How to Tell If a Coin Has Been Cleaned

by Tom Lutzenberger ; Updated July 27, 2017
Old coins will have age and grit within their grooves; it's a mistake to clean them with home cleaning products.

Items you will need

  • Magnifying glass
  • Coin condition reference book
  • Plastic disposable gloves
  • An uncleaned comparable coin

Many coin experts and collectors will immediately balk if presented with a coin that shows signs of being cleaned. In the coin-collecting business, amateur cleaning is a big “no-no” punished by loss of collection value. Collectors and experts want coins that have not been cleaned, but some parties will try to pass off such coins as untouched when in fact they have been tampered with. In this regard, buyers can look for certain signs that will give away a cleaned coin.

Step 1

Put on disposable gloves so that the skin oil from your hands or any dirt won’t rub onto the coin to be examined. Place a magnifying glass nearby for easy access (you may have to use it multiple times). Find the coin you are going to examine in a coin reference book that covers the era of that coin so you have quick data available.

Step 2

Examine the coin for abrasive cleaning by looking at the body to find scratches. Place the magnifying glass close to the coin so that the coin surface is clear and enlarged. Scan the coin surfaces closely, looking for scratches and small bits of dirt still stuck in the coin grooves (brush cleaning won’t always get this out).

Step 3

Sit a second copper coin next to the first coin if the examined one is made of copper. Compare the colors, looking for any clear differences in shades or luster. Use a magnifying glass again to examine silver coins for differences in the raised part of the coin versus the nonraised areas. Look to see if the silver coin body is uniform over the entire coin (uncleaned silver coins will have variations on ridged areas versus sunken areas).

Step 4

Check the luster of the coin by comparing it to a similar one if possible (i.e., compare a penny to a penny). Use the magnifying glass to see if the examined coin is duller or doesn’t have a shine at all compared to your comparison coin (this is a potential sign of solvent burn, which removes the shiny surface).

Step 5

Examine if the coin has been buffed or the color is suddenly uneven across a coin that shows toning. Confirm that the toning looks the same across the whole coin without any wiping marks or uneven areas of shining (toning is natural oxidation, but it can be wiped off by a polish).

Tips

  • When buying coins of significant value, your best approach for avoiding a scam is to look for coins that have already been professionally graded and come in a sealed grade container. These coins have had their condition certified by a recognized coin association, which clarifies their worth. However, certified coins may cost more due to the service of grading and visible confirmation.

Warnings

  • If you’re going to clean your own coins, make sure to use the right chemicals and learn how to do it properly. Work with coin-collecting suppliers to get the right materials for the job so you don’t damage your coins.

About the Author

Since 2009 Tom Lutzenberger has written for various websites, covering topics ranging from finance to automotive history. Lutzenberger works in public finance and policy and consults on a variety of analytical services. His education includes a Bachelor of Arts in English and political science from Saint Mary's College and a Master of Business Administration in finance and marketing from California State University, Sacramento.

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