Denver's 1921 output tells the same story as Philadelphia's, only leaner: 1,080,000 dimes, the lowest mintage of any Mercury dime except the 1916-D itself. The same depression, the same Pittman Act dollar presses running at capacity, the same afterthought status for the humble dime.
Because it carries a mintmark, the 1921-D picks up an extra fraud vector its Philadelphia twin avoids: alongside altered dates, added mintmarks appear on plentiful Philadelphia hosts. The genuine coin is scarce enough in every grade that certification is simply part of the price.
The junior partner of the 1916-D and the senior partner of the 1921. Collectors assembling the series usually face these three coins last, and the 1921-D is frequently the middle purchase that teaches the habits the 1916-D will demand: verify the holder, know the mintmark, trust nothing raw.
| Issue | Mint | Mintage |
|---|---|---|
| 1921 Mercury Dime | Philadelphia | 1,230,000 |
| 1921-D Mercury Dime | Denver | 1,080,000 |
Mintage figures: United States Mint, Annual Report of the Director of the Mint, cross-checked across independent published references. Specifications: United States Mint coin specifications.