@bratink, first welcome to CCF. Second, when I blow up your pic and enhance it, it sure looks to me like the PVC plastic is degrading and leaving behind a bluish-green goo on your coin. That is not good and causes permanent surface damage. I would recommend removing this coin immediately from the plastic (and all others), bathing in acetone, and then storing in a 2x2 or other method with inert plastic windows. Here is a link to an early CCF link talking about this issue:
http://goccf.com/t/37880

http://goccf.com/t/37880

"If you climb a good tree, you get a push."
-----Ghanaian proverb
"The danger we all now face is distinguishing between what is authentic and what is performed."
-----King Adz
-----Ghanaian proverb
"The danger we all now face is distinguishing between what is authentic and what is performed."
-----King Adz





















