Collectible coins include a wide range of types that can hold significant value due to their rarity, historical significance, or unique features. In the context of the United States, the One Dollar coin has various collectible versions, including patterns and trial coins produced in the 1800s. Patterns are experimental versions struck to test new designs or compositions, while trial coins are produced to evaluate the minting process. Both types often attract attention from collectors for their limited quantities and unique characteristics.