Collectible coins, such as the 1861 Denver Colorado DT 10 Patterns Die Trials, represent a unique category of numismatic items. Patterns are experimental designs or compositions made by mints to test new coinage concepts before official production. The 1861 DT 10, linked to the United States Mint, serves as an example of this practice, showcasing the Mint's iterative process in refining currency. These rare coins often attract collectors due to their historical significance and limited availability.

Item Denomination Series Year Mint
1861 DT$10 Clark Gruber Copper Die Trial DT$10 Patterns & Die Trials 1861 Denver, Colorado