Coins - 1998 Proof Set Certificate of Authenticity and Coin Specifications

The US Mint added a folded card in the 1998 proof set with a message from their Director certifying the five proof coins, providing the coins' specifications and describing the proof set process.

The outside of the folded card has a shiny finish. On the front, green script states, "Certificate of Authenticity." In the middle of the card above the script, the US Mint's seal is printed in green ink. Inside the outer circle of the seal, the words "TREASURY" and "UNITED STATES MINT" show in white letters on a green background. In the inner circle, a white shield includes scales at the top, a chevron with thirteen stars in the middle and a key at the bottom.

The Director of the Mint provides a message inside the unfolded card that certifies the five proof coins and describes the proof coin process.

The text states:

The United States Mint certifies that these proof versions of current United States circulating coinage were produced and packaged at the United States Mint, San Francisco, California. Each coin bears the mint mark “S” designation of that facility.

United States proof coins are produced from carefully selected planchets, or blanks, that have been burnished to a high luster. The polished blanks, which are carefully handled to minimize scratches and abrasions, are struck on specially adapted coining presses. Each coin is struck at least twice to bring forth the most minute detail with remarkable clarity.

The surfaces of the coinage dies for striking proof coins are meticulously processed to create a frosted appearance of the image on the die. The background surface is polished and buffed to a mirror-like finish. The dies are also buffed during the striking process.

The finished coin with its frosted cameo image on a mirror-like field is carefully inspected—with gloved hands to protect its surface—before being assembled into sets. The proof coins are then placed into transparent presentation cases.

Proof coins, referred to as “Master Coins” in the early days of the Mint, were originally produced to “prove the correctness of the dies.” These first pieces, struck with extra care and bearing a high polish, were reserved for the Mint’s Cabinet of Coins Collection and sometimes used for special presentations. They were first offered for sale to the public in approximately 1858 and are produced under the authority of Section 5111 (a)(3), Title 31 of the United States Code.

Proof coins are a supplemental program of the United States Mint, produced at no net cost to the government, with profits deposited to the General Fund of the Treasury of the United States.

Philip N. Diehl
Director
United States Mint

Turning the folded certificate of authenticity over, a table includes the specifications for each of the proof coins in the 1998 proof set.

The specifications include:

To preserve the beauty of your proof coin set, store in a cool, dry place.

Click 1998 Proof Set to view the coins and contents of the proof set package.