obsidian
n. Dark glassy rock formed from lava. [latin from obsius, discoverer of a similar stone]
n. A kind of glass produced by volcanoes. It is usually of a black color, and opaque, except in thin splinters.
n. Dark glassy rock formed from lava. [latin from obsius, discoverer of a similar stone]
n. A kind of glass produced by volcanoes. It is usually of a black color, and opaque, except in thin splinters.