• 50 Cents 1991, KM# 139, Australia, Elizabeth II, 25th Anniversary of Decimal Currency
  • 50 Cents 1991, KM# 139, Australia, Elizabeth II, 25th Anniversary of Decimal Currency

The 14th of February 1966 was ‘C Day’, when Australia changed from the pounds, shillings, and pence system to a decimal system of dollars and cents. It was a massive event with shopping tills and calculators across the country needing to be modified or replaced, the government had to have more than a billion new coins minted and ready to be sent into circulation, and the public had to be extensively educated in the new decimal system. Preparation had begun years before with the new mint opening in Canberra in 1965. Because Australia needed so many new coins, decimal coins for 1966 were minted in London, Melbourne, Perth, and the brand new Royal Australian Mint (RAM) in Canberra. The 1991 25th Anniversary of Decimal Currency 50c is one of the lowest mintage circulating commemorative 50c coins.


Third crowned portrait of HM Queen Elizabeth II facing right, wearing the George IV State Diadem.

The George IV State Diadem, officially the Diamond Diadem, is a type of crown that was made in 1820 for King George IV. The diadem is worn by queens and queens consort in procession to coronations and State Openings of Parliament. The piece of jewellery has been featured in paintings and on stamps and currency. It can be seen in the Queen's Gallery at Buckingham Palace.

Engraver: Raphael David Maklouf



The reverse of this commemorative coin was designed using the rams head from the Australian shilling which was minted from 1938 to 1963. The rams head is a depiction of that originally sculpted by George Kruger Gray.

Engraver: Horst Hahne


Type Commemorative Issue (Circulating)
Material Cupronickel
Weight 15.55 g
Diameter 31.5 mm
Thickness 3 mm
Shape polygon
Sides 12
Alignment Medal
Royal Australian Mint (RAM)

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