Mica is an industrial mineral which occurs mainly in the form of igneous rock and metamorphic rock. The word "mica" comes from a Latin word, micus, which means 'to withstand fire'. As its name suggests, mica offers resistance to high temperatures.
There are many large scale mineral deposits around the world. Mica produced in each area has different characteristics, and is mainly categorized as Phlogopite and Muscovite. Their chemical formulas are expressed as below, respectively.
Produced in Canada, USA, Madagascar, Sri Lanka, and Finland. As seen above, Aluminum of Muscovite is replaced by Magnesium in Phlogopite's chemical formula and this is what differentiates their colours.
Produced in India, USA, South Africa, Brazil, and China. Recently, Japan is importing Muscovite for building material mainly from China.
Synthetic Mica is produced artificially by blending, melting, and crystallizing oxidation products such as alumina and magnesia. Although its application is limited due to the expensive cost, it has high purity and colorability.
Application of Mica
Mica has high heat resistance and electrical insulation property, mechanical strength, elasticity, and can be processed easily. Those are advantages which cannot be replaced by other materials and therefore Mica is used in various fields.
Mica's dimensional stability and elasticity make it useful as a reinforcing material for plastics, and its high rigidity is used for vibration control materials. It can also be mixed with plastics and asphalt to be used as a damping material.
Moreover, Mica can be an asbestos replacement material. Asbestos was in widespread use at one time because of its low cost and versatile performance, but it is currently being prohibited in many countries since its hazardousness to the human body was discovered.