Found this in a mint set looks interesting, although I'm not sure what's going on with it. Sorry for pictures had to take them through the cellophane, but they show it well enough.
@rickmp But.. I was thinking also the following.. Rusted Die If not, then I just wanted to share with you http://www.error-ref.com/rusted-die/
@paddyman98 I did come across that rusted die page while looking for something similar. I've just never seen evidence of a rusting die on a more modernish coin before.
paddyman98 is correct...rusted die. This is very common on the 70D Kennedys. The rust pits make for a good die marker for some of the 50c 70D DDR's. like the 70D DDR-001. Larry Nienaber
I asked this exact same question many years ago on the CU Forums and the overwhelming response from the experts was "Rusted Die". I expect this was because the 70-D Kennedy was never intended for circulation and only included in the US Mints sets, As such, the dies were negrlected or at least this one die was neglected. The hoopla surrounding the 1970-D Kennedy was HUGE and I mean HUGE with prices "beginning" at the $20 mark per coin. The mint sets were commanding huge premiums over the 68's and 69's simply because the mintage of the 70-D was so freaking low at 2.150 million. That was nearly a half million coins lower than the 50-D Jefferson and was unheard of for a circulation coin. But, rusted die pits. I've got one.
@19Lyds yep that's exactly how my coin looks. I had trouble capturing the lines going through the D but they look exactly like your example shows. I generally keep all 70 D's I come across in my general collection pile, but I think this one is neat and will move it into my collection that I hang onto and never sell or trade from. I also like your explanation it makes sense that the mint probably let the dies sit around between runs.
IF you've ever had the opportunity to work with a "bare", freshly cleaned engine block, then you'll no that cleaned and polished surfaces rust with amazing speed. If the above die had not been oiled (which I suspect it had not) then the corrosion occurred rather quickly. Perhaps the die stack was the culprit prior to the die making process? Someone with far more experience in metallurgy and die making woul have to examine a fair number of these specific coins to make an accurate determination of what really occurred.
