From Longman Dictionary of Contemporary Englishobsidianob‧sid‧i‧an /əbˈsɪdiən/ noun [uncountable] a type of rock that looks like black glass
Examples from the Corpus
obsidian• A plain black obsidian which the Minoan craftsmen tried may have come from the Siftlik area of Cappadocia.• A glass tide tinkled on the hull of the receiver, its echoing obsidian.• For example, many early human artifacts, such as arrowheads, are made of obsidian, a volcanic glass.• Unlike most volcanic rocks, obsidian does not contain phenocrysts; it is, so to speak, all glassy groundmass.• Walls, ceilings, floors were clad in smooth obsidian and jet carved with runes, sacred hexes and texts.• I had a friend send me some obsidian blades.• A glassy stone beloved by ancient toolmakers, obsidian was found only in two prehistoric spots in Arizona prior to the 1980s.• Pre-Columbian cultures in the New World did sophisticated operations, including skull surgery, with obsidian, he added.Origin obsidian (1300-1400) Latin obsidianus lapis, mistake for obsianus lapis “stone of Obsius”, a Roman traveler said to have discovered the rock 