I am inclined to agree with the suggestion that it has undergone some sort of chemical cleaning.
The thick black spots next to and above Abe's ear also make me rather curious.
XRF may be the 'go' for this coin, if you happened to be really motivated to investigate it.
A bullion dealer or a scrap gold jewelry buyer should have a hand held XRF instrument.
Edited by sel_69l
12/16/2017 4:24 pm