MICA

Micas are a group of silicate minerals that can easily be split into extremely thin elastic plates. Mica is chemically resistant, reflective, refractive, resilient and temperature stable mineral. 

Mica is a highly platy phyllosilicate of aluminum and potassium that occurs naturally in a book-like shape that can be quickly broken into very thin, often transparent sheets that are durable and flexible. Mica is found in igneous, metamorphic, and sedimentary rocks and is fairly common. Granitic pegmatites are the most common source of large mica crystals.
Mica is used in plastics, paints, ceramics, sound-damping, and cosmetics markets.