1)Zinc Sulfate Heptahydrate Agriculture Grade 2)Zn :22.8%,22.51% Min 3)ZnSO4:98%, ... 1.957,Melting point: 100°CWhen the temperature is 280°C, it will become no water substance and lose all crystal ... water. When the temperature is above 500°C, it will decomposeWhite or slight-yellow crystal, loose and no ... , sealed package. Stay away from oxide Zinc Sulfate Heptahydrate Agriculture Grade