Expert: PAPAJACK - 6/12/2007

Question
Hi, I was wondering if you know what to use to clean coins and jewlrey found that have been buried deep in the sand. We have tried toothpaste as recommended to no avail.

Answer
Hello Sharon,              

Great question. I cannot answer for the jewelry you find it would depend on the Metal content and or Stones mounted in them.

But there are methods absolutely inappropriate for coins, like a rubber eraser or acid polishing mediums etc.  

Let me first state as a Coin Collector that coins are worth much less to coin collectors after having been cleaned. There is usually no reason to clean a coin. Unless the substance is destroying the coin (like acid, PVC damage etc.). Any coin that has ever been cleaned will sell for much less.

True coin collectors don't recommend cleaning coins at all.
When a coin is cleaned the original surface is removed thus removing the luster that the purest collectors want to see.
The cleaned surface allows other contaminates to attack the surface. Also the cleaning may deposit other particles on the surface.

Also note that coins that are naturally toned (specially silver coins) often can bring higher prices than cleaned coins. Usually double the amount if the toning is spectacular. Like if the coins have an unusual blue, olive, or rainbow colored toning they sometimes can be sold for many times their usual price.

Cleaning of Bronze, Copper, Silver or any coin can render it virtually valueless! Collectors would rather have a dark deep chocolate brown specimen or spotty brown than a cleaned coin. Even rubbing a coin with a very soft cloth can leave minute scratches on the surface that will adversely affect collector value.

To improve a coin's appearance it sometimes in the past was acceptable--on a very limited basis to gently swish it in a diluted solution of pure soap, rinse with distilled water and allow to air dry.  (or pat dry lightly with a very soft cloth)

You can try other PH natural inert solvents at your own risk like lacquer thinner, acetone etc.. Some people have said letting it soak in non corrosive oil (olive oil, gun oil etc.) wiping and washing or even chipping away  at crusty dirt with a tooth pick or orange stick.
Solutions that are too acid or basic will change the surface of the coin since copper is very reactive.

Whatever method you may use try it on pre 1982 U.S. cents and other modern coins that you are not collecting to see how it will work for you. (If it changes the color it is no good)

As I said when you are done trying any of these methods, wash it in a diluted solution of pure soap like a dishwashing liquid, rinse with distilled water and allow to air dry.  (or pat dry lightly with a very soft cloth).  

Never use any type of commercial jewelry  polish on coins. These compounds contain abrasive grit that will mar their surface, and if used often will eventually wear away the metal. The same advice goes for "home remedies" such as vinegar, lemon juice, tomato juice, etc. All will do more harm than good.

Sorry I cannot be more help.  Feel free to ask any question on U.S. Coins.

Please remember to rate this answer. And check the nomination box below any comments you may have. Thank You.

Good Luck

PapaJack

Below is an excerpt from a professional society (authorized by the US Congress) in reference to cleaning coins.:
"Rule number one of coin collecting is "DON'T CLEAN YOUR COINS." Improper cleaning will reduce the collector value of your coins by 50 percent or more, so don't clean your coins.