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

Early Hawaiians ventured across the plateau to reach a Mauna Kea quarry that produced high-quality basalt for stone tools and to travel between coastal towns. —Audrey McAvoy, Los Angeles Times, 4 July 2025

More recently, basalt was used in the Nashan Geological Museum (2021) in Yangzhou, China, the Radisson Resort & Spa (2023) in Lonavala, India, and an impressive private home called Casa Basaltica (2023) in Querétaro, Mexico. —Francesca Perry, CNN Money, 3 July 2025

The carbon can be stored in deep saline or basalt formations and unmineable coal seams. —Danny Bakst, Fortune, 26 June 2025

Wales tempts with rugged coastlines and windswept castles, and Northern Ireland stuns with the surreal basalt columns of Giant’s Causeway. —Lewis Nunn, Forbes.com, 25 July 2025

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