We have received many questions about the proper way to clean a coin. Many people want to clean their coins until they shine before they bring them in to sell or put on display. Unfortunately, unless you are an expert, cleaning often causes irreparable damage and detracts from the coin’s value.
When you attempt to clean your coin with soap and water, a towel, alcohol, silver polish…etc, you may be scraping away at the natural coating and damaging the coin. Cleaning products are too harsh on most coins and can bring the value of a $50 coin down to $10 in one careful cleaning.
Learning how to clean a coin properly takes years of research and experimentation and even then, you run the risk of damaging it. If you are interested in learning the proper way to clean your coins, do your research. Talk to other coin collectors about methods that have worked for them and practice before taking the chance of damaging a valuable coin. The best way to practice is to get a pile of junk coins that are worth only their face value (such as new coins that are still in circulation) and experiment with different methods. Each time you clean a coin, look at what damage the cleaning caused. Did it scratch the coin? Did it remove a coating? If you see damage, you probably either used a product that was too harsh or you put too much pressure on the coin. Remember, this experimentation can take a lifetime. If you are not dedicated to learning and putting lots of time into this, don’t attempt it.
If you have ancient coins or coins covered in grime and dirt, you can try soaking them in olive oil for just a few minutes. This will loosen the dirt so that you can read the coin properly. Remember to be very gentle with the coins and be sure not to leave them in oil for too long as this may cause more damage than good.
The safest way to assure that your coins do not depreciate in value and that they remain in the best condition possible is to leave them dirty. They may not be as attractive or impressive to display, however they are worth a lot more than if you try to clean them and end up damaging them. It is generally not worth the risk to attempt to clean valuable coins. The rule of thumb for cleaning your coins is: Don’t.