I'm no expert on copper, but as mentioned by another poster, it looks conditioned/filmed with oil. This is done all the time to eliminate a dry and flat look some copper gets when it's been sitting for a long time. It can easily be removed. The tone of the coin under the shine looks right to my eye and would be difficult to replicate such a genuine look IMO. I'm sure there are people out there that disagree, and it probably can be done, but retoned copper seems to stand out to me. This one doesn't appear re-toned. If it is, they did a good enough job, I would be ok with it. Problem free is always the question. I try to buy only coins that are problem free. With that being said, I would buy this coin for a fair price.