bentonite

[ ben-tn-ahyt ]

noun

, Mineralogy.

1. a clay formed by the decomposition of volcanic ash, having the ability to absorb large quantities of water and to expand to several times its normal volume.

bentonite

/ ˈbɛntəˌnaɪt /

noun

1. a valuable clay, formed by the decomposition of volcanic ash, that swells as it absorbs water: used as a filler in the building, paper, and pharmaceutical industries

Other Words From

• ben·ton·it·ic [ben-tn-, it, -ik], adjective

Word History and Origins

Origin of bentonite¹

1895–1900; named after Fort Benton, Montana; -ite ¹

Word History and Origins

Origin of bentonite¹

C19: from Fort Benton , Montana, USA, where found, + -ite ¹

Example Sentences

Millions of years ago a volcanic eruption deposited ash that became bentonite clay.

From Los Angeles Times

Collins, over at Washington State University, has been experimenting with spraying fine-powdered kaolin or bentonite, which are clays, mixed with water onto wine grapes so it absorbs materials that are in smoke.

From Washington Times

Layers of clay — bentonite and montmorillonite, to be specific — are found beneath the ground, interspersed between layers of bedrock.

From Los Angeles Times

A series of barriers—giant copper casks, water-absorbing bentonite clay, and water-resistant crystalline rock—are expected to protect harmful radionuclides from seeping out of the site and into the local ecosystem.

From Science Magazine

If water were somehow able to seep into the repository, it would still have to get past the bentonite and copper to reach the spent fuel.

From Science Magazine