Some dates are listed using different calendar systems. For example, many Moroccan coins use the Islamic calendar and Nepali coins use the Vikram Samvat calendar.
Measure the diameter with a ruler, preferably using the metric increments. Measure the thickness with a caliper. Handle it carefully to avoid damaging the coin.
Color is not an absolute determiner of the metal a coin is made of. A golden color may mean the coin is made of brass, while a silver color may mean the coin is made of a copper-nickel alloy. In the latter case, turning the coin on its edge can help to determine whether the coin is a clad coin using the copper-nickel alloy to sandwich a copper core layer. A clad coin of this kind will show a stripe on its edge. If still in doubt, you can also test the coin with a magnet. If it’s attracted to the magnet, the coin is made of steel, has a steel core, or is steel-plated.
Although large cents minted in 1792 depicted George Washington’s image, it was with the Lincoln penny in 1909 that American coins began to regularly depict presidents and other statesmen. Prior to that, most American coins depicted Liberty as a female figure, shown standing, sitting, walking, in bust form, or just her head. (The so-called “Mercury” dime issued prior to 1946 is properly called the Winged Liberty Head dime. ) Most other coins depict an image of the ruler in power over the country or territory for which the coin was issued, either locally or nationally. Consulting a history book or website can help you identify who the ruler was. Note the image on the reverse (tails) side of the coin as well as the obverse (heads). This sometimes changes over a period of time separate from the obverse image. For example, the Lincoln penny bore a pair of wheat ears from 1909 to 1958, then an image of the Lincoln Memorial until 2009, when it was replaced with a shield.
American coins usually state “United States of America” somewhere on the coin. They also usually bear the word “Liberty” and the mottoes “E Pluribus Unum” (“out of many, one”) and “In God We Trust” (first used in 1863, on all coins since 1938). Non-American coins bearing English inscriptions probably were issued by other countries that were formerly British colonies and may be part of the British Commonwealth of Nations, such as Canada or Australia. Older British coins in contrast, generally display the Latin “Britannia” or some variation of it such as “Britanniar” or “Britanniarum. " Coins issued prior to 1953 commemorating the rule of a particular monarch may include “BRITT:OMN:REX,” short for the Latin phrase meaning “King (or Queen) of all Britons. " Irish coins issued during the rules of Kings George III and George IV (1760 to 1830) displayed “Hibernia” (the Latin name for Ireland), as all of Ireland was part of the United Kingdom at that time. Coins from other British territories may include their colonial names in Latin as well. Latin inscriptions are common on most older European coins as well, including those from countries whose languages don’t derive from Latin, such as Austria, Germany, Hungary, the Netherlands, and Poland. French inscriptions may be found on French coins and also those from Belgium, Canada, French Guiana, or another French colony or overseas department. Spanish inscriptions may be found on Spanish coins and also those from Mexico, Guatemala, Honduras, Panama, Costa Rica, Colombia, Venezuela, or any other country formerly a colony of Spain. Portuguese inscriptions may be found on coins from Portugal or Brazil, or from any other former Portuguese colony. Not all countries use the Roman alphabet to write the legends on their coins, however. A good reference catalog can help you identify other alphabets, such as Arabic, Chinese, or Cyrillic, and which countries use them.
Current American coins bear the mint marks P (Philadelphia), D (Denver), S (San Francisco), or W (West Point). Other mint marks, for coins minted during the 19th century, include C (Charlotte), O (New Orleans), and CC (Carson City). If the coin has no mint mark, it was likely minted in Philadelphia, which did not use a mint mark until World War II, and then dropped it again until 1968. Spanish colonial-era coins marked with a capital “M” and small “o” were minted in Mexico, while a “G” represented “Guatemala” and a “CUZ” represented “Cuzco” (Peru). Sometimes the same mint mark represented different locations at different times, such as “P” representing Popayan (Colombia), Lima (Peru), or La Plata (Argentina). Other times, the same location may have had different mint marks at different times: Bogota (Colombia) used F, FS, SF, N, NR, or S during the two centuries coins were minted there. Mint marks may also be positioned at different places on the same coin design at different times. The American Jefferson nickel displayed its mint mark below and to the right of Monticello on the reverse from 1913 to 1941, over it from 1942 to 1945, below and to the right again until 1971, and on the obverse to Jefferson’s lower right after 1971.
