basalt

noun

ba·​salt bə-ˈsȯlt How to pronounce basalt (audio) ˈbā-ˌsȯlt How to pronounce basalt (audio)
: a dark gray to black dense to fine-grained igneous rock that consists of basic plagioclase, augite, and usually magnetite
basaltic
bə-ˈsȯl-tik How to pronounce basalt (audio)
adjective

Examples of basalt in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
The setting was a lush landscape of rice paddies, red basalt soil, the golden sands of the South China Sea beaches and bamboo thickets. — Pavlo Fedykovych, CNN Money, 12 June 2026 Millions of years ago, the Yakima River carved its way through basalt lava flows to form the Yakima River Canyon. — Terry Ward, Travel + Leisure, 17 June 2026 The 1500 feet-long sculpture, made of 6000 tons of black basalt rock and earth, juts out of the basin and is encrusted with white salt, having been altered over the years by the salty pink water that used to flow there. — Lara Johnson-Wheeler, Vogue, 3 July 2026 The interesting thing is that, according to thermodynamics, the chemical conversion of basalt minerals to calcium oxide only requires around half as much as the conversion from limestone. — Scott K. Johnson, ArsTechnica, 15 May 2026 See All Example Sentences for basalt

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

Time Traveler
The first known use of basalt was in 1601

Rhymes for basalt

See All Rhymes for basalt

Browse Nearby Words

basal rot
basalt
basalt dome
See all Nearby Words

Cite this Entry

“Basalt.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/basalt. Accessed 10 Jul. 2026.

Copy Citation

Kids Definition

basalt

noun
ba·​salt bə-ˈsȯlt How to pronounce basalt (audio) ˈbā-ˌsȯlt How to pronounce basalt (audio)
: a dark gray to black usually fine-grained igneous rock
basaltic
bə-ˈsȯl-tik How to pronounce basalt (audio)
adjective

More from Merriam-Webster on basalt

Nglish: Translation of basalt for Spanish Speakers

Britannica.com: Encyclopedia article about basalt

Last Updated: - Updated example sentences
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!

Popular in Grammar & Usage

See More

Is that lie 'bald-faced' or 'bold-faced'?

'A' or 'an'? What about before 'h'? An Indefinite Article Guide

Why is '-ed' sometimes pronounced at the end of a word?

Commonly Misspelled Words

How to Use Em Dashes (—), En Dashes (–) , and Hyphens (-)
See More

Popular in Wordplay

See More

14 Phobias You Probably Haven't Heard Of

The Longest Long Words List

One-Word Oxymorons: Bittersweet, Spendthrift, and More

Ten Words Ending with a Silent ‘T’

The Words of the Week - Jul 10
See More

Popular

See More

Is that lie 'bald-faced' or 'bold-faced'?

14 Phobias You Probably Haven't Heard Of

The Longest Long Words List
See More

Games & Quizzes

See All
Play Quordle: Guess all four words in a limited number of tries. Each of your guesses must be a real 5-letter word.
Quordle Can you solve 4 words at once?
Play Blossom: Solve today's spelling word game by finding as many words as you can using just 7 letters. Longer words score more points.
Blossom Pick the best words!
Play Missing Letter: a crossword with a twist. Each of the 25 puzzle words start with a different letter of the alphabet. Which letter is missing?
The Missing Letter A daily crossword with a twist
hangman letters and game
Hangman Lightning Round Figure out which word fits in the blanks.
See All