One of the rarest United States coins is the 1894-S Barber dime, which has a mintage of just 24 pieces, all struck as proofs. Today, only nine examples are known, and while numismatists want to find out where the other 15 pieces are, there is perhaps a bigger question that lingers unanswered: why was the 1894-S Barber dime even minted?
The reason most commonly given is that there was a discrepancy of $2.40 in the San Francisco Mint ledgers, so the mint superintendent had 24 dimes struck to fill the void. Another story suggests he minted the 24 dimes as presentation gifts to his friends. In either case, the superintendent reportedly gave three of the 1894-S Barber dimes to his daughter, and that she promptly spent one on a dish of ice cream.
We may never understand why this very popular branch-mint proof issue was created, but what we do know is that it's a rarity with a high price tag. It was already worth well into the six figures in the 1980s, and today these dimes regularly top $1 million when sold at auction. Most recently, an example graded Proof-63 by Professional Coin Grading Service and accompanied by a green label from Certified Acceptance Corporation realized $1,320,000 at an August 2019 Stack's Bowers Galleries auction.