The clays used in Sanitaryware body are of two types:

Primary Clay (China Clay)
Secondary Clay (Ball Clay)

Both belong to Kaolinite mineral group. Hence these clays predominantly contain kaolinite as the major mineral with other impurities.
Primary Clay [China Clay] :
When granite is exposed to chemical process due to weathering, the minerals like Alkali Feldspar, Quartz, Plagio Clase […]