Brookite vs. Brockite

Brookite is the orthorhombic variant of titanium dioxide (TiO2), which occurs in four known natural polymorphic forms (minerals with the same composition but different structure). The other three of these forms are akaogiite (monoclinic), anatase (tetragonal) and rutile (tetragonal).

Brockite is a rare earth phosphate mineral with formula: (Ca,Th,Ce)PO4·H2O. It crystallizes in the hexagonal system in the chiral space group 180 or its enantiomorph 181. It is typically granular to massive with only rare occurrence of stubby crystals.

A mineral form of titanium dioxide, TiO2, having characteristic orthorhombic crystals and a red-brown to black color.

(mineral) A hexagonal-trapezohedral mineral containing calcium, cerium, hydrogen, oxygen, phosphorus, and thorium.

(mineral) A dark brown mineral form of titanium dioxide, with the chemical formula TiO₂.

A mineral consisting of titanic oxide, and hence identical with rutile and octahedrite in composition, but crystallizing in the orthorhombic system.