AM_Polyhalite Formula: K2 Ca2 Mg S4 O18 H4 Name: Polyhalite Unit cell: 6.975 6.984 8.899 104.01 101.19 114.1 , V=362.34 Space group: P-1 (2)

Bindi L , Acta Crystallographica, Section E , 61 (2005) p.i135-i136, Reinvestigation of the crystal structure of polyhalite, K2Ca2Mg(SO4)4*2H2O