When we make mistakes with our money, it’s usually bad for us. When the mint makes mistakes with our money, it can be wonderful for us.
An example of an error minted coin with a mechanical error would be one that did not eject properly and got double stamped.
Sometimes the mistake is in the production of the die. This means the mistake will be replicated time and again until someone catches the error.
First, the mistake has to be popular -- people have to know about it and collect it.
In 1955 there was a remarkable mistake: a double die. The date and “in God we trust” are on each coin twice, rotated slightly. It can be seen with the naked eye. “They maybe made 40,000 of them,” said Coops Coins co-owner Randy Briggs. “It was enough to make that coin worth $500 to $1,000.”
In 1942 one mint had leftover 1941 dies, so someone decided to make new dimes on the cheap by just stamping a 2 over the 1. You can see both. “They made maybe 50,000 of those and it’s pretty darned obvious,” Briggs said.
When there’s a mistake, minters stop making them as soon as they discover it, and they try to recover the coins.
But they make thousands of coins a minute. By the time they catch it, bags and bags have gone through the sorting machine and shipped. They let those go and move on.
In 1969 a 1-cent piece was really significant. “One came through my door here,” said Briggs. “A guy found it in 1971, brought it in and we sold it for $35,000.”
That batch of mistakes is a double die. It will have an S mint mark. The doubling is on the front, on the portrait side of the coin.
If you think you have an error, take it to Briggs at the shop and he will have a look at it.