The physical properties and chemical components : PHYSICAL PROPERTY CHEMICAL COMPONENT
　Coefficient of expansionmm/mm/℃ 6.0×10ˉ6 　SiO2 50%min
　Refractive index 1.63 　CaO 46%min
　Melting point 1450℃ 　Fe2O3 0.3%max
　hardness 4.55.0 　AL2O3 0.46%max
　Specific Gravity 2.91 　MgO 0.60%max
　Whiteness 8892 　MnO 0.02%max
　PH(10% slurry) 9.8 　TiO2 0.02%max
　Aspect Ratio　 2030 　LOI 3.0%max