The four characteristics that have the most influence on a coin's value are condition, rarity, metal value and demand. The most valuable coins are those in perfect condition and of high rarity.
Coin conditions are graded on a scale of 1 to 70. Grades range from a coin that is so worn that it only has an identifiable date and type to a perfect coin that is as struck, full strike.
Rarity can be influenced by the number of coins originally minted and the estimated number of coins still in circulation. Truly rare coins are those with minting errors that were mistakenly released into circulation, such as errors in stamping, lettering and coin composition.
Older coins made with a significant percentage of precious metal can have increased value due to the intrinsic value of the silver or gold contained within them.