Mica
group of phyllosilicate minerals
The mica group of minerals are aluminosilicates with various metals. They split into fine sheets, which puts them in the phyllosilicate group of silicate minerals.
![](http://upload.wikimedia.org/wikipedia/commons/thumb/7/7e/Mica%2C_feldspar.jpg/187px-Mica%2C_feldspar.jpg)
Mica includes several closely related materials having perfect basal cleavage.
All are monoclinic which means their crystals are shaped like one kind of prism. They tend towards pseudo-hexagonal crystals and are similar in chemical composition. The highly perfect cleavage, which is the most prominent characteristic of mica, is explained by the hexagonal sheet-like arrangement of its atoms.
Being excellent electrical insulators, they are used in electronic equipment including capacitors.