Mint-made errors occur when coins are made incorrectly at the mint, including anything that happens to the coin up until the completion of the minting process. Mint error coins can be the result of deterioration of the minting equipment, accidents or malfunctions during the minting process, or interventions by mint personnel. Coins are inspected during production and errors are typically caught. However, some are inadvertently released into circulation. Modern production methods eliminate many errors and automated counters are effective at removing error coins. Damage occurring later may sometime resemble true mint errors. Error coins may be of value to collectors depending on the rarity and condition. Some coin collectors specialize in error coins.

The Mercury dime is a ten-cent coin struck by the United States Mint from late 1916 to 1945. Designed by Adolph Weinman and also referred to as the Winged Liberty Head dime, it gained its common name because the obverse depiction of a young Liberty, identifiable by her winged Phrygian cap, was confused with the Roman god Mercury. Weinman is believed to have used Elsie Stevens, the wife of lawyer and poet Wallace Stevens, as a model. The coin's reverse depicts a fasces, symbolizing unity and strength, and an olive branch, signifying peace.