The Australian 50 cent denomination was first introduced as a silver coin with decimalisation on 14 February 1966, but was changed in 1969 to its current specifications: a large dodecagonal (12-sided) copper-nickel coin; apart from the usual design featuring the Australian Coat of Arms (by Stuart Devlin) which has not been changed since its introduction, the denomination is also often used to issue circulating commemorative coins with various reverses. It is one of the heaviest coins in regular circulation in the world.
Apart from the circulating coinage, the Royal Australian Mint has an extensive program issuing 50 cent coins for collectors (Non-Circulating Legal Tender, or NCLT). Some of them are round, as reference to the original format of the denomination. | 
