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GLATTCOPHANE. 385 York, in separate crystals imbedded in calcite, are hard,, and scratch with ease those from Littleton and Bolton, Massachu setts, and from Hinvenjalo in Finland. If the relative hardness of these minerals does not constitute a specific difference, it must be ascribed to an altered state of the crystals. 220. WICIITISITE.—Wichtisit; Hausmann. Wichtyn; Haidinger. Cleavage in two directions nearly at right angles to each other. Fracture imperfect conchoidal. Dull. Black, g = 3"03. Magnetic. Analysis by Laurent:— Silica 66*3 Alumina 13'3 Bed oxide of iron .... 4’0 Protoxide of iron .... 13’0 Lime 6 p 0 Magnesia 3’0 Soda 3'6 Is found at Wichtis in Finland. 221. GLATJCOPIIANE.—Glaucophan; Hausmann. Cleavage in two directions, not making right angles with oach other. Fracture conchoidal. Translucent...nearly opaque. Lustre vitreous, inclining to pearly on cleavage faces ; vitreous on the surfaces of fracture. Blueish-grcy. Streak the same. H = 6'5. o = 3'103...3'113. In powder attractable by the magnet. Before the blowpipo turns brown, and melts readily into an olive-green glass. With borax fuses with ebullition into a clear glass, showing the colour of iron while hot. Slowly and imperfectly decomposed by acids. Analysis by Schnedermann : — Silica 58-49 Alumina 1223 Protoxide of iron io-9i Protoxide of manganese . . . o - 60 Magnesia 7'97 Lime 2 - 25 Soda with traces of potash- . 9-28 Is found in long slender crystals, and in columnar or granular masses, in a bed of mica slate in the island of Syra.
