Have you ever noticed the letter D on your coin above the year? Have you ever wondered why some U.S coins have a D, and others don't? We decided to have a streetonomic look at US coins, to find out what the D is for, and what it means.

It turns out that 'D' which is found on around half the US coins in circulation, is a mint mark. Philadelphia and Denver are the only two mints in the United States which produce coins for general circulation. Coins minted in Philadelphia do not have a mint mark. Coins minted in Denver are marked with a 'D' for Denver.

It is possible, that you may find some coins with an 'S' mark, while these are more rare, than other coins, they are no more valuable. The 'S' means the coin was minted in San Francisco. Production of coins from the San Francisco mint was put on hold for 10 years from 1955 After 1965, San Francisco continued to mint a limited amount of coins which were marked with the 'S', until the early 1980s, when it was decided that San Francisco would not use any mint mark at all. The San Francisco Mint no longer produces coins for general circulation in the U.S