(Nanowerk Spotlight) The Spaniards called it Tumbaga – an alloy of gold and copper which they found in widespread use by the pre-Columbian cultures in Central America. The popularity of this alloy ...
The Royal Mint has warned people who might consider melting down 1p and 2p copper coins to think again. With copper prices topping $9,000 a tonne, pre-1992 copper coinage is now worth twice its face ...
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