On July 17, 2009, the United States Mint released the 2009 Silver Proof Set. This annually produced set contains coins struck with a composition of 90% silver. The set has been produced since 1992 when the set contained only five coins. This year’s set contains a whopping 18 coins and contains a wide variety of compositions beyond the 90% silver coins.
First the 90% silver coins. Despite the sets name, less than half of the coins in the set have a silver based composition. This includes the Roosevelt Dime, Kennedy Half Dollar, and the six DC & US Territories Quarters featuring the District of Columbia, Puerto Rico, Guam, American Samoa, US Virgin Islands, and Northern Mariana Islands. The composition consists of 90% silver and 10% copper.
Next, the Jefferson Nickel contained in the set contains a composition unique to the coin. It is minted with a composition of 25% nickel and 75% copper. This predominantly copper based composition has been used for the five cent denomination since 1866.
The five different dollar coins included in the set consist of the Native American Dollar and the four 2009 Presidential Dollars honoring William Henry Harrison, John Tyler, James K. Polk, and Zachary Taylor. These coins have a composition which consists of 88.5% copper, 6% zinc, and 3.5% manganese, and 2% nickel. The coins have a core of pure copper, with an outer layer consisting of an alloy of the four metals. This composition was created for the Sacagawea Dollar, first released in 2000.
Lastly, the Lincoln Cents included in the set contain a special copper based composition. Since 1982, Lincoln Cents have been struck with a predominantly zinc based composition, however, for 2009 all Lincoln Cents issued by US Mint in annual collector sets contain the original composition of the Lincoln Cent. This composition consists of 95% copper, 3% zinc, and 2% tin.