Your images are too pixelated for me to tell anything. That is what I hate most about images that are digitally enhanced.
It appears to be a lamination error, improperly annealed bronze that the Philadelphia mint sent out to the lowly branch mints.
I didn't say anything about a camera phone. I don't even own one. Personally, I would rather see images taken with a regular camera with optical zoom.
Why are you arguing with me @cpm9ball ? I'm recommending a cell phone . Not everyone is a professional photographer . JMO
I'm not a pro, either, but I can't be sure based on your images. Have you tried to see if it can be removed with pure acetone?