TRANSPARENT OBSIDIAN. 27 5 Second Subspecies. Transparent Obsidian. Durchsichtiger Obsidian, Hoffmann. Marekanit, Karst. Tabel. s. 36.—Obsidienne de Marikan, Brong. t- i. p. 34*2.—Edler Obsidian, Haus. s. 87-—Durchsichitiger Obsidian, Iloff. b. ii. s. 200.—Marekanit, Lem, b. i. s. 435. Id. Oken, b. i. s. 305. External Characters. The colours are duck-blue, greyish-white, and clove- brown. The blue occurs only massive ; the white and brown *n large and small grains. The surface of the grains is smooth. Internally it is splendent. The fracture is perfect conchoidal. It breaks into angular and sharp-edged fragments. It is perfectly transparent. It is hard. It is brittle. ^ pry easily frangible. Itather heavy, in a very low degree. Specific gravity, 2.333, 2.360, Lovcilx. 2.365, Blumcn- l>ach - 2.366, Hoff. Chemical Characters. . According to Link, it melts more easily than the trans ient obsidian, and into a white muddy glass. Geognostic
