The first member that can tell me what caused the patina on this Silver Eagle will win a coin worth approximately $10-$20. When I say cause, please don't answer toning or oxidation, that much is obvious. What I mean is what was the source of the toning. For example, if I showed a textile toned Morgan Dollar, the answer would be a canvas mint bag. Now here is the coin. I will give hints after a while if nobody guesses the right answer. All answers should be posted in the thread.
