Iron ochre explained

Iron ochre or iron ocher (Greek, Ancient (to 1453);: [[wikt:en:ὠχρός#Ancient Greek|ὠχρός]], pale yellow, orange) — at least three iron ore minerals,^[1] common abrasives and pigments with a red-brown or brown-orange hue and the powdery consistency of ocher, were known under such a trivial name. The term “iron ocher” was primarily used among mineral collectors, geologists, miners and representatives of related craft professions. It may refer to:

• Iron ochre or hematite^[2] — Fe₂O₃, a widespread iron mineral, one of the most important iron ores;
• Iron ochre or limonite^[2] — Fe₂O₃·Н₂О, a mixture of secondary natural minerals, iron oxide hydrates;
• Iron ochre or goethite^[3] — α-FeO(OH), a product of weathering of ores, a secondary iron mineral, the main component of limonite, is part of brown iron ores;
• Iron ochre, brown iron ocher or lepidocrocite — γ-FeO(OH),^[4] a secondary mineral, a product of the oxidation of iron ore minerals, found in brown iron ores;
• Iron ochre or ferric oxide^[5] — Fe₂O₃ (oxides of iron), which also occurs naturally as the mineral magnetite;
• Iron ochre or ferrihydrite^[6] — Fe₂O₃·0.5H₂O, is a widespread hydrous ferric oxyhydroxide mineral at the Earth's surface;

See also

• Ochre
• Ochre (disambiguation)
• Iron (disambiguation)
• Iron(III) oxide
• List of inorganic pigments
• Red pigments
• List of colors
• Yellow

Notes and References

1. Krivovichev V. G. Mineralogical glossary. Scientific editor A. G. Bulakh. — St.Petersburg: St.Petersburg Univ. Publ. House. 2009. — 556 p. — ISBN 978-5-288-04863-0
2. Thomas Egleston, Ph. D. Catalogue of Minerals and Synonyms. — Washington: Government Printing Office, 1887.
3. Kimmo Virtanen. Geological control of iron and phosphorus precipitates in mires of the Ruukki-Vihanti Area, Central Finland. — Geological Survey of Finland, 1994; — 69 p.
4. R. A. Lidin, L. L. Andreeva, V. A. Molochko, edited by R. A. Lidin. Constants of inorganic substances: reference book. 3-rd ed., stereotypical. — Moscow: Drofa, 2008 г. — 685 p.
5. Sigvald Linné. Archaeological Researches at Teotihuacan, Mexico. Sigvald Linne, with a foreword by Staffan Brunius and introduction by George L. — The University of Alabama Press, 2003. — 236p.
6. A.M.O. Mohamed. Principles and Applications of Time Domain Electrometry in Geoenvironmental Engineering. — Taylor & Francis, 2006. — 603 p.