Collectible coins, particularly in the context of the United States, include various types that are highly sought after by numismatists. The 1975 Proof Set is notable as it contains specially struck coins with a mirror-like finish, showcasing finer details than standard circulation coins. This set often features the 1 cent coin (1c) as well as other denominations like the nickel, dime, quarter, and half dollar, all produced with a high level of craftsmanship. Collectors value these Proof Sets for their aesthetic appeal, historical significance, and potential for appreciation in value over time.

Item Denomination Series Year Mint
1975-S 1c-$1 Proof Set 1c-$1 Proof Sets 1975 San Francisco