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

Rh 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. &quot;White acicular crystals from Keystone mine in Colorado. 355. CROCOISITE, PbCr. Oblique prismatic, C 77 27. ooP 93 42 (M), - P 119 12 (&amp;lt;), &amp;lt;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. &quot;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 &quot;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 &quot;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 &quot;4, tungstic acid 71 5. Schlaggenwald, Sadis dorf, Morococha in Peru. Fig 41g (sp&amp;gt; 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&amp;gt;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 &quot;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 &quot;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&quot; 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 &quot;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.