Iron oxides are chemical compounds composed of iron and oxygen. All together, there are
sixteen known iron oxides and oxyhydroxides. Iron oxides and oxide-hydroxides are widespread
in nature, play an important role in many geological and biological processes, and are
widely used by humans, e.g., as iron ores, pigments, catalysts, in thermite and hemoglobin.
Common rust is a form of iron(III) oxide. Iron oxides are widely used as inexpensive,
durable pigments in paints, coatings and colored concretes. Colors commonly available are in
the "earthy" end of the yellowredblack range.
Oxides iron(II) oxide, wüstite
iron(II,III) oxide, magnetite [iron(II,III) oxide],
iron(III) oxide alpha phase, hematite
beta phase, gamma phase, maghemite
epsilon phase,
Hydroxides iron(II) hydroxide2)
iron(III) hydroxide3), Oxide/hydroxides
goethite, akaganéite,
lepidocrocite, feroxyhyte,
ferrihydrite, or 5Fe2O3•9H2O, better recast as FeOOH•0.4H2O
high-pressure FeOOH schwertmannite6(SO)·nH2O or Fe3+16O16(OH,SO4)12-13·10-12H2O)
green rust3x+2y-z(A-)z; where A- is Cl- or 0.5SO42-)
Microbial degradation Several species of bacteria, including Shewanella
oneidensis, Geobacter sulfurreducens and Geobacter metallireducens metabolically utilize solid
iron oxides as a terminal electron acceptor, reducing Fe(III) oxides to Fe(II) containing
oxides. See also
Limonite Iron oxide nanoparticles
References ^ Cornell, RM; Schwertmann, U. The iron oxides:
structure, properties, reactions, occurrences and uses. Wiley VCH. ISBN 3-527-30274-3.
^ "Discovery of the recoverable high-pressure iron oxide Fe4O5". Oct 2011.
^ http:www.mindat.org/min-7281.html Mindat ^ Bretschger, O.; Obraztsova, A.; Sturm, C.
A.; Chang, I. S.; Gorby, Y. A.; Reed, S. B.; Culley, D. E.; Reardon, C. L.; Barua, S.;
Romine, M. F.; Zhou, J.; Beliaev, A. S.; Bouhenni, R.; Saffarini, D.; Mansfeld, F.; Kim, B.-H.;
Fredrickson, J. K.; Nealson, K. H.. "Current Production and Metal Oxide Reduction by Shewanella
oneidensis MR-1 Wild Type and Mutants". Applied and Environmental Microbiology 73: 7003–7012.
doi:10.1128/AEM.01087-07. External links
Information from Nano-Oxides, Inc. on Fe2O3. http:chemed.chem.purdue.edudemosheets/12.3.html
http:minerals.usgs.govpubsiron_oxide/ CDC - NIOSH Pocket Guide to Chemical Hazards