Mica is a Potassium Alumina Silicate (K2O.Al2O3.SiO2). Group of silicate minerals composed of varying amounts of aluminium, potassium, magnesium, iron and water. All micas form flat, plate-like crystals. Crystals cleave into smooth flakes. Biotite is dark, black or brown mica; muscovite is light-colored or clear mica. The various grades of Mica available are as under:
