... 1.99% agricuture grade 2.transparent crystal 3.main contain 99%min 4.special manufacturer Magnesium Sulphate HeptahydrateMOLECULAR FORMULAR: MgSO4.7H2OCAS10034-99 ... .002Cl ,%,≤0.20As ,%,≥0.5Pb ,%,≤1Water insoluble,%,≤0.05 Magnesium Sulphate Heptahydrate fertilizer grade