: a dark gray to black dense to fine-grained igneous rock that consists of basic plagioclase, augite, and usually magnetite
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From there, head over to the Giant’s Causeway, a UNESCO World Heritage site with stunning interlocking basalt stone columns that are the result of a volcanic fissure eruption that took place in the Paleogene period (around 60 million years ago).
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Condé Nast, Condé Nast Traveler, 24 Feb. 2026
That spilled lava solidified into basalt rock that, in Iowa, and most of the country, is buried under thousands of feet of sediment.
—Cami Koons, Iowa Capital Dispatch, 17 Feb. 2026
Interestingly, the concrete differed from standard Roman concrete, as these ancient builders combined tuff, basalt, and limestone, Archaeology News reports.
—Maria Mocerino, Interesting Engineering, 14 Feb. 2026
The most famous is the eight-mile sweep of original basalt that begins at the third Roman milestone, the Mausoleum of Cecilia Metella, and is shared today by walkers, cyclists, and the cars of those who have homes there.
—Erica Firpo, Travel + Leisure, 8 Feb. 2026
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Condé Nast, Condé Nast Traveler, 24 Feb. 2026
That spilled lava solidified into basalt rock that, in Iowa, and most of the country, is buried under thousands of feet of sediment.
—Cami Koons, Iowa Capital Dispatch, 17 Feb. 2026
Interestingly, the concrete differed from standard Roman concrete, as these ancient builders combined tuff, basalt, and limestone, Archaeology News reports.
—Maria Mocerino, Interesting Engineering, 14 Feb. 2026
The most famous is the eight-mile sweep of original basalt that begins at the third Roman milestone, the Mausoleum of Cecilia Metella, and is shared today by walkers, cyclists, and the cars of those who have homes there.
—Erica Firpo, Travel + Leisure, 8 Feb. 2026
See All Example Sentences for basalt
Cite this Entry
“Basalt.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/basalt. Accessed 4 Mar. 2026.
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: a dark gray to black usually fine-grained igneous rock
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