It looks like it's just a small die chip with some corrosion or staining around it. Does it stand above the flat area of the coin? If so, does is the "S" that you see raised or flat with the surface? I can't tell from the photos. I don't think it's a blundered mint mark. I've never seen anything like a mint mark in that area.
ANA ID: 3203813 - CONECA ID: N-5637 Clean a coin that may be worth collecting? Please DON'T! When in doubt, leave it dirty!!


























