Collectible coins, particularly in the context of the United States, encompass various types, including the iconic One Dollar coins. Among these are special categories such as patterns and trial coins, which are prototypes created to test new designs and compositions. The year 1999 saw the introduction of significant designs, especially in the context of the state quarter program, with certain coins gaining collectible status due to their rarity and historical importance. Patterns and trial coins are typically produced in limited quantities, making them particularly sought after by numismatists.