Mica, any of a group of hydrous potassium, aluminum silicate minerals . It is a type of phyllosilicate, exhibiting a two-dimensional sheet or layer structure. Among the principal rock-forming minerals , micas are found in all three major rock varieties—igneous, sedimentary, and metamorphic. Mica , which is essentially a compound of silicate minerals , is comprised of closely related materials that have perfect basal cleavage. They belong to the category of principal rock-forming minerals and are found in various categories like sedimentary, igneous, and metamorphic. Statistics and information on the worldwide supply of, demand for, and flow of the mineral commodity mica The micas include several notable mineral species including black mica , margarite, celadonite, and sericite.
