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, the denomination is also extensively used to issue circulating commemorative coins with various reverses. It is one of the heaviest coins in regular circulation in the world.
Apart from circulating coins, the Royal Australian Mint has a range of Non-Circulating Legal Tender (NCLT) 50 cent coins issued for collectors, such as this one.
The 6th of February 2002 marked the 50th anniversary, or Golden Jubilee of the Accession of Her Majesty Queen Elizabeth ll to the Throne in 1952, following the death of her father King George VI.
The Royal Australian Mint commemorated the event with a two-coin set: a gold coin denominated $100, and this 50 cents coin in silver. Both were designed by Peter Soobik of Orange NSW, and modelled by Mint sculptor Vladimir Gottwald.
Apart from the precious metal version, the mint also released a copper-nickel 50 cents - in a Philatelic Numismatic Cover together with Australia Post - postmarked February 6th 2002, and in a Royal Mint three-coin set together with a Canadian One Dollar and UK Five Pound coins in a plush purple case.
The design was originally intended to circulate but this decision was overruled after advice form the Treasury that there were enough 50-cent pieces already in circulation. Consequently, no coins of this type were released into circulation. | 
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