As many others have said, the perimeter of the obverse face was mechanically eroded. Ground off or polished off, in other words. The sloping...
As several others have correctly concluded, this coin was damaged outside the Mint. Both faces have been pummeled into a mushy mess, probably...
It's a lamination error, with some damage to the flap of metal that lifted off the surface of the coin.
It's a glue job.
The coin appears to be as thick as a normal quarter. Copper toning has invaded the obverse face. Both observations indicate that this is not a...
As far as I know, the source of this discoloration hasn't been established. Tying it to the annealing oven is simply a guess on the part of the...
I don't believe it is genuine. Too much of the "first strike" is preserved and there is too much blended overlap. I do see some of the sharp,...
It's collar clash. It's caused when the obverse die hits the top of the collar and/or scrapes along its working face. The obverse die would have...
Since the weight of this coin approximates that of a missing clad error, perhaps that's what it is. Perhaps the exposed copper core on the...
That's as light as a missing clad error. It's possible this started out as a genuine error and then the reverse was attacked with acid or some...
Very puzzling. As you say, the weakness at 5:00 and 7:00 on the obverse face would point to a genuine planchet error. On the other hand, the...
Rascal first took this coin to the CONECA Forum where he didn't find answers that satisfied him. So he took it to this site. It's clearly a case...
The coin that started this thread looks like it may have been struck through a very late-stage die cap.
The 2009-P dime appears to have been struck on an improperly annealed planchet. Excessive heat, prolonged exposure to heat, or excessive oxygen...
The Mint brings in coils of clad strip already cleaned by its suppliers. I don't know if they ever descale on both sides. I would assume one...
Die scratches arising from intentional die abrasion are largely confined to the field. However, they can show up in low relief areas, like the...
Wire brushes, emery sticks, and other abrasive tools are employed. Scratches vary in thickness from course to fine, pointing to the use of...
Incuse marks on planchets are more likely to survive the strike than raised marks. There are probably several sources for closely-spaced parallel...
A rotating descaling brush cleans the clad and core strip before they enter the bonding mill. Usually this is done only on the side intended to...
These may be roller marks or marks from a rotating descaling brush.
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