nouna colourless or white mineral sometimes tinted by impurities, found in beds as an evaporite. It is used in the manufacture of plaster of Paris, cement, paint, school chalk, glass, and fertilizer. Composition: hydrated calcium sulphate. Formula: CaSO4.2H2O. Crystal structure: monoclinic
Word origin
C17: from Latin, from Greek
gupsos chalk, plaster, cement, of Semitic origin