Mica is a group of silicate minerals, known for its characteristic sheet-like structure, which gives it unique physical and chemical properties. Mica is composed of thin, flexible layers that can easily be split into thin sheets or flakes. These sheets are transparent to translucent, and they have a pearly luster.
Mica is a soft mineral, with a Mohs hardness of 2.5 to 3. It is also a relatively light mineral, with a specific gravity of 2.7 to 3.2. Mica is typically transparent to translucent, but it can also be opaque. The color of mica varies depending on the mineral species. Muscovite is typically colorless or white, while biotite is black or dark green. Phlogopite is brown or yellow, and lepidolite is pink or purple.