... transparent crystal 3.main contain 99%min 4.special manufacturer Magnesium Sulphate HeptahydrateMOLECULAR FORMULAR: MgSO4.7H2OCAS10034-99-8SPECIFICATION:HG/T 2680- ... : mainly used in mixed fertilizer or directly used as fertilizer for rubber, palm trees ;2. In industries: used in tanning, ... 0.002Cl ,%,≤0.20As ,%,≥0.5Pb ,%,≤1Water insoluble,%,≤0.05 Magnesium Sulphate Heptahydrate fertilizer grade