Kaolin is a kind of non-metallic mineral. It is a kind of clay and clay rock dominated by kaolinite group clay minerals. Because of its white and delicate, also known as dolomite.
Kaolin is mainly composed of kaolinite (Al4 [Si4O10] (OH) 8), alloxite (Al4 [Si4O10] (OH) 8·4H2O), hydromica, illite, montmorillonite (NaX(H2O)4{(Al2[Alx Si4-xO10](OH)2)}, quartz, feldspar and other minerals. The main mineral composition is kaolinite, the content is more than 90%.