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Mica is a mineral and belongs to the group of sheet silicate. There are different types of micas, such as:
• Muscovite (Common Mica, potash mica, silvery)
• Biotite (Iron Mica, dark brown)
• Phlogopite (Magnesium Mica, light brown)
The word ‘mica’ is thought to be derived from the Latin word ‘micare’, which means ‘to glitter’.
Images
Occurrence of Mica
Mica sheets have been found in Madagascar, India, USA and Canada. The largest sheet of mica ever mined in the world, came from a mine in Denholm, Quebec.
Properties and specification of Mica
• high dielectric strength
• excellent chemical stability
• resistant to heat, fire resistant
• ultra flat surface, atomically flat
• shines and glitters
• high UV stability
Use of Mica
Ground mica is used as
• Filler and extender in gypsum wallboard joint compound, where it provides a smoother consistency, improves workability and prevents cracking.
• Pigment extender in paint industry, provides increased resistance to water penetration and weathering and brightens the tone of coloured pigments
• Additive to drilling (well drilling)
Sheet mica is used in
• High voltage electrical equipment as insulators
• Manufacturing capacitors for radio frequency applications
• Thermal insulation
• Windows in stove and kerosene heaters
• Decorative panels in lamps and windows
• Field oil insulation, magnet and commutator core insulation
• Production of ultra flat film surfaces
• Substrate for sample preparation for the atomic force microscope (e.g. imaging of DNA molecules)
Powdered mica is often found in
• Mineral cosmetics
• Toothpaste
• Makeup
• Paint for automobile industry
• Decorative and fine art paint
• Shimmery plastic containers
• High quality inks used in advertising and security applications