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CHEYSOBEEYL. 267 Ehanp' ^ r HETS 0® EE ^ L •— Chrysoberyl; Phillips. Cyrno- Kon “ 1 > Mohs ' 0h ^» b “)' 11 i Prismatic. 011,010=39° l'; 101,001 = 30° 7'; 110,100 = 64° 49'. > 100, b 010, e 001 cleavagi e, x 110, S 210, , r 310, t 720, 0 ill, n x b 39° 1' ma 64° 49' zb 60 33 ba 90 0 cb 90 0 rr 109 19 XX 101 68 ss 86 27 zz' 78 64 mm? 60 22 ia 69 53 vb 25 6 ca 90 0 ob 43 8 it 60 14 10b 61 55 ta 81 17 ib na xa oo oo" o'o" nb ns 90° o' S3 62 90 0 40 7 93 44 106 29 51 8 30 34 FIO, 293. FIG. 295. FIG. 294. b Combinations, iab, iosab, iorab, ionrab. Twins. Twin-face i a be faces a, r, s,m, and especially b, striated parallel to their ntersections with each other; the other faces usually smooth and bright; i sometimes rough. Cleavage, a, b not very per- ec t, a being more distinct than b; c very faint traces. Fracture conehoidal. Transparent... semi-transparent. Lustre vitreous. be faces i and a show a blueish opalescence. b= Y76. The optic axes lie in a plane parallel to o, and make angles of 76° 5' with a ornml to b. Greenish-white, asparagus-green, oil-green, green- n-grey. Exhibits trichroism. Streak white, h = 8’5. g =