Australian one cent coins were withdrawn from circulation in February 1992. However, they were not demonetised and are still legal tender.
In 2006, the Royal Australian Mint produced some for mint sets (regular coins and proofs), celebrating the 40th anniversary of the denomination.
Gold proofs have a diameter of 17.53mm, weigh 5.61g and are of 0.999 purity (0.1802 oz. AGW).
Silver proofs of the same year have Her Majesty's "Second Portrait" (by Arnold Machin) and are listed separately.