Just wondering what people thought about this discoloration. It's slightly greenish in tint which makes me think it is PVC. Already soaked it in acetone overnight and...nuthin'. http://img6.imageshack.us/img6/4466/pvcpic.jpg
Allmost all coins contain some copper except for the bullion issues and still can have trace amounts in them. Yes I think what you have is the underlying etching that was caused by the PVC that was removed to late.
But that doesn't leave a green color. Discolored yes, but not green. Silver coins, and even some gold coins, get verdigris too - not just copper coins.
i most believe that its toning, not verdigris or pvc. it would be easier to determine with full pictures of the obverse and reverse.