Misaligned die, finned rim, and collar clash.
It looks like dried glue. If the patch is raised above the rest of the field and design, then that's what it is.
It's a dime that was struck a second time with cent dies. In other words, a double-denomination error. The question is whether the cent dies...
This is a common alteration known as a "Texas cent". The cent was flattened between two relatively soft surfaces, like leather.
Any apparent doubling is undoubtedly due to die deterioration.
As others have indicated, these are uncentered broadstrikes. While some broadstrikes show cupping, this would not make them die caps. By...
What you have is severe die deterioration accompanied by at least one die chip. It's the sort of deterioration that plagues the America The...
Although the coin is in bad shape, it does appear to have been struck through a little bit of "grease".
It's a die break, specifically a "cud". The outer margin of the die broke off, leaving a raised blemish on the coin.
The nickel is a cupped off-center strike. You can alternatively describe it as an off-center strike combined with a stiff collar error. The...
It's more off-center than most. I'd guess it'd bring at least $50 on eBay.
I haven't heard of a clamp being using, but I suppose it's possible. I've seen several cases of incuse roller lines (at least I presume they're...
Nice example of the kind of streaks I wrote about.
Just the writer (me).
In my opinion, these are not improper alloy mix errors. I strongly suspect they are roller marks. See this article for more information:...
It could also conceivably be a Panama half balboa planchet. These were minted on the same silver-clad planchets that the half dollars of previous...
It's not an error and it's not post-strike damage. The planchet was strongly upset and there was a well-developed bevel connecting the apex of...
Maybe 25c.
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