The Australian third-ounce platinum piece (abbreviated as 1/3oz and designated with Pt for "Platinum") is a bullion coin format used by the Perth Mint since 2018 for a series of bullion coins featuring different Australian animals.
The 2021 design features the iconic Australian Platypus.
The platypus (Ornithorhynchus anatinus), sometimes referred to as the duck-billed platypus, is a semiaquatic, egg-laying mammal endemic to eastern Australia, including Tasmania. The platypus is the sole living representative of its family (Ornithorhynchidae) and genus (Ornithorhynchus), though a number of related species appear in the fossil record.
Together with the four species of echidna, it is one of the five extant species of monotremes, and a monotypic taxon as the only member of the family ornithorhynchidae. They are one of the few mammals that lay eggs instead of giving birth to live young. Like other monotremes, it senses prey through electrolocation. It is one of the few species of venomous mammals, as the male platypus has a spur on the hind foot that delivers a venom, capable of causing severe pain to humans. The unusual appearance of this egg-laying, duck-billed, beaver-tailed, otter-footed mammal baffled European naturalists when they first encountered it, and the first scientists to examine a preserved platypus body (in 1799) judged it a fake, made of several animals sewn together.
The obverse of the coin depicts the crowned old bust of Queen Elizabeth II facing right, wearing the Royal Diamond Diadem crown worn for her Coronation (effigy known as the "Fifth Portrait" worldwide but "Sixth Portrait" in Australia, where the Queen's portrait by Vladimir Gottwald was fifth).
The Queen also wears the Coronation Necklace; originally made for Queen Victoria in 1858, it was also worn at the coronations (as Queen's Consort) of Queen Alexandra in 1902, Queen Mary in 1911 and Queen Elizabeth (the Queen mother) in 1937.
Unlike on British coinage, the effigy is "uncouped" (includes the Queen's shoulders). In small letters on the left, the artist's initials JC (for Jody Clark).
Running continuously around the rim is the monarch's legend, the date of issue and the face value: ELIZABETH II AUSTRALIA 1/3oz 9995 Pt 2021 30 DOLLARS.
The inscription around the rim also incorporates the precious metal content. "1/3 oz 9995 Pt" means "one third of a troy ounce of 99.95% platinum" - Pt is abbreviated from platinum.
The reverse designs shows a platypus swimming under water, surrounded by water lilies.
The Perth Mint's P mint mark is above right. On a leaf above left, the initials of the designer, JM, for Jennifer McKenna.
In the rim, which is patterned with thin radial lines, the inscription AUSTRALIAN PLATYPUS around above, and the date of issue 2021 below.