{{Short description|Lead halide mineral}} {{infobox mineral | name = Laurionite | boxwidth = | boxbgcolor = | image = Laurionite-154998.jpg | imagesize = | alt = | caption = Laurionite crystals in a vug from the Laurium district of Greece | category = Halide minerals | formula = PbCl(OH) | IMAsymbol = Lri<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 = Orthorhombic | class = Dipyramidal (mmm) <br/>H-M symbol: (2/m 2/m 2/m) | symmetry = ''Pnma'' | unit cell = a = 7.111, b = 9.6987 <br/>c = 4.0203 [Å]; Z = 4 | color = Colorless, white | colour = | habit = Elongated tabular prismatic crystals | twinning = | cleavage = Distinct on {101} | fracture = | tenacity = Flexible | mohs = 3–3.5 | luster = Adamantine, pearly | streak = White | diaphaneity = Transparent | gravity = 6.241 | density = | polish = | opticalprop = Biaxial (−) | refractive = n<sub>α</sub> = 2.077 n<sub>β</sub> = 2.116 n<sub>γ</sub> = 2.158 | birefringence = δ = 0.081 | pleochroism = | 2V = Measured: 70° | dispersion = | extinction = | length fast/slow = | fluorescence = | absorption = | melt = | fusibility = | diagnostic = | solubility = Sleight in cold water | impurities = | alteration = | other = | references = <ref name=Mindat>[http://www.mindat.org/min-2343.html Mindat.org]</ref><ref name=HBM>[http://rruff.geo.arizona.edu/doclib/hom/laurionite.pdf Handbook of Mineralogy]</ref><ref name=Webmin>[http://www.webmineral.com/data/Laurionite.shtml Webmineral data for laurionite]</ref><ref name="atlas" >[https://www.mineralienatlas.de/lexikon/index.php/MineralData?mineral=Laurionite Mineralienatlas]</ref> }} '''Laurionite''' (PbCl(OH)) is a lead halide mineral. It forms colorless to white crystals in the orthorhombic crystal system and is dimorphous with paralaurionite, both members of the matlockite group.<ref name=Mindat/>
It was first described in 1887 for an occurrence in the Laurium District, Attica, Greece, and named after the town Laurium.<ref name=Mindat/> It occurs as an oxidation product in lead ore deposits, and is also produced on lead-bearing slag by reaction with saline solutions. It occurs associated with paralaurionite, penfieldite, fiedlerite, phosgenite, cerussite and anglesite.<ref name=HBM/>
==References== {{Reflist}}
Category:Halide minerals Category:Orthorhombic minerals Category:Minerals in space group 62 Category:Lead minerals
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