I have a 1955-S Roosevelt dime I looked in my Cherrypickers' Guide and it doesn't show one like it. The S mint mark is quite flattened, the lowest leaf on the left pointing to (UN) ITED is separated from thestem as is the berry below it. On the right of the C and left of the A in AMERICA are missing/very weak. The dime is at least an MS-64. The second coin I found quite interesting is a 1970-D Kennedy half dollar with die rust in the top of the E in STATES, in the AM of AMERICA, and above the ribbon of E PLURIBUS UNUM.
I would say the dime is just a strike issue and not a variety. Don't see anything about the half that makes me think, die rust.
The picture doesn't really show it very well but I have seen coins struck from rust pitted dies and the raised roughness of these areas look exactly the same. If you could see it in hand I am sure you would agree. The dime could be a result of die wear as you say but, I thought I would post it anyway for another opinion. Examining modern coins for die varieties is something I am new at and still learning.
For the dime my vote goes to a combination of a weak strike and some die polishing. As for the Kennedy I'm leaning towards die chips/damage although a rusty die is still in the running.
Extremely unlikely. The '70-D half was only issued in Mint Sets and only had a mintage of about 2 million. So there would be no chance for a die to ever get rusty. The entire mintage would have been run in a few days or less and only required 3 maybe 4 die pairs at most.
Good point. But, if it was something on the die those areas would not be raised, there would be depressions in the coin by that contamination being pressed into the planchet. This roughness is clearly raised up indicating a corresponding depression in the die itself for the metal to flow into. The physical evidence clearly indicates it is an issue with the die however it came about.
I agree and this is not uncommon for the 1970-D Kennedy. Definitely pitting of some type "on the die".
Thank you for posting these great images of the pitting 19Lyds. I just don't have the equipment to take such pictures. Apparently this coin is not anything more special than just being only made for mint sets.
I understand your thinking, but when a die gets rusty that rust creates pits in the die. So a coin struck with a rusty die always has raised bumps on it. That's the primary diagnostic for defining such.
Rust and die wear are not the one and the same. Die wear is the loss of detail caused by the use of the die. Rust, or more appropriately corrosion, is a result of the loss of metal due to environmental damage which pits the surface.
After seeing the images posted by 19Lyds, I would have to agree that that looks like die rust, not die wear.
While there are flow lines on the coin, the rough, pitted appearance of the anomalies do not really match up with what I have seen in terms of die wear.
Die wear can show up in many different forms many degrees of severity. A picture of wear on an actual die, courtesy of Matt -
Personally, I'd stop short at calling it "die wear" in that the die steel did not change dramatically from 64 to early 72 and I've seen plenty of "worn die" Kennedy's but don't recall seeing this anomaly on any of them. In late 1972, the die steel was changed to a harder alloy.
Out of the 12 - 14 reverse dies used to strike the 1970-D half dollar, at least three of them were infected with rust and even on early die state coins struck, the pitty can be seen. It was nothing to do with "die wear".
The photograph of that die shows a damaged die not a die worn from wear. A worn die will not be scratched or gouged. Wear occurs over a period of time, is smooth and exhibits lack of detail.