Frequently asked questions

Coin Wrapping Damage

It is very common to find a coin at one end of a roll with circular scrapes, usually most severe near the rim. This is virtually always crimping damage that occurs to the end of the roll coin where the crimper tucks in the paper to secure the roll. They can also be found in the middle of a roll if the damage occurred earlier and the coin is being rewrapped into a roll again. Of course they can also be found in circulation. It is one of the most common questions we get yet when found on a common dated is worth no more than face value and may just as well be spent. They are damaged coins and nothing more or less. On a semi key or key date coin it reduces the value dramatically and many grading services will not even assign a grade to them. The one shown here is 2016-P 25c Harpers Ferry circulating commemorative found by Bruce Griner of Michigan that he brought to the CONECA table at the Michigan State Numismatic Society Convention, fall 2016 to see what it was.

Die Deterioration Ridges (referred to by the Mint as “ridged-edged cents”) are caused by the upset edge of planchets tearing away at the dies. The effect is exceedingly common on the copper-plated zinc cents due to the zinc being very hard on the dies but it can be found on coins of other alloys and denominations normally to a lesser effect.

I reported upon this effect in the 1990s in my book Doubling: Worthless Or Valuable? where I reprinted a February 25, 1986, letter from George E. Hunter, Ph.D., Assistant Director for Technology for the Department of The Treasury, who explained the cause.

It is considered a normal result of die use and not an error.

The one shown here dated 1929-S is a strong example for a copper alloy cent but many exist that are this strong and stronger on the copper-plated zinc cents from 1982 though present.

Coin courtesy of Michael Campbell.

Plating Blisters This 1988-D Lincoln cent displays what is referred to as Plating Blisters. These can take on the shape of thousands of tiny blisters or just a few odd-shaped ones.

Causes are poor adhesion, usually due to poor pre-treatment (cleaning of the planchets) and foaming. Foaming is due to contaminated electrolyte used in the barrel plating process.

The life of electrolyte can be extended with the use of anti-foaming agents but if planchets fall out of the barrel and break down within the tank, a brassy appearance can occur and the electrolyte needs to be replaced.