If it is a die abrasion, then that is a die error, which is a Mint error in my opinion. However, it could also be from a worn die and could be die deterioration, like this dime below.
A "die variety" means the die had a flaw on it before it even struck a single coin. For example, large over small dates, rpms, and doubled dies. A "die error" is anything unintentional on a die that developed after the striking process started. By default, die errors are Mint errors. Therefore, a cud, crack, split, intentional unintentional die abrasion, clashed dies, die chips, etc. are all forms of some Mint errors.
