SiO2: 35.00~ 60.00% MIN MgO: 30.00~ 31.00% MAX CaO: 0.50~ 2.00% MAX Al2O3: 0.20~ 0.50% MAX Fe2O3: 0.30~ 0.50% MAX Whiteness: 85.0~ 90.0% MIN LOI: 7.00~ 25.00% MAX Moisture: 0.30% ....