PCGS - The $1 coin is Australia's most popular series. It is the nation's second denomination to feature a commemorative design and has been widely collected since it was first issued in 1984, replacing the $1 banknote. Many designs have also been issued in proof finish, in precious-metal formats, with mintmarks and privy marks, colorized features, and in an enlarged silver format. The Royal Australian Mint even has an annual roadshow around the country to strike dollar coins on location with a small portable press. It should therefore be no surprise that one of Australia's most popular coins is a special variety of a dollar coin issued in 2000.

2000 $1 Mule-Struck w/10C Obv (Regular Strike) PCGS MS64Struck with the reverse of a $1 coin but the obverse of a 10 cent piece, this dollar coin mule became a modern classic when it was discovered in late 2000. Having been released into circulation, everyone had a chance of finding one and, as the media reported discoveries and the coin became more widely known, the chase to find an example in one's change became even more frantic. Collectors queued up at banks to withdraw bags of dollar coins to search through. Restaurant and store cashiers swapped out rolls from their tills. Even children checked their change at school canteens before buying their pizza pockets and Ovalteenies! The most diligent "noodlers," as they are known, were able to find dozens of mules, with one Perth resident discovering over 180 examples in the coin bins of slot machines over a period of two years.
The 2000 $1 mule is easy to identify because the dies of a 10 cent coin are slightly smaller than the collar of a $1 coin. When the coin is pressed, the gap between the collar and the die creates an outer rim. These appear as a pair of concentric circles about the rim on the obverse, which is visible without the aid of a loupe. The size of the effigy is also somewhat smaller on the 10 cent piece, so theoretically one could also measure the width of the effigy to identify a mule dollar, although in practice this is not usually necessary. Care must be taken not to confuse this double rim with a similar effect that is caused by a minor misstrike in which the coin was struck slightly off-center. The double rim caused by a minor misstrike only circumscribes a portion of the coin, meaning the double rim effect might appear around the left-hand side of the coin but not around the right, or vice versa. On a mule dollar, the double-rim effect traces the entire circumference of the coin.
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