1. PARTICLE SIZE: The proportion of fragments with particle size under 8 Mesh not be more than 8% 2. IMPURITIES: The proportion of impurities (biotite quartz stone and sand etc.) will not more than 2% 3. CALCINATION: The Mica Flakes will withstand calcination temperature of 850-920 temperature degree centigrade for 30 minutes. The calcined material will turn to silver/white colour.