... be darker.2. The characteristics of mica contains: insulation,high temperature resistant,lustrous appearance, stable physical and chemical property,good heat insulation, excellent ... ,40mesh,60mesh,80mesh,100mesh,200mesh,325 mesh ,400 mesh etc.Physical Property: Diameter-thickness. RatioWhitenessRefractiveIndexSpecific Gravity(g/cm3)PHMoistureSand ContentColour1:3050-701 ...