Mica

What is mica? Mica is a mineral that breaks up into very thin sheets. It is among the world's most useful minerals, although you rarely notice it.

Mica.

Mica is a material like sand, but it occurs in crystals that are made into very thin sheets. Some crystals are even thin enough to see through.

Mica has many uses. You can find mica in most samples of granite, where it makes the small flecks that light bounces from. But most of the useful mica is obtained from places near where magma chambers used to be. This is the place where crystals grow largest.

The largest single crystal of mica was found in Ontario, Canada; it measured 10×4.3×4.3 m and weighed about 330 tonnes. Jharkhand state in India had the largest deposits of mica in the world, but China is the top producer of mica with almost a third of the global share,

Mica’s value is based on its unique properties. It forms layers that can be split into thin sheets which do not react with liquids, they are electrical insulators, they are elastic and flexible, they insulate, they are nearly transparent and it does not break down under heat.

It is used in many appliances. For example, you can find it being used as a support for toaster elements, as an insulator in electrical power stations, and as a filler to put in the roof spaces of homes to stop losing heat. Although you can't see it, tiny pieces of mica (as powder) are used in paint because it makes the paint stay in suspension in the can, but it also makes it stick better when painted on. In fact, the paint industry uses a quarter of all powdered mica. Mica is used in plastic parts of automobiles as a reinforcing material. It adds stiffness, and strength. Mica is used in rubber tyres. Mica is even used in decorative coatings on wallpaper. Tiny mica flakes make the pearly glow and 'metallic' finishes of automobile paints. Mica is used in many cosmetics to make them give a healthy-looking 'glow'; eye shadow, foundation, hair and body glitter, lipstick, lip gloss, mascara, moisturizing lotions, and nail polish all have mica in. Some brands of toothpaste include powdered white mica which acts as a mild abrasive to aid polishing of the tooth surface.

Mica is also used as a soil conditioner because it soaks up moisture and keeps soil wetter for longer.

Sheet mica is used as windows in furnaces, where glass would simply melt.

The leading use of mica is as an electrical insulator in electronic equipment. It will be inside your computer and mobile phone.

Video: Mica.

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