This is the 1986 One Ounce Proof Gold Nugget, issued by Australia's Perth Mint. It is an exemplar of the early Perth Mint proof nugget coins, which showcased renowned gold nuggets on their reverse designs. This particular coin commemorates the Welcome Stranger nugget, the largest gold nugget ever discovered.

Crafted in 9999 (24 carat) fineness, this coin contains one troy ounce of gold and carries a face value of $100 AUD. It is among the initial coins in the Gold Nugget series, with a limited mintage of only 3,000!