A quick look at the numerous buyer’s guides reveals that shine is among the most desirable features when purchasing a coin for your collection. However, the ‘shine’ these guides talk about is often misunderstood. While many believe that it implies the actual polish on the coinage, the shine is actually mint luster and it is achieved during the striking process.

The distinctive sheen is the result of forcing the metal of the planchet to flow into the dies under extreme pressures. The beauty of the mint luster stems from the fact that the changes take place at molecular levels. Once the coinage is in circulation, the impressive surface characteristics described above are lost. The same applies when the coin has been cleaned.

Cleaning reduces the value of the coinage

Granted, if you commonly attend antique road shows, then chances are you’ve heard some appraisers claim that you could get a higher price on your coins if you wash away the grime. While you might be tempted to clean them before your next exhibit, take note that numerous coins are ruined through cleaning and that it’s almost impossible to improve their conditions like this.

Let’s assume for a moment that you intend to sell a silver coin with superficial surface damage or toning. Not only is toning or tarnishing very common among silver coinage, but it is also the direct result of silver molecules interacting with the elements in the environment. Even though the damage is visible on your coin, at a closer inspection with a magnifier you will notice that the surface is still intact. Therefore, the currency has only lost a small portion of its mint value. Moreover, some toning is considered beautiful and can even enhance the intrinsic value of the coin.

Why cleaning coinage is a bad idea

By attempting to clean the tarnish off the coin, you’re likely to cause further damage to the surface, particularly if you use an abrasive cleanser. Some coin collectors argue that dipping is the optimal technique for cleaning this type of metal. In case you didn’t know, dipping entails leaving the coin in a solution for a few minutes and then washing it.

It’s true, this cleaning method is less damaging than the abrasive solution. However, it’s still contraindicated for the coins in your collection. Dipping usually strips a fine lawyer from the surface, therefore leaving the coinage dull and ugly. In addition, this cleaning method is bound to destroy the sensitive fragile flow lines that account for the amazing cartwheel effect.

If you have to clean it, leave it to the professionals

Cleaning coins is acceptable in certain situations, such as when you notice that the coinage presents a green residue on the surface. This type of spoiling is caused by a reaction to plastic (PVC in most cases) and should not be ignored because it progresses and triggers irreparable damage. Then again, even in this case you shouldn’t try to remove the corrosion by yourself. Instead, contact your coin dealer; he will surely be able recommend you a professional coinage cleaning service.