A Proof is a specimen striking of coinage for presentation, souvenir, exhibition, or numismatic purposes. Pre-1968 Proofs were made only at the Philadelphia Mint, except in a few rare instances in which presentation pieces were struck at branch mints. Current Proofs are made at San Francisco and West Point.
The term Proof refers to the method of manufacture and not the condition of a coin. Regular-production coins in Mint State have coruscating, frosty luster; and, often, minor imperfections due to handling during the minting process. A Proof coin can usually be distinguished by its sharpness of detail, high wire edge, and extremely brilliant, mirrorlike surface. All Proofs are originally sold by the Mint at a premium.
Very few Proof coins were made prior to 1856. Because of their rarity and infrequent sales, they are not all listed.
Frosted Proofs were issued prior to 1936 and starting again in the late 1970s. These have a brilliant, mirrorlike field with contrasting satiny or frosted letters and motifs.
Matte Proofs have a granular, “sandblast” surface instead of the mirror finish.Matte Proof cents, nickels, and gold coins were issued from 1908 to 1916; a few 1921 and 1922 silver dollars and a 1998-S silver half dollar were also struck in this manner.
Brilliant Proofs have been issued from 1936 to date. These have a uniformly brilliant, mirrorlike surface and sharp, high-relief details.
“Prooflike” coins are occasionally seen. These are examples from dies that have been lightly polished, often inadvertently during the removal of lines, contact marks, or other marks in the fields. In other instances, such as with certain New Orleans gold coins of the 1850s, the dies were polished in the machine shop of the mint. They are not true Proofs, but may have most of the characteristics of a Proof coin and generally command a premium. Collectors should beware of coins that have been buffed to look like Proofs; magnification will reveal polishing lines and lack of detail.