Appearance: White powder Main content: 99% min MgSO4: 68.3% min MGO: 22.8% min Mg: 13.79% min Chloride (Cl): 0.014% Ferron(Fe): 0.001% max Heavy metal (Pb): 0.0008 %max Arsenic(As): 0.0002% max Insoluble: 0.01%max