china clay, china stone, kaolin, kaoline, porcelain clay, terra alba(noun)

a fine usually white clay formed by the weathering of aluminous minerals (as feldspar); used in ceramics and as an absorbent and as a filler (e.g., in paper)

Kaoline(noun)

a very pure white clay, ordinarily in the form of an impalpable powder, and used to form the paste of porcelain; China clay; porcelain clay. It is chiefly derived from the decomposition of common feldspar