Find a pile of coins while metel detecting and seen some weird things on them my friend says she sees it.
From 1938-1964 the Jefferson Nickels had their mint marks punched there. EDIT: Not on the war nickels
A possible re-punched mint mark on the 1979, ( note the split serif at bottom of MM ) a filled mintmark ( die chip ) on the 1977, the rest looks like damage or die deterioration.
On the 79 the 9 and the D or both doubled or printed over something if you zoom in on the left bottom corner there is a doubling... On the D
I see it. I see little things inside the 9, too, and under the 9, but not all the way under, just half way.
Some are die deterioration , some are wear, the one 79 D looks like it could be a rpm. Go to Varietyvista.com click on Roosevelt dimes then the rpm tab. Match up your mm to those known under the date and mm.
That D on the 79 reminds me of the rmp on a 79 Lincoln. But when you zoom in. It looks like it took a hit, All these coins have been heavily circulated, and have come from the ground IE environmental damage. It is anybodys guess. Here in CO they all come out of the ground Dark red or Black.