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224 OXIDES, EABTHS, AND ACIDS. Forms and combinations, a, o, d, ao, ad, od, aod, odq, aodp, aodn, aodepns. Cleavage, o, surfaces of cleavage smooth, but interrupted. Fracture conchoidal...uneven. Surface smooth and splendent. Semi-transparent...translucent on the edges Lustre adamantine, inclining to metallic. Cochineal-red.. .lead- grey. Streak brownish-red, shining. Brittle, n = 3-5 4 - 0 G = S’89... 6'15. Before the blowpipe in the forceps colours the flame green, moistened with hydrochloric acid colours the flame blue ; on charcoal m the inner flame is reduced. Soluble in nitric acid with effervescence, in hydrochloric acid without effervescenco and in ammonia. 9 Gu, copper 88'79, oxygen n - 2i. Analyses by Klaproth and Chenevix Copper 91 88-5 Oxygen 9 n-5 In attached and imbedded crystals, and granular or earthv masses. J Occurs m beds and veins, especially in granite and in crys-- talline slate rocks, accompanied by copper, redruthite, towanite, bornite, malachite, chessylite, galena, blende, pyrite, gothite. Is tound m beds m gneiss at Moldawa in the Jianat, in beds in sandstone at Katherinenburg in Siberia and at Chessy near Lyons, in veins of tin and copper ore in Cornwall; in the island of Cuba, at Linares in Spain, in Saxony, near Siegen Norway, Australia, Peru, Chile. ’ The fibrous variety has been supposed to be rhombohedral, and therefore to constitute a distinct species. Mr. Brooke has in his cabinet a series of specimens of this mineral from Corn wall and from Siberia, passing from moderately largo and slightly elongated cubic crystals to very slender fibres, which still retain the square form. We have also examined the fibrous specimens in the collection of the late Sir Abraham Humo, now in the Museum at Cambridge, and find these also to bo slender elongated four-sided fibres. It appears probable, there fore, that there has been some mistake in supposing all the fibrous varieties to be rhombohedral. 115. RTJTILE.—Rutile; Phillips. Titane oxidd ; Hauy. Pentomes Titan-Erz ; Mohs. Rutil ; Hausmann, llaidingcr. Pyramidal. 101,001 = 32° 47'-3. "
