Hectorite is a rare soft, greasy, white clay mineral with a chemical formula of Na0.3(Mg,Li)3Si4O10(OH)2.

[2] Hectorite was first described in 1941 and named for an occurrence in the United States near Hector (in San Bernardino County, California,[4] 30 miles east of Barstow.)

Hectorite occurs with bentonite as an alteration product of clinoptilolite from volcanic ash and tuff with a high glass content.

[6] Despite its rarity, it is economically viable as the Hector mine sits over a large deposit of the mineral.

Hectorite is mostly used in making cosmetics, but has uses in chemical and other industrial applications, and is a mineral source for refined lithium metal.