UC-NRLF C 3 DflD 53b PHiCAL TABLRS AN AID TO THF. ttermitmtiiw R O C K - F O R M I N G M I N E R A I - S ROSENBUSCH HATCH REESE LIBRARY OP TRK UNIVERSITY OF CALIFORNIA. Received . Accessions No. T^?^ Shelf No. -go T PETROGRAPHICAL TABLES AN AID TO THE OF ROCK-FORMING MINERALS BY PROFESSOR H. ROSENBUSCH TRANSLATED AND EDITED (WITH THE AUTHOR'S PERMISSION) BY DR. F. H. HATCH OfH.M. Geological Survey. LONDON : SWAN SONNENSCHEIN & CO., PATERNOSTER SQUARE, B.C. EARTH SCIENCES UBRARY Printed by Hazell, Watson, & Viney, Ld., London and Ayleebary. !S ^SE INTRODUCTION. **' IN preparing an English edition of PROFESSOR EOSENBUSCH'S Hulfstabellen, zur mikroskopischen Mineralbestimmung in Gesteinen, I have made a slight alteration in the order of the columns, and added an Index, which, I think, will facilitate reference : in all other respects the original arrangement remains unchanged. Some explanation of the signs and symbols used in the tables is perhaps necessary. The letters a, b, c, represent the crystallographic axes : a and b being the lateral axes, and c the vertical. The axes of the ellipsoid of elasticity are denoted by the Old English letters a, b, C : a being the axis of greatest elasticity, b, the axis of mean elasticity, and t, the axis of least elasticity. The Greek letters a, ft, y, have sometimes been used to denote the axes of elasticity ; but, as the practice is not uniform, and as the Greek letters, moreover, have been adopted by PROFESSOR ROSENBUSCH (and indeed are used invariably in Germany) for the chief indices of refraction in biaxial crystals, I have thought it best to leave the symbols unchanged. After all, the symbols themselves are of little moment, so long as the meaning attaching to them is made clear. The three chief indices of refraction in biaxial crystals are then as follows : a = index of refraction for rays vibrating parallel to a, but transmitted in a direction normal to a. ft = index of refraction for rays vibrating parallel to b, but transmitted in a direction normal to b 7 = index of refraction for rays vibrating parallel to t, but transmitted in a direction normal to C. The mean index of refraction is =i. o 2 E denotes the apparent optic axial angle, or angle between the optic axes measured in air. The expression p < v (under the head of dispersion) indicates that the optic axial angle for red rays is smaller than that for violet ; p > v that it is greater.* While the book was passing through the press some additional data with reference to the minerals monazite and mosandrite have been kindly furnished by PROFESSOR ROSENBUSCH. These data were determined in his laboratory on monazite from Arendal, and mosandrite from Loven, Langesundfjord. F. F. H. * * In addition to the above symbols, the ordinary mathematical signs are used as abbreviations. These are : =, the sign of equality, used in the column headed "Optic Orientation" to express the coincidence of an axis of elasticity with a crystal- lographic axis ; V, greater than ; <, less than ; J_, perpendicular to ; || , parallel to ; -3: , angle ; +, positive ; - negative. INDEX. Table Table Table Acmite III. 00 Dumortierite . III. (a) Muscovite III. OO Actinolite III. (.d) EUeotite . II. () Natrolite . III. (/) Aegyrine . III. (c) Epistilbite III. (/) Nepheline. II. (ft) Ainigmatite III. (d) Eucolite . II. (//) Nosean Albite III. (/) Enstatite . III. (c) Oligoclase. III- (/) Allanite III. (ft) Eudialite . II. (A) Olivine III. (ft) Almandine I. Faujasite . I. Opal . Analcime . I. Fayalite . III. (ft) Orthite III! (ft) Anatase II. (a) Felspars . HI. (/) Orthoclase III. (/) Andalusite III. (a) Fluorite . I. Ottrelite . III. 00 Andesine . HI. (/) Gadolinite III. (ft) Paragonite III. (d) Anhydrite III. (a) Gahnile . I. Pectolite . III. (c) Anomite . III. (d) Garnet I. Pennine . III. 00 Anorthite Gastaldite nr. (d) Perofskite I. Anorthoclase . III' (/) Gedrite in. oo Phillipsite HI. (/) Anthophyllite . III. o/) Gehlenite . II. (a) Phlogopite III. (d) Antigorite III. 00 Gismondite II. (ft) Picotite I. Apatite II. 00 Glass I. Piedmontite III. (J) Apophyllite Aragouite II. (ft) III. 00 Glaucophane Gmelinite . in. oo II. (ft) Piatapitp. , TIeouaste . III. (ft) Arfvedsonite in. 00 Green Augite . III. (c) Prehnite . III (ft) Astrophylliie . III. oo Grossularia I. Pseudobrooki te III. (a) Augite III. 00 Gypsum . III. 00 Pyrope Axinite in. oo Haematite II. 00 Quartz II.' (a) Barkevicite III. (d) Harmotome III. (/) Riebeckite III. (d) Basaltic Hornblende III. (d) Haiiyne Rinkite . III. (ft) Bastite III. (e) Hercynite I. Ripidolite III. 00 Biotite III. (d) Herschelite II. (*) Rosenbuschite . III. (r) Botryolite III. (A) Heulandite HI- (/) Rutile II. (a) Brandisite III. (<0 Homilite . III. (ft) Sanidine . HI- (/) Brewsterite I". (/) Hornblende III. (d) Sapphirine III. (a) Bronzite . III. (c) Humite III. (ft) Scolecite . HI- (/) Brookite . III. (a) Hydro-nepheline II. (ft) Selenite . III. (a) Biucite II. (a) Hypersthene in. 00 Serpentine III. 00 Bytownite III. (/) I'iocrase . III. (ft) Seybertite III. (e) Calcite II. 00 Ilmenite . II. (a) Sillimanite III. 00 Cancrinite II. (ft) Jadelte III. 00 Sismondine III. (e) Carpholite III. (a) Kammererite . III. 00 Sodalite . I. Cassiterite II. (a) Kiolinite . in. 00 Spessartine I. Chabasite II. (ft) Kataphleite 11. (ft) Spheue in. 00 Chalcedony II. (a) Kyanite . in. oo Spinel I. Chiastolite Hi. (a) Laavenite . ill. 00 Staurolite . in. oo Chlorites . III. 00 Labradorite III. (/) Stilbite . III. (/) Chloritoid III. 00 Laumontite III. (/) Talc . in. 00 Chondrodite III. (ft) Lazulite . III. (a) Thomsonite III. (.0 Chroraite . Lepidolite III. (d) Thulite III. (ft) Chromium-Mica III.' (d) Leucite I. Topaz III. (ft) Clinochlore III. 00 Leucophane in. oo Tourmaline II. (ft) Clinohumite III. (4) Levyne II. (ft) Tremolite . III. (d) Clintonite III. 00 Lithionite III. (d) Tridymite . II. (a) Cordierite III. (ft) Magnesite II. (a) Triphane . III. (O Corundum II. (a) Malacolite in. 0) Uwarowite I. Cossyrite . III. (d) Margarite . in. 00 Vesuvian . II. (ft) Couseranite II. OO Masonite . in. (o Withamite III. (ft) Datolite . III. (A) Meionite . II. 00 Wohlerite III. (c) Uelessite . in. oo Melanite . I. Wollastonite III. (c) Besmine . III. (/) Melinophane . II. (ft) Xanthophyllite III. (c) Diaclasite . III. 00 Melitite . II. (ft) Zeolites . III. (/) IMallage . . III. 00 Micas ii r. oo Zinnwaldite III. (d) Dipyre IF. 00 Microcliue in. (/) Zircon II. (a) Disthene . III. (a) Monazite . III. 00 Zoisite III. (ft) Dolomite . II. (a) Mosandrite III. (ft) Q Table I. TABLE OF SINGLY- Name. Cleavage. S-j Forms Opt. Char. System. Characteristic Form. *! Principal Zone Colour. j Quality. Hrection. Angle. II Of Principal Zone. Glass . . . ' colourless, yellow- amorphous ... ... ... < ish, greenish, k brownish, red Opal. . . . amorphous ... ... ... colourless /-Spinel . . regular (Ill), grains colourless, light red TJ Pleonaste . regular (111), grains green 14 3 Hercynite regular (111), grains green Gahnite . regular (111), grains ... green u Picotite . regular (111) ... brown Ul Ichromite. regular (111), grains brown riuorite . . regular good Ill (100), grains ... ... colourless, violet, etc. Grossularia regular bad 110 (110), grains ... ... colourless, pale-green Almandine regular bad 110 (110), (211), grs. red in Melanite . regular bad no (110), (110)(211), brown ?. grains | Spessartine regular bad 110 (110), grains co'ourless.liRht-recldish Pyrope . . regular bad 110 grains blood-red Uwarowite regular bad 110 (110) green Common Garnet . regular bad 110 (110), grains reddish Leuclte . . . regular ... (211), round grs. ... colourless Sodalite . . regular fair 110 (110), grains ... ... (colourless, blue, Nosoan . . . regular fair no (110) . . . green, yellow, etc. Hatlyne . . regular fair % no (110), grains to I ( Analcime . regular fair 100 (211), (211) (100), ... ... colourless J (Faujasite . regular fair in grains (111) ... ... colourless Perofskite regular (111) (109), grs. (greyish brown, < pale violet, ( brownish yellow FRACTING MINERALS. Index of Refraction 00 and d irolsm. Double Refraction. Optic Orienta- tion. 2E Specific Gravity. Behaviour with Reagents. Chemical Composition. Remarks. flt + /3 ~t~v r 0- r-/ 5 3 very small 48 1 1H95 2-22-7 variable in Obsidian 1-45 2-2 soluble in HKO SiO 2 + x aq Occasional weak irregular double refraction. 1-715 3-6-4-5 insol. in acids MgAl 2 4 Not decomp. by fus. with NajOOs . . . >3-65 Ditto (MgFe)(Al 2 Fe 2 )0 4 Ditto 1-749 3-94 Ditto FeAl 2 O 4 Ditto 1-765 4-35 Ditto ZnAl 2 4 Ditto 4-08 Ditto (FeMgXAl.Cr.Fe.X), Ditto 2-096 4-8 Ditto FeCr.j0 4 Ditto 1-433 3-183-2 insol. in HCl CaFlj Gives off HF whan treated, with sulphuric acid. Loses colour on ignition. Occasional weak double refraction. 1-747 3-43-6 insol. in acids Ca 3 Al s Si 3 Oi 2 Scarcely decomposed by fusion with NagCOs. Occasional anoma- lous double refraction. Easily fusible. 1-770 4-14-3 Ditto Fe 3 Al 2 Si 3 Oi 2 Zonal structure not uncommon. 1-784 3-654-3 Ditto Ca 3 Fe 8 Si 3 12 Zonal structure very common. Easily fusible. 3-74-27 Ditto Mn Al Si O Fusible with difficulty. Kely- 1-812 3-73-8 Ditto MgjAL.Si-.Ou pmte-structure. 3-43-51 Ditto ... 3-44-3 Ditto mixtures of the above molecules 1-508 2-422-5 attacked slow lybvHCI.with separation ol pulverulent SiO, (KNa) 2 Al i Si 4 12 Tho lar#e individuals always doubly refracting- with intersect- ing systems nf twin-bunolla;. Weak double refraction => 0-001. 1-484 . 2-282-34 gelatinizes easilv with 2(Na,Al,Si J 8 ) + NaCl Occasional abnormal double re- fraciion. HCl (Marginal or zonal accumulation of Inclusions. In the tflatine :: 1-496 2-272-50 Ditto 2(CaAl,Si,O s ) + CaS0 4 produced by HCl ; few or no needles of gypsum (= nosean). Numerous noodles of gypsum (= ha'iyne). 1-488 2-152-28 gelatinizes with HCl N a i Al 2 Si 4 O l2+ 2aq Often optically anomalous with weak double refraction. 1-923 soluble in HCl H 4 Na,CaA] 4 Si 10 M + 18 aq Frequent anomalous double re- fraction. 2-38 ... 4-1 soluble in ho sulphuric ack CaTiO, The Inrger individuals mostly optically anomalous with twin- laniellution. Table II. (a). TABLE OF DOUBLY-REFR.A Name. System. Cleavage. Characteristic Form. Char, of Minerals. Principal Zone or Face. Forms Opt. Char. Colour. Quality. Direction. Angle. *J Of the Principal Zone. Rutile . . . tetrag. (good | fail- 110 100 90 90 prisms, grains knee & huart-shuped twins sagenite- texture + 110:flO prismatic + yellow, fox-red, violet sc K Cassiterite . tetrag. fair 100 90 graius, rods, prisms, twins + 110:110 prismatic + colourless, yellowish brownish Zirkon . . . tetrag. (good \ fair 110 100 90 90 prisms, pyramids rare + 110:110 prismatic + colourless, yellowish reddish Anatase . . tetrag. (good Igood 001 111 mt pyramidal tabular 001 + colourless, yellowish bluish O 1: Micaceous Haematite (Eisenglim- hex. rhombohedr. scales 0001 red, yellow, grey * mer) . . . Micaceous 1 1 m enite (Titaneisen- hex. rhombohedr. scales 0001 madder or clove- brown glimmer) . Corundum . hex. rhombohedr. prisms, grains, plates colourless, blue c E Quartz . . . hex. rhombo- liedr. (trapes!. ^ tetart.) grains, blebs, doubly-ter- minated pyramids + colourless Chalcedony . hexag. (?) fibrous 1010:0110 fibrous colourless, yellowish Tridymite . . hexag.(?) minute plates + 0001 colourless Brucite . . hex. rhombohedr. good 0001 scales + 0001 lath-shaped colourless [Calotte. . hex. rhombohedr. good ,(10ll) 1055' grains colourless e \\i", orange blue ; pale yellow, JU1 perceptible 2-524 0-061 c = a 3-9 like Rutile TiO 2 Like Rutile. 1-93 1 1 4-55-3 4-34-9 soluble in . HC1 soluble in HC1 with difficulty FeA FeTi0 3 /^^i*^, (**'*;&% Vfif,,** 6 ^ ^$^RNIA^ jreen 1-764 0-009 c = a 3'9 4-0 insoluble in acids A1 2 3 Twinning parallel to R ; not de- composed by fusion with NagCos. 1-551 0-009 c = c 2-65 soluble in HF1 only Si0 2 1-537 >0-009 c = a 2-592-64 like Quartz Si0 2 1-428 0-018? c = c 2-282-33 soluble in alkalies Si0 2 The plates often divided into six biaxial sectors. 1-570 0-021 c = c 2-35 soluble in acids MgHA Becomes brownish, when moisten- ed with silver-nitrate on platinum- foil. 1-601 1-622 0-172 0-179 c = a c = a c = a 2-72 2-852-95 3-0 soluble in acetic acid with effervescence insoluble in acetic acid insoluble in cold HC1 CaC0 3 CaCO 3 + MgCo 3 MgC0 3 Twinning parallel to* (1012), very common. Twinning parallel to K (1012), not observed. Twinning parallel to K (1012), not obseived. > 1-637 0-004 c = a 3-163-22 easily soluble in acids S(Ca,P/U+ Ua(ClFl) 3 Reaction for phosphoric acid with ammonium molybdate in nitric acid solution. 1-578 1-550 0-036 0-015 c = a 2-74 2-57 soluble in HC1 when rich in Ca : insoluble when poor in Ca Mixtures of : Me = ai, 8 Al 12 Ca 8 50 Ma = Si 18 Al 6 Na s O^Cl J Index of refraction, double refrac- tion and specific weight vary witU the percentage of lime. 1-660 0-005 c = a 2-953-0 gelatinizes with HC1 CajAlgSiijOto Table II. (b.) TABLE OF DOUBLY-REFR, Name. System. Cleavage. Characteristic Form. Opt. Char, of tne Mineral. Principal Zone or Face. Forms Opt. Char. Colour. F Quality. Direction. Angle. Of the Principal Zone. Ido erase (Vesuvian) . tetrag. ... isometric ... colourless, yellow- ish, pink, brown- ish, bluish Melilite . . tetrag. fair 001 tablets, short prisms 001 110 : 110 lath-shaped, almost square colourless to yel- lowish Nepheline (Elseolite) hexag. bad 0001 loio short prisms, grains colourless Canerinite . hexag. good loio 120 long prisms, rods lOfO : 0110 lath-shaped colourless Tourmaline . hex. rhombohedr. prisms, grains 1010 :OllO lath-shaped very variable : vio- let, blue, green stro Eudialyte . . hex. rhombohedr. fair 0001 isometric + ... reddish, colourless Eueolite . . hex. rhombohedr. fair 0001 isometric reddish, colourless Catapleite hexag. good loio 120 tabular + 0001 lath-shaped yellowish, colourless Melinophane. tetrag. good 001 tabular 001 lath-shaped + pale yellowish, colourless Apophyl- lite . . tetrag. good 001 leafy, granular * colourless Chabasite hex. rhombohedr. good K(ioii) 86 isometric colourless to & Hydro- nepheline hexag. (?) tetrag. (?) ... ... grains, short rods colourless o N Gismon- dine . . tetrag. ... ... + ... colourless Gmelinite hex. rhoiubohedr. fair loio rhombohedra, plates ... ... colourless Hersche- lite . . hexag. good 0001 tabular lath-shaped + colourless Levyne . hex. rhombohedr. bad 1011 ... ... + colourless PING BIAXIAL MINERALS. oism. Index of Refraction () and Double Refraction. Optic Orienta- tion. 2E Dispersion. Specific Gravity. Behaviour witn Reagents. Chemical Composition. Remarks. a + 3 + v 7 a /3-a Y-P " a 1-726 0-002 ... c = 8 ... 3-403-47 not attacked by HC1 essentially a lime- alumina silicate Melta easily to a glass. Frequent optic anomalies. Double refrac- tion very variable, sometimes even +. 1-629 0-002 c = a 2-9-2-95 gelatinizes easily wiih HC1 (CaMgFe^Al^SigOje Peg-structure. 1-54 0-004 c = a 2-552-61 gelatinizes with HC1 Na^ljSijOg The gelatine produced by treat- ment with HC1 contains cubes of salt. 1-515 0-030 c = a 2-45 dissolves with effer- vescence in HC1 Na 2 Al 2 Si.,O 8 + 2(CaC0 3 ) + 3H 2 > E 1-635 0-023 c = a 3-0 3-24 not attacked by acids isomorphous mixtures of : NaHOB 2 3 3Al,0 3 4SiO, SMgObjOjAljOjSSiOj 5FeOB,O,Al,0,5SiO 2 Often apparently biaxial, with small optic axial angle. 1-620 0-004 c= c c = a 2-953-0 2-852-94 gelatinizes with HC1 Ditto Na 2 (CaFe),(SiZr) 6 16 Na/CaFe) 2 (SiZr) 6 15 ... 1-612 0-030 ... c= c 2-8 gelatinizes with HC1 (Na 2 CaFe)(SiZr) 4 9 + 2 aq Often apparently biaxial. 1-602 0-019 ... c = a 3-0 ... 6NaF+7[(BeCa)3SisO 7 ] Often apparently biaxial. i 1-532 1-50 1-470) 1-52 1-48 1-46 1-50 0-001 0-003 0-008 0-001 0-002 0-002 ... ... c = a or c c = a ... ... 2-352-39 2-15 2-26 2-265 2-042-12 2-06 2-12-2 dissolves in HC1 with separation of pulverulent Si0 2 decomposed by HC1 with separation of flocculent Si0 2 decomposed by HC1 gelatinizes with HC1 gelatinizes with HC1 decomposed byHCl 4H 2 CaSi 2 6 +KF+aq. Ca^AUSigOje+Haq. Na 4 H,A] e Si 4 M +6aq. CaAl 2 Si 2 8 +4aq. (Na 3 Ca)A] 2 Si,0 12 +6aq. (Na 2 K s Ca)Al 8 Si 4 12 + 5aq. CaAl 2 Si 3 Oi +5aq. Often optically anomalous. Frequent twin-lamellation. Invariable separation between crossed nicola into several biaxial areas, in which 2 E = 568 (ap- proximately). Often optically anomalous. Basal sections show a separation into 6 sectors. Frequent separation into 6 sectors in basal section. Table HI. (a). TABLE OF DOUBLY-REFRA Name. System. Cleavage. Characteristic Form. i j! g *i u # Principal Zone or Face. Forms Opt. Char. Colour. Fleocnroism. Quality Direction Angle Of Principal Zone. Brookite . rhombic good 010 plates + 100 narrow lathes fox-red feeble Pseudo- brookite . rhombic ... plates + 100 narrow lathes fox-red feeble Aragonite . rhombic columnar 100010 lath-shaped colourless Anhydrite . rhombic good (010 ^001 (100 isometric + colourless ... Gypsum (Selenite) monoclinic good fair 010 111 100 leafy, granular + ... colourless ... Monazite . moDoclinic good fair 001 100 thick tablets + pale brown Lazulite monoclinic grains, pyramids blue a colourless, b = blue Andalusite (Chiastolite) Sillimanite Kyanite iDisthene) rhombic^ rhombic triclinic good good good fair 110 100 100 010 91 columnar ,granular columnar, acicular columnar, leafy + HOrlTO 100:010 100:010 lath-shaped long lathes lath-shaped + + colourless* colourless colourless, blue c pink, a = colourless feeble, betwe bluish & colourl Topaz . . rhombic good 001 isometric + ... colourless Dumortierite rhombic fair 110 120 acicular, fibrous 110:110 long lathes blue c blue, a = b y lowish to colour] Staurolite . rhombic fair 010 ... < short columnar + 110:110 lath-shaped + yellow, reddish c red, a = b y< lowish Sapphirine monoclinic good fair 010 100 110 80 grains, plates parallel to 010 ... ... pale blue to.'colour- less a pale blue, c = colourless Carpholite monoclinic(?; rhombic (?) ... ... ... acicular, fibrous ... 110:110 rod-shaped lath-shaped + yellowish, colour- less c colourless, a = straw-yellow, y( lowish green Axinite . . triclinic fair 010 grains, plates ... colourless ... :iNG BIAXIAL MINERALS. Index of Refraction () and Double Refraction. Optic Orientation. 11 Dispersion. Specific Gravity. Behaviour with Reagents. Chemical Composition. Remarks. _ + + y a j3-a r-0 n 3 2-53 very hig a = c, c = a or a = t , b = a >90 46 p < v p > i) 3-8 4-15 insoluble in acids TiO 2 The optic axial plane for yellow and red often lies m 001, that for blue in 010. very high very big a = r, b = a 8430i (2H) p < v 4-98 insoluble inHCl 46 47%TiO 2 ,48% to 49%Fe 3 3 ,4 5%MgO Soluble in sulphuric acid on boiling. 1-631 0-156 0-153 0-004 c = a, b = c 30 p < v 2-94 like Calcite CaCO 3 1-587 0-043 0-005 0-038 a = t, c = a 71 2-83 notably soluble in H 2 CaS0 4 180 40 vari- able strong p < v p < v 3-163-2 3-24 3-53-7 unattacked even by HF1 like Andalusite like Andalusite Al,SiO 5 Al 2 Si0 6 AL,Si0 6 Frequent inclusions of carbon- aceous matter. Gliding along 001. Twinning parallel to 100. 1-620 0-010 0-002 0-008 c = c, a = a 70-120 p > v 3-54, like Andalusite 5Al 2 SiOg + Al.,SiFl 10 ... 1-65 0-010 ... c = a, a = t, 50 (p< u ( Bertrd. Ip >u i U. L. 3-36 insoluble in acids Al 8 Si 3 18 Twinning on the Aragonite-type. 7411-762 O'OIO O'OIS 0-005 0-005 c = t, b = a >180 p > u 3-43-8 insoluble in acids FeAl 4 Si 2 On ... 1-665 0-009 ... ... b = b very large p < u 3-43-5 insoluble in acids M g ,Al 10 Si 2 23 Twinning parallel to a face of the zone of the principal cleavage. 1-640 0-024 ... c = t 110 2-93 insoluble in acids H 4 MnAl 2 Si 2 10 A measurement of the angle of ex- tinction to c could not be carried out in Carpholite from Schlaggen- wald. According to Mickel Lecy and Laerolx it is 6 in Carpholite from Wippra. 1-677 0-009 0-005 0.004 a 1(111) 171 horizontal and inclined 3-3 insoluble in acids H(CaFe) 3 Al 2 BSi40,6 Table III. (6). TABLE OF DOUBLY-REFR^ Name. Cleavage. *! Forms Opt. Char. System. Characteristic Form. ll Principal Zone or Face. Colour. Pleodiroism, Quality. Direction. Angle S* Of the Principal Zone. Cordierite . rhombic bad 010 short columns, colourless, blue c yellowish white, b blue or colourles Prehnite . rhombic good 001 leafy, tabular, granular - 001 colourless ... Datolite (Botryolite) mono- clinic ... isometric, fibrous ... ... colourless ... variable, often Homilite . mono- short columns + greenish b > a > t parallel to b or c Gadolinite . mono- clinic ... + bottle-green, brownish Olivine . . rhombic fair (010 (100 tables, short columns, grains + lath-shaped, isometric colourless, greenish,yello\vish Fayalite rhombic fair (010 (100 ditto ditto colourless, reddish, yellowish ... Humite . . rhombic 1 good 001 grains + isometric to elliptical colourless to golden yellow a pale brown, b c deep golden ye Clinohumite \ and Chon- 1 mono- good 001 ditto + ditto ditto ditto drodite | clinic Zoisite . rhombic fgood (bad 010 100 ... short rods, leafy 4- 100:010 lath-shaped colourless Thulite . rhombic fgood (bad 001 100 ditto + ditto ditto reddish c yellowish, b pi a reddish white ni Pistacite mono- clinic fgood (fair 001 100 11524 rods, grains 001:100 ditto colourless, yellowish, green c green, b yellov green, a colour 5 "o W* Piedmon- tite, Wi- thamite 1 mono- j clinic fgood (fair 001 100 ditto + ditto ditto red, yellow c red, b amethys coloured to pii a orange to cit yellow Orthite (Allanite) mono- clinic fgood {fair 001 100 columns, prisms ditto ditto brown c brownish yello b deep brown re a pale brownish g Mosandrite monoclinic good 100 ... plates + 100:010 001 : 100 short lathes colourless to pale yellow ... Rinkite . . monoolinic good 100 ... ditto + ditto ditto yellow to colour- less C yellowish, a= colourless :iNG BIAXIAL MINERALS. Index of Refraction () and Double Kefraction. Optic Orientation. 2 E Dispersion. Specific Gravity. Behaviour with Reagents. Chemical Compositions. Remarks. _+P+Y 7 a /3 a 7-/S 3 1-542 0-009 0-006 0-003 c = a, b = c 64-150 p V 2-83-0 gelatinizes with HC1 H 2 Ca 2 B i Si 2 10 ... 1-678 0-021 b = a, c : t nearly 122 p > v horizon ta 3-3 ditto FeCa i B 2 Si 2 10 Twins parallel to 001 , also 034 and 021 ; often intergrown with yellow amorphous lamellae. >l-78 ... ... b = b, c:c = 3 behind great p < v 44-3 ditto FeBe 2 Y 2 Si 2 10 Often altered to an amorphous substance, then free from Be. 1-678 0-036 0-017 0-019 a c, b = a >180 p < u 3-4 gelatinizes with HC1 (MgFe) 2 Si0 4 Often altered to serpentine. Twins parallel to 01 1 rare. ... 0-W3-OM9 ... ... 44-14 ditto Fe 2 Si0 4 ... 1-622 0-032 0-038 a = c, b = a 153 p < v 3-063-23 soluble in HC1 Mg 6 Si 2 (OF 2 ) 8 Frequent polysynthetic twinning parallel to a face of the zone 001 :010. 1-622 0-033 0-012 0-020 b = c, a : a = 12 30 in front ; above ditto crossed ditto ditto ditto Mostly polysynthetic twins parallel to Oil. 1-696 0-006 0-001 0-005 a = c, c = a a = c, b = a 10-100 p < v p > v 3-253-36 unattacked by HC1 H 2 C a4 Al 6 Si 6 26 ... 0-006 ... p < v 3-283-40 ditto Mn 2 O 3 -bearingZoisit 1-756 0-038 OW, 0-024 0-014 b = fa, c : a 3 5 behind >180 p > v 3-39 ditto H 2 Ca 4 (AlFe) 6 Si 6 26 Twins parallel to 100 not rare. 1-76 0-05 b = b, c:c = 3 5 behind 3-40 ditto H 2 Ca 4 (AlFeMn) 6 Si 6 26 ditto >l-78 0-032 ... ... b = b, a:a = 30 in front >180 ... 3-553-8 attacked by HC1 with difficulty H,(CaFe) 4 (Al Ce Fe) 6 SiA. Twins parallel to 100. Often al- tered to isotropic substances. According to Broyger an orthite from the augite- syenite of Lan- gesund, having a small 2E and (?) double re'raction, gives b=r, c : a (?) = 22 37i behind c > b > from deep brown to pale straw- yellow. 1-7716 0-0122 0-0035 0-0087 b = b, c : a = 2 behind 169 inclined P v 2-933-03 soluble in HC1 II IV. I 2(RE0 3 ) + RHO Twinning parallel to 100. (E = Ce, La, Di,Mg,Ca,Fe), R = Si,Ti; R = K,Na.H. Almost always intergrown with Fluorite. great small ... b = a, c : b = 7f not great horizontal p < v) 3-46 ditto 2(RRO 3 ) + NaF Twinning parallel to 100. Almost always intergrown with Fluoiite. II E = Ce,La,Di,Y.Fe,Ca R = Si.Ti Table III. (4 TABLE OF DOUBLY-REF: Name. System. Cleavage. Characteristic Form. it. Char, of e Mineral. Principal Zone or Face. Forms Opt. Char Colour. Pleoohroisn: duality. Direction Angle oS Of the Principal Zone. ("good 001 Rosenbuschite mono- clinic [fair 100 201 ... rods, needles ~ 001:100 long lathes light orange feeble c > 6 '. Pectolite . . inono- clinic good (001 (100 rods, needles + 001:100 long lathes + colourless (001 Wollastonite . mono- clinic good )002 J100 rods, needles 001:100 long lathes colourless ... doi /Bronzite ] and Enstatite J rhombic fgood [fair 010 110 100 88 short prisms, grains + 100:001 long lathes almost colourless, yellowish feeble Hyper- green, brownis sthene . rhombic fair Ditto ... Ditto Ditto Ditto + greenish, reddish red, reddish yel Diaclasite rhombic fair Ditto Ditto Ditto + yellowish very feeble Diallage . mono- clinic good 100 110 87 grains, short prisms + Ditto isometric ... greenish yellowish variable <0 J Green Augite . mono- clinic good 110 87 prisms, grains + Ditto long lathes colourless to greenish B 9 (Diopside, X Malacolite, G Salite) Augite . . mono- clinic good 110 87 short prisms, grains + Ditto broad lathes green, pink, brownish, violet very variable a green (browr Aegyrine (Acmite) mono- clinic good fair 110 010 87 prisms + (?) Ditto long lathes green (brown) b olive to sap gw (pale brown), grass green (greenish yellow Jadeite mono- clinic good fair 110 100 87 Ditto + Ditto lath-shaped colourless Triphane . mono- clinic good 110 100 87 Ditto + Ditto lath-shaped colourless Wohlerite . . mono- clinic 'good fair 010 100 110 90 tabular 100 tabular lath-shaped pale yellow ... C deep red brow: Laavenite . . mono- clinic good 100 prisms, grains 110:110 lath-shaped yellow b greenish yelkr a light wine- yellow )TING BIAXIAL MINERALS. Index of Refraction 180 pv 3-5 Ditto (FeMg)Si0 3 Ditto. ... ... b=a, c=r p > v >2-8 Ditto like bronzite, but containing H 2 O Intermediate between bronzite and bastite. 1-688 0-024 0-002 0-022 b=&, c : t= 39 in front 99 3-3 Ditto C'a(MgFe)Si 2 O 6 (A1 2 3 ) Intergrown with bronzite. By taking up water, 2 E is apparently reduced. Cleavage-flakes parallel to 100 show the locus of an optic axis. i -680 1-720 0-030 0-008 0-022 Ditto 112 3-3 Ditto Ditto Twinning parallel to 100. 1-715 0-022 ... ... 45-5i in front 70-103 ... 3-4 Ditto Ca(MgFe)Si 2 6 (MgFe)(AlFe) 2 Si0 6 Twinning parallel to 100, more seldom parallel to 001. 1-808 0-052 ... ... 3 5 ... 3-5 Ditto W< 0,, Twinning parallel to 100. Often zonal structure the outer portion brown, the inner portion green. 1-666 (?) 0-029 ... ... b=&, c : c= 31-45 in front ... 3-3 Ditto Na 2 Al 2 Si 4 O 12 Twinning parallel to 100. 1-667 0-016 0-006 0-010 26 in front 101 3-15 Ditto Li 2 Al 2 Si 4 12 1.714 0-026 0-016 0-010 b=C, c : a= 43 behind 176 strong 3-41 soluble in HC1 with separation of silicic and niobic acids cc-^^. Twinning parallel to 100. Cry- stallographic position according to Des Cloizeaux. high large ... b=b, c : a= 21 behind ... 3-51 insoluble inHCl SiO 2 29-63, ZrO 2 =28'79 TajOi=5-20, Fe./).i=4'73 Ti 2 O 3 2-11, MnO-5-59 CaO 9-70, Na.jO=10-77 H 8 0=2-24 ... Table III. (d). TABLE OF DOT Name. System. Cleavage. Characteristic Form. g-d Jjj Princlpa Zone or Face. Forms Opt Char Colour. Pleoclirc Quality Direction Angle Of the Principal Zone. Antho 100 phyllite . rhombic good 110 124 rods + 110:1-10 lath-shaped + almost colourless feeble Gedrite . rhombic ditto ditto ditto ditto ditto + ditto ditto Tremolite. monoclini ditto 110 12i30 ditto ditto ditto + colourless Actinolite (Smaragdite Nephrite) monoclini ditto ditto ditto ditto ditto ditto + green feeble in tints, t > n Common Horn- blende monoclini ditto ditto ditto rod-shaped, leafy, granular ditto ditto + green, brownish strong and c > Ir > a, green, a ye mphib Basaltic Horn- blende monoclini ditto ditto ditto ditto ditto ditto - brown strong in 1 and yellow ^ Arfvedso- nite monoclini ditto ditto ditto prisms + ditto ditto + green,bluish gree between g] and bluii Barkevi- cite monoclini ditto ditto ditto ditto ditto ditto + brown strong in 1 and yell Glauco- phane 3-astaldite monoclinic ditto ditto ditto rod-shaped, leafy ditto ditto + blue C blue, & ] violet, it col to yellowis Riebeckite monoclinic ditto ditto ditto prismatic, fibrous ditto ditto blue, green C green, ir a deep b Ainigmatite = Cossyrite triclinic good 110 ... prisms 110:110 lath-shaped brownish red, coffee brown to feeble opaque Biotite (Meroxene, Lepidomelane) nonoclinic good 001 leafy, tabular 1001 lath-shaped + brown, green, red strong t > Anomite . nonoclinic ditto ditto ... ditto ditto ditto + ditto ditto Phlogopite monoclinic ditto ditto ... ditto ditto ditto + ditto ditto, but feeble Dff i c a s. Zinnwal- } dite Lithionite J monoclinic ditto ditto ditto ditto ditto - pale flax-colour greenish white deep red-brown of variable < Lepidolite onoclinic ditto ditto ditto ditto ditto + colourless ... Muscovite onoclinic ditto ditto ditto ditto ditto + colourless, greenish ... Paragonite onoclinic ditto ditto ... ditto ditto ditto + colourless Chromium- mica ditto ditto ditto ditto ditto + green ... 2UREFRACTING MINERALS. J /> and n. Optic Orientation. 2 E Dispersion. Specific Gravity. Behaviour with Reagents. Chemical Composition. Remarks. a 0-7 39 0-015 c = c, a = ;t 177 p < V 3-153-24 insoluble in HC1 (MgFe) SiO 3 ditto 88 p > v ditto ditto.but containing A1 2 O 3 14 0-014 b = fr, c : C = 18 behind 77 p < v 2-93-0 ditto CaMgsSLA,, ... 1-628 0-025 0-016 0-009 ditto 77 p > v 3-023-1 ditto Ca(MgFe) 3 Si40i 2 ... 1-642 0-023 0-012 0-011 b = b, c : t = 12 22 behind 3-23-3 ditto ditto,butcontainingAl 2 O 3 Twins parallel to 100. 1-71 1-72 0-072 0-045 0-027 b = b, c: r = 10 behind >180 p < V 3-3 ditto ditto, rich in Fe 2 O 3 and AljOj The double refraction is that given by Michel Levy and Lacroix ; they are maximum values, determined on Bohe- mian hornblendes. Twinning parallel to 100. 1-70? b = b,c:r(?) = 14 in front 3-5 ditto essentially Na,Fe^Si 4 0,, 1-698 0-021 0-020 0-001 b = b, c : t 12 3-5 ditto ditto behind 1-644 0-022 b = fr, c : t = 5 behind 3-1 ditto essentially NajA]jSi 4 13 weak b = b, c : a = 5 7 large >3-3 ditto essentially NajFe s Si 4 12 ... ... ... extinction-angle on 100 = 30", on 010 39, measured to cleavage-cracks ... 3-75 insoluble inHCl approximately like hornblendes rich in iron and soda Twinning parallel to 010. 0-050 ... b = b, c : a = 9 73 p" p < v ditto 2-752-97 ditto ditto ditto ditto, often contain- ing fluorium ditto ditto ... ... like biotite 65 p > v 2-823-20 ditto lithium-bearing, rich in iron ditto ... b = r, c : a = 2 50_70 p > v 2-762-85 not attacked by HC1 Si 6 Al e (KLi) 6 24 , F-bearing ... 1-592 0-042 0-039 0-003 b = t , c : a = 2 40_70 p > v 2-763-1 ditto Si 6 Al 6 K 2 H 4 24 ... 1-57? great ... like muscovite 70 p > v 2-778 ditto Si 6 Al 6 Na 2 H 4 O 24 ... ... ... ... ... Si 6 (Al ) Cr) 2 K 3 H 4 O i!4 ... Table III. (e). TABLE OF DOUBLY- Name. System. Cleavage. Characteristic Form. ol Principal Zone or Face. Forms Opt. Char. Colour. Pleochroisr ftuality. Direction. Angle. Of the Principal Zone. Margarite . . mono- clinic good 001 scales, plates j_ 001 lath-shaped - colourless Talc .... rhombic good 001 scales, plates j_ 001 lath-shaped + colourless Kaolinite . . triclinic good 001 scales, plates j_ 001 lath-shaped - colourless ... I Chloritoid, Ottr elite, Sismon- dine, Ma- sonite mono- clinic good 001 scales, plates - j_ 001 lath-shaped green, blue, seldom colourless C yellowish g) b plum colon indigo-blue a oliv'e-grei "O / Chlorite-] Brandisite, Xantho- phyllite Clintonite Seybertite 1 mono- f clinic | mono- j clinic good good ditto ditto ditto ditto ditto ditto ditto ditto + brownish yellow, yellowish green ditto moderate to fi ditto Astrophyllite triclinic good fair 001 010 leafy, tabular + j_ 001 lath-shaped + yellow bet ween yellov yellowish bn Pennine, Ripido- lite mono- | clinic good 001 scales j. 001 lath-shaped green yellowish to dish for ra; X 001, green] 02 Antigorite rhombic good 010 tabular, leafy yellowish very feebl Sphene . I mono- j clinic fail- 110 13352' prisms, grains - colourless, yellow- ish, reddish C = yellowish ft = greenish a = pale yello Leucophane . rhombic (sphen. hem.) good 010 grains ... colourless 3FRACTING BIAXIAL MINERALS. Index of Refraction (ni and Double Refraction. Optic Orientation. 2E. spersion. Specific Gravity. Behaviour with. Reagents. Chemical Composition. Remarks. n ~ y a f-ft s 1-75 0-009 b=h,:a = 9 10_70 P < u 2-83-1 not attacked by HCl H 2 CaAl 4 Si.O 12 1-551 0-04-0-05 b=r, =a 10" 20 p > v 2-72-8 not attacked by HCl H 2 Mg 3 Si 4 O I2 1-54 strong c:a=12, b= 2-342-57 dissolved by boiling sul- phuric acid H 4 Al i! Si z O 12 ... 1-72 0-012 b=fr, a : a= 108 p > v 3-54 unattacked by acids H 2 (FeMgMn)Al,SiO, Twinning according to Tachermak'g law very com- mon. Zonal structure. s 1-654 0-012 ... b=b, c : a= 5 30 p < v 3-03-1 scarcely attacked by acids H 4 (CaFeMg) 6 (AlFe), Twinning accorling . to Tachermalc't law very com- mon. b=, c : a= 10 30 p < v 3-03-1 ditto ditto. d 1-704 0-055 0-025 0-030 a nearly normal to 001, b nearly normal to 010 > 180 3-33-4 insoluble in acids H 8 (KNa) 4 (FoMn),Fe, Polysynthetic twin-lamella- tion parallel to 010. 1-577 O'OOl OW a or appa- rently J_ 001 very small 2-602-96 gelatinizes with HCl H 8 (MgFe),(AlFeCr), Pseudo-hexagonal. 1-589 0-005 O'Oll feeble 0-003 0-008 b = b, c makes an angle of 12 15" with the normal to 001 ditto 75 ditto 2-62-2-76 ditto ditto ditto ditto, contains chro- mium Twinning according to Tidurnuik's law common. 1-619 0-014 a apparently perpendicular to 001 2-89 ditto ditto, rich in FeO ... 1-54 0-009 c=[ _ 2-52-7 gelatinizes with acids H 4 (MgFe) u Si/) 9 1-574 small c=, b=a 20 90 P > v 2-62-8 ditto ditto Cleavage-flakes show tbe locus of a bisectrix. 1-565 0-011 0-010 0-001 c=, b=a 20 90 nearly 2-5 ditto ditto ditto. 1 1-930 0-121 0-006 0-115 b=&,_|_"l02 50 P > v 3-33-7 not attacked by HCl CaSiTi0 6 Twinning parallel to 001. 1-588 0-027 0-024 0-003 c=c, a=a 74 p > v 2-97 6NaF + (Be.Ca) 15 Si 14 43 Intersecting systems of polycynthetic twiu-lamellw frequent. Table III. (/). TABLE OF DOUBLY-REFRAi Cleavage. ~ Forms Opt. Char. In Name. System. Characteristic Form. H II Principal Zone or Face. Colour. Pleochroism. Duality. irection. Angle. la Of the Principal Zone. a+ Orthoclase mono- clinic good 001) 010) 90 jrisms, tables, grains 001:010 110:110 lath-shaped, tabular colourless ... 5231 Sanidine . mono- clinic ditto ditto ditto ditto ditto ditto do. ditto ditto Microcline :riclinic ditto ditto 020' ditto ditto ditto do. ditto 1-55 Anortho- clase . . triclinic ditto ditto ditto ditto ditto ditto do. ditto 1-55 09 h Albite . . triclinic ditto ditto 3to9-l ditto + ditto ditto do. ditto 1-5; a 0) Oligoclase triclinic ditto ditto ditto ditto _ ditto ditto do. ditto 1-5; h Andesine . triclinic ditto ditto ditto ditto ditto ditto do. ditto ... 1-5,' Labrado- rite . . triclinic ditto ditto ditto ditto + ditto ditto do. ditto I-* Bytownite triclinic ditto ditto ditto ditto ditto ditto do. ditto I Anorthite . triclinic ditto ditto ditto ditto ditto ditto do. ditto !* i Natrolite . (Mesotype rhombic good 110 91 needles, prisms + 110:110 narrow lathes + colourless yellowish 1-4: Scolecite . mono- clinic ditto ditto ditto - colourless i-i Desmine . mono- clinic good 010 rods, leaves '001:010 lath- shaped ditto 1-4 Phillipsite mono- clinic ditto 010 001 90 small prisms, needles + ditto ditto + ditto 1-5 CO f Refraction () and uble Refraction. Optic Orientation. 2 E Dispersion. Specific Gravity. Behaviour with Reagents Chemical Composition. Remarks. 70 /S a f-ft )-007-0-010 0-004 0-003 b = c, a : a = 5 above 125 p> v 2-56 insoluble in acids (KNa) 3 Al 2 SiA Twins on the Carlsbad type fre- juent ; Baveno and Manebach types rarer. ditto ditto ditto ditto, or b= b, a : a = 5 above 50 > v 2-56 ditto ditto [ntersecting systems of polysyn- thetic twin-lamellae almost invari- ably present. 0-007 0-006 0-001 a:ain010=+6 2 tolO 2 88 P >. 2-582-60 ditto (Na s K,Ca)Al s SiA Extremely fine, intersecting twin- lamellae frequent. 0-008 0-002 0-006 a : a in 001 = + 4 a:ain010= + 18 155 ,< 2-62 ditto Na 2 Al 2 SiAo Twin-lamellation on the Albite and Carlsbad types very common ; less Frequent on the Periclme and Baveno types. 0-008 0-004 0-004 a:ain001 = + 1 a:ain010= +4 p < v 2-64 ditto Ab,;Ani Ab 2 Ani ditto 0-008 0-004 0-004 aiainOOl = 2^ a : a in 010 = 9 2-65 ditto Ab 3 An 2 Ab 4 An 4 ditto 0-008 0-003 0-005 a:ain001 = 7 a: a in 010 = 20 p > v 2-69 scarcely attacked by HC1 iW^M* ditto ... a:ain001 = 25 a:sin010 = 33 p > v 2-71 much attacked by HC1 Abi An 3 Abi An 6 ditto 0-013 a:ain001 = 37 a:ain010 = 36 ,>, 2-75 dissolved by HC1 with gelatinization CajAl^Si^Oie ditto 0-012 0-003 0-009 c = t , a = a 94 96 pv 2-22-4 soluble in HOI H 4 (SrBaCa)A],Si,0 18 + 3aq. Division into cuneate areas be- tween crossed nicols frequent. 0-027 0-005 0-022 b == c, a = a 83 p< 2-312-38 soluble in HC with separatio of gelatinous SiOz (CaNa 2 ) 2 Al 2 Si 2 O 8 + 5 aq. ... 0-012 0-010 o-oo b=fr,c:t= 20 behind 54 p< 2-282-41 ditto H 4 CaAl 2 SiAH + 2aq Twinning parallel to 100. THIS BOOK IS DUE ON THE LAST DATE STAMPED BELOW FINE OF 25 CENTS FAILURE TO RETURN PENALTY ^b RETURN EARTH SCIENCES LIBRARY TO * 642-2997 LOAN PERIOD 1 1 MONTH 2 3 4 5 6 ALL BOOKS MAY BE RECALLED AFTER 7 DAYS Books needed for class reserve are subject to immediate recall DUE AS STAMPED BELOW FORM NO. DD8 UNIVERSITY OF CALIFORNIA, BERKELEY BERKELEY, CA 94720 GAYLORD BROS., INC. ManufacJurtrt Syracuse, N. Y. Stockton, Calif. U.C. BERKELEY LIBRARIES