Akey date is a term used incoin collecting and it refers to a date (or date andmint mark combination) of a given coin series orcoin set that is harder to obtain than other dates in the series. A key date coin is usually one with a lower mintage total and it is more valuable than others in the series. Many coin collectors collect coins to fill out a complete set of a series.
There are also semi-key dates in coin collecting. A semi-key date coin is typically one that is not as rare as the key date. The semi-key date often sells for a premium over common date coins, but less than the cost of a key date coin.
A key date is the term for a coin which is scarcer and harder to obtain in a series.[1][2][3] Often coins with certain years orMint marks are key date coins.[4][5] Some factors that influence whether a coin is a key date include: demand, quantity of coins struck, the population of surviving examples and rarity of mint sate examples. The cost of the key date coins in a series are usually the most expensive to obtain.[6] The coins are also often referred to as the rarest in a series.[3]
Key dates are an important component of coin collecting because many collectors collect coins which fill acoin set: key date coins are the most important. They are valued by collectors because they are needed to complete coin sets.[7]
For the United States collectors of theLincoln cent series, the1909-S VDB Lincoln Cent is the rarest and most expensive of cents.[8] The 1909-S VDB Lincoln cent is considered to be a key date due to its low mintage of only 484,000.[9]
The United States1893-S Morgan dollar is known as the key date in the Morgan series.[10] The 1893-S Morgan dollars were struck at the United StatesSan Francisco Mint. Only 100,000 coins were struck making it the lowest mintage of anybusiness strike Morgan Dollar.[11]
The next level of difficult to obtain coins in series are often referred to as semi-key dates or simply semi-keys.[12] The semi-key date coins are scarce and sell for a premium but they are not as scarce and rare as a key date.[6][13] There are not rules which determine which coins are semi-key dates. Some coin collectors the coins in the series with lower mintage figures to be semi-key dates.[6]
Numismatic Guaranty Company (NGC) produced a list of counterfeited coins: many of them are key date coins. One of the most common methods of counterfeiting involves adding a mintmark to the coin, in order to turn it into a key date coin.[14]
