This 1979 Jefferson Nickel is a special coin from the United States, minted in San Francisco, designated with an 'S' mint mark. It belongs to the Jefferson Nickels series, which is known for its iconic depiction of Thomas Jefferson on the obverse, with Monticello featured on the reverse. As a proof coin, this nickel exhibits a high level of detail and a mirror-like finish, making it a favorite among collectors. The coin has a composition of copper-nickel, weighing in at 5 grams, with a diameter of 21.21 mm. It is a 5-cent denomination, often referred to as a nickel or half dime. With a total mintage of 3,677,175, this piece is relatively common among proof nickels but remains a significant addition to any collection, especially for those focused on U.S. minting history or Jefferson Nickels. Its combination of a clear production history and minting attributes makes it an excellent example of late-20th-century U.S. coinage.