Copper in coinage
Copper has played a key role in the history of coinage. The first coins of Ancient Greece were made of copper and gold, since they were relatively easy to find and offered good corrosion resistance.
Nowadays, copper and its alloys continue to be chosen for coinage. Euro coins are one example of a copper-based currency.
Copper alloys are easily made into coins thanks to their workability, and provide good resistance to impact and wear. These features are indispensable to items that will be continuously handled.
Their corrosion resistance is well known, which is why several ancient objects (many copper coins among them) have lasted almost unaltered up to the present day, even if exposed to atmospheric agents or submerged in seawater.
Beyond being fully recyclable without loss of properties, copper alloys offer different colours depending on the ratio of copper and other metals. For example, the golden-yellow 10, 20 and 50 euro cents coins are 89% copper.
Euro coins must have precise electrical and magnetic features in order to be recognisable by vending machines. The addition of nickel can modulate the magnetic permeability of the alloys, so the electrical conductivity of 10, 20 and 50 coins is one seventh that of pure copper.
Click here to read more about the properties of copper.
No, they are made from steel coated with a thin layer of copper.
An alloy with 89% copper, 5% aluminium, 5% zinc and 1% tin. 10, 20 and 50 Euro cent coins use this alloy.
Since ancient times copper has been used in coins; the Romans used copper widely in this application. The reasons for using copper are its excellent corrosion resistance, ease of stamping, good electrical conductivity for vending machines and ease of recycling.