Specimens Brookite is a polymorph with two other minerals. At higher temperatures, about 750 degrees Celsius, brookite will automatically revert to the rutile structure. Rutile is the more common and the more well known mineral of the three. Brookite shares many of the same properties as rutile such as color and luster and some properties are nearly the same such as hardness and density. However due to structural differences brookite and rutile differ in crystal habit and cleavage.
Color is dark brown to greenish black.
Luster is adamantine to submetallic. Transparency crystals are opaque. Crystal Habits include the typical tabular to platy crystals with a pseudohexagonal outline. Magnet Cove specimens tend to be more equant with complex facets. Cleavage is poor prismatically and in the basal direction.