Here are five pennies, all in the 70's that I suspect may be D/D's. I find many of the 70's pennies to have mint marks that are very blobby and indiscernible as it is. These just look to have another layer/tier but it may just be PMD/DDD/MD or even D/S. Thanks in advance! 1) 1973 D - Possible DDD since I see tiers on the left and right of the D. 2) 1974 D 3) 1976 D 4) 1978 D 5) 1979 D - For this year, according to one reference, it appears that the reference error shows not only what to look for, but also an "A" impression looks to be inside of the D. Similarly, an "A" looks to be incused on mine, but a little higher up. I don't really see the notching the arrows are pointing at, but there is a tier on the left.
1). MD: look at the right side of the 973. 2). D took a hit to top left. PMD. 3). MD: look at right side of D & 6. 4). Hit top left. PMD. 5). Hit top left. Look at pic provided. There is a notch like a V splitting each individual Mint Mark. It shows that there were 2 separate MM punches into the die. Those are my opinions anyway. Wait for more.
I agree too - BUT have a question as to what kind of mint damage makes the date and mint mark look slightly doubled??
iPen - if you ever see the same effect on the mintmark and the date at the same time, it is extremely likely that it is machine doubling. There are DDO's with RPMs known, but they are very uncommon. This is a function of how the die was created - the hubbing process took place first (where a true doubled die would be formed) and then the mintmark was individually punched into the working die. All of the coins that you posted show machine doubling or post mint damage. As a further note (not just for you, but for many people on these forums) - I highly encourage you to find and read a book about the minting process, learn how doubled dies are created, and what they look like. The number of actual doubled dies posted here is incredibly small, and the number of machine doubled or strike doubled coins posted here is incredibly large.
Yeah that makes sense about it being an MD if there is doubling in the date and mint mark. I understand the die making process at the basic conceptual level (the method described in your first paragraph makes complete sense, but I acknowledge that it's just a basic overview). I'm sure there's a lot of reading material that gets deep into it, but for now, I found this video. I think it was posted on this forum before, but it's relevant now.
Also on 1979D cents, the mint mark always look s like an RPM. In fact though it was a damaged D punch. That D was used on several denominations but again, it is the result of a damaged punch and they all look like that.
