ferrous iron compound

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June 26, 2026

Quick Summary

Ferrous compounds contain iron in the +2 oxidation state, while ferric compounds contain iron in the +3 oxidation state. Iron is a chemical element and a metal, making up about 5% of Earth's crust and being the most abundant element in the planet as a whole.123

Key iron compounds include:
* Ferrous oxide (FeO): A greenish to black powder used as a pigment.1
* Ferric oxide (Fe₂O₃): A reddish-brown to black powder, also known as hematite, used as a pigment and for polishing.145
* Ferrosoferric oxide (Fe₃O₄): A black, magnetic iron oxide, also known as magnetite, used as a pigment and polishing material, and in electronics.16

Iron compounds have various uses, including in medicine to treat anemia, as pigments, and in agriculture.14

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seawater
The transition stage
…was the role played by ferrous iron. The concentration of dissolved iron in the present-day oceans is low because of the insolubility of oxidized iron oxides. During the period 3.5 to 1.5 billion years ago, oxygen-deficient environments were prevalent; these favoured the formation of minerals containing ferrous iron (reduced state…
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…was the role played by ferrous iron. The concentration of dissolved iron in the present-day oceans is low because of the insolubility of oxidized iron oxides. During the period 3.5 to 1.5 billion years ago, oxygen-deficient environments were prevalent; these favoured the formation of minerals containing ferrous iron (reduced state…
Read More