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 type of hydrogen the company is searching for is created by water that seeps through the earth’s surface or rises through the core and interacts with iron-rich rock — like basalt — underground, creating gas that collects there. —Nicole Blanchard, Idaho Statesman, 9 Sep. 2025

The helicopter then lands inside the canyon, where participants start their epic journey on the river to the infamous Eyjafjallajökull volcano, past glaciers, waterfalls, and basalt columns. —Mia Taylor, Boston Herald, 7 Sep. 2025

Industry officials defended carbon capture and storage as having an inherently low risk and say emerging technologies, such as storing carbon dioxide in basalt formations where it becomes mineralized, could dramatically increase total storage volumes. —Emma Burleigh, Fortune, 5 Sep. 2025

Visit its world-famous Giant’s Causeway—where hexagonal basalt columns stride into crashing surf, steeped in myth and legend. —Lewis Nunn, Forbes.com, 14 Aug. 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