I was looking at this 1977 penny under a scope. I seen what I thought was just some sort of PMD. Theres a crack/line something that runs around the coin from a spot on the rim to another spot on the rim. I wouldnt have even cared to take pics but I looked and noticed its definitely raised. Its not dramatic at all or even much interesting but I am now curious as to if this is a die crack, planchet error or just some dumb luck PMD. It appears to not run across any of the letters which just adds to my curiosity. If it were PMD Id assume it would run across the top flat parts of the letters too right? IDK, thats why Im posting.
A stain of some type, acid probably, that ate away at the surface and left a trail. Post mint damage. But also a slight misaligned die. IMHO.
Have you tried an acetone soak? It might give a clearer image of the coin. If it is a stain, it might remove it or at least clean it up.
