{{Short description|Colorless mineral}} {{infobox mineral | name = Paralaurionite | boxwidth = | boxbgcolor = | image = Paralaurionite.jpg | imagesize = | alt = | caption = Platey clear paralaurionite crystals from slag in the Thorikos area, Lavrion, Attica, Greece | category = Halide mineral | formula = PbCl(OH) | IMAsymbol = Plri<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 = | strunz = 3.DC.05 | dana = | system = Monoclinic | class = Prismatic (2/m) <br/><small>(same H-M symbol)</small> | symmetry = ''C2/m'' | unit cell = a = 10.865(4)&nbsp;Å, <br/>b = 4.006(2)&nbsp;Å, <br/>c = 7.233(3)&nbsp;Å; <br/>β = 117.24(4)°; Z&nbsp;=&nbsp;4 | color = Colorless, white, pale greenish, yellowish, yellow-orange, rarely violet | colour = | habit = Elongated tabular crystals | twinning = Contact twinning on {100} | cleavage = Perfect on {001} | fracture = | tenacity = Flexible, non-elastic | mohs = 3 | luster = Subadamantine | streak = | diaphaneity = Transparent to translucent | gravity = 6.05–6.15 | density = | polish = | opticalprop = Biaxial (−) | refractive = n<sub>α</sub> = 2.050 n<sub>β</sub> = 2.150 n<sub>γ</sub> = 2.200 | birefringence = δ = 0.150 | pleochroism = Visible | 2V = | dispersion = | extinction = | length fast/slow = | fluorescence = | absorption = | melt = | fusibility = | diagnostic = | solubility = | impurities = | alteration = | other = | prop1 = | prop1text = | references = <ref>[https://www.mineralienatlas.de/lexikon/index.php/MineralData?mineral=Paralaurionite Mineralienatlas]</ref><ref name=HBM>[http://rruff.geo.arizona.edu/doclib/hom/paralaurionite.pdf Handbook of Mineralogy]</ref><ref name=Mindat>[http://www.mindat.org/min-3096.html Paralaurionite on Mindat.org]</ref><ref name=Webmin>[http://www.webmineral.com/data/Paralaurionite.shtml Paralaurionite on Webmineral]</ref> }} '''Paralaurionite''' is a colorless mineral consisting of a basic lead chloride PbCl(OH) that is dimorphous with laurionite. It is a member of the matlockite group.<ref name="Britain)Press2006">{{cite book|title=Mineralogical magazine|url=https://books.google.com/books?id=KGfzAAAAMAAJ|accessdate=26 January 2012|date=1 January 2006|publisher=Mineralogical Society, HighWire Press|pages=643–8}}</ref> The name is derived from para-, the Greek for "near", and laurionite, because of its polymorphic relationship to it.<ref name=Mindat/> Bright, yellow tips of thorikosite can form on paralaurionite crystals and paralaurionite may also be intergrown with mendipite.<ref name="The Mineralogical record">{{cite book|title=The Mineralogical record|url=https://books.google.com/books?id=nT0eAQAAMAAJ|accessdate=26 January 2012|year=1986|pages=185–88}}</ref><ref name="Williams1990">{{cite book|last=Williams|first=Peter A.|title=Oxide zone geochemistry|url=https://books.google.com/books?id=T1cSAQAAIAAJ|accessdate=26 January 2012|date=August 1990|publisher=E. Horwood|isbn=978-0-13-647553-8|pages=262–4}}</ref>

==Occurrence== It was first described in 1899 for an occurrence in slag in Laurium, Attica, Greece.<ref name=HBM/> In 1952 an occurrences of it was reported from the Mammoth Mine, Arizona.<ref name="Britain)1952">{{cite book|author=Mineralogical Society (Great Britain)|title=The Mineralogical magazine and journal of the Mineralogical Society|url=https://books.google.com/books?id=oSuMAAAAIAAJ|accessdate=26 January 2012|year=1952|publisher=Mineralogical Society.|pages=341–2}}</ref>

It occurs in lead bearing slag which has been exposed to seawater. It also occurs in polymetallic ore deposits. It occurs associated with laurionite, penfieldite, fiedlerite, phosgenite in slag deposits; and with leadhillite, matlockite, cerussite, hydrocerussite, diaboleite and wherryite in the Mammoth mine location.<ref name=HBM/> [[File:Paralaurionite-177497.jpg|thumb|none|Unusually large crystals of Paralaurionite, Touissit, Oujda-Angad Province, Morocco. Size: 6 x 5.5 x 5 cm.]]

==References== {{Reflist}} ==External links== *{{Commons category-inline}} Category:Halide minerals Category:Monoclinic minerals Category:Lead minerals Category:Minerals in space group 12

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