I believe that a common effect to see on steelies. I don't think it's an RPM. Then again, the pics aren't the clearest...
I cleared it up here at home just a min ago, and it dont look like anythind but a blemish, I Will keep Looking got more coins in , today,, They might be good ones, 90 year family member past a few years ago, And his doughter asked me if I wanted to by all his old coin's , And I just can't say no, So I dished out the cash..But I will Have to post any silver, I don't know anything or any errors there! I only Mess with pennies.. Thanks NoN cents
CLEANED IT UP? Although there are millions of them but of all the coins out there steel & zinc coins are most susceptible to corrosion issues. It costs more to clean them then they are worth.