15 Dollars - Elizabeth II 4th Portrait - Koala - Platinum

Australia's platinum Koala series launched in 1988, making Perth one of the earliest sovereign mints to issue a dedicated platinum bullion program in direct competition with the Canadian Maple Leaf. The 1/10 oz denomination was always the entry-level piece in the set, designed to attract investors unwilling to commit to the full-ounce format. The fourth portrait of Elizabeth II, sculpted by Ian Rank-Broadley, was adopted on Australian coinage in 1999 — the same year this two-year type begins — replacing the Raphael Maklouf effigy that had served since 1985.