Looks like something that might be removable if the proper solution was used. At first I thought it might be a carbon spot, but I think it may be a bit of black gunk. Nice for you (OP) if I'm right. And please do respond to this thread. Too often your threads lack commentary by you, the OP.
Looks like a bit of gunk stuck on. Very *very* carefully, use a wooden toothpick and try to loosen it. If that doesn't work, use an acetone bath.
I would like to see some pics of the coin taken out of the album. Placed on a gray or black background. I use computer mouse pads some times. I agree with Paul M. it is cockeyed in the album whole. There seems to be some gunk or other stuff around the edge under the bust going up by L in Liberty and continuing thru IN GOD WE TR I would net grade it VF-38