Australia has two mints, the Royal Australian Mint (which also makes the country's circulating coinage) and the Perth Mint, which are both very active in the bullion coinage space; coins issued by them are legal tender.
Additionally, there are private issuers of bullion which is not legal tender and is targeted at investors and not at coin collectors - such as this one.
The Mint says about this Diwali 1oz Silver Coloured Medallion:
Marking the beginning of the Hindu New Year, the Diwali festival is celebrated all around the world. This vividly coloured, thoughtfully designed silver medallion is a fitting tribute to the occasion, featuring proof quality 99.99% pure silver and a vivid coloured deity design featuring Lakshmi and Ganesha.
The ancient "festival of lights", Diwali is celebrated by millions around the world in October or November each year depending on the cycle of the moon. Deities honoured during this five-day period in particular are Lakshmi, the goddess of wealth and prosperity, and Ganesha, the god of intellect and overcomer of obstacles.