kieserite, a sulfate mineral, hydrated magnesium sulfate (MgSO4·H2O), that is abundant in evaporite deposits. It often occurs as intergrowths with halite or associated with carnallite and other potassium salts. Sites of occurrence include Stassfurt, Ger.; Ozinki, Russia; western Texas; and New Mexico. For detailed physical properties, see sulfate mineral (table).