Cleaning coins may be a very attractive issue, especially for those who have just started the numismatic hobby. However, this can be such a bad idea, as it may present serious deterioration hazards. This article's purpose is to instruct this first-time collectors how to proceed when they acquire an apparently dirty coin.
First of all, you should make a thorough analysis to evaluate if the coin really should be cleaned. This might be hard and numismatic experts never reached a consent about it. Anyway, most collectors prefer their coins untouched.
Searching the internet for photos of the coin is a good idea because you can picture how the coin should be like in good conditions. If you have doubts, asking a numismatic expert might help a lot.
Common mistakes on evaluating
"The cleaner the better" It's frequently wrong! Most of times, old coins have a higher value in their natural state. Cleaning these coins will probably lower their rating, even though it looks better to you.
Patina and rust are not the same Although they seem to be the same, there's a huge difference! While the rust may spoil the metal, the patina is beneficial to it, because it creates a layer that protects from...rust. Furthermore, patina can also be a valuable charm, because it tells the story behind your coin, such as the age and the place where it has been before you get it.
Patina vs. Rust
Now that you are sure that your coin can be cleaned, you should be aware of how to proceed. The method you should use depends on the metal your coin is made of.
The following instructions may be useful:
Advisable methods to all coins
Use running water in tepid temperature to remove light stains and dust.
For heavier stains, use a magnifying glass to see the exact spot and a soft stick to remove (like a soaked toothpick, for instance).