Chemical name: Magnesium Sulfate Synonyms: magnesium sulphate heptahydrate, magnesium sulphate, magnesium (II) sulphate, magnesium (2+) sulfate, Epsomite, bitter salts Magnesium sulfate heptahydrate (Agriculture grade):AppearanceWhite small granularMain content99.5% minMgSO448.59% minMgO16.24% minMg9.8% minPH(5W/V%Sol)5-9Ferron(Fe)0.002% maxChloride(CL)0.02%Heavy metal (Pb)0.001 %maxArsenic(As)0.0002% maxInsoluble0.01%maxSize (mm)0.1-1 0.2-3 1-4