Collectible coins include various types issued by governments, such as bullion coins, commemorative coins, and numismatic coins. In the United States, notable examples include the Gold Buffalo and Gold High Relief coins. The Gold Buffalo, introduced in 2006, features the iconic Buffalo nickel design and is composed of 24-karat gold. The Gold High Relief coin, released in 2009, showcases a detailed design that requires a higher minting process, resulting in a more pronounced relief. These coins are often sought after by collectors for their artistic appeal and precious metal content.