You bring up a good question that I do not know the answer to. I will say that I tend to see this fairly often on quarters that are in or near mint uncirculated condition.
It’s not marker I know it looks like a black mark but it’s not. The spot on his forehead and infront of his nose don’t have the nice sheen like the rest of it. And it’s almost a bronze color as well. Could the spots be a lamination error?
