Nordic Gold ( Swedish: nordiskt guld [1]) is the gold-coloured copper alloy from which many coins are made. The alloy is a type of aluminium brass. It has been used for a number of coins in many currencies, most notably in euro 50, 20, and 10 cents, [2] [3] in the Swedish 5 and 10 kronor coins (for which it was originally developed and introduced in 1991), [4] as well as the Polish 2 złoty commemorative coins. Its composition is 89% copper, 5% aluminium, 5% zinc, and 1% tin. [5] [2]
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 [6] and weak antimicrobial (especially after abrasion) [7] attributes, and resistance to tarnishing. It has been studied for its antimicrobial hospital applications. [8]
Nordic Gold was developed by Mariann Sundberg while she worked for the Finnish metal company Outokumpu. [9] The European Central Bank says that the alloy is "difficult to melt and used exclusively for coins." [10]
Compared to commercial copper metal, Nordic Gold has significantly smaller grains. A thin oxide material is formed after abrasive polishing. [11] The alloy's antimicrobial properties were studied extensively in 2014 because it showed promise for use in hospitals, to help prevent MRSA infections. A rather complete description of its electrochemical properties was one result.
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Yhtiön tutkimus- ja kehitysasiantuntija Mariann Sundberg on kehittänyt Nordic Gold -kuparimetalliseoksen