Collectible coins, including dimes, are often sought after by numismatists for their historical significance, rarity, and condition. The 1938 Denver dime, known as the Mercury dime, features the Greek goddess Liberty on the obverse and a fasces with an olive branch on the reverse. Dimes from this year and mint, especially in high grades, can be valuable to collectors. A 10c roll refers to a collection of ten dimes, making them a practical way to acquire multiple examples of this popular series.