Coin minting isn't precise. Even though most coins are perfect and consistent, tiny errors can produce valuable and fascinating error coins.
It's unclear if this coin error was intentional or accidental, as just three examples exist. The 1900 Indian-head penny die was used on a gold planchet to make a pure gold penny.
Not all valuable coin faults are old. One of the most valuable mistake coins is from 1999. Lincoln penny and Roosevelt dime on opposite sides. This sculpture sold for $138,000 in 2006.
Like the 1900 specimen, a gold planchet was produced with 1905 penny dies. Only one of them was found in 1905, making it the rarest. This solid gold penny sold for $123,375 in 2015 in gem-grade condition without circulation.
The rare 2001-D Lincoln cent mule is another recent coin mistake collectors value. The four known instances of this mule were likely struck by mistake on the same day. One perfect example sold for $114,000 in 2024.
This odd coin error has three pieces, but they form an Eisenhower dollar. Three dime planchets were connected in a clover leaf and struck using Eisenhower dollar dies.
An error doesn't always entail the wrong planchet or dies. This ultra-rare example uses an 1898 five-dollar gold coin as a proof 1970-S quarter planchet. Gold coins fit wonderfully because they're approximately the same size.
The "heads" side of a Sacagawea dollar planchet and "tails" side had George Washington's profile. No date is stamped on it, but it's probably 2000.
A die that hit the planchet off center is one of the worst coin blunders. The 1904 $20 double eagle gold coin portrays Lady Liberty in profile surrounded by stars, but a minting fault distorted the "heads" and "tails" sides to one side of the planchet.
A US currency emblem, the buffalo nickel is always silver. Most of the time. In 1913, a five-dollar gold half eagle was more than most people made in a day, yet one of these planchets was imprinted with buffalo nickel dies.
Off-center strikes distinguish the 1880-S Morgan dollar, like the 1904 double eagle. This strike is 40% off center. A major part of the coin has a blank planchet.