basalt

American  

[buh-sawlt, bas-awlt, bay-sawlt] / bəˈsɔlt, ˈbæs ɔlt, ˈbeɪ sɔlt /

noun

1. the dark, dense igneous rock of a lava flow or minor intrusion, composed essentially of labradorite and pyroxene and often displaying a columnar structure.

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basalt British  

/ ˈbæsɔːlt /

noun

1. a fine-grained dark basic igneous rock consisting of plagioclase feldspar, a pyroxene, and olivine: the most common volcanic rock and usually extrusive See flood basalt

2. a form of black unglazed pottery resembling basalt

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basalt Scientific  

/ bə-sôlt′,bā′sôlt′ /

1. A dark, fine-grained, igneous rock consisting mostly of plagioclase feldspar and pyroxene, and sometimes olivine. Basalt makes up most of the ocean floor and is the most common type of lava. It sometimes cools into characteristic hexagonal columns, as in the Giant's Causeway in Anterim, Northern Island. It is the fine-grained equivalent of gabbro.

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basalt Cultural  

1. A hard, dense igneous rock that makes up much of the material in tectonic plates. The part of the Earth's crust beneath the oceans consists mainly of basalt whereas continental crust consists mainly of less dense rocks, such as granite. (See plate tectonics.)

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Other Word Forms

• basaltic
  adjective
• basaltine
  adjective
• subbasaltic
  adjective

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Etymology

Origin of basalt

1595–1605; < Latin basaltēs, a misreading, in manuscripts of Pliny, of basanītēs < Greek basanī́tēs ( líthos ) touchstone, equivalent to básan ( os ) touchstone (ultimately < Egyptian bh̬n ( w ) graywacke) + -ītēs -ite ¹

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Compare meaning

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

• gabbro vs. basalt

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Example Sentences

See Examples For:

basalt

Elephant remains were unearthed alongside handaxes and cleavers made from basalt, a volcanic rock.

From Science Daily ● Oct. 29, 2026

Blessed with a tropical climate and rich basalt soil, the lush Central Highlands produces vast quantities of robusta beans, and Vietnam trails only Brazil in coffee output.

From Barron's ● Aug. 30, 2026

This lava flowed and then cooled, contracted and cracked, creating around eight-sided basalt columns.

From BBC ● Aug. 18, 2026

The 129-foot waterfall — a wide curtain of white water cascading from a basalt cliff face — generates its own rainbow and once was dubbed the “Eighth Wonder of the World” by President Theodore Roosevelt.

From Los Angeles Times ● May 5, 2026

Then he shouldered his quiver and bow, and scrabbled in the wreckage for his small black basalt axe.

From "Wolf Brother" by Michelle Paver

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Related Words

• magma
• slag

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