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Maghemite (Fe2O3, γ-Fe2O3) is a member of the family of iron oxides. It has the same spinel ferrite structure as magnetite and is also ferrimagnetic. ''Maghemite'' can be considered as an Fe(II)-deficient magnetite with formula 〔Cornell, R. M. and Schwertmann, Udo (2003) ''The Iron Oxides: Structure, Properties, Reactions, Occurrences and Uses''. Wiley-VCH. p. 32. ISBN 3527302743.〕 where represents a vacancy, A indicates tetrahedral and B octahedral positioning. ==Occurrence== Maghemite forms by weathering or low-temperature oxidation of spinels containing iron(II) such as magnetite or titanian magnetite. Maghemite can also form through dehydration and transformation of certain iron oxyhydroxide minerals, such as lepidocrocite and ferrihydrite. It occurs as widespread brown or yellow pigment in terrestrial sediments and soils. It is associated with magnetite, ilmenite, anatase, pyrite, marcasite, lepidocrocite and goethite.〔 Maghemite was named in 1927 for an occurrence at the Iron Mountain mine, northwest of Redding, Shasta County, California.〔 The name alludes to somewhat intermediate character between MAGnetite and HEMatite. It can appear blue with a grey shade, white, or brown.〔Gaines, Richard V.; Skinner, H. Catherine W.; Foord, Eugene E.; Mason, Brian and Rosenzweig, Abraham (1997) ''Dana's new mineralogy'', John Wiley & Sons. pp. 229-230. ISBN 0471193100.〕 It has isometric crystals.〔 Maghemite is formed by the topotactic oxidation of magnetite. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「maghemite」の詳細全文を読む スポンサード リンク
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