The Australian tenth-ounce gold piece (abbreviated as 1/10 oz and designated with Au for "gold") is a bullion coin format. Uniquely, in Australia there are two mints independently authorised to strike legal tender: the Royal Australian Mint (which also makes the country's circulating coinage) and the Perth Mint which only makes collector and bullion coins, as well as other bullion products.
The Australian Koala series by the Perth Mint comes in several sizes and compositions. The reverse design changes every year, always featuring a koala - one of the most famous and distinctive animals native to Australia. The gold tenth-ounce coins have a face value of 15 dollars, but this is only symbolic - as the bullion value of their precious metal content is much higher. The overall weight is slightly more than one tenth of an ounce, so that the pure gold content is exactly 0.100 AGW (one tenth of a troy ounce Absolute Gold Weight). | 
