It’s time to have a look at some of the most interesting error coins available to Australian buyers via eBay auctions or BIN listings.

Australian 1966 Upset Coin Error

The upset 1966 London minted 10 cent is a particular favourite of ours. The result of a moving obverse die these errors are available in a variety of degrees of upset. The one in this eBay auction is upset by what appears to be a bit less than 270 degrees, which is very similar to one of the coins in our article about this interesting error. The upset 10c available in the eBay auction appears to be circulated, but it’s an error that shows up infrequently and with uncirculated examples worth quite a bit more might be a bargain for the collector looking for one for their collection.

View the 1966 Upset 10 Cent Error on eBay

1947 Great Britain Sixpence Struck on a Split Planchet

Coins struck on split planchets are among the scarcest of decimal errors. These are different from the much more common split planchet coins, in that they are split BEFORE the coin is struck, while split planchet coins split AFTER the coin is struck. They are rare enough that we’re aware of less than 10 extant examples in the Australian decimal series. As a consequence if you want one you’ll most likely have to look at a foreign coin. In this eBay auction we’ve got a 1947 British sixpence that was struck on a split planchet. It shows the tell-tale striations on the obverse and strike weakness on the reverse. It’s a decent example of this unusual type of error.

View the 1947 Sixpence on a Split Planchet Error on eBay

2001 Centenary of Federation Upset Full Clockface Set

The 2001 Centenary of Federation Upset Dollar Error is the best known of all Australian upset coin errors. They are reasonably common and at any one time there’s usually several on eBay. What’s not common is someone having the patience to put together of 12 of the coins whose amount of die upset represents each hour of the clock face. That is, 30 degrees as 1 o’clock, 60 degrees as 2 o’clock, and so on. This eBay item does represent that though, 11 upset COF dollars and one properly manufactured coin giving a full clock face of upsets. We know of a few other people who have searched many thousands of coins to put together one of these sets!

View the 2001 Upset Dollar Coin Set on eBay

Disclaimer
Information provided in this article is our opinion only on the coin depicted in the images shown in the eBay listing. It is not an endorsement of any seller and any purchase our readers make through eBay is at their own risk and adheres to eBay’s terms and conditions.

We get questions from readers most days of the week asking about interesting coins they found and wondering what sort of error they’ve got their hands on. Sadly in a lot of cases these coins are not errors and are either perfectly normal coins, or some sort of post mint damage. We also tend to see the same sort of thing over and over. This article shows the more common things we come across and explains why they ARE NOT errors.

Acetone or Solvent Treated Coloured Coins

Acetone Treated $2 Coin Removes Colour

The recent glut of coloured coins released by the Royal Australian Mint have made acetone or solvent treated coins the single most common post-mint-damage coin that is NOT an error. If the colour is missing from a coloured coin, then there’s about a 99.9999% chance that someone has removed it from the coin with solvent. And this is not a new thing, it’s been going on since 2001 when unscrupulous coins sellers were removing the printed map of Australia from the reverse of 2001 dollar coins from proof sets and selling them as errors. In fact, removing colour from coins is something we’ve been writing about for almost 10 years, including this article on “uniface” 2004 dollar coins, this one about no colour $2 coins, and this one on removing the colour from printed wildlife dollar coins.

Sanded or Ground Coins

$2 Coin with a Ground Down Obverse

If you’ve found a coin that is missing a lot of the obverse design or the reverse design and had a strangely flat appearance then you’ve almost certainly got a coin that someone has sanded on a belt sander or ground down on a bench grinder. Why? Honestly, we have no idea. But just look for the telltale parallel lines across the missing part of the design and that’s a sure sign of a ground down coin. Some people argue with us that their coin is a “filled die” but that’s simply not true, filled dies are never ever ever so flat, nor do they show parallel lines or striations

Acid Treated Coins

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People have been putting coins in acid for decades. Again, we’re not sure why but we see several pictures of acid treated coins a month. They are described variously as filled dies, strange strikes, and thin planchets. Sometimes they are treated on one side, mostly on both. But they are all just post mint damage. Above you can see a 50 cent we found in circulation that exhibits all of the characteristics of an acid treated coin. Note how the lettering appears spidery, note also they the strange indentations that are parallel and seem to be more clustered around the areas of high relief such as the portrait, the lettering, and the rims. That’s because when a coin is struck the grain microstructure of the metal is altered, with larger grains around the areas of high relief (the greatest metal deformation). These larger grains are more easily attacked by acid and hence you tend to see more erosion in those areas than in the flat and less deformed part of the coin. Some readers have tried to argue with us that it can’t be acid because it would attack all surfaces equally. Well, if those readers would like to go away and do a 4 year engineering degree that included several courses on metallurgy like one of your authors did then they are welcome to do so and come back and discuss the issue again.

Hammer, Vice, or Shed Jobs

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The sorts of damaged coins you can see above are probably one of the most troubling we see. Mostly because they are created deliberately to deceive error collectors. So called “shed jobs”, or “hammer coins”, or even “vice jobs” are created by squashing a coin between two other coins. They are then sold variously as brockages, double strikes, or multiple strikes. The coins at the top of the image above were bought at a legitimate public auction, so not only did they deceive the buyer, they also deceived the auction house. The coins at the bottom of the image were made by a friend of ours in about 5 minutes using tools from his shed. So why are they not errors? In every case the second “strike” is ALWAYS low pressure, much much much lower pressure than a real coin strike. In fact, when a coin really is double struck almost all evidence of the first strike is obliterated by the second. Other reasons these are impossible is because they require two simultaneous die caps (which is basically impossible), or even have improbable strike combinations like a 2 cent impressed on one side by 10 cent and the other by a 1 cent, a circumstance that is impossible. Our warning with this type of coin (and every other type of error) is that if you do not understand how it was made then don’t buy it. Go away and get a basic understanding of the coin manufacturing process and you’ll quickly see that these “shed jobs” are nothing more than damaged coins.

Roadkill or Mower Coins

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Coins like that above are what we like to call roadkill coins or mower coins. Why? Because they’ve most likely spent part of their lives getting run over by vehicles on a road or in a car park. Or perhaps made close acquaintance with the spinning blades of a lawnmower. They are horrifically damaged and so horrifically damaged that we’re amazed anyone would think they are an error. And yet, somehow people do. We’ll just re-iterate what we said earlier, go away and get a basic understanding of the coin manufacturing process and you’ll quickly see that these damaged coins could never have got they way they are during the coin manufacturing process.

The rarest form of the clipped planchet error is the elliptical clipped planchet or elliptical planchet error coin. This unusual type of clipped planchet error occurs (just like the other clipped planchet errors) during the manufacture of the blanks for coin manufacture. It’s called a an elliptical clip due to the shape of the resultant error coins, one of which you can see below, an impressive 1961 shilling with a distinct elliptical shape.

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How does this sort of error occur? One must think about how the blank manufacturing process occurs, in the case of this shilling the silver strip runs through a blanking press and metal tools punch out disks of silver that will me made into coins. In between punching operations the strip moves along, and stops ready for the next blanks to be punched out. However, what happens if the strip doesn’t move along far enough when the next blank is punched and the blank that was just punched doesn’t detach properly? We’ve done our best to explain this in the image below:

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In this image the first coin blank punching operation is the blue disk, and for whatever reason, when the metal strip moves along under the punching press after the first punch it does not move far enough and the coin blank does not leave the strip. When the next coin blank punch occurs (the green disk) it happens OVER the blank that is still sitting in the metal strip. This forms a crescent shaped clipped planchet on both edges, and an elliptically shaped planchet in the middle. It seems likely that the crescent shaped clips do not make it through quality control because they are so small, whereas the elliptical planchet does. And of course a coin is struck on it and the elliptical planchet error coin is formed.

1921 Half Penny Struck on Elliptical Planchet

To the new collector it may not be immediately obvious how to distinguish a real elliptical clip error from a coin that someone has either cut or ground to shape. Well, as it turns out, the same techniques we’ve described to determine a real clipped planchet error can be applied to elliptical clipped planchets. Both elliptical clips shown in this article show fish-tailing of the legends near the missing regions of the coin, plus both have extremely poorly formed obverse rims. Both of these factors indicate that they were struck on incomplete clipped planchets, rather than being entire coins that were somehow trimmed down later.

19xx 2 Cent Double Struck Error

197x 2 Cent Double Struck Error

The eye candy for error coin collectors today are these two double struck Australian two cent pieces. They were struck once normally and then struck again after failing to exit the press in a timely manner. These coins are lovely collectable examples of off-centre double struck errors. As they are grossly misshapen these error coins would never have left the Mint in a roll, most likely in a mint bag or an employees pocket at a time when little value was put on error coins. The Arnold Machin portrait used from 1966 to 1984 dates these coins to within that time with one coin showing a 7 indicating it was struck in the 1970’s. It’s not possible to determine the Mint of origin because of the error. Both coins have endured the same experience, let’s look at the coin from the 1970’s in closer detail.

It all started with a regular struck coin. The main strike is quite normal with no interesting features. The partial strike off the edge of the coin is another story. This occurred after the coin failed to eject from the press and was caught on the edge and struck (partially) with a second strike. This was likely due to a press malfunction. The edge of this second strike is out of round indicating it wasn’t held by the collar and metal flowed upward (inward). This is confirmed by prominent fishtailing and thinning of the lettering II and AUST as again, the metal flowed upward during that second strike.

Those that may be confused by this type of error we’re still looking at a single (normal weight) planchet and not somehow a joining of two coins, extra metal piece or an overweight planchet. The partial second strike has been struck over the existing metal obliterating the original strike.

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