Niobium Coinage Applications

In numismatics, niobium is sometimes used as a precious metal on commemorative coins along with gold and silver. For example, Austria has produced a series of silver niobium euro coins since 2003, whose color results from the diffraction of oxide surfaces formed by an anodic polarization process. in 2012, there are ten coins with differently colored centers, including a total of blues, greens, browns, purples and yellows. Other coins containing niobium include the 150th anniversary of the Austrian Semmering Railway in 2004 and the European Satellite Navigation Coin in 2006. 2011 saw the Royal Canadian Mint begin minting the $5 Canadian dollar sterling silver and niobium coins known as "Hunting Moons". The niobium in these coins undergoes a special oxidation process so that no two pieces are exactly alike.