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

Prior research shows that some forms of metals production from gabbro and similar rocks aren’t commercially feasible—they can be costly because of more complex and energy-intensive processes that produce a lot of waste.

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

Basalt and gabbro are the extrusive and intrusive names for mafic igneous rocks, and peridotite is ultramafic, with komatiite as the fine-grained extrusive equivalent.

From Textbooks • Jan. 1, 2017

The granites pass into gneiss and granulite; the gabbros into flaser gabbro and amphibolite; the slates often contain andalusite or chiastolite, and show transitions to mica schists.

From Encyclopaedia Britannica, 11th Edition, Volume 12, Slice 3 "Gordon, Lord George" to "Grasses" by Various