Ferrihydrite

Ferrihydrite Latest News

A recent study revealed that the red color of Mars could be due to the presence of an iron-containing mineral called ferrihydrite.

About Ferrihydrite 

• It is a poorly crystalline nanomineral buildup of about 20% (FeO4) and 80% (FeO6) polyhedra.
• Formation: It forms by rapid oxidation and hydrolysis, and exists in varying degrees of structure disorder.
• It is one of the initial corrosion products in the oxidation of iron, and is the precursor to the formation of the more stable mineral phases goethite (α-FeO(OH)) and hematite (α-Fe2O3 ). 

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Occurrence of Ferrihydrite

• It is widespread in the soluble fraction of soils and weathered rock.
• It precipitates around cold and hot springs, especially those supporting iron-metabolizing bacteria; in acid mine effluent.
• The iron bacteria, especially Gallionella ferruginea, Leptothrix ochracea and Toxothrix trichogenes create ferrihydrite as a waste product of their metabolism.
• It is known to trap water and protect organic molecules and forms rapidly in cool water.
• It forms a significant proportion of soils, especially soils formed under cool, moist conditions and it occurs as a pre-terrestrial weathering product in meteorites.

Ferrihydrite FAQs

Q1. What is the formula for ferrihydrite?

Ans. (Fe3+)2O3·0.5H2O

Q2. What is the formation of ferrihydrite?

Ans. Formation and transformation of ferrihydrite depend on Fe(III) hydrolysis rate, and silicate and Mn(II) concentration.

Q3. What type of rock is goethite?

Ans. Goethite is an iron oxyhydroxide containing ferric iron

Source: DH