You can find most popular coin collecting phrases in this coin glossary.
D mint mark - mintmark used to designate that the coin was struck at the US mint in "Denver Colorado". Between 1838 and the civil war the "D" mint mark was used by the US mint in Dahlonega Georgia. DCAM - see "Deep Cameo"
damaged - A damaged coin would be one that has had something happen to it to cause a defect. Examples would be: holes, bent, major nicks, corrosion, scratches, mutilation. Usually makes the coin worth much les than one without any defects.
denomination - different values of money. For example US coins currently have 6 different denominations: cent, nickel, dime, quarter, half dollar and dollar.
deep cameo - describes the appearance of some proof coins. A coin with a cameo design will have a somewhat frosted appearance to the raised features of the design, with a polished or mirror like background (field). Deep cameo means this frosted cameo effect is very obvious. Often, a proof with this attribute will be of higher quality and may be rarer, particularly in older proof coins.
denticles - small tooth like raised areas around the edge of a coin. Particularly on older coins. Often found all around the front (obverse) and back (reverse) of the coin, right next to the edge.
designer - artist who creates the design. Not the engraver (who actually makes the coin producing dies). Although, in years past some designers were also engravers.
die - an engraved metal stamp used for stamping out the design of a coin. The die is often hardened so that when it strikes the metal blank an impression will be left indicating the coins design, value, and wording. See "anvil die" and "hammer die"
die clash - damage to a coin die that occurs when the top and bottom dies collide without a coin in the press. The dies will may hit each other with such force that they damage each other leaving a trace of the impression on one or both dies. Resulting coins produced may exhibit "clash marks". Clash marks will show some of the reverse design on the obverse side of the coin, some of the obverse design on the reverse, or both.
die defect - damage or defect of a coin die. The coins produced by that die will exhibit the same defects.
die trial – this is any off-metal striking from production dies. In the early years, pre-1800, die trials were just that; coins struck to test the dies. In later years, the 1860s, 1870s and 1880s many were deliberately struck for sale to collectors often in complete sets. Many so-called die trials are actually off-metal restrikes. Examples of this include trimes, half dimes and dimes offered in sets with such coins as the 1863-1865 with motto reverse coins. Other die trials are actually mint errors. Possible candidates include Indian cents, plain edge half dimes and three dollar pieces struck in nickel.
die variety - an alteration in the basic design of a coin. Comes from slight differences in the designs on the dies used to stamp coins.
dipped (dipping, dip) - a coin that has been treated with chemical solution to enhance its appearance. Solutions are often a form of diluted acid.
doubloon - nick name given to a popular Spanish gold coin. Often associated with pirates and buried treasure.double die - a coin that shows numbers or letters doubled. Caused by the coin die having been made with a doubled design on parts of it. Example: 1955 double die Lincoln cent.
double eagle - used to describe a twenty dollar gold piece, the likes of those made between 1850 and 1932. Called a double eagle because the gold content was twice that of an "eagle" $10 gold piece. Double Eagle gold pieces contain "almost" an ounce of gold.