Chemical Formula : H3PO4*12WO3*xH2O Formula Weight : 2898.17 Appearance : Off-White crystalline powder Turning yellow on exposure to light Assay (with Cinchonine) : 65.0% to 70.0% Insoluble Matter : 0.10% maximum Chloride (Cl) : 0.30% maximum Nitrate (NO3) : 0.05% maximum Sulfate (SO4) : 0.20% maximum Ammonium (NH4) : 0.05% maximum Heavy Metals (as Pb) : 0.05% maximum Iron (Fe) : 0.02% maximum