Is It a Valuable Error Coin or Just Damage? A Guide to Identification
Have you ever found a coin in your pocket change that just looks… strange? Maybe the design is off-center, a letter is doubled, or it has an unusual ridge. For a moment, your heart might race with the thought of finding a rare and valuable error coin worth a fortune.
But how can you be sure? This is the most common question in the world of coin collecting: is it a true mint error or just post-mint damage?
Distinguishing between a genuine, valuable error coin and a coin that was simply scratched, corroded, or altered after it left the mint is the most crucial skill for a budding collector. This guide will teach you how to tell the difference.
What is a True Mint Error vs. Post-Mint Damage (PMD)?
Understanding these two categories is the first step.
- A Mint Error: This is a mistake that happens during the manufacturing process at the U.S. Mint. These errors are created by flawed dies, incorrect striking pressure, or mishaps with the coin blank (planchet). Because they are genuine mint-made mistakes, they carry collectible value.
- Post-Mint Damage (PMD): This is any damage or alteration that happens to a coin after it leaves the mint. This includes scratches, dents, corrosion from being buried, deliberate alterations, or chemical reactions. PMD almost always destroys any collector value a coin might have had.
Common Examples of Valuable Error Coins
Genuine errors have distinct characteristics. Here are a few famous types to look for:
- Off-Center Strike: Part of the coin’s design is missing and replaced by a blank, crescent-shaped area.
- Doubled Die: The letters, numbers, or design elements appear clearly doubled due to a flaw in the coin die.
- Clipped Planchet: The coin will have a smooth, curved clip missing from its edge, which happened when the blank was punched from the metal sheet.
- Broadstrike: The coin was struck without its retaining collar, causing it to be wider and thinner than normal with a plain edge.
Common Examples of Post-Mint Damage
Unfortunately, most unusual coins found in circulation are just damaged. Here are common examples of PMD that are often mistaken for errors:
- Scratches and Gouges: Damage from circulation or contact with other objects.
- Corrosion or Staining: Discoloration caused by environmental exposure (being buried, exposure to chemicals).
- Deliberate Alterations: Someone may have hammered, squeezed, or engraved the coin.
- Dryer Coins: Coins tumbled in a clothes dryer can have their rims worn down and heated, creating a smooth, rounded edge that can be mistaken for a broadstrike error.
Case Study: When Glue Looks Like a Major Error
Sometimes, what appears to be a dramatic minting mistake is actually a simple case of post-mint damage. We recently received an inquiry that provides a perfect real-world example.
A collector sent us this photo and message:
Name: Stephen
What do you think? Do you think that this is an error coin? Please get back with me and let me know. Thanks. Obviously well circulated.
At first glance, the coin appears to have a strange, ghostly impression on it. However, upon closer inspection, our staff identified the issue.
Our Response:
Hi Stephen,
Thank you for inquiring with us regarding your coin. The item you have presented is not a mint error coin. This is not an error coin but rather glue residue from two coins being stuck together and forced apart after drying. You’re seeing the reverse and incuse image of the reverse of another nickel, the word “UNITED” is visible but orientated backwards. If you soaked this coin in acetone (nail polish remover) for a few minutes, that glue would come right off.
AR Staff
The collector was thrilled with the clear explanation and confirmed our analysis. This case is a perfect reminder to always consider the simplest explanation first and to look for signs of artificial substances or alterations.
How to Check Your Coin: A Quick Checklist
Before you get too excited, run your coin through this quick check:
- Use Magnification: A 5x or 10x magnifying glass is essential.
- Compare It: Hold your coin next to a normal, undamaged version of the same coin. Does the “error” look like something was added or taken away?
- Look for Unnatural Details: Do you see signs of scraping, tool marks, or a substance like glue on the surface? Mint errors are created with immense pressure; they don’t involve foreign substances.
If you’re still unsure, consult a reputable coin dealer or a reference guide. Differentiating between a treasure and trash is a skill that takes time, but it makes the hunt all the more rewarding. Happy collecting!
