{{Short description|Rare mineral}} {{Infobox mineral | name = Phosgenite | boxwidth = | boxbgcolor =#C4B353 | image = Phosgenite-34631.jpg | imagesize = | alt = | caption = Crystal of phosgenite from the Monteponi Mine, Iglesias, Sardinia, Italy (size: 3.0 x 3.0 x 2.5 cm) | category = Carbonate minerals | formula = (PbCl)<sub>2</sub>CO<sub>3</sub> | IMAsymbol = Pho<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 = 5.BE.20 | dana = | system = Tetragonal | class = Ditetragonal dipyramidal (4/mmm)<br>H-M symbol: (4/m 2/m 2/m) | symmetry = ''P4/mbm'' | unit cell = a = 8.16&nbsp;Å, c = 8.883(6)&nbsp;Å; Z&nbsp;=&nbsp;4 | color = Pale yellow to yellowish brown, pale brown, smoky brown, smoky violet, colorless, pale rose, gray, yellowish gray, pale green | colour = | habit = Short prismatic crystals, granular, massive | twinning = | cleavage = Distinct on {001} and {110}, indistinct on {100} | fracture = Conchoidal | tenacity = Sectile, flexible perpendicular to {001} | mohs = 2–3 | luster = Adamantine | streak = White | diaphaneity = Transparent to translucent | gravity = 6.12 – 6.15 | density = | polish = | opticalprop = Uniaxial (+); anomalously biaxial if strained | refractive = n<sub>ω</sub> = 2.118 n<sub>ε</sub> = 2.145 | birefringence = δ = 0.027 | pleochroism = Weakly pleochroic with O – reddish and E – greenish in thick sections. | 2V = | dispersion = | extinction = | length fast/slow = | fluorescence = Fluoresces yellow under LW and SW UV | absorption = | melt = | fusibility = | diagnostic = | solubility = Soluble in dilute nitric acid with effervescence, decomposes slowly in cold water | impurities = | alteration = | other = | references = <ref>[https://www.mineralienatlas.de/lexikon/index.php/MineralData?mineral=Phosgenite Mineralienatlas]</ref><ref name=HBM>[http://rruff.geo.arizona.edu/doclib/hom/phosgenite.pdf Handbook of Mineralogy]</ref><ref name=Mindat>[http://www.mindat.org/min-3195.html Mindat.org]</ref><ref name=Webmin>[http://www.webmineral.com/data/Phosgenite.shtml Webmineral data]</ref> }}

'''Phosgenite''' is a rare mineral consisting of lead carbonate chloride, (PbCl)<sub>2</sub>CO<sub>3</sub>. The tetragonal crystals are prismatic or tabular in habit: they are usually colorless and transparent, and have a brilliant adamantine lustre. Sometimes the crystals have a curious helical twist about the tetrad or principal axis. The hardness is 3 and the specific gravity 6.3. The mineral is rather sectile, and consequently was earlier known as corneous lead ({{langx|de|Hornblei}}).<ref name=EB1911>{{EB1911 |wstitle=Phosgenite |volume=21 |page=474 |first=Leonard James |last=Spencer |inline=1}}</ref>

==Name and occurrence== [[File:Phosgenite-RoyalOntarioMuseum-Jan18-09.jpg|thumb|left|An example of the mineral Phosgenite on display at the Royal Ontario Museum]] The name phosgenite was given by August Breithaupt in 1820, after phosgene, carbon oxychloride, because the mineral contains the elements carbon, oxygen, and chlorine.<ref name=EB1911/>

It was found associated with anglesite and matlockite in cavities within altered galena in a lead mine at Cromford, near Matlock: hence its common name cromfordite.<ref>[http://www.mindat.org/jrs/JRS%20Vol%2001-2.pdf "Phosgenite and Matlockite in Derbyshire (Part 1). T. Bridges, M. E. Smith.] Journal of the Russell Society Volume 1, No. 2, p.7–14, 1983 Retrieved on 2011-01-11</ref> Crystals are also found in galena at Monteponi near Iglesias in Sardinia, and near Dundas in Tasmania.<ref name=EB1911/> It has also been reported from Laurium, Greece; Tarnowitz, Poland; the Altai district, Siberia; the Touissit mine, near Oujda, Morocco; Sidi Amor ben Salem, Tunisia; Tsumeb, Namibia; Broken Hill, New South Wales; and Boleo, near Santa Rosalía, Baja California Sur. In the US it has been reported from the Terrible mine, Custer County, Colorado; the Stevenson-Bennett mine, Organ Mountains, Doña Ana County, New Mexico; and the Mammoth mine, Tiger, Pinal County, Arizona.<ref name=HBM/>

Crystals of phosgenite, and also of the corresponding bromine compound (PbBr)<sub>2</sub>CO<sub>3</sub>, have been prepared artificially.<ref name=EB1911/> {{Clear left}}

==See also== * Barstowite, another lead chloride carbonate

==References== {{Reflist}} {{Commons category|Phosgenite}} {{Refbegin}}

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Category:Carbonate minerals Category:Halide minerals Category:Lead minerals Category:Luminescent minerals Category:Minerals in space group 127 Category:Tetragonal minerals