Sodium Sulfate Anhydrous 99% MinSpecification as follows:Na2SO4 Purity 99.0-99.3%minWater Insoluble Metter 0.05%maxMagnesium& calcium (as Mg & Ca) 0.15%maxChloride (As Cl) 0.35%maxIron (As Fe) 0.002%maxMoisture 0.2%maxWhiteness 82%minPH Value about 5-9