Mica is a silicate mineral which is common in igneouse and metamorphic ricks. Its individual mica crystals can split into thin plates. Micas are used in products such as drywalls, paints, fillers, especially in parts for automobiles, roofing and shingles, as well as in electronics. It can also be used as insulation material. The mineral is used in cosmetics to add “shimmer” or “frost.”