a compound formed by replacing hydrogen in an acid by a metal (or a radical that acts like a metal)

a common white or colorless mineral (hydrated calcium sulphate) used to make cements and plasters (especially plaster of Paris)

any of several gypsum cements; a white powder (a form of calcium sulphate) that forms a paste when mixed with water and hardens into a solid; used in making molds and sculptures and casts for broken limbs