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How to Clean Roman Coins

ancientromancoinUnlike certain modern coins, Roman coins have significant intrinsic value. For most of its lifetime, Roman currency consisted of gold, silver, brass, and copper coinage. However, many Roman coins are more valuable than their precious metal content.

Due to their age, Roman coins often have patina, which is a colored layer, usually green or brown that has built up over the centuries. When cleaning your Roman coins, it’s important not to remove the patina. Removing the patina can decrease the coin’s value and you risk damaging the coin.

There are many ways to clean ancient coins. What may work for one, may not work for another. Here’s a list of cleaning techniques that can help preserve your Roman coins:

    1. Let your coins sit in distilled water for 24 hours. Note: distilled water is not the same as tap water. You can purchase distilled water at your local grocery store. After letting them soak, rub them gently with a soft bristle toothbrush.
    2. Next, categorize coins into good, average and worst. The coins that look the worst, or are still very dirty, should be returned to the distilled water. Let these coins sit for another 24 hours or until you start to see a change.
    3. Fill a bowl with olive oil – try not to use Extra Virgin olive oil as the regular stuff often provides better results. For the good coins, olive oil alone should do the trick. However, for the average to worst coins, add half a teaspoon of lemon juice to the mix. The coins can sit for up to 48 hours, or until the oil goes green and thick with muck. Then rinse the coins off with distilled water and return them to a new bowl of olive oil.
    4. After a few days of this process, you should start to see some good results. Once coins look in good condition clean them all off with distilled water and a soft toothbrush. At this point, you can probably pick the dirt and encrustations off with a tooth pick. However, be very careful so that you do not damage the coin.
    5. Finally, store your newly cleaned coins in protective gear. This may include individual coin holders or sleeves. For long term storage, use coin tubes or hard plastic holders. Make sure your coins are fully dry before storage. Dampness and pollution can damage valuable, ancient coins.

There are other extreme methods of cleaning Roman coins such as ultrasonic cleaning and electrolysis. While these are both effective coin-cleaning tactics, they can damage the patina or the surface of the coin. I would only use these methods as a last resort effort. That being said, if a crusty coin cannot be cleaned with conventional methods it may be best to leave the coin as is.

Gary Dyner is the owner of Great American Coin Company. Connect with him on 


How to Properly Clean Your Coins

Coins in High ContrastOne of the fastest and easiest ways to ruin a rare a coin is by sticking it in silver dip cleaner or rubbing it with something abrasive, like silver polish. For that reason, most coin collectors will advise you not to clean your collectable coins. Improperly cleaning coins will reduce their monetary value—some by up to 50 percent.

However, there are certainly some instances in which dirty coins can benefit from a good cleaning. For example, if you are giving a child their first collection it’s probably a best to clean the coins the first. Coins found in circulation tend to be very unclean and carry many germs. And these coins most likely have little to no value. Cleaning coins is also acceptable when they have such a build-up that cleaning will actually increase their value.

Soap and Water

Having said that, cleaning your coins is as simple as using soap and water. A mild detergent and warm water will adequately remove dirt and grease from the coin without damaging it. Never purchase metal cleaners offered in stores and on TV. These cleaners contain harmful chemicals that can remove some of the surface metal during the cleaning process.

Olive Oil

However, if coins are heavily encrusted, soaking them in olive oil for an extended period of time can help. The oil will eventually dissolve the crust without damaging the coin. After cleaning coins, you should rinse them with distilled water. Tap water can have chlorine in it, which can discolor coins. Lastly, allow coins to air dry or gently them down. You should never rub coins, even with a soft cloth.

ToningToned Roosevelt Dime 1948D

Discoloration on silver coins is called tarnish, or “toning” as collectors call it. Toning can range from black to many of the rainbow colors. Do not remove toning from coins; some collectors will actually pay a premium for nice looking toning.

For the most part, cleaning coins is NOT recommended. While lower-grade coins may benefit from a cleaning, higher-grade coins should be left alone. If you feel that your coin may be valuable, consult with a professional coin collector before cleaning. And lastly, never purchase coins that have already been cleaned. These coins will not appreciate as quickly as coins that have been left unclean.

Gary Dyner is the owner of Great American Coin Company. Connect with him on