Collectible coins, particularly those from the United States, encompass various types, including the twenty-dollar gold pieces and trial coins. The 20 Dollar coins, commonly known as double eagles, were minted primarily during the 19th and early 20th centuries, with notable examples such as the Liberty Head and Saint-Gaudens designs. Trial coins, or patterns, are experimental pieces created to test designs and compositions before official minting. The 1859 patterns are significant examples, showcasing innovative designs that were often never released for general circulation, making them highly sought after by collectors.