Bottom left of the D is what appears to look like a leg or something of metal. Sorry for the poor picture but all I could do to take a picture is take a picture through the loupe. Any help is appreciated
To me, it looks like the normal serif on the "D" got mashed by something post-Mint. It may be accidental but more likely intentional.
Having the serif is almost universal, isn't it? I don't ever recall seeing a Helvetica mintmark on U.S. coins.
I've seen subtle serifs and I've seen obvious ones, but I don't honestly remember ever seeing a U.S. coin's mintmark without serifs. Even the "CC" has the "top of the C" serif.
I apologize. My mistake thought the mint mark had no serif but it was just worn down to the point of the appearance of sans serif
Just like words, emotions, and (apparently only) certain colors, reality does "matter" too.... Nah... scratch that. Participation trophies for all!