Page:Encyclopædia Britannica, Ninth Edition, v. 16.djvu/443

Rh MINERALOGY 425 Hacon, and in a boulder on Ben Bhrcck in Sutherland, in crystals (fig. 585) ; Lo wb near Brevig, Nor way. Uranqthoritc, from Arendal, lias 50 per cent, thoria and 10 uranous oxide ; found also at Hittero and at Champlain (U. S. ) 645. ORANGITE, 3ThSi + 2H. Massive. Orange-yellow to cinna- inon-red. Other characters like tho rite. C.c. : 17 silica, 75 thoria, 7 water. Ben Bhreck, Langesund near Brevig. The mineral from Ben Bhreck passes gradually into thorite, which thus would appear to be altered orangite. 646. TRITOMITE, R,Si 3 + 4H. Cubic. In tetrahedra. H. =5 5; G. -3 9 to 4 66. Lustre vitreous. Dull brown ; streak yellowish grey. Subtranslucent. C.c. complex: silica Fig. 585 (sp. 644). 21, alumina 2 5, ceria 40, lanthania 15, yttria 4 6, lime 4, water 8. Lamb near Brevig. MAGNESIAN SILICATES. 647. AGALMATOLITE (Figure Stone], 4 AlSi 2 + KSi 3 + 3H. Massive or slaty. Fracture splintery, rather sectile. H. = 2 to 3; G. = 2 8 to 2 - 9. Translucent; glimmering. Green, grey, red, and yellow. Feels somewhat greasy, but does not adhere to the tongue. Sol. in s. acid. C.c. : 55 silica, 33 alumina, 7 6 potash, and 5 water; but in many localities magnesian. Calligaig in Sutherland ; China, where it is cut into various works of art; also Nagyag in Hungary, and Saxony. 648. OXCOSIN, 2A- lSi 2 + (K, Mg)Si 2 + 2H . Fracture uneven or splintery; sectile. H. -&amp;gt;2; G. -=2 8. Trans lucent; slightly resinous. Apple-green or brown. Sol. ins. not in h. acid. Salzburg. 649. LlEBENERITE. Hexagonal. ooP ; OP. Cl. prismatic, perfect ; fracture hackly. H.=3 5; G. -=2 8. Oil-green, bluish green, and greenish grey. Greasy lustre. C.c.: silica 447, alumina 36 5, potash 9 9, water 5 5. Monte Viesena near Forno, Predazzo in Tyrol. 650. GIESECKITE. Hexagonal. ooP; OP. Fracture splintery. H. =3 to 3 5; G. =27 to 2 - 9. Kangerdluarsuk in Greenland, Diana in New York. 651. KILLINITE, 2AlSi 2 + RSi 2 + 3H. Crystalline, foliated. Cl. along a prism of 135 44. G. =2 65. Greenish grey, yellow, or brownish green. C.c. : 48 silica, 31 alumina, 2 &quot;3 protoxide of iron, 6 5 potash, 10 water. Killiney near Dublin. 652. HYGROPHILITE. Scaly. H. = 2 to 2 5 ; G. = 2 7. Greenish grey. Lustre and feel greasy. C.c.: silica 48 4, alumina 321, protoxide of iron 3 3, potash 5 7, water 9. Sol in h. acid. Halle on the Saale. 653. BRAVAISITE, R.&amp;gt;Si 3 + 2AlSi 3 + 4H. Aggregates of thin plates. H. = 1 to 2 ; G. = 2 6. C.c.: silica 51 4, alumina 18 9, peroxide of iron 4, magnesia 3 3, potash 6 5, water 13 - 3. Noyant in Allier. 654. PINITOID. Massive. Leek- and oil-green. H. -=2 - 5; G. =2 8. C.c.: silica 48 5, alumina 28, protoxide of iron 8, potash 5 8, water 4 5. Frei berg and Chemnitz in Saxony. 655. BOLE. Earthy, in nests and veins. Conchoidal. H. = 1 to 2; G. = 2 2 to 2 5. Opaque ; dull resinous; streak shining. Brown, yellow, or red. Feels greasy; some adhere strongly to the tongue, others not at all. In water crackles and falls to pieces. C.c. hydrous silicates of alumina and iron peroxide, in various proportions. Scotland, Ireland, Dransfeld, Clermont in Auvergne. Stolpenite, Rock Soaj), Flinthite, Yellow Earth or Pelinite, Fetbol, and Ochran are varieties. 656. CARPHOLITE, AlS i + MnS i + 2H . Right prismatic. Plll27 . Radiating stellated. H. = 5to5 5; G. =2 9. Translucent; silky; straw- to wax-yellow. B.B. intumesces and fuses to an opaque brown glass. C.c. : silica 38, alumina 29 4, protoxide of iron 2 &quot;9, peroxide of iron 4, protoxide of manganese 11 8, water 10 - 8. Schlaggenwald, &quot;Wippra in the Harz, Meuville in the Ardennes. 657. NONTROXITE, FeSi 3 + 5H . Massive; fracture uneven. H. =2 to 3; G. =2 to 2 3. Opaque; dull or glimmering; streak resinous. Straw-yellow or siskin-green. B.B. decrepitates, becomes black and magnetic, but without fusing; sol. and gelatinizes in warm acids. C.c. : 43 silica, 36 iron peroxide, and 21 water, with 3 5 alumina and 2 magnesia. Nontron in France, Harz, and Bavaria. Chloropal is similar. B.B. brown. Unghvar in Hungary, and Passau. 658. PINGUITE. Massive; fracture splintery; sectile. H. 1; G. 2 - 3. Light to dark green. Lustre vitreous. Feels greasy. C.c. : silica 36 9, per oxide of iron 29 - 5, protoxide of iron 61, water 25 &quot;1. &quot;V r olkenstein, Suhl. 659. HISINGERITE, Fe 2 Si 3 + 2FeSi -f 9H. Reniform, and in crusts. H. =3 5 to 4 ; G. ~2 6 to 3. Opaque, resinous. Brownish or bluish black; streak liver-brown or yellowish brown. C.c.: various, but 32 5 silica, 33 5 iron peroxide, 151 iron protoxide, and 19 water, in the Thraulite from Bodenmais. Also Gilling and Riddarhyttan in Sweden, and Breitenbrunn (Polyhydrite). 660. BERGHOLZ. Fine fibrous; glimmering lustre. Wood-brown to green. G. =2 4. C.c. : silica 55 5, peroxide of iron 19 - 5, magnesia 15, water 10 3. Sterzing in Tyrol. Xylitc, probably from the Urals, is similar. 661. UMBER. Massive; fracture conchoidal. H. 1 5; G. 2 2. Liver-brown; streak shining. Mixtures of peroxide of iron, oxide of manganese, and alumina with water. Cyprus, llypoxanthite and Sidtrosili- cite are similar. 662. KLIFSTEINITE, (R 3, R 3 ).&amp;gt;Si 3 + R 3 H 3. Compact. H. = 5 to 5 &quot;5; G. =3 &quot;5. Liver-brown to black ; streak yellow-brown. C.c.: silica 25, peroxide of iron 4, sesquioxide of manganese 57, water 9. Klapperud in Dalecarlia, Herborn near Dillenburg. 663. WOLKONSKOITE. Amorphous. Horny; bluish green to grass-green. Fracture con choidal ; brittle. C.c. : silica 36, alumina 3, sesquioxide of chromium 19, ferric oxide 10, water 21. Okhansk in Siberia. 664. ROTTISITE, 3NiSi + 4H. Amorphous and reniform. Apple-green to emerald-green. H. 2 to 2 5; G. = 2 35 to2 37. C.c.: silica 437, nickel oxide 35 9, water 11 - 2. Rbttis near Reichenbach in Saxony. Komarit is similar. 665. URANOPHAXE, Right prismatic. ooP 146; oopoo ; Poo ; with polar angle 90. Crystals honey-yellow ; when massive leek-green. H. 2 5; G. 2 6 to 2 8. C.c. : silica 17, alumina 6 1, oxide of uranium 53 3, lime 5 1, water 151. Kupferberg in Silesia. 666. URANOTILE, CaSi + tF 3 Si 2 -f 9ft. Right prismatic. ooP 164. In stellate groups. Lemon-yellow. G. =3 96. C.c. : silica 13 8, oxide of uranium 6675, lime 5 27, water 12 67. Wblsendorf in Bavaria, Joachimsthal, Mitchel county in North Carolina. 667. BISMUTOFERRITE, fii, Si 2, +2Fe,Si. Crypto-crystalline ; oblique prismatic. Siskin- to olive-green. H. =3 5; G. =4 48. C.c.: silica 24, oxide of bisnruth 42 8, peroxide of iron 331. Schneeberg in Saxony. Hypoclilorite is a variety containing 13 of bismuth. In a third variety, from Braunsdorf, antimony replaces bismuth. SILICATES WITH TITANATES, NIC-BATES, &c. 668. SPHENE, CaSi 2 + CaTi 2. Oblique prismatic, C 85 22. ooP (I) 1332 ; iP oo(z) 55 21 ; Poo (y) 34 21 ; ooP c oo (q) : OP (Pore) 90; ooP c 3 (J/)767 ; P c oo (r) 113 30 ; 1P C 2 (n) 136 12 ; 4P C 4 (s) 67 57. Crystals vary extremely in form, being generally appar ently oblique-tabular, from predominance of 71, which are hemidomes in alternate position on opposite ends ; also, but more rarely, pris matic, with dominance of I and M. Twins fre quent. Twin face c, and formed by revolution either (a) on an axis nor mal to cor(J) on a vertical axis ; the former very common and usually pro ducing thin tables with a re-entering angle along one side, and sometimes elongated. Occasionally in double twins. Some- Fig. 586. Fig. 587. times granular or foliated. Cl. in some (1), in others (r), H. = 5 to 5 5 ; G. =3 4 to 3 6. Semitransparent ; adamantine or resiuous. XVI. 54