Berzelianite

{{Short description|Sulfide mineral}} {{Infobox mineral|name=Berzelianite|boxwidth=|boxbgcolor=|image=Berzelianite, Calcite-361052.jpg|imagesize=|alt=|caption=Berzelianite included in calcite from the Skrikerum mine in Sweden.|category=Selenide minerals|formula=Cu<sub>2</sub>Se| IMAsymbol=Brz<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.BA.20|dana=2.4.10.1|system=Isometric|class=|symmetry=|unit cell=|color=Silvery white, tarnishes easily|colour=|habit=Dendritic crusts, fine-grained inclusions|twinning=|cleavage=None|fracture=Uneven|tenacity=Slightly malleable|mohs=2.7|luster=Metallic|streak=Shining|diaphaneity=Opaque|gravity=|density=6.71 (measured) 7.28 (calculated)|polish=|opticalprop=|refractive=|birefringence=|pleochroism=|2V=|dispersion=|extinction=|length fast/slow=|fluorescence=None|absorption=|melt=|fusibility=|diagnostic=|solubility=|impurities=Ag|alteration=|other=|prop1=|prop1text=|references={{ref|1}}{{ref|2}}{{ref|3}}}}

'''Berzelianite''' is a rare copper selenide mineral with the formula Cu<sub>2</sub>Se.<ref name="Nekrasov1996">{{cite book|author=I.Y. Nekrasov|title=Geochemistry, Mineralogy and Genesis of Gold Deposits|url=https://books.google.com/books?id=HUWRZecignoC&pg=PA238|date=1 January 1996|publisher=CRC Press|isbn=978-90-5410-723-1|page=238}}</ref><ref name="CastorFerdock2004">{{cite book|author1=Stephen B. Castor|author2=Gregory C. Ferdock|title=Minerals of Nevada|url=https://books.google.com/books?id=flAhr0MbxM8C&pg=PA163|year=2004|publisher=University of Nevada Press|isbn=978-0-87417-540-0|page=163}}{{Dead link|date=October 2023 |bot=InternetArchiveBot |fix-attempted=yes }}</ref><ref name="Pracejus2015">{{cite book|author=Bernhard Pracejus|title=The Ore Minerals Under the Microscope: An Optical Guide|url=https://books.google.com/books?id=nkibBwAAQBAJ&pg=PA202|date=25 June 2015|publisher=Elsevier Science|isbn=978-0-444-62737-7|page=202}}</ref> It occurs as thin dendritic crusts or as fine-grained inclusions. It crystallizes in the isometric system,<ref>{{Cite web|url=http://www.handbookofmineralogy.org/pdfs/berzelianite.pdf|title=Handbook of mineralogy Berzelianite|last=|first=|date=|website=|publisher=|access-date=}}</ref><ref name=":0">{{Cite web|url=http://www.mindat.org/min-645.html|title=Berzelianite: Berzelianite mineral information and data.|website=www.mindat.org|access-date=2016-10-23}}</ref><ref>{{Cite web|url=http://www.webmineral.com/data/Berzelianite.shtml#.WAzdXOh9600|title=Berzelianite Mineral Data|last=Barthelmy|first=Dave|website=www.webmineral.com|access-date=2016-10-23}}</ref> unlike its dimorph, bellidoite, which crystallizes in the tetragonal system.<ref>{{Cite web|url=http://www.mindat.org/min-611.html|title=Bellidoite: Bellidoite mineral information and data.|website=www.mindat.org|access-date=2016-10-23}}</ref> The crystals are opaque and slightly malleable.{{Citation needed|date=October 2025}}

== Occurrence and name == Berzelianite was first identified at the Skrikerum Mine (also spelled as Skrickerum Mine) in Valdemarsvik, Östergötland, Sweden in 1850.<ref name=":0"/>

It was named by James Dwight Dana to honor Jöns Jakob Berzelius, a Swedish chemist who is seen as the father of analytical chemistry. He invented chemical symbol notation and discovered the elements cerium, selenium, silicon, and thorium.<ref name=":0" />

Berzelianite often occurs together with eucairite, clausthalite, tiemannite, umangite, klockmannite, aguilarite, crookesite, athabascaite, stromeyerite, polybasite, pearceite, gold, uraninite, pyrite, marcasite, calcite.{{Citation needed|date=October 2025}}

== References == {{reflist}}

Category:Selenide minerals Category:Copper(I) minerals Category:Cubic minerals Category:Minerals in space group 225