Collectible coins encompass a wide variety of numismatic items, including those from the United States, such as the 1 One Dollar coin. Patterns and trial coins are specialized categories of collectible coins created to test designs before mass production. The year 1839 is notable for the introduction of several trial coins, which were often not intended for circulation and serve as historical artifacts in numismatic collections. The designation "N A" typically refers to coins that are not applicable for standard grading or classification, often due to their unique nature.