Chief Chemical Composition： References Examination Results： CaCO3 97% 97.5% Specific Gravity 0.65?.4 0.64 PH 8-10 9.38 Acid Insoluables 0.1% 0.1 Fe2O3 0.01% 0.09 Al2O3 0.1% 0.1 MgO 0.2% 0.2 Brightness 93 Specific Surface Area 1800cm3/g Moisture 0.5 Fineness 325 Remainder 0.1 Oil Absorbency 0.6