Brookite
Also found in: Dictionary, Wikipedia.
brookite
[′bru̇‚kīt] (mineralogy)
TiO2 A brown, reddish, or black orthorhombic mineral; it is trimorphous with rutile and anatase, has hardness of 5.5-6 on Mohs scale, and a specific gravity of 3.87-4.08. Also known as pyromelane.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.
Brookite
a mineral of composition TiO2. Sometimes contains admixtures of iron and niobium. Layered structure, consisting of octahedral groups of TiO6, united by common ribs. Crystallizes in a rhombic system. The crystals are usually tabular, less frequently prismatic and dipyramidal. Their color is yellowish brown to reddish brown; their luster is adamantine or metallic. The hardness of brookite on the mineralogical scale is 5.5-6; density, 3,900-4,200 kg/m3. The crystals are found in gold placers and in alpine-type veins in the Urals (USSR); abroad the mineral is found in Switzerland, France, Austria, and the USA.
The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.