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Related to Martite: hematite


Hematite occurring in iron-black octahedral crystals pseudomorphous after magnetite.
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 It might be outdated or ideologically biased.



a mineral, the product yielded upon conversion of magnetite, Fe3O4 into hematite, Fe2O3. The crystals and crystalline grains of magnetite, upon conversion into martite, are usually replaced, without alteration of their original form, by finely aggregated hematite and exhibit the physical properties characteristic of the latter. Martite forms during the oxidation of magnetite in the weathering zone of the earth’s crust as well as deep within the earth under conditions characterized by increased oxidation potential of hydrothermal solutions surrounding the previously formed magnetite. Martite ores are high-grade iron ores.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.
References in periodicals archive ?
Twin peaks, Millard County, Utah, is one of the most frequently mentioned localities for hematite, variety martite, though the octahedral "crystals" found in Ouro Preto, Minas Gerais, are equally noteworthy.
Insignificant ore mineralization is present in these schists, consisting of magnetite, pyrite, chalcopyrite and some magnetite alteration products, i.e., martite, limonite and lepidocrocite.
There was a chance occurrence of an extraordinary number of octahedra of martite on the surface of the surrounding rock, a schistose-veined biotite gneiss.
Development work at the famous fluorapatite locality in Cerro de Mercado, Durango, has resulted in the recovery of a number of interesting specimens, including octahedral crystals of "martite" (hematite pseudomorphs after magnetite) to 10 cm on an edge, in groups to 30 cm.