@PE, my first thought was fire damage, but I do see that on Abe's right shoulder and up through LIBERTY, the copper plating is lifting up from the coin's surface. It can't be struck through and damage seems to be the simplest explanation. Perhaps whatever was resting on this coin was hot enough to slightly melt into the zinc (i.e. more than 800 degrees F or so).
"The danger we all now face is distinguishing between what is authentic and what is performed."