U.S. Coins – Technical

Below you will find answers to many commonly asked numismatic questions about coins minted in the United States. If you have a question that does not appear below or for more information about the American Numismatic Association, please contact us at ana@money.org or call 1-800-367-9723.

Our museum and library staff will be happy to assist you as you discover and explore the world of money. Depending upon the extent of the research necessary to answer individual questions, a research fee may be required. If a fee is required, our staff will provide you with a cost estimate before conducting research on your behalf.

  • What is a “proof” coin?

    The term "proof" is often mistakenly used to describe the condition of a coin. The correct use of the term describes a method of manufacture. Proof coins are made from specially prepared planchets and dies that are struck at least twice. The end product is a coin with a highly mirrored field and frosted detail. Proof coins are produced for, and generally sold to collectors. Even though proof coins are legal tender, the Mint sells them at a premium so they are rarely found in circulation.

  • What is an uncirculated coin?

    In theory, an uncirculated coin is a coin that has never been touched by human hands or used in commerce. A more practical definition of an uncirculated coin is a coin that shows absolutely no trace of wear. Due to the minting and transportation process, an uncirculated coin may exhibit flaws such as nicks or scratches as it encounters similar coins in a Mint bag.

  • What is a bullion coin?

    Bullion coins are coins that are produced out of precious metals and are typically sold to investors. Even though bullion coins have a denomination and are legal tender in the country from which they were minted, their value is determined by the spot price of their metal content on the world market, rather than the collector or numismatic value. The U.S. Mint currently produces bullion issues in three metals: silver, gold and platinum.

  • What is a mintmark?

    What U.S. Mints are currently operating? A mintmark is a record keeping device for the mint. Mintmarks designate where a coin was struck.

    Mintmarks, or more often, the lack of a mintmark, can be confusing. Until 1980, most coins minted in Philadelphia did not bear a mintmark and U.S. cents produced at that mint still do not. Before assuming the lack of a mintmark dictates an error, consult a value guide to determine which mintmarks were used in a given year.

  • I have recently seen two coins with two heads or two tails. Are these rare and valuable?

    In most instances, a two-headed coin is a fantasy piece. Two coins have been altered to produce one coin. Usually these coins are sold as novelty items or as magician's tools. As an altered piece, the coin holds no legal tender or numismatic value. Examples of legitimate error two-headed coins have been discovered. If you are unsure as to the authenticity of your coin, consider taking your coin to an  ANA affiliated dealer.

  • I have a quarter that looks like an accordion. What is it?

    In 2003, the U.S. Mint began using machines into which error coins were fed during the quality control process. The machines create a distorted or "waffled" surface on the coins.

  • Do older coins have more value then newer coins?

    Not necessarily. The age of a coin is not as important as other variables in determining the value of a coin. Three primary variables that determine value are mintage number, condition and demand. In general, U.S. coins that have little or no wear and small mintage number s are highly prized regardless of age.

  • My coin has an error, some of the date or design is missing. What should I do?

    Although the U.S. Mint adheres to strict quality control standards, errors in coin production do occur. Values are based on the rarity and severity of the error, as well as the denomination. It is best to take the coin to an ANA affiliated dealer. The dealer will first determine whether the coin is a true error or a coin that had been altered after entering circulation. If the dealer determines the coin to be a legitimate error, they can then give guidance as to its value.

  • I have an old Continental Currency coin. It must be real because I found it in my grandmother’s jewelry box. How much is it worth?

    Many people believe counterfeit coins to be only a recent phenomenon. Actually, counterfeit coins have been around almost as long as coins themselves. Many copies of Continental Currency have been made. Most copies were not produced to deceive but were created as a souvenir to remind people of our colonial history. Many souvenir coins have the word "copy" engraved on the coin in an inconspicuous place. If you believe your coin to be authentic, take the coin to your local ANA affiliated dealer. They should be able to authenticate the coin for you.

  • I just purchased a colorized U.S. coin for my grandchildren. Can you tell me if it will be valuable in the future?

    While it is impossible to look in to the future and determine the value of coins, a colorized coin is considered altered and therefore has little numismatic interest. The coin may prove valuable as a keepsake but will most likely have little collectible interest above its face value.