U.S. Proof Coin Sets
1999-Present with State Quarters
Each year, from 1999 through 2008, the U.S. Mint has produced five different state quarters. Each quarter has an unique reverse design that is emblematic of the particular state. The obverse of the coin remains a constant, a portrait of George Washington.
Proof coins are produced when two dies strike a blank piece of metal with tremendous force. One die is engraved with the front (obverse) design for the coin, while the other die has the back (reverse) design. A proof coin is made with a specially treated die. Through this process, it gives the coin a different appearance. Modern technology allows the high points on the coin design to be acid treated. The background (or field) design of the coin die is polished, resulting in a mirror-like look on the coin when it is struck. The raised parts of the coin have a frosted-look to them. This contrasting finish is often called "cameo." On some older coins a cameo appearance is quite rare. When the attribute "CAM" is added to a coins description, it means cameo appearance. "DCAM" means deep cameo and indicates that this special appearance is strong and easy to observe.
Composition Sacagawea Dollar: 77% Copper, 12% Zinc, 7% Manganese, 4% Nickel
Composition Jefferson Nickel, Roosevelt Dime, Washington Quarter, and Kennedy Half Dollar: 75% Copper, 25% Nickel
Composition Lincoln Cent: 98% Zinc, 2% Copper
U.S. Proof Coin Sets are sold with the original U.S. Government protective plastic packaging.
U.S. Proof Coin Sets: 1999-Present with State Quarters