1. 1894-S Dime (also known as the Barber Dime): This dime has a mintage of only 240,000 pieces, making it one of the rarest dimes in the Barber series. It is distinguished by its "S" mintmark, indicating that it was minted at the San Francisco Mint.
2. 1895-O Dime: Another rare dime from the Barber series, the 1895-O has a mintage of just over 40,000 pieces. It is known for its "O" mintmark, signifying the New Orleans Mint.
3. 1916-D Mercury Dime: This dime from the Mercury Dime series is relatively rare due to its low mintage of 264,000 pieces. It carries the "D" mintmark, indicating the Denver Mint.
4. 1921-S Mercury Dime: The 1921-S Mercury Dime has a mintage of approximately 1,150,000 pieces, making it scarce compared to other dimes from the series. It features the "S" mintmark of the San Francisco Mint.
5. 1942-D Mercury Dime: The 1942-D Mercury Dime is considered rare because it was minted during World War II, when copper was needed for war production. As a result, the 1942-D Dime was composed of silver instead of the usual copper-nickel alloy. It bears the "D" mintmark of the Denver Mint.
6. 1955-D Roosevelt Dime: While the Roosevelt Dime series is generally common, the 1955-D Dime stands out as a relatively scarce issue due to a production error that resulted in a lower mintage of 2,365,000 pieces. It carries the "D" mintmark of the Denver Mint.
These are some of the rare dates for US dimes, and their values can vary significantly based on factors such as condition, rarity, and demand among collectors.