Kaolinite

Kaolinite or Kaolin is a clay mineral. It is in a group with the chemical composition Al2Si2O5(OH)4. It is a layered silicate mineral, with one tetrahedral sheet linked through oxygen atoms to one octahedral sheet of alumina. Rocks that are rich in kaolinite are known as kaolin or china clay.
The name is after Kao-Ling, a village near Jingdezhen, Jiangxi province, China. The name entered English in 1727 from the French "kaolin", used in a Jesuit priest's reports from Jingdezhen. In Africa, kaolin is sometimes known as "kalaba" or calaba.
Kaolinite is a soft, earthy, usually white mineral (dioctahedral phyllosilicate clay). It is 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.
Kaolinite is said to have a low shrink-swell capacity and a low cation-exchange capacity, which makes it ideal for various industrial applications.