Collectible coins, often referred to as numismatic items, encompass various types, including patterns and trial coins. In the United States, a notable example is the 1836 One Dollar coin, which was struck as a pattern to test designs and specifications for future coinage. These trial coins are rare and sought after by collectors due to their historical significance and limited mintage. Patterns typically differ from regular issue coins in design and can provide insight into the evolution of American coinage.