U.S. Proof Coin Sets
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 Roosevelt Dimer, Washington Quarter, and Kennedy Half Dollar: 90% Silver, 10% Copper
Composition Jefferson Nickel: 75% Copper, 25% Nickel
Composition Lincoln Cent: 98% Zinc, 2% Copper
U.S. Silver Proof Sets are sold with the original U.S. Government protective plastic packaging.
U.S. Proof Coin Sets: 1999-2007 Silver