What is "kaolinite"

n. (context mineralogy English) A common hydrous aluminosilicate mineral found in sediments, soils and sedimentary rocks, aluminium₂silicon₂oxygen₅(hydroxide)₄; one of the kaolin group of minerals.

n. a mineral consisting of aluminum silicate; main source of kaolin

Kaolinite is a clay mineral, part of the group of industrial minerals, with the chemical composition Al Si O( OH). It is a layered silicate mineral, with one tetrahedral sheet of silica (SiO) linked through oxygen atoms to one octahedral sheet of alumina (AlO) octahedra. Rocks that are rich in kaolinite are known as kaolin or china clay.

The name is derived from Chinese Gao Ling , a village near Jingdezhen, Jiangxi Province, China. The name entered English in 1727 from the French version of the word: kaolin, following Francois Xavier d'Entrecolles's reports from Jingdezhen.

Kaolinite has a low shrink–swell capacity and a low cation-exchange capacity (1–15 meq/100 g). It is a soft, earthy, usually white mineral (dioctahedral phyllosilicate clay), produced by the chemical weathering of aluminium silicate minerals like feldspar. In many parts of the world, it is colored pink-orange-red by iron oxide, giving it a distinct rust hue. Lighter concentrations yield white, yellow or light orange colors. Alternating layers are sometimes found, as at Providence Canyon State Park in Georgia, United States. Commercial grades of kaolin are supplied and transported as dry powder, semi-dry noodle or as liquid slurry.