what is mica

Mica is a group of silicate minerals that are physically and chemically similar. They are known as sheet silicates because they form in distinct layers and can be easily split into extremely thin elastic plates, a characteristic known as perfect basal cleavage. Mica is common in igneous and metamorphic rock and is occasionally found as small flakes in sedimentary rock. There are 37 different mica minerals, with the most common being purple lepidolite, black biotite, brown phlogopite, and clear muscovite. Mica is used in a variety of applications, including as a color additive in cosmetics, as filler in cement and asphalt, and as insulation material in electric cables. However, long-term inhalation of mica poses a health risk to workers, specifically those working in muscovite mills and other occupations such as agriculture and construction work.