- any of a complex group of hydrous silicate minerals, containing chiefly calcium, magnesium, sodium, iron, and aluminum, and including hornblende, tremolite, asbestos, etc., occurring as important constituents of many rocks.
Origin of amphibole
1600–10; < French < Late Latin amphibolus amphibolous
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Examples from the Web for amphibole
Both are common alteration products of magnesian silicate minerals such as olivine, pyroxene, and amphibole.The Economic Aspect of Geology
C. K. Leith
Pargasite, pr′ga-sīt, n. a dark-green crystallised variety of amphibole or hornblende.
The fibrous variety of serpentine is the principal source of asbestos, an amphibole asbestos being less common.Geology
William J. Miller
- any of a large group of minerals consisting of the silicates of calcium, iron, magnesium, sodium, and aluminium, usually in the form of long slender dark-coloured crystals. Members of the group, including hornblende, actinolite, and tremolite, are common constituents of igneous rocks
C17: from French, from Greek amphibolos uncertain; so called from the large number of varieties in the group
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
- Any of a large group of usually dark minerals composed of a silicate joined to various metals, such as magnesium, iron, calcium or sodium. Amphiboles occur as columnar or fibrous prismatic crystals in igneous and metamorphic rocks. Most are monoclinic, but some are orthorhombic. Hornblende, actinolite and glaucophane are amphiboles. Chemical formula: (Mg,Fe,Ca,Na)2-3(Mg,Fe,Al)5(Si,Al)8O22OH2.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.