Collectible coins, particularly from the United States, include a variety of denominations such as the penny (1 cent) and half dollar (50 cents). Proof sets, which are specially minted coins with a high-quality finish, were produced by the U.S. Mint for collectors. In 1991, the San Francisco Mint issued proof sets that featured coins struck with a polished die, enhancing their aesthetic appeal. These sets often include coins from various denominations and are sought after by both novice and experienced collectors for their artistry and historical significance.

Item Denomination Series Year Mint
1991-S 1c-50c Proof Set 1c-50c Proof Sets 1991 San Francisco