My coin is missing a Mint mark, words, letters or numbers. Where did they go?
Your coin most likely features a filled-die error. A filled die occurs when grease, dirt and metal particles compact into a die. The dies that strike coins are recessed so that when they strike a planchet (a metal blank), the metal of the planchet rises to fill in the die. That’s why letters, numbers, words and designs are raised on coins. If the recesses of the die fill up with sludge, (which is a very common occurrence in a factory like the Mint), this sludge will prevent letters or numbers from forming during the strike. A filled die is a very common form of minor error and does not add numismatic value to the coin. Filled die errors are known on every series and denomination of coin ever struck by the U.S. Mint – from the very first large cent to the State Quarters being struck today. You should also know that many U.S. coins do not bear Mint marks on purpose. All coins struck at the Philadelphia Mint from 1793 to 1978 lack Mint marks, except for some 1942 to 1945 5-cent coins. Beg
