Nordic Gold

{{Short description|Copper alloy used in many coins}}

{{use dmy dates|date=May 2024}}

File:Euro 50 cent.jpg made out of Nordic Gold.]]

Nordic Gold (Swedish: nordiskt guld{{Cite web |last=Predecimal.com |title=The selection of the alloy for the New Euro Coins |url=https://www.predecimal.com/euroarticle.htm |access-date=2020-03-20}}) is the gold-coloured copper alloy from which many coins are made. The alloy is a type of aluminium bronze. It has been used for a number of coins in many currencies, most notably in euro 50, 20, and 10 cents,{{Cite news |title=Common sides of euro coins |url=https://economy-finance.ec.europa.eu/euro/euro-coins-and-notes/euro-coins/common-sides-euro-coins_en |access-date=14 July 2022 |publisher=European Commission website}} in the Swedish 5 and 10 kronor coins (for which it was originally developed and introduced in 1991),{{Cite book |last=Rohrig |first=Brian |url=https://books.google.com/books?id=eK8IEAAAQBAJ |title=The Chemistry of Money |date=2020 |publisher=Royal Society of Chemistry |isbn=9781782629832 |page=146}} as well as the Polish 2 złoty commemorative coins. Its composition is 89% copper, 5% aluminium, 5% zinc, and 1% tin.{{Cite web |title=What is Nordic Gold? |url=https://copperalliance.gr/resources/what-is-nordic-gold/ |access-date=14 July 2022 |publisher=European Copper Institute}}{{Dead link|date=October 2023 |bot=InternetArchiveBot |fix-attempted=yes }}{{Cite news |title=Brass Material and Specifications Review |url=https://www.engineersedge.com/brass.htm |access-date=14 July 2022 |publisher=Engineer's Edge LLC}}

Being a copper alloy, it contains no gold. Its colour and density are unlike pure gold. It is non-allergenic; its other advantages include antimycotic{{Cite journal |last=Quaranta |first=Davide |display-authors=etal |date=January 2011 |title=Mechanisms of Contact-Mediated Killing of Yeast Cells on Dry Metallic Copper Surfaces |journal= Applied and Environmental Microbiology|publisher=American Society for Microbiology |volume=77 |issue=2 |pages=416–426 |bibcode=2011ApEnM..77..416Q |doi=10.1128/AEM.01704-10 |pmc=3020553 |pmid=21097600}} and weak antimicrobial (especially after abrasion){{Cite journal |last=Horton |first=D. |display-authors=etal |date=2015 |title=Tarnishing and Cu Ion release In Selected Copper-Base Alloys: Implications Towards Anti-Microbial Functionality |url=https://www.sciencedirect.com/science/article/pii/S0013468615008774 |journal=Electrochimica Acta |volume=169 |pages=351–366 |doi=10.1016/j.electacta.2015.04.001 |access-date=2020-03-20|url-access=subscription }} attributes, and resistance to tarnishing. It has been studied for its antimicrobial hospital applications.{{Cite thesis |last=Foster |first=Leanna |title=Tarnishing of a Cu-Al-Zn-Sn Alloy Compared to Commercially Pure Copper: Implications Toward Antimicrobial Function |date=2014-08-13 |degree=MS |publisher=University of Virginia |url=https://libraetd.lib.virginia.edu/public_view/x633f118z |doi=10.18130/v3q08v |doi-access=free }}

Nordic Gold was developed by Mariann Sundberg while she worked for the Finnish metal company Outokumpu.{{Cite web |last=Kuparinen |first=Tuulikki |date=19 December 2001 |title=Kultaiset eurokolikot syntyvät Outokummun kupariseoksesta |url=https://www.is.fi/taloussanomat/art-2000001355265.html |access-date=7 February 2021 |website=Ilta-Sanomat |language=fi |quote=Yhtiön tutkimus- ja kehitysasiantuntija Mariann Sundberg on kehittänyt Nordic Gold -kuparimetalliseoksen}} The European Central Bank says that the alloy is "difficult to melt and used exclusively for coins."{{Cite news |date=2022 |title=Security features |url=https://www.ecb.europa.eu/euro/coins/security/html/index.en.html |publisher=European Central Bank}}