basalt

noun

ba·​salt bə-ˈsȯlt  ˈbā-ˌsȯlt 

: a dark gray to black dense to fine-grained igneous rock that consists of basic plagioclase, augite, and usually magnetite

basaltic

bə-ˈsȯl-tik 

adjective

Examples of basalt in a Sentence

Recent Examples on the Web

The falls are fed by underground springs flowing through porous volcanic basalt in the Cascade Range, creating the appearance that water is emerging directly from the cliff face itself. —Corey Schmidt, Sacbee.com, 6 May 2026

Instead, the data point to a surface dominated by basalt, a dark volcanic rock rich in iron and magnesium commonly found on the moon and Mercury, the researchers say. —Sharmila Kuthunur, Space.com, 4 May 2026

Fashioned from basalt, stone, and slate, this is the empty canvas upon which every ray of light and the sounds of birds and waves create a dynamic of its own and restore a sense of equilibrium. —Condé Nast, Condé Nast Traveler, 23 Apr. 2026

This prompts the parents to check on the ancient basalt sarcophagus in the archeological warren under the house. —David Rooney, HollywoodReporter, 16 Apr. 2026

Word History

Etymology

Latin basaltes, manuscript variant of basanites touchstone, from Greek basanitēs (lithos), from basanos touchstone, from Egyptian bḫnw

First Known Use

1601, in the meaning defined above

Rhymes for basalt

• asphalt
• assault
• cobalt
• default
• exalt
• gestalt
• alt
• fault
• gault
• halt
• malt
• sault

Kids Definition

basalt

noun

ba·​salt bə-ˈsȯlt  ˈbā-ˌsȯlt 

: a dark gray to black usually fine-grained igneous rock

basaltic

bə-ˈsȯl-tik 

adjective