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318 SILICATES. FIG. 331. According to Rummler the olivine from the Pallas iron, and the iron from Atacama, contains a trace of arsenious acid. In attached, imbedded and isolated crystals; in granular masses, the grains being slightly coherent. The green transparent variety (chrysolite) is found in Egypt, Natolia, and the Brazils. The less transparent varieties (oli vine) in imbedded crystals and granular aggregations, in the islands of Palma and Bourbon, in the basalts of the Habichts- wald, the Eiffel, the Upper Palatinate, Geysingberg near Alten- berg, Hutberg near Herrenhut, Kapfenstein in Stiria, in masses of rock ejected by Yesuvius, in cavities of the obsidian of Cerro de las Navajas in Mexico, in syenite at Elfdalen in Sweden, in the meteoric iron of Krasnojarsk, Otumba, and Steinbach. The brown variety (hyalosiderite) is found at Sasbach and Irmgen on the Kaiserstuhl, and in dolerite near Freiburg in Baden. 5 The angles of Levy’s ‘ forsterite,’ de duced from the measurements of some very good crystals in Mr. Brooke’s col lection, do not diifer sensibly from those of olivine. The combination abdkhrmefl ' was observed. The faces r, s truncating the edge an, d truncating ee, h truncat ing ee", I, f truncating ae, were all very narrow. Cleavage, a, c. Transparent. Lustre vitreous. Colourless. ^ n = 7-o. According to Children contains silica and magnesia. Is probably Jft 2 si. Occurs in attached crystals with pleonaste and augite on Vesuvius. 178. BATBACHITE.—Batrachit; Mohs, Hausmann, Hai- drnger. Cleavage in two directions, making with each other an angle of 116° and 65° nearly, and a third bisecting the obtuse angle between the two former; all imperfect. Fracture imperfect conehoidal. Translucent. Lustre resinous, inclining to vitreous. Light greenish-grey, white. Streak white. n = 6'0. g = 3'033. Fusible before the blowpipe. Ca s Si -f- Mg’Si, part of the Mg being replaced by Fe. Analysis by Bammelsberg:— Silica . . 37‘60 Lime Magnesia .... Protoxide of iron . . . . 209 Water . .' 1-27 Is found at Rizoni in the Tyrol.