... powderWhite block shapeAverage particle size(um)1-3/BET(m2/g)6-12/Loose density(g/cm3) 0.4-0.6/Density of ... platelet shape (g/cm3) /3.2~3.9Content of Al2O3,% 99.99999.999Si (ppm)55Na (ppm)11Fe ... , Single crystal of sapphire2, Laser Crystal(YAG)and artificial gem 3, Colourful gem4, White gem,red gem Packing:25kg/barrel 5N ...