Hi, I got this lovely 50¢ from South Africa. It has a small green spot. What can I do about it, if anything. I'd really appreciate the help! Thanks! Ben
It might be PVC residue/damage. You could give the coin an acetone bath, assuming you have access to pure acetone and know how to not damage the coin in the process.
Thanks for the speedy answer. No, I don't have access to pure acetone (any for that matter), nor would I risk doing that. Is there an easier way? By the way, is that considered "cleaning"? I know that's such a broad term, and everybody seems to have their own opinion if dipping is cleaning.
You can buy pure acetone at any hardware or home improvement store. And no, using acetone on a coin is not considered harsh cleaning. Acetone is used on coins all the time. That said, I don't think acetone would help in your case. That green spot looks like verdigris to me and acetone has no effect on verdigris. My advice would be to just leave it alone and store the coin properly.
IMO you should buy some pure Acetone at the hardware store. (Do not use nail polish remover). Soak the coin for a few minutes in an open container in a ventilated room. If the spot does not disappear, then roll a cotton swab over the affected area. Avoid rubbing the surface of the coin with the cotton swab. Remove the coin from the Acetone & let it dry. (Discard the used Acetone). Place the coin in an archival quality coin holder. Flips that are pliable are not good for long term storage because they can secrete PVC residue onto the coin & cause green spots, corrosion, etc.