- a dark granular igneous rock composed essentially of labradorite and augite.
Origin of gabbro
< Italian; akin to Latin glaber smooth
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Examples from the Web for gabbro
Anorthite is an essential constituent of many basic igneous rocks, such as gabbro and basalt, also of some meteoric stones.
A soil of very close texture, the gabbro, is found, most largely in the north-east.
Still more common is the occurrence of sheared, foliated or schistose forms of gabbro.
Rocks of the gabbro group, though perhaps not so common nor occurring in so great masses as granites, are exceedingly widespread.
Gabbro, gab′ro, n. a rock composed of feldspar and diallage—also Euphotide.
- a dark coarse-grained basic plutonic igneous rock consisting of plagioclase feldspar, pyroxene, and often olivine
C19: from Italian, probably from Latin glaber smooth, bald
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
Word Origin and History for gabbro
type of igneous rock, 1837, from Italian (Tuscan) gabbro, from Latin glaber "bare, smooth, bald" (see glad).
Online Etymology Dictionary, © 2010 Douglas Harper
- A usually dark, coarse-grained igneous rock composed mostly of plagioclase feldspar and clinopyroxene, and sometimes olivine. Gabbro is the coarse-grained equivalent of basalt.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.