Iron ochre

Iron ochre or iron ocher (ὠχρός, pale yellow, orange) — at least three iron ore minerals, 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 — Fe2O3,  a widespread iron mineral, one of the most important iron ores;
 * Iron ochre or limonite — Fe2O3·Н2О,  a mixture of secondary natural minerals, iron oxide hydrates;
 * Iron ochre or goethite — 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), a secondary mineral, a product of the oxidation of iron ore minerals, found in brown iron ores;
 * Iron ochre or ferric oxide — Fe2O3 (oxides of iron), which also occurs naturally as the mineral magnetite;
 * Iron ochre or ferrihydrite — Fe2O3·0.5H2O, is a widespread hydrous ferric oxyhydroxide mineral at the Earth's surface;