Is this a mint error it's strange because there is not an indention of any kind on the back of his quarter ?
The quarter was affected by extreme heat which caused the clad layer to bubble up. Torch or fire are the culprits. Not a Mint error of any kind. Welcome to CoinTalk
Hello and welcome to CT. If your coin looks like the coin the OP showed it’s suffering from the same issue, heat. It was heated and that is what caused the damage.