Collectible coins encompass a variety of types, including historical, commemorative, and bullion coins. The United States has produced notable collectible coins, such as the Four Dollar Gold piece, also known as the St. Gaudens Indian Head, which was minted from 1907-1933. The Coronet Head cents, issued from 1816 to 1857, feature a classic design with a portrait of Liberty and are highly sought after by numismatists, particularly those from the year 1818, which may be rarer due to lower mintages. Collectors value these coins for their historical significance, artistry, and potential for appreciation in value.