Brookite is a mineral composed of titanium dioxide, often found in metamorphic rocks. It typically appears as brown or black crystals and is known for its unique tetragonal crystal structure. Brookite is one of the three main polymorphs of titanium dioxide, alongside Rutile and Anatase. This mineral is primarily used in various industrial applications, including the production of pigments and as a photocatalyst. Brookite can also be found in some gemstones, where it is valued for its rarity and distinctive appearance. Its occurrence is less common compared to its counterparts, making it an interesting subject for mineral collectors.