To identify the value of a U.S. gold coin, go to CoinStudy.com, and click Gold Coin Values on the right side of the page. Find the type of coin you seek, and determine its estimated value from the table based on the condition of the coin and the year it was issued. A numismatic service can identify the value of the coin more accurately. For foreign coins, go to World Coin Gallery, and follow the instructions.
Several factors affect coin values, such as condition, age, rarity, supply and demand. Age has the least influence on the value of a coin, such that coins from recent decades often cost more than coins from ancient civilizations. As for the condition of a coin, an uncirculated coin can cost 100 times as much as a coin in worn condition.
If a coin becomes popular among collectors, its value increases. However, if the demand for a coin is low, even an old, uncirculated coin can cost very little. Trends change regularly, so if a coin quickly becomes popular, its value can increase dramatically. Coins are also more valuable if minted in small numbers. The rarity of a coin is a strong predictor of its value.