{{Infobox mineral | name = Volborthite | boxwidth = | boxbgcolor = | image = Volborthite-65625.jpg | imagesize = 260px | alt = | caption = Neon green crystals of volborthite are nestled in a vug in the matrix | category = Polyvanadate minerals | formula = Cu<sub>3</sub>V<sub>2</sub>O<sub>7</sub>(OH)<sub>2</sub>·2H<sub>2</sub>O | IMAsymbol = Vbo<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 = 8.FD.05 | dana = 40.03.10.01 | system = Monoclinic | class = Prismatic (2/m) <br/><small>(same H-M symbol)</small> | symmetry = ''C2/m'' | unit cell = a = 10.610(2) Å, b = 5.866(1) Å <br/>c = 7.208(1) Å; β = 95.04(2)°; Z = 2 | color = Olive-green, yellow-green; green to yellow-green in transmitted light | colour = | habit = Aggregates of scaly crystals, rosettes | twinning = | cleavage = Perfect | fracture = | tenacity = | mohs = {{frac|3|1|2}} | luster = Vitreous, waxy, greasy, pearly | streak = light green | diaphaneity = Translucent | gravity = 3.5 - 3.8 | density = | polish = | opticalprop = Biaxial (+/-) | refractive = n<sub>α</sub> = 1.793 n<sub>β</sub> = 1.801 n<sub>γ</sub> = 1.816 | birefringence = δ = 0.023 | pleochroism = Weak | 2V = Measured: 63° to 83° | dispersion = Translucent to Subtranslucent | extinction = | length fast/slow = | fluorescence = Non-fluorescent | absorption = | melt = | fusibility = | diagnostic = | solubility = Soluble in acids | impurities = | alteration = | other = | prop1 = | prop1text = | references = <ref name=HBM>[http://rruff.geo.arizona.edu/doclib/hom/volborthite.pdf Handbook of Mineralogy]</ref><ref name=Mindat>[http://www.mindat.org/min-4200.html Mindat with location data]</ref><ref name=Webmin>[http://webmineral.com/data/Volborthite.shtml Webmineral]</ref> }}
'''Volborthite''' is a mineral containing copper and vanadium, with the formula Cu<sub>3</sub>V<sub>2</sub>O<sub>7</sub>(OH)<sub>2</sub>·2H<sub>2</sub>O. Found originally in 1838 in the Urals, it was first named knaufite but was later changed to volborthite for Alexander von Volborth (1800–1876), a Russian paleontologist.<ref>[http://www.galleries.com/Volborthite Mineral Galleries]</ref>
Tangeite (synonym: calciovolborthite), CaCuVO<sub>4</sub>(OH), is closely related.
==Occurrence== Volborthite was first described in 1837 for an occurrence in the Sofronovskii Mine, Yugovskii Zavod, Perm, Permskaya Oblast, Middle Urals, Russia.<ref name=Mindat/>
It occurs as an uncommon oxidation mineral in vanadium bearing hydrothermal copper ores. It is associated with brochantite, malachite, atacamite, tangeite, chrysocolla, baryte and gypsum.<ref name=HBM/>
==References== {{Reflist}}
Category:Copper(II) minerals Category:Vanadate minerals Category:Phosphate minerals Category:Monoclinic minerals Category:Minerals in space group 12
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