The occurrence of gypsum at MSH is rare. Color is usually colorless or white. Diaphaneity is transparent. Crystal Habits include sharp, thin elongated prisms and blades to 5mm and drusy microcrystals.
Fracture is splintery.
Hardness is 2. Streak is white. Associated Minerals include mica group and natrolite. Known from antiquity, its name come from the Greek gypsos, plaster, alluding to its principal use.