While looking for some roulettes, I came across my meager amount of Paris jetons (1 each of all 3 different $5's) and I noticed a darkness at several locations around the rolling edges of the jetons. The darkness also had a slight relief (a raised spot) and under magnification I found that where the metallic fillagree (threads) within the acrylic were exposed at the rolling edges of the jetons, there was a dark greenish colored corrosion.

With the aid of a Zorb device (a digital magnifyer) I was able to make these snapshots.

This may or may not be more pronounced depending on the color of the other denominations, as well as moisture content in a storage location.

Is anyone else experiencing this condition?

Jim