volcanic glass


noun

a natural glass produced when molten lava cools very rapidly; obsidian.

Origin of volcanic glass

First recorded in 1830–40

Example sentences from the Web for volcanic glass

British Dictionary definitions for volcanic glass

volcanic glass

noun

any of several glassy volcanic igneous rocks, such as obsidian and pitchstone

Scientific definitions for volcanic glass

volcanic glass

Natural glass produced by the cooling of molten lava too quickly to permit crystallization. Obsidian is a type of volcanic glass.