The Australian one ounce silver piece (abbreviated as 1 oz and designated with Ag for "silver") is a bullion and commemorative 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.
This silver one-ounce coin by the Perth Mint is intended as a birthday gift.
The Mint says about it:
"If you have ever struggled to find a unique birthday gift unlike any other, the Happy Birthday silver coin is the answer to your prayers! This festive coin features a vivid colour design and is sure to bring a smile to the birthday boy or girl.
The coin's reverse design features two birthday gifts, a party hat, streamers, and a cake in colour, along with musical notes.
The Happy Birthday coin is housed in a square shaped illustrated presentation card that opens to reveal the coin and space to write a birthday message inside." | 
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