Collectible coins, particularly in the United States, include a variety of types such as patterns and trial coins. Patterns are test pieces produced to evaluate designs or compositions for potential circulation coins, while trial coins are made to assess minting processes or designs before full production. The 1915 Fifty Cents coin, for example, may include notable varieties or designs that attract collectors due to their historical significance and rarity. Both categories are sought after by numismatists for their unique characteristics and limited availability.

Item Denomination Series Year Mint
1915-P (Philadelphia) Patterns & Trial Coins 50¢ (Fifty Cents) Patterns & Trial Coins 1915 Philadelphia