: a dark gray to black dense to fine-grained igneous rock that consists of basic plagioclase, augite, and usually magnetite
Examples of basalt in a Sentence
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Visit its world-famous Giant’s Causeway—where hexagonal basalt columns stride into crashing surf, steeped in myth and legend.
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Lewis Nunn, Forbes.com, 14 Aug. 2025
The landscape around a nearly 3,000-square-mile glacier shifts frequently as roiling magma thrusts the ground upward, and glacial rivers carve canyons into the basalt.
—Robin Catalano, Robb Report, 7 Aug. 2025
They’re paved with black basalt, referred to as sampietrini in Italian.
—Sarah Gearhart, Outside Online, 28 July 2025
Melt inclusions from mare basalts (MI in basalt) are from refs.
—Keith Cooper, Space.com, 16 July 2025
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Lewis Nunn, Forbes.com, 14 Aug. 2025
The landscape around a nearly 3,000-square-mile glacier shifts frequently as roiling magma thrusts the ground upward, and glacial rivers carve canyons into the basalt.
—Robin Catalano, Robb Report, 7 Aug. 2025
They’re paved with black basalt, referred to as sampietrini in Italian.
—Sarah Gearhart, Outside Online, 28 July 2025
Melt inclusions from mare basalts (MI in basalt) are from refs.
—Keith Cooper, Space.com, 16 July 2025
See All Example Sentences for basalt
Cite this Entry
“Basalt.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/basalt. Accessed 5 Sep. 2025.
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: a dark gray to black usually fine-grained igneous rock
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