In 2010 to celebrate the Koala the Perth Mint released a very special Limited Issue $100 One Hundred Dollar Gold Proof Coin struck in solid fine .9999 Gold weighing one ounce of pure Gold and struck in High Relief.
The reverse depicts a Koala while the obverse has Ian Rank Broadley's portrait of Her Majesty Queen Elizabeth II.
These legal tender coins have been struck to proof quality using specially prepared dies and highly polished blanks.