Brookite

Site hosted by Angelfire.com: Build your free website today!

Brookite

General Information

Brookite is a polymorph with two other minerals. Rutile, anatase and brookite all have the same chemistry, TiO₂, but they have different structures. At higher temperatures, about 1023.15 Kelvin, brookite will revert to the rutile structure. Rutile is the more common and the more well known mineral of the three. Brookite shares many properties with rutile (i.e., color and luster). However, due to structural differences, brookite and rutile differ in crystal habit and cleavage.

Chemistry: TiO₂, Titanium Oxide	Class: Oxides and Hydroxides	Subclass:	Color: Dark Brown to Greenish Black, Dark Blue	Streak: Light Brown	Luster: Submetallic
Transparency: Opaque	Crystal System: Orthorhombic	Hardness: 5.5-6	Cleavage: Poor prismatically and in the basal direction	Fracture: Subconchoidal and Uneven	Specific Gravity: 3.9-4.1
Crystal Habits: Tabular to platy crystals with a pseudohexagonal outline. Magnet Cove specimens tend to be more equant with complex facets	Uses: Minor ore of titanium and as mineral specimens	Associated Minerals: Anatase, Rutile, Quartz, Feldspars, Chalcopyrite, Hematite, Sphene	Other Characteristics: Sometimes intergrown with staurolite	Notable Occurrences: Magnet Cove, Arkansas; Butte, Montana; Somerville, Massachusetts; Ellenville, New York, USA; Eicham, Austria; Tremadoc, Wales, England; Ural Mountains, Russia; St. Gotthard, Switzerland	Best Field Indicators: Crystal habit, Luster, Density, Streak, Associations and Locality

Home | Jewelry | Fossils | Minerals
Back to Mineral Index