wollastonite

A white to gray mineral, essentially CaSiO₃, found in metamorphic rocks and used in ceramics, paints, plastics, and cements.

A mineral occurring in tabular crystals (hence called tabular spar), also massive, cleavable, with fibrous structure.

A silicate of lime of a white to gray, red, or yellow color, occurring generally in cleavable masses, rarely in tabular crystals; tabular spar.

A grey inosilicate mineral, mostly calcium silicate, CaSiO3, found deposited in limestone.

a white or greyish mineral typically found in metamorphic limestone; a silicate of calcium