1. A mineral form of titanium dioxide (TiO₂) that occurs as orthorhombic crystals, typically brown or black in color.
Usage: technical; mineralogy

Examples

• Brookite is one of three naturally occurring polymorphs of titanium dioxide.
• The geologist identified brookite crystals in the rock sample under the microscope.
• Brookite deposits are found in metamorphic and igneous rocks worldwide.
• Unlike rutile and anatase, brookite is relatively rare in nature.
• The mineral brookite was named after Henry James Brooke, a British mineralogist.