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-{{otheruses}}
-{{Infobox mineral
-| name        = Hematite
-| category    = Oxide mineral
-| boxwidth    =
-| boxbgcolor  =
-| image       = Hematite.jpg
-| imagesize   =
-| caption     = Hematite (blood ore) from the US state of [[Michigan]] (''unknown scale'')
-| formula     = [[iron(III) oxide]], Fe<sub>2</sub>O<sub>3</sub>, α-Fe<sub>2</sub>O<sub>3</sub>
-| molweight   =
-| color       = Metallic Grey to earthy red tones
-| habit       = Tabular to thick crystals
-| system      = [[Hexagonal]] (rhombohedral)
-| twinning    =
-| cleavage    = None
-| fracture    = Uneven to sub-conchoidal
-| mohs        = 5.5 - 6.5
-| luster      = Metallic to splendent
-| refractive  = Opaque
-| opticalprop =
-| birefringence =
-| pleochroism = None
-| streak      = Bright red to dark red
-| gravity     = 4.9 - 5.3
-| density     =
-| melt        =
-| fusibility  =
-| diagnostic  =
-| solubility  =
-| diaphaneity =
-| other       =
-| references  = <ref>http://webmineral.com/data/Hematite.shtml Webmineral data</ref><ref>http://www.mindat.org/min-1856.html Mindat mineral data</ref>
-}}
-[[Image:Hematite in Scanning Electron Microscope, magnification 100x.GIF|thumb|Hematite in SEM, magnification 100x]]
-[[Image:MichiganBIF.jpg|thumb|Close-up of hematitic [[Banded Iron Formation]] specimen from Upper Michigan. Scale bar is 5.0 mm.]]
-'''Hematite''', [[Spelling differences#Simplification of ae .28.C3.A6.29 and oe .28.C5.93.29|also spelled as]] '''hæmatite''', is the [[mineral]] form of [[Iron(III) oxide]] (Fe<sub>2</sub>O<sub>3</sub>), one of several [[iron oxide]]s. Hematite crystallizes in the [[rhombohedral]] system, and it has the same [[crystal]] structure as [[ilmenite]] and as [[corundum]]. Hematite and ilmenite form a complete [[solid solution]] at temperatures above 950°C.
-Hematite is a mineral, colored black to steel or silver-gray, brown to reddish brown, or red. It is [[mining|mined]] as the [[Iron_ore#Hematite_ore|main ore of iron]]. Varieties include ''kidney ore'', ''martite'' ([[pseudomorph]]s after [[magnetite]]), ''iron rose'' and ''specularite'' (specular hematite). While the forms of hematite vary, they all have a rust-red streak. Hematite is harder than pure iron, but much more brittle. [[Maghemite]] is a hematite- and [[magnetite]]-related oxide mineral.
-Huge deposits of hematite are found in [[banded iron formation]]s. Grey hematite is typically found in places where there has been standing water or mineral [[hot spring]]s, such as those in [[Yellowstone National Park]] in the [[United States]]. The mineral can [[Precipitation (chemistry)|precipitate]] out of water and collect in layers at the bottom of a lake, spring, or other standing water. Hematite can also occur without water, however, usually as the result of [[Volcano|volcanic]] activity.
-[[Clay]]-sized hematite crystals can also occur as a secondary mineral formed by [[weathering]] processes in [[soil]], and along with other iron oxides or oxyhydroxides such as [[goethite]], is responsible for the red color of many [[tropical]], ancient, or otherwise highly weathered soils.
-Good specimens of hematite come from [[England]], [[Mexico]], [[Brazil]], [[Australia]], [[United States]] and [[Canada]].
-==Etimology and history==
-{{main|Ochre}}
-The name hematite is derived from the [[Greek language|Greek]] word for blood (haima) because hematite can be red, as in [[iron(III) oxide|rouge]], a powdered form of hematite. The color of hematite lends it well in use as a [[pigment]].
-Ochre is a clay that is colored by varying amounts of hematite, varying between 20% and 70% <ref name="MZ">{{cite web | title = Ochre | work = Industrial Minerals | publisher = Minerals  Zone  | url = http://www.mineralszone.com/minerals/ochre.html  | accessdate = 2008-04-29 }}</ref>. [[Red ochre]] contains unhydrated hematite, whereas [[yellow ochre]] contains [[hydrate]]d hematite ([[Iron|Fe]]<sub>2</sub>[[Oxygen|O]]<sub>3</sub> • [[Hydrogen|H]]<sub>2</sub>[[Oxygen|O]]). The principal use of ochre is for tinting with a permanent color<ref name="MZ" />.
-The [[red chalk]] [[winning]] of this mineral was one of the earliest in history of mankind. The powdery mineral was first used 164.000 years ago by the [[Pinnacle-Point man]] obviously for social differentiation<ref>[http://www.eurekalert.org/pub_releases/2007-10/asu-rfe101207.php Researchers find earliest evidence for modern human behavior in South Africa]</ref>. Hematite residues are also found in old graveyards from 80.000 years ago. Near Rydno in [[Poland]] and Lovas in [[Hungary]], palaeolitic red chalk mines have been found that are from 5000 BC, belonging to the [[Linear Pottery culture]] at the [[Upper Rhine]].
-Rich deposits of hematite have been found on the island of [[Elba]] that have been mined till the time of the [[Etruscans]].
-=== Ancient Egyptian booby trap ===
-In 2001, Egyptian government [[archaeologist]] [[Zahi Hawass]] was the first to enter a previously undisturbed tomb, believed to be that of an ancient regional mayor, in the [[Bahariya Oasis]] below the town of [[Bawiti]]. Upon entering the burial chamber, Hawass discovered a [[booby trap]] consisting of 8 inches of finely powdered hematite dust covering the floor and sarcophagus.<ref>"Bahariya - Valley of the Golden Mummies". Hawas, Zahi (quoted). <http://www.lost-civilizations.net/ancient-egypt-bahariya-valley-golden-mummies.html>. Retrieved 12 JAN 2009.</ref> When disturbed by a [[tomb robber]], the sharp, metallic dust was intended to become airborne and irritate the skin, eyes and mucous membranes, eventually causing lethal [[siderosis]] if exposed for long enough. The archaeological team was forced to retreat and don full body suits and respirators in order to confirm the identity of the [[mummy]]. Hawass cites the ancient Egyptians' experience with powdered hematite as a paint pigment as proof that they were aware of its irritating properties.<ref>Hawass, Zahi. "The Real Tomb Hunters: Snakes, Curses, and Booby Traps" (2003). [[The History Channel]]. <http://www.history.com/shows.do?action=detail&showId=274135></ref>
-=== Jewelry ===
-[[Image:hematite.bear.660pix.jpg|thumb|Hematite carving, 5&nbsp;cm (2&nbsp;in) long.]]Hematite's popularity in jewelry was at its highest in Europe during the [[Victorian era]], and has since seen a strong resurgence in [[North America]], especially in the western [[United States]]. Due to it delicate nature, the mineral is found only in precious jewelry. Extreme care should be taken in handling hematite items due to the material's susceptibility to irreversible damage.
-It is also used in art such as [[Intaglio (jewellery)|intaglios]] where it is used for making hollow portraits.
-==Magnetism==
-Hematite is an [[antiferromagnetic]] material below the [[Morin transition]] at 260 K, and a canted antiferromagnet or weakly [[ferromagnetic]] [http://www.earthsci.unimelb.edu.au/ES304/MODULES/MAG/NOTES/typesmag.html] above the Morin transition and below its [[Néel temperature]] at 948K, above which it is [[paramagnetic]].
-The magnetic structure of a-hematite was the subject of considerable discussion and debate in the 1950s because it appeared to be ferromagnetic with a Curie temperature of around 1000 K, but with an extremely tiny moment (0.002mB). Adding to the surprise was a transition with a decrease in temperature at around 260 K to a phase with no net magnetic moment.{{Fact|date=September 2007}}
-Dzialoshinksi and later Moriya showed that the system is essentially antiferromagnetic but that the low symmetry of the cation sites allows spin–orbit coupling to cause canting of the moments when they are in the plane perpendicular to the c axis. The disappearance of the moment with a decrease in temperature at 260 K is caused by a change in the anisotropy which causes the moments to align along the c axis. In this configuration, spin canting does not reduce the energy.{{Fact|date=September 2007}}
-Hematite is part of a complex solid solution oxyhydroxide system having various degrees of water, hydroxyl group, and vacancy substitutions that affect the mineral's magnetic and crystal chemical properties.<ref> M.-Z. Dang, D.G. Rancourt, J.E. Dutrizac, G. Lamarche, and R. Provencher.  Interplay of  Surface Conditions, Particle Size, Stoichiometry, Cell Parameters, and Magnetism in Synthetic Hematite-like Materials.   ''Hyperfine Interactions'' 117 (1998) 271-319.</ref> Two other end-members are referred to as protohematite and hydrohematite.
-== Hematite on Mars ==
-[[Image:07-ml-3-soil-mosaic-B019R1 br.jpg|thumb|Image mosaic from the Mars Exploration Rover Microscopic Imager shows Hematite [[Martian spherules|spherules]] partly embedded in rock at the Opportunity landing site. (Scale: image is approximately 5&nbsp;cm (2&nbsp;in) across)]]
-The spectral signature of hematite was seen on the planet [[Mars]] by the infrared [[spectrometer]] on the [[NASA]] [[Mars Global Surveyor]] ("MGS") and [[2001 Mars Odyssey]] spacecraft in orbit around Mars.<ref>NASA MGS TES Press Release, May 27 1998 "Mars Global Surveyor TES Instrument Identification of Hematite on Mars",  [http://tes.asu.edu/webdata/hematitepr.html available here]</ref> The mineral was seen in abundance at two sites <ref>Bandfield, J.L., Global mineral distributions on Mars, J. ''Geophys Res., 107,'' 2002.  See: [http://jmars.asu.edu/data/tes_hematite Mars Global Data Sets: Hematite Abundance]</ref>  on the planet, the [[Terra Meridiani]] site, near the Martian equator at 0° longitude, and the second site [[Aram Chaos]] near the [[Valles Marineris]].<ref>Glotch, T. D., and P. R. Christensen (2005), "Geologic and mineralogic mapping of Aram Chaos: Evidence for a water-rich history," ''J. Geophys. Res., 110,'' E09006, doi:10.1029/2004JE002389 [http://www.agu.org/pubs/crossref/2005/2004JE002389.shtml abstract here]</ref> Several other sites also showed hematite, e.g., Aureum Chaos.<ref>T. D. Glotch, D. Rogers, and P. R. Christensen, [http://www.gps.caltech.edu/~tglotch/lpsc_aureum.pdf A Newly Discovered Hematite-Rich Unit in Aureum Chaos: Comparison of Hematite and Associated Units With Those in Aram Chaos], Lunar and Planetary Science Conference XXXVI, 2005</ref>  Because terrestrial hematite is typically a mineral formed in aqueous environments, or by aqueous alteration, this detection was scientifically interesting enough that the second of the two [[Mars Exploration Rover]]s was targeted to a site in the Terra Meridiani region designated [[Meridiani Planum]].  In-situ investigations by the [[Opportunity rover]] showed a significant amount of hematite, much of it in the form of small [[Martian spherules| spherules]] that were informally tagged by the science team "blueberries" (a term which is somewhat confusing, since in spectrally-correct color images they are, in fact, silver-grey in color).  Analysis indicates that these spherules are apparently [[concretion]]s formed from a water solution.
-==See also==
-* [[Iron ore]]
-* [[List of minerals]]
-* [[Wüstite]]
-* [[Magnetite]]
-* [[Mineral redox buffer]]
-* [[Scientific information from the Mars Exploration Rover mission]]
-==References==
-{{reflist}}
-*[http://www.mindat.org/min-2583.html Martite - Mindat w/ location data]
-*[http://www.mindat.org/min-26770.html Iron rose - Mindat w/ locations]
-==External links==
-* [http://www.ironminers.com Abandoned Mine Research].
-* [http://marsrovers.jpl.nasa.gov/gallery/press/opportunity/20040212a/07-ml-3-soil-mosaic-B019R1_br.jpg Mars spheres image].
-* [http://marsrovers.jpl.nasa.gov/gallery/press/opportunity/20040219a/08-AY-3-shiny-B026R1_br.jpg Mars trench image showing a shiny texture of half-buried spheres] (dark line is equipment shadow)
-* [http://www.visitcumbria.com/wc/florence.htm Florence Mine, Cumbria, UK].
-* [http://www.mindat.org/min-1856.html MineralData.org]
-[[Category:Oxide minerals]]
-[[Category:Iron minerals]]
-[[Category:Iron oxide pigments]]
-[[Category:Hematite group]]
-[[ca:Hematites]]
-[[cs:Hematit]]
-[[de:Hämatit]]
-[[et:Hematiit]]
-[[el:Αιματίτης]]
-[[es:Hematita]]
-[[eo:Hematito]]
-[[eu:Hematite]]
-[[fr:Hématite]]
-[[gl:Hematita]]
-[[hr:Hematit]]
-[[it:Ematite]]
-[[he:המטיט]]
-[[lt:Hematitas]]
-[[hu:Hematit]]
-[[nl:Hematiet]]
-[[ja:赤鉄鉱]]
-[[no:Hematitt]]
-[[pl:Hematyt]]
-[[pt:Hematita]]
-[[ro:Hematit]]
-[[ru:Гематит]]
-[[simple:Hematite]]
-[[sk:Hematit]]
-[[fi:Hematiitti]]
-[[sv:Hematit]]
-[[tr:Hematit]]
-[[uk:Гематит]]
-[[zh:赤铁矿]]