Collectible coins, such as dimes from the United States, are often sought after by numismatists for their historical value and potential investment return. A specific example is the 1935 D dime, minted in Denver, which is part of the Mercury dime series. These coins, typically composed of 90% silver and 10% copper, are popular among collectors, particularly in rolls of 10 cents. The value of such collectible coins can fluctuate based on factors like rarity, condition, and demand within the market.