Garry L. writes:Â I used to polish my coins everyday…then one day I stopped polishing the coins, after a few months there is some green substance on the surface of the coin and I try to rub it away but I was unable to do it…can you tell me how can I get rid of it…thanx
Polishing your coins was a mistake. Anything that disturbs a coin’s surface, whether it is dipping the coin in tarnish remover, polishing the surface with a cloth or with an abrasive substance or treating the coin with heat, degrades the specimen. Natural oxides of silver or copper that are formed over a long period of time are wonderful preservers of coins. You might note that the oxygen that is in combination on the surface of naturally toned coins, is the same oxygen that was present within a few years of the coins’ minting. Possibly the same air that Julius Caesar breathed could be locked up in that beautifully toned silver denarius. Scrubbing away the patina destroys the protection built up over a very long period of time and leaves the coin exposed to modern chemical air pollution.
The green substance that you mentioned is is a corrosive called verdigris and is usually seen on copper coins but I have personally seen something like that on silver coins as well (possibly because of the presence of a copper alloy). You might go to a drug store and ask for some copper soap, Vitrolin. Try using a moist cloth,that has been dipped in the soap, and gently daubing the verdigris.
