You could have a valuable coin or two jingling around in your pocket. We really do not look at the coins in our pockets, we just give them to a clerk or feed them to a vending machine. It is perfectly possible, however, that you might have a valuable coin in there. When you think about all the change that has passed through your hands, it's even probable. You could have had your hands on a coin or two worth hundreds of dollars!
Valuable Error Coins
The valuable coins most likely to go unnoticed are error coins. They get passed over because, superbly, they do not look any different than other coins. Even if you make it a habit to check the dates on your coins, you could easily still miss an error coin. You have to take a closer look.
Error coins are produced when a die miss-strikes a coin blank or has a defect in it. The die may produce a double image on one side of the coin, the images might not line up correctly or there may be a defect mark on the coin. If the mint discovers that a die is creating error coins, of course they correct the problem as quickly as possible. They also try to recover the error coins. So, when error coins do get into circulation they can be quite valuable.
Double Die Errors
Some of the more valuable coins have a slightly double image on one side. If the entire image is doubled, it is a double strike. If just part of the image is doubled, however, it is because the double image is on the die that stamps the coin. As you can imagine, these are very rare and valuable coins.
The most valuable double die coin is a 1969 S-Lincoln penny. It is very rare and, if it's in decent condition, could be worth $ 35,000 or more. Unfortunately, if you do find one, it's likely to be a counterfeit. Have it checked by an expert before you get too excited.
Axis Rutation Errors
These errors are actually fairly common in the new State quarters. The images on the opposite (front) and reverse (back) of a coin should be exactly 180 ° apart. If you hold the coin with the opposite straight upright and rotate it, the reverse should be straight downright. If it's not, the die was not lined up right. If both sides are straight up (a full 180 ° rotation), the coin could be worth about $ 20.00.
Sometimes the die develops a defect that gets stamped onto coins. Two examples of die defects are the 2004-D "Extra Leaf" Wisconsin State quarter, and the 2005-D Speared Bison nickel. A defect in the die for the Wisconsin quarter made an image that looks like the ear of corn on the back of the quarter has an extra leaf. A defect in the nickel die makes it look like there is a spear sticking in the bison between his front and rear legs.
You never know what you might find in your pocket change. There's probably not a valuable coin there. But you will not know unless you check it out, will you?