Kaolin Guide

Kaolinite is a clay mineral, part of the group of industrial minerals, 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 octahedra.[4] Rocks that are rich in kaolinite are known as china clay, white clay, or kaolin.

The name is derived from Chinese: 高陵/高嶺; pinyin: Gaoling or Kao-ling ("High Hill") in Jingdezhen, Jiangxi province, China.[5] The name entered English in 1727 from the French version of the word: "kaolin."[6]

Kaolinite has a low shrink-swell capacity and a low cation exchange capacity (1-15 meq/100g.) 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 colours. Alternating layers are sometimes found, as at Providence Canyon State Park in Georgia, USA....