Editing Gibbsite (section)

{{short description|Form of aluminium hydroxide, mineral}}
{{Infobox mineral
| name        = Gibbsite
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| image       = Gibbsite-fiu14a.jpg
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| caption     = Gibbsite
| category    = [[Hydroxide minerals]]
| formula     = Al(OH)<sub>3</sub> 
| IMAsymbol   = Gbb<ref>{{Cite journal|last=Warr|first=L.N.|date=2021|title=IMA–CNMNC approved mineral symbols|journal=Mineralogical Magazine|volume=85|issue=3|pages=291–320|doi=10.1180/mgm.2021.43|bibcode=2021MinM...85..291W|s2cid=235729616|doi-access=free}}</ref>
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| strunz      = 4.FE.10
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| system      = [[Monoclinic]]
| class       = Prismatic (2/m) <br/><small>(same [[H-M symbol]])</small>
| symmetry    = ''P2''<sub>1</sub>/n
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| mohs        = 2.5–3
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| gravity     = 2.35
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}}

[[Image:Gibbsite-crystal-3D-balls.png|thumb|right|[[Ball-and-stick model]] of the part of the [[crystal structure]] of gibbsite]]
<!-- [[File:Gibbsite-270400.jpg|thumb|upright|An unusual specimen of Gibbsite from [[Linwu County]], [[Hunan Province]], China. Size: 9.1 x 4.6 x 4.4 cm.]] -->
'''Gibbsite''', Al(OH)<sub>3</sub>, is one of the mineral forms of [[aluminium hydroxide]]. It is often designated as γ-Al(OH)<sub>3</sub><ref name=":0" />{{rp| 2}} (but sometimes as α-Al(OH)<sub>3</sub><ref>N.N. Greenwood and A. Earnshaw, "Chemistry of Elements", 2nd edition, Butterworth and Heinemann, 1997</ref>). It is also sometimes called '''hydrargillite''' (or '''hydrargyllite''').

Gibbsite is an important ore of [[aluminium]] in that it is one of three main [[phase (matter)|phases]] that make up the rock [[bauxite]].

Gibbsite has three named structural [[polymorphism (materials science)|polymorphs]] or [[polytype]]s: '''bayerite''' (designated often as α-Al(OH)<sub>3</sub>,<ref name=":0" />{{rp| 2}} but sometimes as β-Al(OH)<sub>3</sub>){{Citation needed|date=October 2020}}, ''[[doyleite]]'', and '''nordstrandite'''. Gibbsite can be [[monoclinic]] or [[Triclinic crystal system|triclinic]], while bayerite is monoclinic.<ref name=":0">{{Cite book|last1=Wefers|first1=Karl|url=http://worldcat.org/oclc/894928306|title=Oxides and hydroxides of aluminum|last2=Misra|first2=Chanakya|date=1987|publisher=Alcoa Research Laboratories|oclc=894928306}}</ref>{{rp| 13}} Doyleite and nordstrandite are triclinic forms.<ref name=":0" />{{rp|13}}