Cobalt(II) sulphate heptahydrate, min. 97 %, extra pure, Molar mass (M) 281,10 g/mol, Density (D) 1,95 g/cm³, CAS No. [10026-24-1], UN-Nr. 3077, EG-Nr. 233-334-2, Empirical formula CoSO4 · 7 H2O