basalt

[buh-sawlt, bas-awlt, bey-sawlt] /bəˈsɔlt, ˈbæs ɔlt, ˈbeɪ sɔlt/

noun

the dark, dense igneous rock of a lava flow or minor intrusion, composed essentially of labradorite and pyroxene and often displaying a columnar structure.

Origin

1595-1605; < Latin basaltēs, a misreading, in manuscripts of Pliny, of basanītēs < Greek basanī́tēs (líthos) touchstone, equivalent to básan(os) touchstone (ultimately < Egyptian bh̬n(w) graywacke) + -ītēs -ite¹

Related forms

basaltic, basaltine

[buh-sawl-tin, -tahyn] /bəˈsɔl tɪn, -taɪn/ (Show IPA), adjective

subbasaltic, adjective

Examples from the web for basalt

The surging water washed away the basalt and much of the rich topsoil.
But under the water, volcanoes continued to erupt, sending up magma and forming mountains of basalt.
Craters dot the surface of a lunar mare, or basalt sea, on the dark side of the moon.
Scientists have looked for evidence of life in rocks before but only on the surface of basalt rocks or in sedimentary layers.
basalt from the excavation will be used to make concrete to build the locks.
Some raised moon areas are dark in contrast to surrounding areas because of volcanic basalt flows, previous researchers found.
The exterior walls are of basalt from nearby cliffs and bricks woven into a basketlike pattern.
The walls of stone enclosed in wire mesh filter in natural light-at night, light from inside shines out through the basalt rocks.
The land's rise and fall over time, they say, can be attributed to variation in what may be a continuous flow of molten basalt.
Thick slabs of charcoal-colored basalt were made into roomy countertops.

British Dictionary definitions for basalt

basalt

/ˈbæsɔːlt/

noun

a fine-grained dark basic igneous rock consisting of plagioclase feldspar, a pyroxene, and olivine: the most common volcanic rock and usually extrusive See flood basalt

a form of black unglazed pottery resembling basalt

Derived Forms

basaltic, adjective

Word Origin

C18: from Late Latin basaltēs, variant of basanītēs, from Greek basanitēs touchstone, from basanos, of Egyptian origin

Word Origin and History for basalt

c.1600, from Late Latin basaltes, misspelling of Latin basanites "very hard stone," from Greek basanites "a species of slate used to test gold," from basanos "touchstone." Not connected with salt. Said by Pliny ["Historia," 36.58] to be an African word, perhaps Egyptian bauhan "slate." Any hard, very dark rock would do as a touchstone; the assayer compared the streak left by the alleged gold with that of real gold or baser metals. Hence Greek basanizein "to be put to the test, examined closely, cross-examined, to be put to torture."

basalt in Science

basalt

(bə-sôlt', bā'sôlt')
A dark, fine-grained, igneous rock consisting mostly of plagioclase feldspar and pyroxene, and sometimes olivine. Basalt makes up most of the ocean floor and is the most common type of lava. It sometimes cools into characteristic hexagonal columns, as in the Giant's Causeway in Anterim, Northern Island. It is the fine-grained equivalent of gabbro.

basalt in Culture

basalt [(buh-sawlt, bay-sawlt)]

A hard, dense igneous rock that makes up much of the material in tectonic plates. The part of the Earth's crust beneath the oceans consists mainly of basalt whereas continental crust consists mainly of less dense rocks, such as granite. (See plate tectonics.)