OBSIDIAN

obsidian

(noun) acid or granitic glass formed by the rapid cooling of lava without crystallization; usually dark, but transparent in thin pieces

Source: WordNet® 3.1

Etymology

Noun

obsidian (usually uncountable, plural obsidians)

(mineral) A type of black glass produced by volcanoes.

Adjective

obsidian (comparative more obsidian, superlative most obsidian)

(poetic) black

Anagrams

• anobiids

Source: Wiktionary

Ob*sid"i*an, n. Etym: [L. Obsidianus lapis, so named, according to Pliny, after one Obsidius, who discovered it in Ethiopia: cf.F. obsidiane, obsidienne. The later editions of Pliny read Obsianus lapis, and Obsius, instead of Obsidianus lapis, and Obsidius.] (Min.)

Definition: A kind of glass produced by volcanoes. It is usually of a black color, and opaque, except in thin splinters.

Note: In a thin section it often exhibits a fluidal structure, marked by the arrangement of microlites in the lines of the flow of the molten mass.

Source: Webster’s Unabridged Dictionary 1913 Edition