Bio is right on !
The workers would take a punch, that had the mint mark on it, and a hammer and punch the mint mark onto the die. Then that die was used to make coins. I can imagine, if a mintmark on the die was hit extremely hard and is just a TAD higher than the rest of the die, it may cause issues like this. On zinc cents it is VERY common to the split zinc plating, which will eventually cause the coin to fall apart. If you have more zinc cents, look around the obverse of the coins, especially between the rim and In God We Trust, and you'll see more of the split plating that Bio is talking about. = )
The workers would take a punch, that had the mint mark on it, and a hammer and punch the mint mark onto the die. Then that die was used to make coins. I can imagine, if a mintmark on the die was hit extremely hard and is just a TAD higher than the rest of the die, it may cause issues like this. On zinc cents it is VERY common to the split zinc plating, which will eventually cause the coin to fall apart. If you have more zinc cents, look around the obverse of the coins, especially between the rim and In God We Trust, and you'll see more of the split plating that Bio is talking about. = )



















