Page:Encyclopædia Britannica, Ninth Edition, v. 16.djvu/421

MINERALOGY 403 TELLURATES AND CHROMATES. 353. MONTANITE, BLJTe + 2H 2 . Incrusting, earthy. Lustre waxy. Yellowish. Opaque. C.c. bismuth 66 8, tellurium 26 8, water 5 9. Highland in Montana. 354. MAONOLITE, Hgfe . "White acicular crystals from Keystone mine in Colorado. 355. CROCOISITE, PbCr. Oblique prismatic, C 77 27 . ooP 93 42 (M), - P 119 12 (<), <P e 2 (/) 56 10 , oo PC* (g), (fig. 409). Cl. oo P, distinct; sectile. H.=2 5to 3 ; G. =5 9 to 6 1. Translucent ; ada mantine. Hyacinth- or aurora-red ; streak orange-yellow. C.c.: 31 chromic acid, and 69 lead protoxide. Berezoff, Mursinsk, and Nijni-Tagilsk in the Urals, Cougonhas do Campo in Brazil, Rfzbanya, Moldawa, and Tarnowitz. Used as a pigment, but not permanent. 356. PH(EXico-CHKOiTE,2l J bCr + Pb. Right prismatic ; dimensions un known. H. =3 to 3 5; G. =575. Translucent on the edges ; res!uous or adamantine. Cochineal- to hya- Fig. 409 (sp. 355). ciuth-red; streak brick-red. C.c.: 23 chromic acid, and 77 prot oxide of lead. Berezoff. 357. VAUQUELIXITE, Oblique prismatic, C 67 15 . Crystals OP, - P, - Poo (or P, f, h), always twinned (fig. 410), the faces of OP forming an angle of 134 30 ; also botryoidal or reniform. H. =2 5 to 3 ; G. =5 5 to 5 8. Semi- translucent or opaque ; resinous. Blackish or dark olive-green; streak siskin-green. C.c.: 61 lead protoxide, 11 copper protoxide, 28 chromic acid. Leadhills, Berezoff, Cougonhas do Campo (Brazil). MOLYBDATES AND TUNGSTATES. 358. "WtJLFENiTE, PbMo . Pyramidal. P 131 48 . OP (a), -|P (b), P, ooP (m), ooP2 (r) (figs. 411-414). Cl. P; brittle; fracture uneven, or con- choidal. H. =3; G. =6 3 to 6 9. Pellucid; resinous to adamantine. Orange- yellow, honey-yellow, and colourless. C.c.: protoxide of lead 61 5, molybdic acid 38 "5; red varieties have some chromic acid. Lack- entyre in Kirkcudbright (fig. 412), Bleiberg, Rez- banya, Pennsylvania, Za- catecas. 2PbOMo0 3 + CaOMo0 3 , with 6 "88 of lime, occurs in Chili. Fig. 413 (sp. 358). Fig. 414 (sp. 358). 359. EOSITE. Pyramidal. OP (c) : p 117 10 ; p : p 125 40 (fig. 415). H. =3 to 4. Colour deep aurora-red. Streak orange- c yellow. A vanadio-molybdate of lead. Lead- hills. 360. MEGABASITE, Mg 4 W 3 . Oblique prismatic; similar to wolframite. In fine needles. H. =3 5 to 4 ; G. = 6 45 to 6 97. Vitreous to adamantine. Yellowish brown to brownish red, translucent hyacinth- red ; streak ochre-yellow. C.c.: protoxide of manganese 23 1, protoxide of iron 5 "4, tungstic acid 71 5. Schlaggenwald, Sadis dorf, Morococha in Peru. Fig 41g (sp> 359) 361. SCHEELITE, CaW. Pyramidal; with many of the modifying planes hemihedric. P. 113 32 . Cl. 2Pw (n) 130 33 , perfect; Pand OP less so. Frac ture conchoidal. H. =4 to 4 5 ; G. =5 9 to 6 2. Translucent; resinous to adamantine. Colourless, and grey, yellow, or brown ; streak white. C.c.: 19 - 4 lime, 80 6 tungstic acid. Caldbeckfell near Keswick, Pengelly in Cornwall, Zinnwald, Schlaggenwald, Salz burg, Chili, Si beria, Connecti cut. Employed for the extrac tion of yellow tuugstic acid, a fine pigment. 362. STOLZ- ITE, PbW. Fig. 416 (sp. 361). Pyramidal, generally hemihedric. P. 131 25 . Crystals sometimes spindle- shaped. Cl. P, imperfect. H. =3 ; G. = 7 9 to 8 1. Translucent ; resinous. Grey, yellow, brown. C.c.: 48 - 4 protoxide of lead, 51 6 tungstic acid. Keswick, Zinn wald, C oquimbo (Brazil). 363. REINITE, FeW. Fig. 417 (sp. 361). Pyramidal. P 103 32 ; basal angle 122 8 . Cl. ooP. H. = 4; G. =6 64. C.c.: protoxide of iron 23 4, tungstic acid 75 45. Kimbosau in Japan. 364. WOLFRAMITE, (Fe, Mn) W. Oblique prismatic, C 89 22 . ooP (M) 100 37 , -Poo (P) 61 54 , P c oo (w) 98 6 , ooPoo (r), o>P2 (b), -P (a), ^2P c 2(s). Twins common. Also laminar. Cl. clinodiagonal, perfect ; fracture un even. H. =5 to 5 5 ; G. =7 1 to 7 5. Opaque ; resinous, metallic, adamantine on the cleavage. Brownish black ; streak black (varieties with most iron) to reddish brown (most manganese). C.c.: 76 tungstic acid, 9 5 to 20 protoxide of iron, and 4 to 15 protoxide of manganese, in some with I l uiobic acid. East Pool, Carnbrae, and mines near Redruth; Godolphin s Ball in Cumberland ; Alten- berg, Geyer, Ehrenfriedersdorf, Schlag- genwald, Zinnwald, the Harz ; also Urals, Ceylon, and North America. Fcrbcrite, with 26 protoxide of iron Fig. 418. and 2Fe W + Fe (H. = 4 to 4 "5 ; G. = 6 7 to 6 8), from Spain, may be different. 365. HUBNERITE, MnW. Right prismatic. ooP (J/). lf:J/105. Cl. oopoo, perfect; usually foliated or columnar. H. = 4 5 ; G. = 7 1 4. Adamantine on cleavage ; elsewhere greasy. Brown-red ; streak yellow-brown. C.c. : protoxide of manganese 28 "4, tungstic acid 76 6. Mammoth district in Nevada. ANHYDROUS PHOSPHATES, ARSENIATES, AND VANADIATES. polar angle 124 30 . Fig. 419 (sp. 366). 366. XEKOTIME, Y 3 P. Pyramidal. P 82 22 middle angle Crystals P; ooP ; ooPoo. Cl. ooP. H. =4-5; G. =4-6 to 4 -55. Translucent in thin splinters ; resinous, Yellowish and flesh-red. C.c.: 62 yttria, and 38 phosphoric acid ; but some with 8 to 1 1 cerium protoxide. Lindesnaes and Hit- tero in Norway, Ytterby (Sweden), Georgia, and ( Wiserinc] St Gotthard, 367. CRYPTOLITE, Ce 3 P 2 . Acicular crystals, embedded in apatite. G. =4 6. Transparent. Pale wine-yellow. Powder sol. in con. s. acid. Wb hler found 73 70 cerium protoxide, 27 37 phosphoric acid, and 1 51 iron protoxide. Occurs in the apatites of granite in Scotland, but not in those of limestones. Also at Arendul. 368. MONAZITE, (Ce, La, Th) 3 P" 2 . Oblique prismatic, C 76 14 . ooP 93 23 ; crystals (tig. 420) generally thick or tabular. Cl. basal, perfect; translucent on edges. Flesh-red and reddish brown. C.c.: 28 phosphoric acid, 37 to 46 cerium prot oxide, 24 to 27 lanthanum oxide; that from Zlatoust from 18 to 32 "5 of thoria. Nb tero Fig. 420 (sp. 368). in Norway, Miask, Norwich in Connecticut, and the Rio Chicj in Colombia. Turneritc, from Dauphiue, in complex transparent

honey-yellow crystals, is monazite.