illite

American  

[il-ahyt] / ˈɪl aɪt /

noun

1. any of a group of clay minerals, hydrous potassium aluminosilicates, characterized by a three-layer micalike structure and a gray, light green, or yellowish-brown color.

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illite British  

/ ˈɪlaɪt /

noun

1. a clay mineral of the mica group, found in shales and mudstones. Crystal structure: monoclinic. Formula: K 1–1.5 Al 4 (Si 6.5–7 Al 1–1.5 O 20 )(OH) 4

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Other Word Forms

• illitic adjective

Etymology

Origin of illite

First recorded in 1937; Ill(inois) ² ( def. ) + -ite ¹

Example Sentences

These include the clay minerals kaolinite, illite, and smectite, and although they are difficult to study because of their very small size, they are extremely important components of rocks and especially of soils.

From Textbooks • Jan. 1, 2015