Page:Encyclopædia Britannica, Ninth Edition, v. 16.djvu/444

From Wikisource
Jump to navigation Jump to search
This page needs to be proofread.
ABC—XYZ

426 MINERALOGY Yellow, brown, and green. B. B. fuses with micro-salt in the red. flame, gives reaction for titanic acid. C.c. : silica 30 6, titanic acid 40 8, lime 28 6. In Scotland, typical of syenites and primary lime stones. In minute hair-brown crystals in the first ; as at Lairg (Sutherland), Achavarasdale (Caithness), and Criffel (Kirkcud- Fig. 588. 89. bright) (figs. 586 to 588). In the latter often in highly complex twins, yellow to brown, at Shinness (figs. 193, 589), Urquhart, Dalnain, Torbane, &c., also with ilmenite and allanite in exfiltra- tion veins of grey granite. Dauphine, Mont Blanc, St Gotthard, Tyrol, Arendal, America. Grecnovite, flesh-red from Glen Gairn in Aberdeenshire (like 194), and St Marcel in Piedmont ; contains manganese at the latter locality. 669. KEILHAUITE ( Yttrotitanite), 5(CaY) (Sif i) + (A- lFe) (Sif i) 3 . Oblique prismatic, C 58. ooP 114. Cl. - 2P, 138. H.=6to 7 ; G. =3 "5 to 37. Blackish brown ; streak greyish yellow. B.B. with borax forms blood-red glass in the red. flame ; other features like sphene. C.c.: 297 silica, 287 titanic acid, 21 1 lime, 10 8 yttria, 6 2 alumina, and 6 5 iron peroxide. Near Arendal. 670. SCHORLOMITE (Ferrotitanite), CagS i + Fe 3 Si a + CaTi 2 . Cubic ; oo and 202 ; generally massive ; fracture conchoidal. H. =7 to 7 5 ; G. = 3 8. Black ; streak grey-black ; vitreous. C.c. : silica 26, titanic acid 23 3, peroxide of iron 20, lime 29 4. Arkansas, Kaiserstuhl, Ivaara in Finland. Perhaps a titaniferous garnet. 671. TSCIIEWKINITE. Massive ; fracture flat conchoidal. H. = 5 to 5 - 5 ; G. = 4 5. Opaque, vitreous, splendent. Velvet-black ; streak dark brown. B.B. intumesces greatly, becomes porous, and often incandesces ; in white heat fuses to black glass ; gelatinizes with h. acid. C.c.: 21 silica, 20 titanic acid, 11 iron protoxide, 45 peroxides of cerium metals with perhaps thoria, lime 4. Miask, Coromandel. 672. MOSANDRITE. Oblique prismatic, C 71 24J . ooP (t) 88 36 ; ooP2 (n); ooPoo (a); -P (e) 124 1 ; -Poo (q) ; ooP c oo . t: a 134 18 ; n : a 152 52 ; q : a 138 2 . Twin face the orthopinacoid. Generally massiv?.. Fracture uneven. H. =4; G. =2 93 to 3. Yellowish or reddish brown; streak pale green. Vitreous to resinous lustre. C.c. : silica 29 "9, titanic acid 9 9, oxide of cerium metals 26 - 5, lime 19, water 8 9. Brevig and Langesundfiord. 6 2 >" 673. EUDIALITE (Eukolite), 6RSi 2 + RZr. Rhombohedral ; E, 73 10 . R (p), OR (a, also ooR, |R, -R, - 2R, -|R, R3, P2 (fig. 591). Generally massive, granular. Cl. j and a. 2 ; fracture uneven. H. = 5 to 5 5 ; G. = 2 84 to 2 "95. Peachblossom- red to brownish red ; streak white. Trans lucent; vitreous. B.B. fuses easily to a light-green opaque glass ; gelatinizes in h. acid. C.c. : silica 50, zirconia 16 9, protoxide of iron 7, lime 11, soda 12. Kangerdluarsuk in Greenland, Sedlova- toi Island in White Sea, Brevig (Euko lite), Magnet Cove in Arkansas. 674. CATAPLEiTE,2(Na 2 Ca)(SiZr) 9 + 9H. Hexagonal. P 114 43 . OP, ooP, P, also with 2P, and JP. In lamellar aggre gates. Cl. prismatic and P ; fracture uneven. H. =6 ; G. =2 8. Yellowish brown to pale green ; streak yellow, lustrous. C.c.: silica 467, zirconia 29 6, soda 10 8, water 9. Brevig. 675. (ERSTEDITE. Pyramidal. P 84 25 . P, ooP, ooPoo. Like zircon. H. -5 5; G. =3 63. Lustre adamantine. Reddish brown. C.c.: silica 197, titanate of zirconia 68 96, water 5 6. Arendal. Fig. 591 (sp. 673). Fig. 592. 676. WOHLERITE, 9RSi + 3RZr + RNb. Oblique prismatic, C 70 45 . ccP 90 14 ; oP2 127 4 ; -Poo 43 18 . OP : ooPoo 109 15 ; -Poo : ooPoo 136 42 ; OP : ooP 103 31 . Crystals tabu lar and prismatic. Cl. clinodia- gonal ; fracture conchoidal. H. = 5 to 6; G. -=3 4. Light yellow, honey- yellow to brownish grey : streak yellowish white. C. c. : silica 28, zirconia 19, niobic acid 13 9, lime 27 8, soda 8 3, protoxide of iron 3. B.B. fuses to yellowish glass. Sol. in h. acid. Langesundfiord, Brevig. 677. ARDENNITE. Right prismatic. ooP 131 2 ; P*> 11224 ;ff; ooFf ; ooP2 ; oopoo ; ooPoo . Crystals like ilvanite. Cl. brachydiagonal, and oo P. H. =6 to 7; G. =3-62. Yellow to yellow-brown. Dichroic; brittle. C.c. : silica 27 8, alumina 24, protoxide of manganese 267, lime 2 2, magnesia 4 - 3, vanadic acid 3 2, arsenic acid 6 3, water 5. Ottrez in the Ardennes (Luxemburg). 678. ROSCOELITE. Foliated masses, sometimes stellated. H. =1; G. =2 3 to 2 9. Dark green to greenish blue. Pearly lustre. C. c. : silica 47 7, vanadic acid 22, alumina 141, magnesia 2, potash 7 6, water 5. Eldorado in California. TITANATES WITH NIOBATES. 679. TITANOMORPHITE, CaTi 2 . Oblique prismatic. Like sphene. o>P, OP, 4? > P > |P C 2. C.c.: titanic acid 74 3, lime 25 3. Lam persdorf in Silesia, Weistritz. 680. PEROVSKITE, CaTi . Right prismatic. In complicated twins, often distorted, pseudo- cubic. H. =5 5; G. =4 to 41. Lustre metallic- adamantine. Pale yellow, reddish brown to iron-black; streak grey. C.c.: 58 8 titanic j acid, 41 - 2 lime. B. B. with micro-salt in outer flame gives a bead greenish while hot, colour less on cooling; in inner flame grey-green when hot, violet-blue when cold. Decomposed by boiling s. acid. Zlatoust, Schelingen, Zer- matt, Malenco Valley near Sondrio, Pfitsch in Tyrol, Magnet Cove in Arkansas. 681. KOPPITE, R 5 Nb 2 . Cubic; ooOoo. G. = 4 - 45 to 4 56. Brown. Transparent. C.c.: niobic acid 62 46, oxide of cerium 67, oxide of lanthanum 3. Schelingen on the Kaiserstuhl in Baden. 682. ANNERODITE, 2R 2 Nb + 5H : Right prismatic. H = 6. G 57. Metallic to greasy. Black. Streak black, brown, greenish grey. Translucent in splinters; brittle. C.c.: 48 niobic acid, with zirconia, thoria, ceria, yttria, and uranium oxide. Annerod near Moss (Norway). 683. DYSANALYTE, 6RTi + RNb. Cubic; ooOoo. Cl. cubic. G. =413. Black. C.c. : titanic acid 41 5, niobic acid 23 "2, cerium oxide 57, lime 19 8; protoxide of iron 5 8, soda 3 6. Vogtsburg on the Kaiserstuhl. 684. PYROCHLORE, Cubic (fig. 594). Cl. octahedral H. =5; G. =4 2 to 4 -4. Resinous, opaque. Red-brown to black, ruby- red and transparent rarely ; streak pale brown. C.c.: niobic acid 53-2, titanic acid 10 5, thoria 7 6, cerium oxide 7, lime 14 2, soda 5, fluorine 31. Miask, Kaiser stuhl, Brevig, and Frederiksvarn. Microlite, from Chesterfield in Massachusetts, has tantalic acid 68 - 4, niobic acid 775, 11 7 lime and 77 protoxide of manganese. Pyrrhitt from Mursinsk in the Urals, San Piero in Elba, and the Azores may be the same ; at the last locality it is in orange-red octahedra, and is a niobate of zirconin. brittle ; fracture conchoidal. Fig. 594. 685. BLOMSTRANIHTE, (Ca,Fe),

Massive. H = 5 5. G. =4 17 to 4 -25. Vitreous, black. Streak