... , and Hardness of2-3, the proportion of 2.70-3.20, a loose density of 0.3-0.5. The refractive index ... mica minerals, according to the texture exploration department, there is a broken mica reserves of 1,700,000 tons. They are ... , welding electrode, cosmetics, aerospace and other fields. Mica powder specifications: 20 meshes, 4o meshes, 60 meshes, 100 meshes, 200 meshes, 325 ...