So I went to a local bank and got $20 Dollars (Or 2 rolls) of Half Dollars, after scouring through them looking for Silver, I soon discovered it was all clad... A sad day indeed... After doing some research on key things to look for on JFK pieces, I soon found... Pause for dramatic effect... Keep Pausing... ABSOLUTELY NOTHING! Yet just when I thought my coin roll expedition was over, preparing to set them aside and take them back to the bank, I noticed my stack of coins slightly tilting. Then when I thought all was lost, I find this guy sitting 3 from the top in my stack of coins. Long story short, it looks like a massive bubble where his hair should be. Defiantly raised above the ever other spot of the coin. Like a mountain!
You did not post a photo of the reverse side, but I will say your coin seems to have been heated enough to form a gas bubble. Clad coins can form these due to the layers they have. I'm sure this is considered damage, and worth only face value. It is an interesting effect.
