The Gold and Silver Mine > When to clean coins: NEVER!

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coins A weekly column dedicated to “digging out” current information about precious metals, coins and other numismatics.

To clean or not to clean my coins, that is the question. Well, the answer is quite simple, never, ever, ever (did I say never?) clean a coin. I can’t emphasize that enough.

Many a coin collection has been ruined by improper cleaning, usually by someone who is not familiar with the natural appearance of coins as they age and develop a patina (toning) through exposure to the air or whatever was used for their storage. This toning is actually oxidation and the degree to which it affects the coins’ surface is dependant on the metal content. Gold coins are not affected, but silver and copper coins darken if not protected by storing them in airtight, inert containers. Toning does not affect the value of a coin as long as the toning is naturally occurring, and in some special cases toning can actually enhance the coins value.

Cleaning coins actually results in a loss of metal from the coin, depending on the method or material used. Even lightly rubbing a coin can result in fine, hairline scratches on the surface of the coin, which will be visible when viewed through a magnifying glass. This is the reason cleaning coins reduces their value and desirability to collectors.

Some of the worst examples of cleaning I have seen are; steel wool (yes someone actually used steel wool to clean a coin and the result was one ugly coin with deep scratches); an eraser on a pencil which also put scratches into the surface of the coin; commercial metal polish which also is an abrasive that scratches the coins surface but over time the coin will tone worse because the polish itself causes oxidation; and liquid jewelry cleaner, which although not an abrasive, still removes a minute amount of surface metal from the coin. And if the coin is not thoroughly rinsed in water and dried, the residue from the cleaner will also cause the coin to become even darker later.

Collectors can always tell if a coin has been cleaned because the coin will have an unnatural appearance in relation to a new coin. And if the coin is a circulated specimen, the cleaning is even more evident, because a circulated coin is not supposed to have a bright, shiny appearance. 

Remember, you can never unclean a coin. Once a coin has been cleaned, the damage has been done and is irreversible.

Douglas Keefe is the president of Beachcomber Coins, Inc. He and his wife Linda operate Beachcomber Coins and Collectibles formerly in the Shore Mall, now located at 6692 Black Horse Pike in the old WaWa building just past the former Cardiff Circle. The also have  satellite offices in both Brigantine and Absecon. Between them they have more than 70 years experience in the coin and precious metals business. They are members of The American Numismatic Association, The Industry Council of Tangible Assets, The Numismatic Guarantee Corporation, The Certified Coin Exchange and the Professional Coin Grading Service.

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