I am surprised that no one asked the OP about the condition of the obverse or reverse. For a 25 year old coin it’s entirely possible that the edge is simply worn down isn’t it?
We either need a photo or you need to post to a coin forum.
Not really no, the reeding would be the last thing to disappear , it wouldn’t even be recognizable as US currency and still have signs of reeding showing.
The penny without any markings at all was probably from a mint tour. They give penny blanks to the attendees as a souvenir (sealed in a little plastic bag when I went, but it would be easy to take it out of the bag if you wanted to).
I have what I think is a unique us quarter, with a raised edge, not reeded, and very lightly stamped observe and reverse, 1983. is it worth anything?
If you can find 3 more of them, I’ll give you $1 for the set!
Mint errors aren’t that uncommon. I have a bunch of off-center pennies, and a quarter that is missing it’s nickel clad (it’s just looks like the brown cupro-core, but with the correct obverse and reverse). I have some double-struck coins, and some coins struck only on obverse or reverse, but not both. I don’t know what the exact mechanism would be, but I suppose a quarter could miss getting the edges reeded, and it could also miss inspection and end up in circulation.
I doubt it’s worth anything, but it’s a neat curiosity, and I’d hang onto it.
The most unusual “mint error” I own is a Lincoln cent, triple-struck, with the 2nd and 3rd strikes extremely off-center. There are two additional partial Lincoln heads on the obverse, and two additional partial Lincoln Monuments (one broadstruck) on the reverse.