Collectible coins, particularly within the United States, include various denominations such as the quarter (25 cents). Proof sets are special collections of coins that are struck using a polished die to create a high-quality finish, often with limited mintage and special themes. In 2024, the U.S. Mint is expected to release new proof sets that may feature updated designs or commemorative elements, appealing to collectors and investors alike. These sets are prized for their aesthetic appeal and potential value appreciation over time.