When the extra mint mark is flat and shelf like it's like I said above. There was some chatter in the coining chamber that caused this. A true doubled mint mark comes from the hubbing process, which is not what this is. A true doubled die is hub doubled, not strike doubled. There is a lot of good info on both of these terms on www.doubleddie.com. When it's faulty machine problems these are not errors, just sloppy coin making.
Most of the time when you see your Mint Mark and date doubled it's normally SD (strike doubling) or MD Machine Doubling from my understanding. Dave
Good eye Chris! Keep this one in a 2X2 and use it to remind yourself of the differences in doubling. It can be difficult at times. I still question myself!
More likely a die chip. The 1968-1974 "S" cents were notorius for die chips. I did enlarge your pic and am pretty sure it's a chip.
It could also be damaged. The 969 are worn flat at the top and on the right side. I can't enlarge the mintmark enough to see a chip.
I also can't tell if this is a proof coin. It is shiny like glass. It's this one real? I apologize if any of this is in the wrong spot I'm very new to all this and still learning thank you for your help and your patience.
