Mica, which is essentially a compound of silicate minerals, is comprised of closely related materials that have perfect basal cleavage. They are monoclinic with a tendency of pseudohexagonal crystals, having similar chemical composition. They belong to the category of principal rock-forming minerals and are found in various categories like sedimentary, igneous, and metamorphic.
How is Mica Formed?
Micas do originate as a result of diverse processes and several conditions. There are various processes of formation that includes deposition by fluids derived from magmatic activities, consolidating magmas, deposition of fluid circulating by both contact and regional metamorphism, and also by alternate process. They are even caused by weathering of feldspar and minerals. The presence of mica or chemical composition can serve as geothermometers or geobarometers.
Distinct crystals of micas occur in few rocks, like igneous and pegmatites. Micas may occur in large crystals or books, and they measure up to several meters across. The mica grains are extremely small and have characteristic shiny cleavage surfaces.
Glauconite, an iron potassium phyllosilicate of the mica group formed in marine environments, is also found in seafloors where clastic sedimentation occurs. Although the glauconite is interpreted to be formed from pre-existing layered silicates, most of it appears to be crystallized from the aluminosilicate gels, which is influenced by biochemical activities that reduce the environment.
The common rock-forming micas are distributed widely. Biotite occurs in igneous rocks, pegmatite occurs in masses. During chemical weathering, it’s usually rare in the sedimentary rocks and sediments. Also, biotite tends to lose its elasticity and become decolorized due to the appearance of greyish silver flakes.
Weathered biotite is golden yellowish, having a bronzy luster and having the appearance of gold flakes.
Muscovite is another hydrated phyllosilicate mineral that commonly occurs in metamorphic gneisses and phyllites. Muscovite occurs as microscopic grains and gives the rock a silky luster. Much of the muscovite in igneous rocks is thought of being having formed late. It’s relatively resistant to weathering and occurs in soils, clastic sediments and sedimentary rocks are derived from them.
Phlogopite is rare in igneous rocks, but it contains some ultramafic rocks. It occurs in periodontitis, kimberlites where rocks in diamond occur. They are a unique constituent of some magnesium-rich pegmatites. It’s generally found in impure limestone that has undergone contact metasomatism, a procedure through which the chemical composition of the rocks is changed.
What is Mica Used For?
Mica is a naturally occurring stone directly applying to a set of minerals having silica in its highest form. Mica finds various usages in different industries. Let’s find out some of them.
- Mica is used in paint as a pigment extender, which also helps to brighten the tone of colored pigments.
- In the case of the electrical industry, the same is used as thermal insulators and electrical insulators in the case of isotonic equipment.
- The shiny and glittery appearance makes it ideal for toothpaste and cosmetics.
- Due to the high thermal resistance, it is used as insulators in many electronic appliances.
- Mica shields or gauge glass mica is generally used in securing the liquid level gauges from the corrosive and acidic solutions.
- Mica is invariably used for fillers, extenders that provide smoother uniformity, thereby improving workability and preventing cracks.
- Mica can be added to grease, thereby increasing its durability and giving it a better surface.
- Mica can be used as a soil conditioner and also in potting soil mixes and other gardening plots.
- Mica is used in gardening plots.
- It finds its usage in the automotive industry as a superior thermal barrier. That makes it ideal for improving heat transfers in clutches and brake pads.
- For the foundry and steel industry, mica is used for coating in iron and aluminum production casting.
Various Properties of Mica
Mica belongs to a very important and large group of minerals that are highly suitable for various applications. Mica has some properties distinguished from others.
- Physical Properties: Mica is translucent and can be easily split into thin films along its cleavage. Its optically flat, colorless, firm like thin sheets, elastic, and of course, incompressible.
- Chemical Properties:It is a compound of hydrous silicate of aluminum, containing iron, potassium, magnesium, sodium fluorine, and also a few traces of numerous other elements. It is static to the action of water, and even acids barring a few like hydrofluoric and concentrated sulfur. It remains unchanged by atmospheric effects.
- Electrical Properties:Mica has the exclusive combination of uniform dielectric steadiness, capacitance stability, and enormous dielectric power. It has a high Q factor and lower power loss, low-temperature coefficient, and high electrical resistance. It has a high resistance to arc, corona discharge without causing any lasting injury effect.
- Thermal Properties:Mica is highly fireproof, non-flammable, incombustible, infusible, and can resist temperature up to 1000 degrees Celsius. Although the thermal properties largely depend on a lot on the type and variety of mica used, it has excellent thermal stability. Mica is characterized by low heat conductivity and can be easily exposed to high temperatures without any visible effect.
- Mechanical Properties:Mica is highly tough and has high tensile strength. It’s elastic and also flexible. Mica possesses immense compression power and can be machined, hand-cut or die punched.
What was the Use of Mica in Early History?
The use of mica dates back to the 21st century AD. Various countries like Greece, India, Egypt, Rome, China, and the Aztec world used mica for various purposes since the pre-historic ages. The earliest use of mica was seen in the case of cave paintings created during the Upper Palaeolithic age. The first hues, which were red, or black, were discovered. The elements used were red oxide, red ochre or hematite.
White colors from kaolin or mica were often used. The pyramid of the sun that stands a few kilometers northeast of Mexico City, there stands the ancient site of Teotihuacan. Natural mica was used to make pottery. Mica flakes are also used in Pakistan in embellishing women’s clothes.
Dupattas are striped using mica added to hot starch. Mica powder is used in decorating traditional Japanese woodblock printing. Ayurveda, the traditional Hindu medicine discipline, uses mica in the process of treating respiratory and digestive ailments.
Various Benefits of Using Mica
Since mica has reflective property, they are used in case of preparing cosmetics for women. They are a great choice for women with sensitive skin. Mica is non-irritating and helps to calm down sensuous skin. The chemical ingredients often cause swelling, redness and irritation. Mica is widely used in the process of preparing beauty products like foundation, facial powders, eye shadows, blushes, lotions, body powders, beauty creams and natural sunscreens.
Various Disadvantages of Using Mica
It’s been observed that the usage of mica causes skin diseases and ailments, especially cancer. The top approved colors to mica are blue, citrus red, green, orange, and red. It’s also a known fact that children who work in mines die due to the ill effect of mica on health. Sometimes, cosmetics, where mica is used, can cause microscopic lesions in your skin, leading to irritation and redness.
Countries That Mine Mica
The countries that produce mica are China, Russian Federation, Finland, the United States, Republic of Korea, Canada, India, Argentina, Madagascar, Iran, Malaysia, Spain, Sri Lanka, South Africa, Sudan, and Peru. These countries extract mica, which is generally obtained by mining procedures, for various purposes.
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FAQs
What is mica and how is it formed? ›
Mica minerals are major rock forming minerals found in gneiss, schist and granite. The mica group includes muscovite mica and biotite mica. They usually form in layers of sediment on ocean floors. Weathering of continental rocks breaks large and small chunks of rock off the larger older rocks.
What is mica and how is it used? ›Mica is a naturally occurring mineral dust often used in makeup foundations, as filler in cement and asphalt, and as insulation material in electric cables. Mica is a naturally occurring mineral dust often used in makeup foundations, as filler in cement and asphalt, and as insulation material in electric cables.
What are some properties for mica? ›Mica sheets have thermal stability at high temperatures, amazing dielectric strength, chemical inertness, elasticity, lightweight, and good reflective & refractive properties. However, the properties of mica sheets also vary based on the type of mica used to manufacture the sheets.
What is mica made out of? ›Mica is a colored powder that's made from a natural mineral called muscovite. Muscovite is a silicate mineral, in the same family as quartz. Before it's processed, mica comes out of the ground in large pearlescent sheets or flakes, which have a naturally shimmering, iridescent property.
What is mica short answer? ›mica, any of a group of hydrous potassium, aluminum silicate minerals. It is a type of phyllosilicate, exhibiting a two-dimensional sheet or layer structure. Among the principal rock-forming minerals, micas are found in all three major rock varieties—igneous, sedimentary, and metamorphic.
What is mica in simple words? ›(maɪkə ) Word forms: plural micas. variable noun. Mica is a hard mineral which is found as small flat crystals in rocks. It has a great resistance to heat and electricity.
Why is mica used? ›It is used as a pigment extender in paints and also helps to lighten the tone of coloured pigments. Because of its sparkly look, it is ideal for toothpaste and cosmetics. Because of its excellent thermal resistance, it may be utilized as an insulator in a variety of electrical devices.
Where is mica used? ›Mica can be made into thin sheets. They are heat tolerant, insulating and dielectric. Because of these properties, they are used in electrical appliances. They are used in control devices, heating devices, neon lights and other lighting equipment.
Where is mica made? ›'Mica' refers to a group of minerals used to give sparkle to consumer products. 37 different varieties of mica are found and mined all over the world, with the majority coming from illegal mines in India and Madagascar.
What is mica also known as? ›Mica is a generic name for a group of complex hydrous potassium-aluminum silicate minerals that differ somewhat in chemical composition; examples are biotite, lepidolite, muscovite, phlogopite, and vermiculite.
Is mica a rock or mineral? ›
Mica, any of a collection of hydrous potassium, aluminum silicate minerals. It is a kind of phyllosilicate, showing a -dimensional sheet or layer structure. Among the most important rock-forming minerals, micas are located in all 3 foremost rock types—igneous, sedimentary, and metamorphic.
Who produces mica? ›India is the largest producer and the monopoly when it comes to mica production. India produces 60% of the world's mica. In India, mica mines are found mainly in three states. These are Jharkhand, Rajasthan and Andhra Pradesh.
Where is mica found in the USA? ›Most of the mica deposits of the United States occur in . regions of highly metamorphic gneisses and schists. A few have been found in less altered granites or other igneous rocks.
What are 3 common things that mica is used in? ›Micas are used in products such as drywalls, paints, fillers, especially in parts for automobiles, roofing and shingles, as well as in electronics. The mineral is used in cosmetics and food to add "shimmer" or "frost."
Why is mica a problem? ›Mica can also absorb water and excess amounts of water can cause problems in cold winters as freezing and thawing damages the blocks. More than five thousand houses, and an unknown number of office and other buildings, have been affected, with some owners moving out of their homes as they are no longer safe.
Is mica like asbestos? ›Is Mica a Safe Alternative to Asbestos? Unlike asbestos, mica does not possess the same airborne risks to health. But, like asbestos, mica has many applications when it comes to thermal insulation, heat resistance and fire proofing.
Which country is the largest producer of mica in the world? ›India is the largest producer and the monopoly when it comes to mica production. India produces 60% of the world's mica. In India, mica mines are found mainly in three states. These are Jharkhand, Rajasthan and Andhra Pradesh.
Where is mica made from? ›As a naturally-forming silicate mineral, mica occurs in igneous rock, which consists of layers of volcanic material. At this stage, mica is crystal in form and is mined to extract it.
Which state is the largest producer of mica in world? ›Andhra Pradesh is the largest producer of mica in India.
Can you live in a house with pyrite? ›Trace amounts of pyrite are common in building materials and generally do not cause an issue, however when there is a large amount present in ground backfill (the material used to fill the area the concrete slab of the house is poured on), it can start to swell.
Is mica harmful to the environment? ›
Despite being a human-made substance, synthetic mica is an environmentally-friendly alternative to commonly used plastic glitters.
Is mica toxic to humans? ›Routes of exposure Mica can affect the body if it is inhaled. Effects of overexposure Exposure to mica dust over a period of years may cause scarring of the lungs. The symptoms which may occur with this condition are cough, shortness of breath, weakness, and weight loss.
Is mica safe for humans? ›* Mica can affect you when breathed in. * Repeated high exposure to the dust can irritate the lungs and may cause lung scarring (fibrosis). This causes an abnormal chest x-ray, cough and shortness of breath.
How can you tell if a rock is mica? ›The identification of a sheet of mica is never much of a problem even for an untrained eye. All forms of mica have perfect basal cleavage, unique hexagonal shaped crystals, and an unmistakable "snap" of cleavage flakes when they are bent together and then released.