 Other compositions were also used for 1 cent coins such as the 1978 (incorrectly listed as 1968 at Downies) specimen struck in aluminium or fine silver proofs in 1991, 2006 and 2011.After removal from circulation, the coins were melted down to make bronze medals for the 2000 Sydney Olympics.In 2017, a limited edition "Possum Magic" themed coin set was released.