kainite

A white, gray, pink, or black mineral, MgSO₄·KCl·3H₂O, used as a fertilizer and a source of potassium compounds.

A hydrous magnesium sulphate with potassium chlorid, occurring in beds of considerable extent at the salt-mines of Stassfurt, Germany.

A compound salt consisting chiefly of potassium chloride and magnesium sulphate, occurring at the Stassfurt salt mines in Prussian Saxony.

A saline evaporite, consisting of magnesium sulphate and potassium chloride with the chemical formula MgSO4·KCl·3H2O, found in German salt mines.

a white mineral consisting of magnesium sulphate and potassium chloride; a source of potassium salts; used as a fertilizer