Editing Strontianite (section)

{{Short description|Rare carbonate mineral and raw material for the extraction of strontium}}
{{Use dmy dates|date=April 2022}}
{{Infobox mineral
| name        = Strontianite
| boxwidth    = 
| boxbgcolor  = 
| image       = Mineraly.sk - stroncianit.jpg
| imagesize   = 260px
| alt         = 
| caption     = Strontianite from [[Slovakia]]
| category    = [[Carbonate minerals]]
| formula     = SrCO<sub>3</sub> 
| IMAsymbol   = Str<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   = 147.63 g/mol 
| strunz      = 5.AB.15 (10 ed) <br /><small>5/B.04-20 (8 ed)</small>
| dana        = 14.01.03.03
| system      = [[Orthorhombic]]
| class       = Dipyramidal (mmm) <br />[[H-M symbol]]: (2/m 2/m 2/m)
| symmetry    = ''Pmcn''
| unit cell   = a = 5.1&nbsp;[[angstrom|Å]], b = 8.4&nbsp;Å <br />c = 6.0&nbsp;Å; Z&nbsp;=&nbsp;4
| color       = Colourless, white, gray, light yellow, green or brown; colourless in transmitted light
| habit       = Prismatic, acicular, pseudo hexagonal, columnar to fibrous, granular, massive
| twinning    = Very common, usually contact, rarely penetration, also repeated
| cleavage    = {110} nearly perfect, {021} poor, {010} traces
| fracture    = Subconchoidal to uneven 
| tenacity    = Brittle 
| mohs        = {{frac|3|1|2}} 	
| lustre      = Vitreous, resinous on breaks, greasy 
| streak      = White			
| diaphaneity = Transparent to translucent
| gravity     = 3.74 to 3.78 Transparent versions are heavier than the other ones
| density     = 
| polish      = 
| opticalprop = Biaxial (−) 
| refractive  = n<sub>α</sub> = 1.52, n<sub>β</sub> = 1.66, n<sub>γ</sub> = 1.67 
| birefringence = 0.15 
| pleochroism = 
| 2V          = Measured: 7°, Calculated: 12° to 8° 
| dispersion  = 
| extinction  = 
| length fast/slow =
| fluorescence = Almost always fluorescent
| absorption  = 
| melt        = 
| fusibility  = 
| diagnostic  = 
| solubility  = Soluble in dilute HCl 
| impurities  = 
| alteration  = Celestine SrSO<sub>4</sub>
| other       = 
| prop1       = 
| prop1text   = 
| references  = <ref name=Dana>Gaines et al (1997) Dana’s New Mineralogy Eighth Edition.  Wiley</ref><ref name=Mindat>[http://www.mindat.org/min-3805.html Strontianite on Mindat.org retrieved 23/08/11]
</ref><ref name=Webmin>{{cite web|url=http://www.webmineral.com/data/Strontianite.shtml|title=Strontianite Mineral Data|first=Dave|last=Barthelmy|access-date=August 23, 2011}}</ref><ref name=HOM>{{cite web|url=http://rruff.info/doclib/hom/strontianite.pdf|title=Strontianite in the Handbook of Mineralogy |access-date=August 24, 2011}}</ref>
}}

'''Strontianite''' ([[Strontium|Sr]][[Carbon|C]][[Oxygen|O]]<sub>3</sub>) is an important raw material for the extraction of [[strontium]]. It is a rare [[carbonate mineral]] and one of only a few strontium minerals.  It is a member of the aragonite group.

Aragonite group members:<ref name=Dana/> [[aragonite]] (CaCO<sub>3</sub>), [[witherite]] (BaCO<sub>3</sub>), strontianite (SrCO<sub>3</sub>), [[cerussite]] (PbCO<sub>3</sub>)

The ideal formula of strontianite is SrCO<sub>3</sub>, with [[molar mass]] 147.63 g,<ref name=Webmin/> but [[calcium]] (Ca) can substitute for up to 27% of the strontium (Sr) [[Ion|cations]], and [[barium]] (Ba) up to 3.3%.<ref name=Dana/>

The mineral was named in 1791 for the locality, [[Strontian]], Argyllshire, Scotland, where the element [[strontium]] had been discovered the previous year.<ref name=Dana/>  Although good mineral specimens of strontianite are rare, strontium is a fairly common [[Chemical element|element]], with abundance in the [[Crust (geology)|Earth's crust]] of 370 parts per million by weight, 87 parts per million by [[Mole (unit)|moles]], much more common than [[copper]] with only 60 parts per million by weight, 19 by moles.<ref name=Chemicool>{{cite web|url=http://www.chemicool.com/elements/strontium.html|title=Strontium|access-date=August 24, 2011}}</ref> 
Strontium is never found free in nature. The principal strontium ores are [[Celestine (mineral)|celestine]] SrSO<sub>4</sub> and strontianite SrCO<sub>3</sub>.  The main commercial process for strontium metal production is [[Redox|reduction]] of [[strontium oxide]] with [[aluminium]].<ref name=Chemicool/>