# Dawsonite

> Mediated Wiki article. Canonical URL: https://mediated.wiki/source/Dawsonite
> Markdown URL: https://mediated.wiki/source/Dawsonite.md
> Source: https://en.wikipedia.org/wiki/Dawsonite
> Source revision: 1305049896
> License: Creative Commons Attribution-ShareAlike 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/)

{{Infobox mineral
| name        = Dawsonite
| category    = [Carbonate mineral](/source/Carbonate_mineral)s
| image       = Dawsonite-165134.jpg 
| imagesize   = 260px
| caption     = Dawsonite from Mont Saint-Hilaire, Rouville RCM, Montérégie, Québec, Canada
| formula     = NaAlCO<sub>3</sub>(OH)<sub>2</sub>
| IMAsymbol   = Dws<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>  
| molweight   = 144.00 g/mol
| strunz      = 5.BB.10
| dana        = 16a.03.08.01
| system      = [Orthorhombic](/source/Orthorhombic_crystal_system)
| class       = Dipyramidal (mmm) <br/>[H-M symbol](/source/H-M_symbol): (2/m 2/m 2/m)
| symmetry    = ''Imam''
| color       = white
| habit       = encrustations or radial
| twinning    = 
| cleavage    = perfect on {110}
| fracture    = uneven
| mohs        = 3
| luster      = vitreous
| refractive  = ''n''<sub>α</sub> = 1.466<br/>''n''<sub>β</sub> = 1.542<br/>''n''<sub>γ</sub> = 1.596
| opticalprop =
| birefringence = ''δ'' = 0.130
| 2V          = 77°
| pleochroism =
| streak      = white
| gravity     = 2.436
| density     =
| melt        =
| fusibility  = 
| diagnostic  =
| solubility  =
| diaphaneity = transparent
| other       =
| references  = <ref name="MinDat">{{MinDat-ref | name = Dawsonite | id = 1240 | accessdate = 2009-12-06}}.</ref><ref name="Webmineral">{{WebMineral-ref | name = Dawsonite | url = https://webmineral.com/data/Dawsonite.shtml | accessdate = 2009-12-06}}.</ref>
}}
'''Dawsonite''' is a mineral composed of [sodium](/source/sodium) [aluminium](/source/aluminium) [carbonate](/source/carbonate) [hydroxide](/source/hydroxide), chemical formula NaAlCO<sub>3</sub>(OH)<sub>2</sub>. It crystallizes in the [orthorhombic](/source/orthorhombic) [crystal system](/source/crystal_system). It is not mined for ore.  It was discovered in 1874 during the construction of the [Redpath Museum](/source/Redpath_Museum) in a feldspathic [dike](/source/dike_(geology)) on the campus of [McGill University](/source/McGill_University) on the [Island of Montreal](/source/Island_of_Montreal), Canada.<ref name="MinDat"/>  It is named after [geologist](/source/geologist) Sir [John William Dawson](/source/John_William_Dawson) (1820–1899).<ref name="Webmineral"/>

The type material is preserved in the collection of the Redpath Museum.<ref name="MinDat"/>

==See also==
*[Dihydroxialumini sodium carbonate](/source/Dihydroxialumini_sodium_carbonate), the commercial (artificial) form, used as an antacid
*[List of minerals](/source/List_of_minerals)
*[List of minerals named after people](/source/List_of_minerals_named_after_people)

==References==
{{reflist}}

Category:Sodium minerals
Category:Aluminium minerals
Category:Carbonate minerals
Category:Orthorhombic minerals
Category:Minerals in space group 74
Category:Luminescent minerals

{{carbonate-mineral-stub}}

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Adapted from the Wikipedia article [Dawsonite](https://en.wikipedia.org/wiki/Dawsonite) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/Dawsonite?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.