Maghemite


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maghemite

[mag′he‚mīt]
(mineralogy)
γ-Fe2O3 A mineral form of iron oxide that is strongly magnetic and a member of the magnetite series.
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 It might be outdated or ideologically biased.

Maghemite

 

a mineral, a magnetic modification of the ferric oxide γ — Fe2O3. Generally containing admixtures of FeO and TiO2, maghemite is unstable in the natural state and is readily converted into stable hematite. It crystallizes in the tetragonal (pseudoisometric) system characterized by a defective spinel structure of the magnetite type. Maghemite has a hardness of 5-6 on Mohs’ scale and a density of 4,700-4,900 kg/m3. It is opaque and has a dark brown color with a steel-like hue. Maghemite occurs in nature only in the form of microscopically fine depositions in magnetite oxidation products and in titanomagnetite (with hematite, iron hydroxides). It is sometimes found in limonite and laterite as the product formed during the surface weathering of minerals containing iron.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.
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