As originally published in Australasian Coin and Banknote Magazine September 2021
What Went Wrong -error coins that escaped the Mint
If you’re even slightly active in the online coin community you’ll know that a major Australian media company published an article in early 2021 about 1988 and 1989 $2 coins. The general gist of the article was that these coins might be valuable because of the letters HH on the rib cage of the Aboriginal elder shown on the reverse. Of course, these are the initials of the coin designer Horst Hahne and they were removed from the coin after 1989. Are they valuable? Generally no, however in the image shown with this article you can see a 1988 $2 coin that is indeed quite valuable.
You’ll notice that there is a curved portion of the coin missing at the bottom edge. The curved shape is characteristic of the “curved clipped planchet error”. There was a failure during the process that manufactured the blank from which this coin was made. A failure that lead to one blank being punched from an area of a metal strip that had already had another blank punched from it, resulting in the missing part of the coin you see before you.
How do we know this is a real clipped planchet error? The technical details are beyond the scope of this article but please refer to a previous article we have written that covers the topic in detail. In brief, the most obvious indicator of authenticity is the smooth flowing outward transition of the inner rim toward the outer rim on both sides of the clipped area. In particular the bottom of those HH letters flowing outward into the clip site. This is a result of unconstrained radial metal flow into the missing region of the coin.
In conclusion, what we see here is a genuinely interesting 1988 $2 coin with the HH initials on the reverse. It’s a fine example of a genuine curved clipped planchet error in an excellent grade with an unfortunate obverse fingerprint. Despite this detracting feature it is still a difficult to find error on an aluminium bronze $2 coin.
Mark Nemtsas and Kathryn Harris own and run The Purple Penny coin shop in Adelaide coin shop in Adelaide and are passionate about error coins.
 The Australian Coin Collecting Blog, 2012, How to Determine if a Clipped Planchet Error is Real, The Australasian Coin and Banknote Magazine, Vol 15, No. 5, pp 10-11