tube, they give ofi" traces, merely. Talc proj)er is readily distinguished by its occurrence in very soft, flexible, scaly and foliated examples, of a pearly- white, a])ple-green or other colour, distinctly soapy to the touch. Steatite is a compact or fine-granular talc, white, grey, greenish, reddish, or mottled in colour, very sectile, and also soapy-feeling. (Hence frequently called " soap- stone," but this name is vaguely ap[)lied to compact chlorite, serpentine, &c., as well). H (in Talc) 1 ; in Steatite 1*5 to 2*5 ; sp. gr. 2*67 to 2*8. BB, both harden considerably, and usually exhibit signs of fusion on very thin edges, but, |)ractically may be regarded as infusible. In the bulb-tube, traces of water are often given off; but the actual (basic?) water, present to the amount of about 4*5 per cent, in these minerals, is only expelled by intense and long-continued ignition. Mronzite occurs in schistose or foliated examples of a dark- brown or dark-gieen colour, with pseudo- metallic bronze-like lustre, and perfect cleavage in one direction. H 4 to 5 ; sp. gr. 2-9 to 3-5. Not attacked by acids. Infusible, or vitri- fvino- onlv on thinnest edges in a well-sustained flame. Usually regarded as a foliated variety of Enstatite ; closely related also to Anthophyllite, a substance of very similar Aspect, but shewing in typical examples a cleavage angle of 124'' 30', characteristic of Atnphihole. These minerals are TABLE XX. 117 distinguished from micas, by being brittle or non-elastic in thin laminge, and by their greater hardness. Muscovite, Phloyopite and Biotite — characteristic species of Mica — are distinguished by their metallic-pearly lustre and their occurrence in foliated and scaly masses which admit of ready separation into thin, elastic lo.ves. They occur also in crystals and crystal- plates of hexagonal or rhoml)ic shajie, which split in the same manner into fine leaves parallel with the base. BB, thin scales become white and opaque, and fuse more or less readily on the edges ; and most examples give off traces of water by ignition in the bulb-tube. M^is- covite is commonly brown, black, whi*-,;or greenish in coloui-, and is insoluble in acids. Phlogopite is commonly brownish- yellow or golden-brown in colour, and is decomposed, in [)Owder, by strong sul})huric acid, the silica sei)arating in minute, colourless scales. Biotite is a ferro-niiignesian mica, mostly of a dark-green, black, or dark-brown colour, also decomposable by sulphuric acid. Muscovite forms an essential component of granite, ordinary gneiss, and mica slate ; Phlogojnte is found chiefly in connection with the crystalline limestones which are frequently interstratified with gneissoid rocks, and it is very commonly associated with apatite de- posits ; Biotite, on the other hand, occurs princip.dly in lavas, trachytes, and basalts. Ruhellane (in hexagonal plates and scaly masses of a red or brownish-red colour) is probably an alteied Biotite. i>. :i,^ y Ui H 1 ^^E F 1^.. v S^^f; 1 1 INDEX. I Acinite, HI, 38. Actiuolite, 49. Aclaniantine 8par, 57, 58. Agalinatolite, 114, 115. Agate, 62. Aikinite, '25. Alabaniline, 30, 31. Alhertite, 72. Albite, 48, 50, (':;. Allanite, 3 J, 35. Allopbane, 108, 110. Aliiiaiidino. 47. Alstoiiite, 74. Altaite, 21. Alum, (»8. Aluminito, lOlt. Alunite, 10!). Alunogene, ♦W. Amalgam, 21. AiuIkt, 72. Amblygoiiite 40. Aiiietbyst, ()•_'. Am])]iib()le, 37, 48. Ampliigeiie ( Leucitcl. 54. Analeime, 40, 42, !IS, 1(H). Auatast', 15, KJ, r^}. Audalusiti!, 57, 00. Angk'sitc, 0(». 01. • Anhy.lritc', 02, 04. Anki'iite, 75, 70. .Amiaboigito. 83. Aiiortbitc. 45. Antliopliyllite. 110. Aiitlira(!it,o, 107. Antigoritt^ 112. Antimony, 20. Antimony (i lance, 2(). 27. Antimonial Silvt!i'( l)ysi'i'asiti.';,21 Antimony (K-luv. 80. Apatito, "54, 11.3. 114. AploMie, 47. Apopliyllitf, 41. 42, 09. Aragonite, 77, 79. Argentite, 18, 19. Arkansite, 55. Arsenical Nickel, 22. Arsenical Pyrites, 14. Arsenic, 20. As))estus. 95, 90. Asbolan, 100. Asphalt. 71. Atacamite. 80. Atlasite, 80. Augite, 37, 38. Automolite ((Jaliuite), 57. Autunitt'. 87. Axinitc, 40. Azurite, 74. Barytine 92, 93. Harvtocalcite, 74. Uastitt", 1(»8, 112. Bauxito. 109. Beryl . 02, 03. Biotito, 95, 97, 117. Binnmtli. 20. Bismnthine (Bissnmth CJ lance), 20, 27. Bismuth ( ilance, 20. Bitii.nen, 71. Bituminous Coal, 71. Blemle, 30, 31, 103. 104. Blood-stnnc, 02. Blue Vitridi. OS. 09. Bog Iron t Ire, 103. Bog .Manii.inesc (Wad), 100, lioracic Amd, 05. Boracite, 3!l, 40. Borax, 05. I'.ornito, 22, 23. BotryoyiMU', OS, 09. Hotryoiitr. 40. lioulangiirite, 28. Bournonitc, 24, 25. i\ u P 120 INDEX. it] 1 * 'V ''I Breithauptite, 21. Breuuerite, 78. Brewsterite, 43, Brochantite, 86. Bronilite, 74. Bronzite, 114, 116. Hrookite, 55. Browu Coal, 71. Brown Iron Ore, 103. Brown Spar, 78. Bruoite, 108, 113. 108, 110. 77, 78. Cairngorm, 6'2. Calaite. 51. Calamine, 51, 5! CVlcedony, &2. Calcite, \ Calc-Spar, j Carnelian, (i2. Cassiterite, 56. Cats-Kye, 62. Celestine, 92, 93. Cerine, 32. Cerite, 51, 52. Cerussite, 74, 75. Cervantite, 89. Chabasite, 41, 42, 98, 99. Chalcantliite, 68, 69. Chalkosine, 24, 25. Chalkophvllite, 81, 82. Chaloopyrite, 20, 23. Chalcolite, 86, 87. Chalcosine, 25. Chert, 62. Chiastolite, 60. Chiolite, 93. Chili-Saltpetre, 66. Chlorastrolite, 46. Chlorite, 98, 101, 106, 112. Chloritoid, 51, 52. (Jhondroilite, 53, 54. Chromic Iron Ore, | ,5 jo, ;^2. Cliromite, J ' ' (!hrome (larnet, 57, 59. Ciirysoberyl, !){}, 58. Chrysolite, 53. Chrysoprase, 62. Chrysotile, 101, 112. ChrysocoUa, 105. Cinnabar, 70, 71. Clausthallite, 28. ' Clinoclase, 81, 82. Clay Ironstone, 76. Coals, 71,72. Clinochlore, 101. Cobalt Bloom, 83. Cobaltine, 14. Cohimbite, 34. Comptonite, 42. Copper, 18. Copper (i lance, 24, 25. Copper Mica, 82. Copper Nickel, 22. Copper Pyrites, 22, 23. Copper Uranite, 86, 87. Corclierite, 63. Corundum, 'A), 57. Crociilolite, 96. Crocoisite, 84, S'). Cryolite, 92, 93. Cubauite, 23. Cuprite, 84. (Jyanite, 57, 60. (!ymophane, 58. Danalite, 44. Dark l{ed Silver Oiv, 26, 27. Datolite, 39, 40. Desminc, 98. Deweylite, 102, 111. Diallogite 7(). Diamond, 57, 59. « Diaspore, 51. Dichroite, (53. Diopside, 48, 49. Dioptasc, 106. Disthene, 60. Dolomite, 77, 78. Dyscrasite, 21. Ehlite, 86, 87. Klu'olite, 45. INDEX. 121 !7. Elaterite, 72. Emeralil, 62, 63. Emery, 57. Enstatite, 48, 49. Epidote, 36, 37, 47, 48. Epsomite, 67, 69. Erinite, 81, 82. Erythiine, 83. Euchroite, 81, 82. Eulytine, 90, 92. Eukairite, 25. Fahlerz, 25. Faujasite, 43. Feldspars, 48, 49, 63. Flint, 62. Fluor Spar, 92, 93. Franklinite, 15, 32, 33. Freislebenite, 28. Gadolinite, 33, 34. Gahnite, 57, 58. Galena, 26. Garnet, 36, 47. Gaylussite, 63, 64. Gehlenite, 50, 51. Gersdorffite, 22. Gibbsite, 108, 109. Gismondine, 43. Glaserite, 67, 68. Glauberite, 67, 68. Glauber's Salt, 67, 68. Gold, 18. Goslarite, 69. Graphite, 29. Green Vitrol, 67, 69. Grey Antimony Ore (Antimony Glance), 26, 27. Grey Copper Ore, 24, 25. Greenockite, 103, 105. Grossular, 47. , Gypsum, 94, 95. Halotrichite, 69. Harmotome, 98, 100. Hartite, 72. Hatchettine, 72. Hauerite, 30, 103, 105. Hauyne, 43, 44. Heavy Spar, 92, 93. Heliotrope, 62. Helvine, 43, 44. Hematite, 15, 16, 32, 33. Hessite, 19. Heulandite, 98, 99. Hornblende, 37, 38, 49. Ho: u Silver Ore, 90. Horn Stone, 62. Horseflesh Ore, 23. Hyalite, 62. Hydrargillite, 108, 109. Hypersthene, 87, 38. Icthyopthalmite, 42, 98, 99. Idocrase, 36, 37, 47, Ilmenite, 15, 16, 33. Ilvaite, 32. loUte, 61, 63. Iridium, 20. Iron, 19, 20. Iron Pyrites, 13. Ironstone, 75. .Tamesonite, 26, 27. Jasper, 62. Jet, 72. Kalaite, 51. Kaolin, 108, 111. Kerargyrite, 90. Kermesite, 84. Krokidolifce, 95, 96. Fsyauite, 57, 60. Labradorite, 45, 46. Lapis Lazuli, 43, 44. Lamontite, 98, 100. Lazulite, 51. Lead (ilauce, 26. Lepidolite, 95, 96. Leucite, 54, 55. Libethenite, Sii, 87. m l'g2 INDEX. A'^ 1 k L m Lievrite, 32. Light Keil Silver Ore, 79. Lignite (Brown Coal), 71. Limonite, 17, 32, 33. Liroconite, 81, 82. Lithia Mica, 96. Magnesite. 77, 78. Magnetic Iron Ore, 15, 32, 33. Magnetic Pyrites, 22. Magnetite, "l5, 32, 33. Malachite, 74. Manganite, 30. Manganese Spar, 75, 76. Marcasite, 13. Margarite, 90, 97. Mascagnine, 67, (',8. Meerschaum, 108, 111. Melaconite, 85, Melantherite, 67. Mtngite, 34. Mercury, 20. Mesotype, 42. Meteoric Iron, 19, 20. Miargyrite, 28. Micas, 117. Millerite, 24. Mimetesite, SO. Minium, 85. Mirabilite, 67, 68. Mispickel, 14, 22. Molybdenite, 2i>. Muscovite, 95, 96, 117. Nacrite, 108, 111. Nagyagite, 28. Nastiirane, 33. Native Antimony, 20, 21. Native Arsenic, 20. N. Bismuth, 20. N. Copper, 18. N. Gold, 18. N. Iridium, 20. N. Iron, 19, 20 ' N. Mercury, 20. N. Platinum, 19. N. Silver, 18. N. Sulphur, 70. N. Telhirium, 21. Natrolite, 41, 42, 98, 100. Natron, 67. Naumanite, 19. Nepheline, 45. Nickelino, 22. Nigrine, 55. Nitratine, 66. Nitie. 66. Nitrocalcite, 06. Nitromagnesite, 66. Obsidian, 38, 39, 48, 50. Ochres, 102, 106. Octahedrite, 55. Okenite, 43. Oligon Spar, 76. Olivenite, 81, 82. Olivine, 53. • Onyx, 62. Opal, 61, 62. Orpiment, 70. Orthite, 32. Orthoclase, 4S, 50. Ozokerite, 72. Pearl Mica, •'(), 97. Petalite, 40. Petroleum, 72. Petzite, 19. Phacolite, 42. PharmacoHte, 83. Pharmacosiderite, 80. Phillipsite, 98, 100. Pldogopite, 95, 97, 117. Picrolite, \iio Picrosmine, / Phos])horchalcite, 86, 87. Pimelite, 105, 106. Pinite. 108. HI. Pistacite, 36. Pitchblende, 33. Pitchstone, 38, 39. Plagionite, 28. INDEX. 123 Platinum, 19. Pleonaste, .57, 58, Plumbago, 29. Polvbasite, 28. Polyhallite, 94,95. Polymignite, 34. Prehnite, 41, 46. Pronstite, 79. Psilomelane, 17, 33, Purple Copper Pyrites, 22, 23. Pyrargyrite, 20, 27, 84. Pyrites : — Arsenical, 14. Capillary, 24 (Millerite). Cockscomb, 13. ("opper. 22, 23. Iron, 13. Magnetic, 22. lladiated, 13. Pyrolusite, ."iO. Pyroniorphite, 90. Pyrope (( laraet), ."{7. Pyropliyllite. 114, 115. Pyroxene, 37. 48. Pvrrhotine. 22. Quartz, (il. r»2. Quicksilver, 2(». 13. Eadiated Pyrites, Realgar, 7<'. Ped Antimony Ore (Kermesite), 84. Ked Co]>per Ore, 84." Red Hematite, ] , ,y ^^ ^,,3 Red Iron Ore, J ' ' ' Red Lead, 85. Red 0(;hre, 102. Red Silver Ores, 2(), 27, 79, 84. Red Zinc Ore. 103, J 05. Rhodoclirosite, 75. 70. Rhodonite, 48, 49. Ripidolite, 101. Rock Crystal, 02. Rock Salt, 04. Roselite, 83. Rose Quartz, 62. Rubellaiie, 117. Rubellite, 61. Ruby, 58. Ruby Blende (V. Rutile, 16, 33, 34. Red Silver Sahlite, 49. Sal-Ammoniac, 64, ()5. Saltpetre, (50. Samarskite, 34. Sapphire, 58. Sassoline, 65. Scaly Red Iron Ore, 29. Scapolite. 45. 40. Scheelite, 113, 114. Scheererite, 72. Schiller Spar, 108, 112. Schorl, 37, 3^. Scolezite, 41, 42, 98, 100. Scorodite, 8<>. Selenite, 94. Senarmontite, 89. Serpentine, 98, 101, 111. Siderite, 75. Silver, 18, 19. Silver Clance, 18, 19. Smithsonite, 77. - Snuvltine, 14. SoaDstone,, 1 16. Sodalite, 43, 44. Soda Nitre, 60. Spathic Iron Ore, 75. Specular Iron Ore, 16. Spha-rosideiite, 73. Sphalerite, 30. Sphene, 45. Sijinel, 56, 5S. Spodumene, 39, 40. Staurolite, 57, 59. Steatite, 98, 114, 110. Stephanite, 28, Stibnite (Antimony Clatice), 20, 57, Stilbite, 98, 99. 124 INDEX. .» If A 'i- Stiblite, 89. Stolzite, 90, 91. Stromeyerine, 25. Strontianite, 73, 74. Sulphur, 70. Sylvanite, 28. Sylvine, 64, 65. Tabular Spar (V. WoUas- tonite), 45. Tagilite, 86, 87. Talc, 96, 97, 115, 116. Tantalite, 34. Tellurium, 20, 21. Tenuantite, 24, 25. 'J'enorite, 26. Tetradymite, 28. Tetrahedrite, 25. • Thsuardite, 67, 68. Thomson! te, 41, 42, 98, 100. Tiemannite, 28. Tinkal, 65. >_ Tinstone, 56. Tirolite, 81, 82. Titaniferous Iron Ore, 16. Titanite, 35, 36, 45. Topaz, 57, 59. Topazolite, 47. Tourmaline, 57, 61. Tremolite, 49. Tiiphane (Spodumene), 40, 41. Triphylline, 92, 94. Triplite, 35. Trona, 67. Troostite, 53. Ti rquoise, 51. Uran Blende. "\ „„ Uraninite, / '"• Uranite, 87. Uran Mica (Chalkolite) 86, 87. Uwarowite, 57, 59. Valentinite, 89. Vermiculite, 108, 113. Vesuvian, 36, 47. Vitriol : — Blue, 68, 69. Green, 67, 69. White (Goslarite), ()9. Vivianite, 88. VVavellite, 108, 109. VVernerite, 45, 46. Willemite, 53. Witherite, 73. Wolfram, 15, 17, 24, 32. Wollastonite, 45. Wood Opal, 62. Wood Tin, 56. Wulfenite, 90, 91. Yellow Ochre, 102. Yenite, 32. Yttro tantalite, 34. Zeagonite, 43. Zeolites, 41, 99. Zinc Blende, 30, 31, 103, 104. Zincite, 103, 105. Zinc Spar, 54, 77. Zinkenite, 26, 27. Zircon, 56, 57. Zoizite, 47, 48.. For Actynolite, pajjfe 49, read Actinollte. To Table on page (i8, add Goslnrite (ZiiO, SO', Il-O). - ' . - 1 : - ■■ . '^" -,- i • '..•"'-.'' * , 87. • " ■•■ ',^ " > ■ ■1 ( ■:.-■ ? --""■-,• * ■' ■ ^ ■ \ % - : ■ ' ' i % .; , '^ ' ^ ■ , ' \ • 'i 104. ■- ' "" \ • ' • >- ■ •