Mica main crystallization monoclinic crystal was thin at the six-party Flake, Flake, tabular and sometimes six-party column was false. Hardness 2 -3, the proportion of 2.70-3.20. Mica of refractive index increased iron content and the corresponding increase was protruding from low to CKS processes. Non-ferrous variant SHEET colorless, higher iron content, the greater the color and multi-color and enhance the absorbability.