Need help classifying this error quarter I came across a while back. 1991 P Raised mounds on obverse and reverse with very uneven surfaces. The pitting(?) does not appear to be from circulation. Any comments / input will be appreciated.
Not an error. Looks damaged by heat. You should post full sized photos of both sides to help us see the coin more clearly. Some of our members are almost blind.
When I find a coin like that, I find it helpful to ask myself the question: How could this have happened at the mint? If there isn't any way, then it is NOT an error. Being familiar with the minting process can help discount many anomalies on coins.