Category:Gypsum

Gyp"sum, n. Etym: [L. gypsum, Gr. jibs plaster, mortar, Per. jabs lime.] (Min.)

Defn: A mineral consisting of the hydrous sulphate of lime (calcium). When calcined, it forms plaster of Paris. Selenite is a transparent, crystalline variety; alabaster, a fine, white, massive variety.