ETYM Latin mica crumb, grain, particle; cf. French mica.
Any of various minerals consisting of hydrous silicates of aluminum or potassium etc. that crystallize in forms that allow perfect cleavage into very thin leaves; used as dielectrics because of their electrical resistance; SYN. isinglass.
A transparent mineral used as window material in high-temperature ovens.
Group of silicate minerals that split easily into thin flakes along lines of weakness in their crystal structure (perfect basal cleavage). They are glossy, have a pearly luster, and are found in many igneous and metamorphic rocks. Their good thermal and electrical insulation qualities make them valuable in industry.
Their chemical composition is complicated, but they are silicates with silicon-oxygen tetrahedra arranged in continuous sheets, with weak bonding between the layers, resulting in perfect cleavage.
A common example of mica is muscovite (white mica), KAl2Si3AlO10(OH,F)2.
Gruppe gesteinsbildender Minerale. G. bildet dünne, blättchenförmige Kristalle (meist aus Tonerde, mit Perlmutterglanz) aus und kommt in Granit, Gneis, Sand- und Kalkstein vor.