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216 SULJUIIDES. Is found in attached crystals, massive and disseminated, at Braunsdorf near Freiberg in Saxony. The forms t, r, h, I, q, 4T, %, y, h, z were observed in crystals in Mr. Brooke’s collection. 102. XANTIIOCONE.—Xanthokon; Hausmann,Haidinger. Bhombohedral. 100.111 ■ = 69° 30'. o ill, r 100, s 111. JIG. 222. ro rr' so sr 69° 30' 108 28 79 25 58 21 116 42 Frac- Combination. or s. Cleavage, o, r, ture conchoidal, uneven. Transparent...translucent. Lustre adamantine. Orange-yellow...brown. Streak the same, but darker. Brittle. H = 2'0...3'0. g = 6-158...5 4 191. In the matrass melts at a heat below redness, becomes lead- grey, and yields a slight sublimate of sulphuret of arsenic. In the open tube evolves sulphurous and arsenious acids. Before the blowpipe emits fumes of sulphur and arsenic. The re mainder fused with soda yields a globule of silver. I tun im . . - Ag 3 As + 2Ag s As, silver 64-07, arsenic 14-82, sulphur 2m. Analyses by Plattner:— Silver . . . 04-18 63-88 Iron . . . 0-07 — Arsenic . . . 13-40 1432 Sulphur . . . 21-36 21'80 Is found in crystals of extreme thinness in tho direction per pendicular to the faces o, and in small reniform aggregations, m the Himmelsfiirst mine near Freiberg in Saxony. 103. FEUERBLEXDE.—Feuerblende; Molis, Ilaidinger. ■+ Ou v „ , o Oblique. 101,100=62° 35'; 111,010=50° 84'; 101,001=53° 51 . a 100 twin-face, b 010, t Oil, u 012, m no. a truncates tho edge formed by m and the plane parallel to m.
