What is Mica?

Mica is a naturally occurring material that belongs to a group of silicate minerals composed of varying amounts of aluminum, potassium, magnesium, iron, and water. It has a thin, sheet-like or plate-like structure with diverse compositions and physical characteristics.

All types form flat, six-sided monoclinic crystals with remarkable cleavage along large surfaces, allowing them to be easily split into optically flat films. When divided into thin layers, they remain tough and elastic, even at high temperatures.

It possesses an exceptional combination of chemical, physical, electrical, thermal, and mechanical properties that are unmatched by any other insulating material.

As a biaxial birefringent crystal, its average refractive index in the visible spectrum is around 1.6. Due to this birefringence, it can introduce a phase delay between two orthogonal components of linear polarization, making it suitable for use as a retardation device.