So, so difficult to get pictures of this I hope my labels help. Is this a common error? Damn it! 1990 D!
That is a great question. There are 2 one was 1991P and the other was a state quarter. I didn't even think about that making a difference. Let me see if I have another 1990 to compare
The collar is the 3rd die, creating the reeded edge and will wear and deteriorate just like the obv and rev dies do.
@expat beat me to it. Being part of the minting process, the collar, i.e. the reeding, is subject to wear just like the dies, so I would expect to see some variations.
A few things come to mind: is there a difference in the diameters of the two specimens? It could be that the reeding is affected by the diameter. It's a possibility that the collar is worn too, as Collecting Nut suggests. Or combinations of these two and other factors. Probably all within tolerances, but maybe on the edge here-or-there.
You guys are probably right, but I thought I might as well share something I found that is similar: https://www.error-ref.com/collar-damage/ "The upper member of these two 2008-P New Mexico quarter dollars displays unusually wide, flat valleys between the reeds, with the valleys carrying heavy horizontal scratches. This appearance reflects the fact that the ridges on the working face of the collar were abraded and truncated. Similar damage is known from other dates, including 2007-P Wyoming quarters. This damage may have been produced when the beveled entrance of the collar was being machined or de-burred. The rotating machine tool may have slipped into the functional portion of the collar, damaging the reeding."
