Main uses and applications

There are 37 different types of mica minerals [3].The most common include purple lepidolite, black biotite, brown phlogopite and clear muscovite [4]. Individual mica crystals can easily be split into extremely thin elastic plates [5]. Mica is common in igneous and metamorphic rock and is also found in small flakes in sedimentary rock. 

Micas are extremely versatile. Muscovite and phlogopite micas are characterised by their flexibility and elasticity, infusibility, low thermal and electrical conductivity, and high dielectric strength [6]. These types of mica are used in products ranging from parts for electronics and automobiles and are used in paints and cosmetics to add “shimmer”. Mica with these compositions is also used in electrical condensers, as insulation sheets between commutator segments, or in heating elements [7].

Ground mica is used in many ways, such as a dusting medium to prevent, for example, asphalt tiles from sticking to each other, and as a filler, absorbent, and lubricant [8]. In the paint industry, ground mica is used as a pigment extender that also facilities suspension due to its light weight and platy morphology. It also reduces chalking, prevents shrinkage and shearing of the paint film, and provides increased resistance to water penetration and weathering [9]. Lepidolite has been mined as an ore of lithium, with rubidium generally recovered as a by-product – this is used in the manufacturing of heat-resistant glass [10].

In terms of electrical industries, micas are often used as electrical insulators in electronic equipment, thermal insulation, in stoves and kerosene heaters, dielectrics in capacitors, decorative panels in lamps, insulation in electric motors and generator armatures, field coil insulation, and magnet and commutator core insulation.