During World War II, a few copper pennies were mistakenly minted instead of the zinc-coated steel ones. These rare coins can be worth thousands of dollars.
A small number of 1970-S pennies were minted with a small date, making them rare and valuable, especially in mint condition.
This coin features a mistake in the flag design, making it highly sought after by collectors and worth more than its face value.
Some 2007 Presidential Dollar coins were minted without the motto "In God We Trust," making them valuable to collectors.
In 1983, the Royal Mint mistakenly minted a small number of 2p coins with the old "New Pence" wording, making them valuable to collectors.
In 1992, a small number of pennies were minted with a close "AM" in "America" on the reverse side, making them rare and valuable.
This coin, issued to commemorate the Beijing Olympics, is sought after by collectors, especially the rarer versions with certain designs.
In 2000, a small number of nickels were mistakenly minted with the "P" mintmark (for Philadelphia) instead of the usual "D" (for Denver), making them valuable to collectors.