Determining how a coin error occurred is the key to a valuable collection

April 28, 2011


The road taken to understand a coin error is an interesting one. When presented with an error coin, the first thing we ask ourselves is "how did this happen?" The understanding of how the error occurred is the key to a return on your investment true to the real value of the coin.

We often see misrepresented errors on sites such as eBay or at public auction, often to benefit the seller and often to benefit the buyer. So as not to "do your dough" in the first instant it's important to be able to recognise post mint damage and realise when a coin just couldn't possibly be like that and must have encountered some foul play in the toolroom or the back shed. Just having a talk with friends or a discussion on an internet coin forum might bring the answer that you need about how that coin error occurred. An understanding of how the coin press works is also valuable knowledge when it comes to determining how the malfunction occurred and what caused the problem with the coin. If you can recognise the error that you have and can accurately explain the process of the fault then this might mean a return on your investment of hundreds of dollars instead of ten dollars.
Some examples you ask?


  1. A bulk lot at public auction includes a 5c coin described as a thin planchet and sold it for around $15. Ok, at first glance it is, but have a closer look. There are striations in the fields and yes, the planchet is in fact thinner than it should be and the coin weight is considerably less. Some of the design is weak. It is in fact a split planchet coin which has been through the press and struck after the 2 coin halves split. One half of the coin missing and the coin in question struck on a planchet only half the thickness. A coin worth a few hundred dollars.
  2. A 1944s shilling represented on eBay as being struck on an underweight planchet sold for $300. It has, however, been struck on a foreign planchet and is worth over a thousand dollars. Read the story in our entry Foreign planchet error coins.
  3. Blank coin planchets regularly sell for $15-$40 and are simply blank metal rounds that didn't pass through the press. But what if they have actually ventured through the press and been part of a minting malfunction? Any part of the design featured on a coin turns a $15 blank into a $100-200 error coin as can be seen here in the Die Adjustment Strike coin error entry. These types of errors are the result of a low striking pressure.



Posted by harrisk at April 28, 2011 9:26 AM
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