Mica

Introduction Mica is known as Moscow glass. Muscovite (hydrated potassium silicate aluminum) is the most common type of mica. The ideal structure for talc and pyrophyllite is derived in environments containing ions containing aluminum, potassium, sodium, or calcium, so that instead of a quarter of tetrahedral silica, aluminum is added and potassium is added between the sheets. To maintain electrical neutrality. The bond between the muscovite sheets is weaker than the internal bonds, and this is evident from its one-sided appearance, but it is stronger than the pyrophyllite bond and makes the Muscovite not feel greasy. Muscovite is formed as the primary igneous mineral in granites and Percilis rocks and in many metamorphic rocks and is also one of the major components of sedimentary schist .

In the monoclinic system, it is crystallized as flat crystals, often false hexagonal, scattered in thick sheets in igneous rocks, and in the form of strips in schist and gneiss, and also in the form of clay in sedimentary rocks. The face has a full direction and separates into sheets with uneven edges, but it is elastic and strong. It is colorless, pale green-gray, brown, yellow, clove, or purple. Its effect line is white. It has a glass or pearl polish. It varies from opaque to semi-transparent. When it is in the form of thin sheets, it is transparent. It has a hardness of 2 to 3 mice and a specific gravity of 2.7 to 3.1.

In electrical work, it is used as an insulation sheet in electrical tools, aircraft spark plugs, in ironing, brake pads, and so on.