What type of material is primarily used in vermiculite insulation?

Vermiculite insulation is primarily made from a type of rock known as mica. This mineral is expanded when heated, resulting in lightweight, fire-resistant, and insulating properties. The structure of vermiculite allows it to effectively trap air, making it an excellent thermal insulator used in various building applications. The choice of vermiculite reflects its benefits in soundproofing and fire resistance, which are crucial in both residential and commercial construction. This characteristic also sets it apart from the other materials mentioned, which do not provide the same level of performance when used as insulation.