Has anybody ever seen this before? There is a definite ring around Lincoln's statue. It passes behind his back and legs so it must have been cut into the surface of the die. Far too small to be a ring of some sort just placed on the die, under the planchet.
Saw it on a nickel b4, but my pics were 2 bad for anyone to tell we what it was. Guesses on that one were lamination. And it wasn't as perfect a circle as yours. Good eye. I'll be watching this to find out how it happens.