79. GEKSDOREITTE.— Disomose; Beudant. Eutomer Kobalt-Kies (in part) ; Mohs. Nickelglanz; Hausmann. Gers- dorffit; Haidinger. The form e is hemihedral 'with SULPHIDES. Cubic. a 100, o in parallel faces. 90 0 70 82 51 It 20 31 (fig. 190.) Eorm and combination, o, ao. Cleavage, a, tolerably per fect. Eracture uneven. Opaque. Lustre metallic. Light lead-grey, inclining to tin-white; acquires a grevish-black or iridescent tarnish by exposure. Streak greyish-black. Brittle II = 5*0.. .5*5. G = 6*1. ..6*13. Decrepitates in the matrass. In the open tube yields a yel lowish-brown sublimate of sulphuret of arsenic. The reactions of the residue are the same as those of kupfernickel. Before the blowpipe on charcoal deposits a white sublimate, and fuses into a black, brittle globule, which imparts a green colour to glass of borax. Partially soluble in nitric acid, leaving a residue of sulphur and arsenious acid. Analyses of gersdorffite a from Loos by Berzelius, b from Haueisen near Lobenstein, c from llarzgerode (g = 5'fii.. .5*05) both by Rammelsberg, d in crystals from Sehladming, the mean of three analyses, and e from Prakendorf by Lowe, / from Miisen, in octahedrons, by Schnabel:— ’ Nickel. Iron . Cobalt. Arsenic Sulphur a b c d e / 30*21 31*82 30*30 20*14 28*75 32*00 4*15 — 0*01 9*55 8*90 2*38 0*92 antimony 0*80 — 45*78 48*02 44*01 49*83 40*10 40*02 19*61 20*10 18*83 14*13 10*25 18*94 In crystals and granular or lamellar masses. Is found at llarzgerode and Tanne in the Harz, Sehladming in Stiria, Kamsdorf, Lobenstein in Voightland, near Loos in Helsingland in Sweden, Prakendorf in Hungary, in Spain and in the Brazils. A mineral from Lichtenberg near Steben in the Fichtclge- birge, v. Kobell’s ‘ amoibite,’ occurring in crystals belonging to the cubic system, o = 0'08, consists according to v. Kobell of: