30 Dollars - Elizabeth II 4th Portrait - Australian Kookaburra - Silver Bullion Coin

The one-kilogram Kookaburra is Perth Mint's flagship bullion format, introduced in 1993 as the series expanded beyond the standard one-ounce offering. Each year's reverse design is changed — a deliberate strategy to drive collector demand alongside investment buying, a dual market Perth has cultivated more aggressively than almost any other sovereign mint.

Ian Rank-Broadley's fourth portrait of Elizabeth II, used here, was adopted by Australian coinage in 1999 and remained current until 2019.