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

Australia's platinum Koala series, launched in 1987, was among the first government-issued platinum bullion programs in the world — arriving just after the Canadian Maple Leaf broke that ground in 1988 and competing directly with the Isle of Man's Noble. The Perth Mint positioned the fractional weights, including this 1/4 oz denomination, to capture investor demand that the heavier one-ounce pieces couldn't reach. By 2002, platinum was trading well above gold, briefly touching $600/oz that year before the automotive catalytic converter market drove it past $900 the following year.

Ian Rank-Broadley's effigy, adopted for Australian coinage in 1999, makes its appearance here in only its third year on the Koala series.