The Platinum Koala coin was introduced by the Perth Mint of Australia in 1988 and ran through 2000. Initially offered in 1 oz, 1/2 oz, 1/4 oz and 1/10 oz sizes, the series was expanded to a 1/20 oz coin in 1990. The series diversified into larger sizes in 1992, when the 2 oz, 10 oz and giant 1 kilogram Platinum Koala coins debuted.
While very popular internationally, with a reported 18 tons of platinum used to mint them, the Platinum Koala was never advertised in the U.S. and remains relatively unknown here. Since 2011, the series has been replaced by the 1 oz Platinum Platypus coins.