So I put this 1990 no mint mark aside because of its shininess. I think I have come to terms that this is not a proof, but verification would put my mind at ease....
However, the reason for posting this is that when I looked at it under the microscope, the reverse shows some what is likely Die Deterioration
, but not like I've seen in other coins.
The "doubling" starts in "United" and goes all the way to "America" but the but in the letters "ERI" the doubling seems more detached.
Further the "FG" mark also shows some doubling.
As always, your comments are much appreciated.