Kaolin

The search for kaolin defined the European race to develop domestically produced hard paste porcelain. This was an intense industrial and political competition that endured from the 1500s to the late 1700s. The search for white porcelain spurred technological developments and added to chemical and material knowledge.

Kaolinite is the mineral form, and kaolin is the refined clay material.

​

Kaolin is a pure white clay, and has the ideal formula of Al2O3·2SiO2·2H2O. It is written in this form to demonstrate the relationships of the chemical species, that is: Alumina, Silica, and Chemically-bound Water.

​

Kaolin is highly refractory (non-melting) and has been called the "bones" of fired porcelain, whereas feldspars and silica enable a clay body to fuse and melt together (vitrify).​

​

Only the purest kaolins can be used to make white porcelain objects. These are frequently found in deeper (i.e. earlier) geological deposits.