Finely pulverized gypsum used especially as a pigment.
2.
Fine white clay used in making tobacco pipes and pottery and in whitening leather. Synonym:pipeclay.
3.
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). Synonyms:china clay, china stone, kaolin, kaoline, porcelain clay.