Ammonium ferrous sulphate hexahydrate, min. 98 %, extra pure, Molar mass (M) 392,14 g/mol, Density (D) 1,86 g/cm³, CAS No. [7783-85-9], EG-Nr. 233-151-8, Empirical formula (NH4)2Fe(SO4)2 · 6 H2O