The Australian ten kilograms silver piece (abbreviated as 10 kg and designated with Ag for "silver") is an extremely large and rarely used bullion coin format.
Uniquely, in Australia there are two mints 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.
Both mints endeavour to create coins with attractive designs, and to introduce new designs and themes often, in order to raise the numismatic value of the coins over the value of previous metal used. The Perth Mint uses the format mainly for its Lunar Series coins dedicated to the Chinese Zodiac. | 
