gabbro

American  

[gab-roh] / ˈgæb roʊ /

noun

Petrology.

plural

gabbros

1. a dark granular igneous rock composed essentially of labradorite and augite.

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gabbro British  

/ ˈɡæbrəʊ /

noun

1. a dark coarse-grained basic plutonic igneous rock consisting of plagioclase feldspar, pyroxene, and often olivine

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gabbro Scientific  

/ găb′rō /

1. 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.

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Other Word Forms

• gabbroic adjective
• gabbroid adjective
• gabbroitic adjective

Etymology

Origin of gabbro

< Italian; akin to Latin glaber smooth

Compare meaning

How does gabbro compare to similar and commonly confused words? Explore the most common comparisons:

• gabbro vs. basalt

Example Sentences

Bags of gabbro and similar calcium-bearing silicate rocks fill a shed out back and dot the office.

From The Wall Street Journal • Dec. 10, 2025

"These elements allowed us to look back through the chemical changes that TTG magmas go through and trace the melt compositions back to their initial state and source -- most likely a sort of gabbro."

From Science Daily • Jan. 31, 2024

Not getting a sample of this gabbro was frustrating, but scientists are already extracting valuable lessons from the momentary failure.

From Scientific American • Aug. 12, 2021

These dark ferromagnesian minerals are commonly found in gabbro, basalt, diorite, and often form the black specks in granite.

From Textbooks • Jan. 1, 2017

Rocks vary considerably in the cementing properties of the dust, but usually the rocks classed as "trap," such as andesite, gabbro and rhyolite, and schist and basalt possess good cementing properties.

From American Rural Highways by Agg, T. R. (Thomas Radford)