Mica is a general term for mica minerals. It is a compound composed of potassium, aluminum, silicon and other elements. There are two kinds of muscovite and biotite. The composition is different. It is flaky or scaly, and the color varies with the composition, with pearl luster, transparency or translucency. Mica has a group of the most perfect cleavage. It is a widely distributed rock-forming mineral and can be used as a heat-resistant insulating material.