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212 SULPHIDES. 61 13 fo 82 22 11 9 rr r mm ee’ r VO yo CO zo ho xo wr tr pr re" 71 18 113 14 42 2 98 46 118 11 67 27 75 61 79 46 54 9 66 24 78 16 12 23 15 55 22 22 35 39 PIG. 217. nr vr yr or ir dr rs" xa vb 14° 26' 29 26 38 46 43 10 13 8 30 15 49 23 15 67 29 14 db yr zr rb" ms" vs" va // va va' 64° 27' 16 63 22 7 70 20 66 37 37 12 72 24 52 48 24 66 FIG. 218. er p Combinations, oa.e.t.u.v, ea.t, ra.u..e.t.v.s, ta..r.v.y, eas', eaV, rab'.v.e, hva, tva.y.r, ueva.rs, esvya, etra.b'o', etrdkva, etdhsvab. Twins. 1. Twin-face u. 2. Twin-face r. 3. Twin-face o. Cleavage, r, tolerably perfect. Fracture conchoidal. Trans lucent on the edges. Opaque. Lustre adamantine, inclining to metallic. Carmine-red...blackish lead-grey. Acquires a tarnish. Streak cochineal-red...cherry-red. Slightly sectile. H = 2-0...2-6. G = 6-76...6-86. Decrepitates when heated. In the open tube yields sul phurous acid and fumes of antimony, and sometimes a crystalline sublimate of oxide of antimony. Melts easily before the blow pipe on charcoal with disengagement of sulphurous acid and vapour of antimony, leaving a globule of silver. Partially soluble in nitric acid, leaving a residue of sulphur and oxide of antimony. Caustic potash dissolves out sulphide of antimony. Ag’Sb, silver 68'98, antimony 23'48, sulphur 17'56. Analyses of Pyrargvrite a from Andreasherg by Bons-
