50 Dollars - Elizabeth II 3rd Portrait - Koala - Platinum

Australia's platinum koala series launched in 1988 as a direct competitor to the Canadian Maple Leaf and American Eagle bullion programs, with the Perth Mint positioning the .9995 fine specification fractionally above the .9990 fineness common among rivals. The 1989–1990 issues are the first to carry Ian Rank-Broadley's predecessor Raphael Maklouf's third portrait of Elizabeth II, a distinction that gives this two-year window a transitional appeal within the series.

Platinum bullion coinage was still a novelty in Western sovereign minting at this date — the Soviet Palladium and platinum issues of the 1970s were largely the only precedent.