CHEMICAL COMPOSITION Fe2O3: 25-31% Al2O3:17-21% MgO:5-6% SiO2:34-40% CaO:5.0-10.0% MnO:0-1.0% PHYSICAL PROPERTIES Specific Gravity:3.8-4.1g/cm3 Bulk Density:1.8-1.9 g/cm3 Hardness (Mohs):7.5-8.0 Melting point:1300 C Grain shape: Sharp, Angular Chloride content 25ppm Acid solubility(HCL) 1% Conductivity 25 ms/m Toxic substances:None