Definition of obsidian in English:

obsidian

noun

mass noun
  • A hard, dark, glasslike volcanic rock formed by the rapid solidification of lava without crystallization.

    • ‘Hard stones such as obsidian and rock crystal were added to the repertoire of the stone-vase maker.’
    • ‘The earliest mirrors were of obsidian, a black volcanic rock that could be carved and polished.’
    • ‘The presence of basalt and obsidian is a sign of volcanic activity and the instability of the earth's crust in this area.’
    • ‘Silent as stones like two black pillars carved from obsidian rock.’
    • ‘Obsidian looks like coal and while both are black, obsidian is shinier.’

Origin

Mid 17th century from Latin obsidianus, error for obsianus, from Obsius, the name (in Pliny) of the discoverer of a similar stone.

Pronunciation

obsidian

/əbˈsɪdɪən/