What annealing? It's all copper. Blurry but it looks like a silverish metal was added to the copper and now it's peeling off.
Hell of a time with pictures. We get out of sheltering next week and I'll go to my LCD to have a look. I thought adhesive too but under high magnification I didn't think so. Let you know when I have it looked at. Thanks all
From the Red Book: Indian Head Cents Variety 3 - Bronze (1864-1909) Composition .950 copper, .050 tin and zinc.
Red Book.950 copper, .050 tin & zinc Variety 3 Bronze 1864-1909 Small Cents page 115, 2013 66 Edition
Even though the pics are poor (my pics are bad too ) it looks like the material is raised above the surface of the coin. It also appears that their is some sort of residue around the perimeter. Looks a lot like residue on the reverse, as @paddyman98 said earlier. It's highly unlikely that the zinc and/or tin would remain segregated in the melt especially with no other evidence of improper alloying. Objectively look at the coin to determine if this stuff on the rev is raised. If it is, it wasn't there before minting. You can also Try soaking it in acetone (not nail polish remover) and see if the residue dissolves
In hand it appears raised but under a microscope it is actually gouged and looks like a trough or furrow. I will try acetone. How long should I soak the coin?
