main specifications: -10 / +20mesh, -20 / +40 mesh, -40 / +60 mesh, -60 / +100 mesh The color are black, dark brown, sometimes with light red, light green or other colors. The titanium-containing red-brown color, is rich in high iron green. A transparent to opaque. Glass sheen, there was a black semi-metallic sheen. Hardness 2-3, the proportion of 3.02-3.12. black mica