Mint marks are letters or symbols used to identify the particular mint that made a coin. They also reflect an important role in assigning responsibility for coinage and keeping production standardized. The custom reaches back to ancient Rome and Greece, while the United States adopted mint marks in 1838. Most modern U.S. coins use a “D” for the Denver Mint, “P” for Philadelphia, “S” for San Francisco, and “W” for West Point, New York. Because U.S. Mints have changed over time, these marks can also help indicate a coin’s rarity and value.
The History of Mint Marks
These marks were placed on coins to show which facility produced the coinage if a question arose about metallic composition. Mints were located in areas with dependable access to raw materials. Every year, each mint sent coin samples to U.S. Mint headquarters for review by a board of inspectors. The inspectors then measured each piece for diameter, thickness, and weight to see whether it met the recommended precious-metal composition.
Inspectors also chemically tested coins to determine whether they had the correct fineness of precious metal, generally gold or silver. If a coin’s quality fell below standard, the inspectors would investigate the mint responsible for it. However, because the coins circulating in the United States at the time of publication did not contain precious metal, mint marks primarily continued as part of the marking tradition.
Location of Mint Marks on Coins
In the United States, most coins dated 1964 or earlier display mint marks on the reverse. Coins dated from 1965 through 1967 lack mint marks because of the Coinage Act of 1965. The practice resumed in 1968, when the mark was permanently moved to the coin’s front. Since Philadelphia was the original U.S. Mint, many coins produced there have no mark. On most coins, the mark appears near the bottom, close to the date, or beneath the eagle or wreath.
A coin’s mint mark may significantly affect its value. When this article was originally published, Atlanta Gold & Coin Buyers said its evaluation process considered several factors, including identifying the mark and the place where the coin was made. The original article reported regularly purchasing rare and numismatic coins, along with platinum, gold, silver, and palladium coins at competitive prices. At publication, readers were invited to contact 404-236-9744 to arrange a private meeting.
