Habit: Colorless or white; also pink or green. Crystals rare; usually fibrous to acicular crusts, elongated botryoidal masses or stalactitic. Vitreous luster, but also silky or earthy; transparent to translucent. White streak.
Environment: Found as efflorescence or crusts on the walls of mines, caves and outcrops of sulfide-bearing magnesian rocks or as a product of evaporation at mineral springs and saline lakes; rarely occurs as a fumarolic sublimate.
Etymology: From its occurrence at Epsom, in England.
Epsomite is the same as common household Epsom salts, which are traditionally used for muscle-soothing baths and as a component of bath products.