Biotite, often referred to as black mica, is another well-known type of mica. Unlike muscovite, biotite is rich in iron and magnesium, giving it a dark, opaque appearance. This mineral is primarily used in the construction industry, particularly in producing roofing materials and as a filler in asphalt. Biotite's unique properties give it good thermal stability and resistance to chemical weathering, making it an excellent choice for outdoor applications. Additionally, biotite serves as an essential source of potassium in soil, benefiting agricultural practices.