Also found in: Thesaurus, Acronyms, Encyclopedia, Wikipedia.
Related to gabbro: obsidian
n. pl. gab·bros
A usually coarse-grained igneous rock composed chiefly of pyroxene and calcic plagioclase feldspar. Also called norite.
[Italian, perhaps from Latin glaber, bald, beardless.]
gab·bro′ic (gă-brō′ĭk), gab′broid′ (găb′roid′) adj.
n, pl -bros
(Minerals) 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]
gabˈbroic, ˌgabbroˈitic adj
n., pl. -bros.
a dark granular igneous rock composed essentially of labradorite and augite.
[1835–40;< Italian; akin to Latin glaber smooth]
gab•bro•ic (gəˈbroʊ ɪk) gab`bro•it′ic, adj.
A usually dark, coarse-grained igneous rock composed mostly of plagioclase and pyroxene. It is mineralogically similar to basalt but has larger crystals. See Table at rock.
A dense, dark, coarse-grained, intrusive igneous rock that largely consists of feldspar and pyroxene.