mineraal CaSO4 · 2H2O; puhtal kujul looduslik kips sisaldab (massi%): CaO – 32,56; SO3 – 46,52 ja H2O – 20,93, crystalline mineral of hydrated calcium sulphate, CaSO4 . 2H2O used in making of plaster of Paris, plaster and plasterboard, and is important constituent of Portland cement