Brookite

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.

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.

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References in periodicals archive ?

Rutile is the most stable phase at high temperatures, whereas anatase and brookite are largely common to nanometric scale in natural or synthetic form.

Harnessing titanium dioxide surface toward novel functional materials

The optical absorption edge of brookite TiO2" Solid State Communications, 2006, 137, 154-157.

[Ce.sup.3+] doped Ti[O.sub.2] nanoparticles; synthesis and photocatalytic activity

The anatase and brookite phases were found with the strongest peaks at 2[theta] = 25.

Preparation and characterization of nanocrystalline and mesoporous strontium titanate thin films at room temperature

A remarkable number of other species have also been identified as inclusions in Zambian emeralds, including actinolite, tremolite, chlorite, dravite, apatite-(CaF), magnetite, hematite, quartz, fluorite, magnesite, siderite, dolomite, calcite, ankerite, niobium-rich rutile, pyrite, talc, zircon, barite, albite, lepidocrocite, glauconite, quartz, chrysoberyl, margarite, muscovite, biotite, brookite, tourmaline and chrysotile (Huong, 2008; Zwaan et al.

The Kagem emerald mine: Kafubu Area, Zambia

70) At temperatures below 600[degrees]C, nanophase brookite dominated.

Raman spectroscopy in coatings research and analysis: Part II. Practical applications

The Brookite range (available from model and toy shops) features easy-to-assemble lightweight and affordable kites, which vary in size.

Flight of fancy; Kite-flying is the latest pursuit of the fashionable - so get with it and go fly one, it's a breeze

62% of the Earth's crust and occurs primarily in the minerals anatase, brookite, ilmenite, leucoxene, peovskite, futile, and sphene.

Surge in demand from commercial aerospace

Titanium (iv) oxide exists in three different forms namely anatase, rutile and brookite.

The adsorption of water molecules on titanium (iv) oxide surface as studied by near infrared spectroscopy

Titanium dioxide has three common modifications, anatase, brookite, and rutile, the latter generally being the most stable one.

Nanoparticulate inorganic UV absorbers: a review

Titanium oxide is found in three structures of anatase, rutile and brookite.

On the investigation of the optimal housing pattern using nanotechnology approach

In 1856 he acquired a fine brookite from Tremadog, Wales and sold it to the British Museum.

Famous mineral dealers: Bryce McMurdo Wright, SR. (1814-1875) and Bryce McMurdo Wright, JR. (1850-1895)

2]) is a naturally occurring mineral found primarily as futile, anatase, brookite, and ilmenite (1).

Evidence that ultrafine titanium dioxide induces micronuclei and apoptosis in Syrian hamster embryo fibroblasts. (Articles)