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324 SILICATES. silica, when boiled with a solution of carbonate of soda, left behind a remainder of from 2 09 to 4’29 per cent. The titanic acid appears to contain glucine, alumina and yttria. Is found •with felspar in the Ilmen mountains near Miask. 184. ILVAITE.—Lievrite; Phillips. Fer calcareo-siliceux; Hauy. Diprismatisches Melan-Erz; Mohs. Ilvait ; Haus- mann. Lievnt; Haidinger. Prismatic. 011,010=50° 20'; 101,001=24° 31'; 110,100=65° 36'. a 100, b 010, e 001 , r Oil, w 031, e 201, n 102, m : s 210, t 310, V 120, d 410 0 ill 121. n truncates edge ec; v the edge mb S d truncate the edge sa, x is in zone oh. re 33° 40' da 20° 3' oc 38° 65' wc 63 25 ta 25 67 or 20 47 be 90 0 sa 36 8 00' 41 34 rr ! 67 20 ma 65 36 00" 62 26 wid 126 50 va 71 6 om 61 5 ne 12 51 ba 90 0 xc 64 38 ec 42 23 ss' 107 44 xx' 30 38 ac 90 O mm 68 48 XX v 100 68 ed 84 45 FIG. 337. FIG. 338. a' Combinations, om, ot, rm, mso, mro, rso, roms.e.c.v.ve.cc, rowbmsa. The faces a, t, s, m, v, b striated parallel to their inter sections with each other; 0, r striated parallel to their common intersection. Cleavage, a, c, r, m, the two former more distinct than the two latter. Fracture imperfect conchoidal...uneven. Opaque. Lustre imperfect metallic inclining to resinous, ■"lack, inclining to grey, brown and green. Streak black, sometimes inclining to green. Brittle. 11 = 6 - 5...0'0. a = 3'989 feebly magnetic. Is a good conductor of electricity. -Before the blowpipe melts readily into, a black magnetic ",° e ‘ -,, r m P ar *' 8 colour of iron to borax and salt of phos- p orus. With salt of phosphorus leaves a skeleton of silica. In