This is perhaps only semi-relevant... some years ago, I opened a roll of quarters from the bank and found one (dated 1983) with huge bubbles in the metal, opposite each other on the front and reverse. (see back of Washington's neck, and eagle's left wing in the photos) For what it's worth, you can see that the coin also has dark staining on it, from an unknown source. A couple years ago I showed it to a coin dealer in NH and he produced a similar coin (1970s) that a customer wanted graded and slabbed by PCGS. Some months later I visited the dealer again and he said that the company had declined to grade or slab the coin, stating that they were uncertain of its authenticity. As they are one of the top two grading outfits in the country, I am unsure how to interpret this. Can they really not be sure if the coin is genuine? Or perhaps PCGS had a pretty good idea the coin was fishy but decided the easiest way to deal with it was to simply send it back and avoid getting involved? I still don't know the story on my quarter; but I have measured it, weighed it, felt it and smelt it, and the darn coin just seems like the real thing. It remains a mystery how the copper-nickel layers could have separated out like that, not to mention the quarter continuing go through the production machinery!
Mint equipment has been changed during the past 20 years and it is much harder for error coins to be produced; and if they have, to find their way into circulation. Someone with decades of coin experience told me that he knows of even small denomination coins having been counterfeited -- nickles, dimes, quarters-- very possibly in Asia. And now that silver is hitting high prices, Morgan silver dollars from the 1800s are being faked (China is specifically suspected) -- often with the coveted Carson City mintmark (CC). They are base metal plated with silver. The diameter is off (38.1 mm on the real thing) and it does not ring like a real silver dollar when dropped onto a tabletop. Just joined the site today... sort of amusing that my first post is about coins, not marbles!
