One Dollar Coins Missing One Side

March 25, 2010


If you're a regular reader of this blog you'll know that we've written a comprehensive series of articles on many of the different types of error coins. You may also remember that we've written a few articles on fake coin errors like this one on double headed coins and this one on creating your own fake error coin. Well in the spirit of exposing fake coin errors for what they are (fakes) here's another one that's popped up a couple of times in the last month on eBay. You can see these 'one dollar coins missing one side' below.


Now firstly let me say that genuine one sided coins most certainly do exist, and the correct numismatic term for these is 'uniface' coins. They are quite well known in Australian numismatic circles because one of the most desirable pre decimal coins one can acquire is the 1937 uniface pattern florin of 1937. It just so happens that one of these sold in the last week or two in the International Auction Galleries Auction 71 for $152,000 plus buyers commission. So uniface coins do exist, so let's think for just one minute how these might be manufactured. Staff at the mint would deliberately need to install a single die with the coin design into one side of the coin press and another die that is completely blank into the other side. Insert a blank planchet, strike the coin and hey presto you have a uniface coin. So as you can see it is a very deliberate exercise on the part of the mint and not something that can happen 'accidentally'.

But wait, I hear some of you saying what happens if two blanks happen to enter the coining chamber at the same time, are perfectly aligned and struck? Well this would result in two uniface coins too, but there would be some tell tales for these especially for Australian dollar coins. Firstly one or other of the coins probably wouldn't engage properly and you'd either have no rim graining or partial rim graining. The other indicator would be extremely poorly formed rims on both coins. Australian dollar blanks are pre-rimmed and as you can imagine the raised rims of two blanks pressing against each other while being struck would flatten the rims considerably. I should say here while I can accept the possibility of two coins being in a coining chamber at the same time I think the chances of them being so perfectly aligned that some sort of indent error doesn't occur is so minuscule that it hardly bears thinking about. But in the interests of completeness I do mention the possibility of such an error occurring.

In either case, whether it be a deliberately mint produced uniface coin or an accidental uniface coin what would each 'error' weigh? Well if it was a dollar coin it would be 9.0g, the mass of a normal dollar coin. So, now we have two indicators of what constitutes a genuine uniface dollar coin error, firstly it will weigh the correct amount, secondly if it is a genuine accidental uniface error then it should have poorly formed or damaged rims. So let's take a look at the coins above. Both have perfectly formed rims. Wow, they must be deliberately produced uniface coins! So what do they weigh? Well what does the seller on the left say when asked the weight of his coin?

"Sorry no scales"

What does the other seller say?

"I don't have any scales but it feels the same weight as a normal coin"

Hmmm, no scales. What's to stop them going to a jeweler and asking to have these coins weighed? Well nothing of course, nothing at all. So clearly neither sellers have the interests of the buyers in mind and probably have something to hide. The coin on the left has a major red flag that should scare off any potential buyer, you can CLEARLY see concentric circles on the blank side of the coin. This is a clear indicator that this coin has had the design skimmed off by a lathe or mill. This coin is clearly not an error and anyone paying more than one dollar on it is simply throwing their money away.

But what about the coin on the right? There's no tool marks on that is there? Well honestly that doesn't mean anything, tool marks can easily be burnished out by a competent machinist. But for the sake of argument let's just consider for second that this coin really does weigh 9g, this seller really has found a uniface coin! Amazing! In 2004 (because the seller says it is a 2004 coin but never actually shows you the obverse in the auction so you can't tell) the mint deliberately made a uniface coin and somehow it got out of the mint and this person obtained it! That's just amazing! Find of the century! Sadly no, in 2004 the RAM made 50,000 uniface dollar coins to proof standards and put them in the 2004 proof sets but not before sticking a pretty hologram mob of roos design on it. Break one of these 2004 proof sets up, apply a bit of acetone to the dollar coin (like we did here) and you have a uniface 2004 proof dollar coin. Of course the seller doesn't want us to know it's a proof (and never actually shows the obverse for anyone to see) and not an error coin at all, just post mint damage.

So if you see a uniface coin for sale what lessons should you take from this?

  1. Ask for the mass of the coin, if the seller doesn't have scales tell them to take the coin to a jeweler and have it weighed to the nearest 10th of a gram. If the seller refuses or stalls don't walk away from the coin, run!
  2. If the blank side of the coin shows tool marks AND the coin mass is unknown run away even faster! I should say here that the presence of tool marks doesn't preclude a genuine coin, the 1937 uniface florins show tool marks from the blank reverse die.
  3. As in any potential coin purchase demand to see images of both sides of the coin before committing to purchase, if the seller refuses or stalls walk away.
  4. Do your research, 5 minutes of work would have revealed that in 2004 the proof set contained a pad printed coin issue. It's your money, if you're not willing to spend some time making sure it's spent properly then why should anyone else?

So the coin on the right sold for nearly $500 and the coin on the left has been bid up to $30 or so as this article was written. The seller of the coin on the right has gotten away with numismatic murder and the seller of the coin on the left is bottom grubbing in the worst way by trying to cash in on some people's ignorance. If you had any doubts of this just take a look at the two ebay auction titles:

Coin on right (first coin sold)
"1 Dollar ERROR Missing OneSide!! Estate Sale On Coins!!"

Coin on left (being auctioned right now)
"1 Dollar ERROR Missing OneSide!!"

Note the spelling an capitalising, exactly the same. Awful behaviour. That's all I have to say on these 'errors', don't bid on them, don't buy them, don't support such behaviour by these sorts of sellers.


Posted by mnemtsas at March 25, 2010 7:45 AM
Subscribe to our Newsletter

Bookmark and Share