Patterns are a specific type of collectible coin that are created to test designs or compositions before official minting. The United States produced various patterns, including the P25c series in 1860, which featured proposed designs for the quarter. These pieces are often struck in limited quantities and can be made from different metals than the final production coins, making them highly sought after by collectors. The rarity and unique design elements of these coins contribute significantly to their value in numismatic circles.