montmorillonite

American  

[mont-muh-ril-uh-nahyt] / ˌmɒnt məˈrɪl əˌnaɪt /

noun

1. any of a group of clay minerals characterized by the ability to expand when they absorb large quantities of water.

---

montmorillonite British  

/ ˌmɒntməˈrɪləˌnaɪt /

noun

1. a clay mineral consisting of hydrated aluminium silicate: an important component of bentonite

---

Other Word Forms

• montmorillonitic adjective

Etymology

Origin of montmorillonite

1850–55; named after Montmorillon, France, where it was found; -ite ¹

Example Sentences

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

From Los Angeles Times • Jul. 13, 2023

El Hachemi Bouali, assistant professor of geosciences at Nevada State College, said it all comes down to clay — bentonite and montmorillonite, to be specific.

From Los Angeles Times • Mar. 6, 2023

In another location, Opportunity sees an aluminium-rich variety called montmorillonite.

From BBC • Jan. 24, 2014

Esperance is the most clay-laden rock seen by Opportunity in its nine and a half years on Mars The clays are aluminium-rich, possibly of the type montmorillonite.

From BBC • Jun. 10, 2013

In analyzing these spectra, O. B. Toon, J. B. Pollack and I found that certain features seem best accounted for by montmorillonite and other kinds of clay.

From "Cosmos" by Carl Sagan