{{Short description|Mineral}} {{Infobox mineral | name = Polybasite | boxwidth = | boxbgcolor = | image = Polybasite-37890.jpg | imagesize = | alt = | caption = | category = Sulfosalt minerals | formula = {{chem2|[(Ag,Cu)6(Sb,As)2S7][Ag9CuS4]}} | IMAsymbol = Plb<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 = 2.GB.15 | dana = | system = Monoclinic and trigonal polytypes | class = Prismatic (2/m) <br/><small>(same H-M symbol)</small> | symmetry = ''C2/c'' | unit cell = | color = | colour = steel black | habit = | twinning = | cleavage = poor on (001) | fracture = uneven | tenacity = | mohs = 1.5–2 | lustre = metallic, adamantine or glimmering | streak = black with reddish tint | diaphaneity = | gravity = 6–6.2 | density = | polish = | opticalprop = | refractive = | birefringence = | pleochroism = | 2V = | dispersion = | extinction = | length fast/slow = | fluorescence = | absorption = | melt = | fusibility = | diagnostic = | solubility = | impurities = | alteration = | other = | prop1 = | prop1text = | references = <ref>[http://www.mindat.org/min-3256.html Polybasite: mindat.org]</ref><ref>[http://www.webmineral.com/data/Polybasite.shtml Webmineral.com]</ref><ref>{{Cite web |url=http://www.handbookofmineralogy.com/pdfs/polybasite.pdf |title=Handbook of Mineralogy |access-date=2011-05-16 |archive-date=2016-03-03 |archive-url=https://web.archive.org/web/20160303171441/http://www.handbookofmineralogy.com/pdfs/polybasite.pdf |url-status=dead }}</ref><ref>{{cite book|title=Minerals of the World|year=1990|isbn=0-517-68030-0|author=Rudolf Dǔd'a and Luboš Rejl|publisher=Arch Cape Press|page=40}}</ref> }}
'''Polybasite''' is a sulfosalt mineral of silver, copper, antimony and arsenic. Its chemical formula is {{chem2|[(Ag,Cu)6(Sb,As)2S7][Ag9CuS4]}}.
It forms black monoclinic crystals (thin, tabular, with six corners) which can show dark red internal reflections. It has a Mohs hardness of 2.5 to 3. It is found worldwide and is an ore of silver. The name comes from the number of base metals in the mineral.
== Images == <gallery widths="140px" heights="130px"> File:Polybasite-tmu16a.jpg|Unusual polybasite specimen from Mayo Mining District, Yukon Territory, Canada. </gallery>
== References ==
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{{commons category|Polybasite}} Category:Silver minerals Category:Copper(I) minerals Category:Antimony minerals Category:Arsenic minerals Category:Sulfosalt minerals Category:Monoclinic minerals Category:Minerals in space group 15 Category:Glances Category:Minerals described in 1829
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