Collectible coins, particularly from the United States, encompass a variety of types and designs, including commemorative coins, bullion coins, and constitutional coins. One significant category is the Proof Set, which contains coins minted with a high-quality finish, allowing for detailed designs and mirror-like surfaces. The 1977 Proof Set, for example, includes coins issued for that year, such as the Lincoln penny (1-cent coin), each produced in limited quantities for collectors, enhancing their value and appeal. Collectors often seek these sets for their aesthetic quality and historical significance.

Item Denomination Series Year Mint
1977-S 1c-$1 Proof Set 1c-$1 Proof Sets 1977 San Francisco