13 Common Mint Errors of Little Value


Machines that make coins do so with tens of tons of pressure from incredibly high-speed mass production coining presses that use brittle steel dies on all manner of planchets, some with thin-plating zinc. As working dies reach the end of their lives, or as machines rattle from all that pressure, these common errors occur on different denominations (consult the Illustrated Glossary for definitions):

  • die chatter
  • die chips
  • die cracks
  • die gouge
  • delamination
  • die dent
  • die deterioration
  • filled mint marks
  • machine doubling
  • plating blisters
  • roller marks
  • split plating
  • struck through

These are only worth a few dollars, if you can find anyone who wants to buy them. Go to the “sold” button on eBay and you’ll see the results.

Here’s some die crack examples:


How, specifically, do these errors happen?

Die Deterioration, Chips, Cracks, Gouges, Die Chatter: These occur when working dies–minting hundreds of thousands of coins–become worn from the pressure and brittle. Minute pieces of the die break or crack from the pressure, and metal fill the voids with raised appearance.

Machine Doubling, Die Deterioration Doubling, Die Dents: These are mechanical errors as opposed to mint errors. They occur when the die bounces or moves during coining. The result is not raised but shelflike.

Filled Mintmarks: Until the late 1980s, mintmarks were punched directly into the working die. This was an extra step back then, so not only do the mintmarks appear in different places but also, depending on the punch, were susceptible to clogging.

Plating Blisters, Split Plating Doubling: After 1982, cents were made of zinc. these are caused by trapped gas or thin copper plating breaking over the zinc core, often mimicking doubling.

Roller Marks: Not technically an error, these resemble the mint error on cents called “woodies” (again, consult the glossary) that look like wood grain due to improper annealing. But roller lines are caused by uncleaned rollers used in the minting process.

Delamination: This happens a metal alloy does not cohere properly, resulting in the surface peeling off. These are common in older coins, especially zinc cents.

You do not need a coin microscope to see these. Magnification makes these common errors look significant; they are not. At best these sell for a few dollars on eBay.

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Difference between dryer and spooned coins


Everyday on Facebook coin groups, Reddit and eBay, dryer and spooned coins appear with their owners believing they have found valuable errors. Let’s look closely at both examples of post mint damage in this article so you can identify what you have if you found examples in pocket change (literally) and rolls.

Also, this article showcases examples of sellers claiming dryer and spooned coins are valuable errors. They are not. They have no collector value.

Dryer Coin

A coin left in a home dryer or, more probably, a commercial dryer at a laundromat is known in numismatics as a “dryer coin,” dramatically changing dimensions so that it appears vastly different than the denomination.

The coin typically remains in a person’s pocket after being washed and tumbled and then falls out of the clothing and is exposed to high heat in a dryer. Sometimes it falls into the gap between the rotating inner drum and the stationary outer frame of a commercial dryer where it suffers even more damage due to grinding, friction and heat.

If you put the phrase “dryer coin” into a search engine, you get dozens of examples on Facebook and Reddit.


Dryer coins undergo these transformations: a flattening and widening of the edge, losing any reeding in the process. The heat pushes from the center outward resulting in a state that often resembles a bicycle tire with enhanced rim. The diameter becomes smaller.


Also, the result is a “mushy” discolored surface with devices literally melting away, as in the above coin. That is not a grease strike. It is a cent that was exposed to high heat in a commercial dryer. Compare:


It is important to distinguish between dryer coins and spooned ones. While both are considered damage, there are distinct differences.

Spooned

A spooned coin often looks like a dryer coin. In this case, however, the edge of a coin is intentionally hammered or pressed with the back of a spoon, eventually flattening and widening it.

The process is used to make a coin ring, as in this example:


The process of tooling the coin varies from a kitchen spoon to a handy person’s tool box and machinery. Basically, the coin is secured on a hard surface so that the person can use the back of a metal spoon, tapping, rotating and rubbing the coin over a long period (we’re talking days or even weeks).

Eventually the coin starts to mushroom toward the edge, developing an extended ring-like edge as in the above coin. At that point what remains of the coin is punched or drilled out, leaving the ring, which eventually is polished.

Some finished rings are lovely, as in this example:


Of course the finished ring looks nothing like a dryer coin. The confusion happens when the person abandons the spooning process and leaves the coin with a large ring-like edge but with the remaining devices of the coin still visible without the mushy appearance of a dryer coin.

That’s how you tell the difference between a spooned and dryer coin. Compare:


As you might expect, unknowledgeable people sell dryer and half-spooned coins as valuable error. Here’s an example of a dryer coin offered for $150.


Here’s an example of a spooned quarter misidentified as an error for $500.


Proxiblog has the largest illustrated glossary on the web. Click here. You can compare dryer and spooned coins to sunken dies and heat damage. Study all the examples so that you, too, can become a coin expert.

If you like posts like this, subscribe to Proxiblog so you can be informed whenever there is a new article or column.

Proxiblog also has thousands of followers on Facebook Coin Groups, YouTube and social media. To get the latest discussion and commentary, be sure to friend us by clicking here.

You can find more information about types, varieties, errors, grading, bidding and buying in Coin News Updated: The Essential Guide to Online Bidding. Please consider buying or gifting the work for a friend, as it underwrites this hobbyist blog. Thank you.