Collectible coins encompass a variety of types, including commemorative, bullion, and error coins. In the United States, one notable category includes patterns and trial coins, which are experimental versions of standard coins, often struck in limited quantities to assess designs and materials. A specific example is the 1976 Philadelphia trial coins, produced as part of the bicentennial celebrations, showcasing unique designs that were tested prior to mass production. These coins are sought after by collectors due to their historical significance and rarity.

Item Denomination Series Year Mint
1976-P (Philadelphia) Patterns & Trial Coins Other / Varied Patterns & Trial Coins 1976 Philadelphia