anthracite n.

"non-bituminous coal, hard coal," 1812, earlier (c. 1600) a type of ruby-like gem described by Pliny, from Latin anthracites "bloodstone, semi-precious gem," from Greek anthrakitēs "coal-like," from anthrax (genitive anthrakos) "live coal" (see anthrax). Deep black with a brilliant luster, it is nearly pure carbon and burns almost without a flame and formerly was mined extensively in eastern Pennsylvania and south Wales. Related: Anthractic (adj.), anthracitic.