a natural glass produced when molten lava cools very rapidly; obsidian.
George GlassRead more in this article about some frequently asked questions and fun facts related to our definitions.
Origin of volcanic glass
First recorded in 1830–40
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
Examples from the Web for volcanic glass
She armed herself with an obsidian or volcanic-glass knife, and waited their coming.Legends of Ma-ui--a demi god of Polynesia, and of his mother Hina|W. D. Westervelt
British Dictionary definitions for volcanic glass
any of several glassy volcanic igneous rocks, such as obsidian and pitchstone
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Science definitions for volcanic glass
Natural glass produced by the cooling of molten lava too quickly to permit crystallization. Obsidian is a type of volcanic glass.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.