Biotite

  Biotite color is black, dark brown, sometimes with light red, light green or other colors. Titania's pale reddish-brown, rich in high-priced iron are  green, Transparent to opaque. Glass gloss, black is a semi metallic luster. Hardness 2-3, specific gravity 3.02-3.12. The role of biotite heated solution can be altered to chlorite, muscovite and sericite and other minerals. Because biotite has the high iron content, poor insulation, much less than muscovite. Biotite flakes usually is used as filler of building materials. Black mica flake of larger particle size easily according to their shape, dark colors, and flexibility, with complete cleavage of mica, and after heating, can be slightly magnetic characteristics of differential in deep diagenetic and shallow diagenetic, especially in acidic or alkaline rocks, mostly contains black mica.
  Biotite widely used in building materials industry, the fire industry, fire extinguishing agents, welding, plastics, electrical insulation, paper, asphalt paper, rubber, pearlescent pigments and other chemical industries. Ultra-fine mica powder for plastics, coatings, paints, rubber and other functional fillers can increase the mechanical strength, enhanced toughness, adhesion and anti-aging and anti-corrosion type. In addition to very high electrical insulation, anti-acid corrosion, flexibility, toughness, and sliding resistance, heat insulation, thermal expansion coefficient and other properties, but also the first to introduce chip and Two smooth surface, radius to thickness ratio, regular, with with strong characteristics.