Collectible coins often include various types such as commemorative coins, bullion coins, and limited-edition releases that appeal to numismatists and investors. The United States Mint produces these coins, which can vary by year, mint mark, and design. For example, a roll of 1999 Denver minted dollars would include coins specifically produced in Denver during that year, potentially featuring unique designs or attributes that enhance their collectible value. Collectors often seek specific attributes, such as condition and rarity, to determine a coin's market value.