Editing Limonite (section)

{{Short description|Hydrated iron oxide mineral}}
{{Infobox mineral
| name        = Limonite
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| image       = LimoniteUSGOV.jpg
| imagesize   = 260px
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| category    = Amorphous, mineraloid
| formula     = {{chem2|FeO(OH)*''n''H2O}}
| strunz      = Unclassified
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| color       = Various shades of brown and yellow
| colour      = 
| habit       = Fine grained aggregate, powdery coating
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| twinning    = 
| cleavage    = Absent
| fracture    = Uneven
| tenacity    = 
| mohs        = 4–5.5
| luster      = Earthy
| streak      = Yellowish brown
| diaphaneity = Opaque
| gravity     = 2.9–4.3
| density     = 2.7–4.3&nbsp;g/cm<sup>3</sup>
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| references  = <ref>{{Mindat |title=Limonite |id=2402 |access-date=2011-10-16}}</ref><ref>{{cite web |title=Mineral 1.0: Limonite |url=http://www.spaceman.ca/mineral/index.php?ViewMineral=47 |access-date=2011-10-16}}</ref><ref>{{cite web |title=Limonite (hydrated iron oxide) |url=http://www.galleries.com/minerals/oxides/limonite/limonite.htm |access-date=2011-10-16}}</ref>
}}

'''Limonite''' ({{IPAc-en||ˈ|l|aɪ|m|ə|ˌ|n|aɪ|t|}}) is an [[iron ore]] consisting of a mixture of [[hydrate]]d [[iron(III) oxide-hydroxide]]s in varying composition. The generic formula is frequently written as {{chem2|FeO(OH)*''n''H2O}}, although this is not entirely accurate as the ratio of [[oxide]] to [[hydroxide]] can vary quite widely. Limonite is one of the three principal [[iron ore]]s, the others being [[hematite]] and [[magnetite]], and has been [[mining|mined]] for the production of [[iron]] since at least 400 BC.<ref>MacEachern, Scott (1996) [http://www.panafprehistory.org/images/papers/IRON_AGE_BEGINNINGS_NORTH_OF_THE_MANDARA_MOUNTAINS_CAMEROON_AND_NIGERIA_Scott_MacEachern.pdf "Iron Age beginnings north of the Mandara Mountains, Cameroon and Nigeria"]  pp. 489&ndash;496 ''In'' Pwiti, Gilbert and Soper, Robert (editors) (1996) ''Aspects of African Archaeology: Proceedings of the Tenth Pan-African Congress'' University of Zimbabwe Press, Harare, Zimbabwe, {{ISBN|978-0-908307-55-5}}; archived [https://web.archive.org/web/20120311184136/http://www.panafprehistory.org/images/papers/IRON_AGE_BEGINNINGS_NORTH_OF_THE_MANDARA_MOUNTAINS_CAMEROON_AND_NIGERIA_Scott_MacEachern.pdf here] by [[Internet Archive]] on 11 March 2012</ref><ref>Diop-Maes, Louise Marie (1996) [http://www.ankhonline.com/revue/diop_lm_metallurgie_fer_afrique.htm "La question de l'Âge du fer en Afrique" ("The question of the Iron Age in Africa")] ''Ankh'' 4/5: pp. 278&ndash;303, in French; archived [https://web.archive.org/web/20080125103929/http://www.ankhonline.com/revue/diop_lm_metallurgie_fer_afrique.htm here] by [[Internet Archive]] on 25 January 2008</ref>