Gypsum 2
Gypsum 2 : (n). Geology. [CaSO472H2O] A highly insoluble sulfate mineral that is the first to precipitate from evaporating seawater. Dehydration of gypsum can produce anhydrite. Fine-grained gypsum is called alabaster. See: calcium mud, carbon dioxide, evaporite, halite, hydrate, scale, sedimentary