Forming of Mica

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Mica is a group of silicate minerals formed in sedimentary and metamorphic rocks, generally mica minerals are flexible and resistant against the pressure and temperature, mica minerals commonly known as muscovite, biotite and phlogopite. Most of mica minerals contained aluminum and silicates, on the other hand, mica also contained some chemical elements such as iron, magnesium, lithium, vanadium, flour etc. Mica muscovite was formed in the acid freezing process and undergoes the crystallization at 1000°C however it is soft and transparent. Some industries use mica as a raw material for the manufacture of electrical appliance, cosmetic, tooth paste and glass window. A few people know about mica minerals, their assumption mica is a rare mineral. However mineral mica can be synthesized. Chemically, the mica has a general formula with  X₂Y₂–6Z₈O₂₀(OH,F)₄, which :

X is Alkali Metal (Kalium, Calsium, Natrium)

Y is Aluminium or Alkali Earth (Magnesium) 

Z is Silicon (Si) or Aluminium (Al)

For example : 

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Mica Muscovite : KAl2(AlSi3)O10(OH)2 

Synthetic Mica : KMg3(AlSi3)O10F2

Base on chemical formula, mica contained potassium element, where each potassium ion (K⁺) can prevent swelling and hold water molecules. Outwardly, the natural and synthetics mica have the difference, in which the natural mica was yellowish and contained potassium and aluminium compounds, while synthetic mica contained potassium and magnesium (Mg³⁺) compounds, so the color synthetic mica looks a bright white. 

Application of Mica

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Mica was used in the electrical and mechanical industries because it has weak electrical conductivity, and has high dielectric properties so that it applied in the radio frequency manufacture, it can separate electrical conductors that can prevent short circuit. Some other industries use mica to produce glass windows, because it is more resistant against the heat than ordinary glass, a mica mineral of the muscovite type is able to withstand heat up to 700^oC, so it is suitable applied as a regular glass substitute. Another type of mica is a phlogopite mineral, in which it is able to withstand heat up to 900^oC and is often reversed in the manufacture of heating wires such as nikhom and khantal.

In addition, mica also applied in health and beauty clinics because the character of mica substrate can coat the surface so that the surface looks white and glowing, such as the utilization of mica in toothpaste and cosmetics. Usually, the mica used for toothpaste shaped powder,it can make the teeth surface of back into white.

Conclusion

Mica compounds have different compositions, the variations of chemical composition can make mica applied for different materials, for example mica muscovite is more suitable to be applied in the window industry because it is resistant against the heat to a temperature of 700^oC, whereas phlogopite type is more suitable to be applied in wire making field such as nikhom because it able to resistant to heat up to 900^oC.

Source :

Mika

Mica in Science and Geology

The Utilization of Mica

The Function and Benefits of Mica as a Mining

Chemical Substance in Cosmetic