volcanic glass

volcanic glass

n. Natural glass produced by the cooling of molten lava too quickly to permit crystallization.

volcanic glass

n (Geological Science) any of several glassy volcanic igneous rocks, such as obsidian and pitchstone

volcan′ic glass′

n. a natural glass produced when molten lava cools very rapidly; obsidian. [1830–40]

Thesaurus

Noun

1.

volcanic glass - a kind of natural glass produced when molten lava cools very rapidlyobsidian - acid or granitic glass formed by the rapid cooling of lava without crystallization; usually dark, but transparent in thin piecespitchstone - dark acid granitic glasstachylite - a basic or basalt glassvolcanic rock - extrusive igneous rock solidified near or on the surface of the Earth