Ron Guth:
The 1856-S Dime is a true prize in the Seated Liberty Dime series. It is the first year in which the San Francisco Mint produced Dimes. The 1856-S Dime has a low mintage of only 70,000 pieces. It is decidedly rare in Mint State. Even low grade examples are scarcer and desirable.
The late Gene Gardner, one of the foremost collectors of Seated Liberty coinage, rated this date High R7 in Mint State. A small number of MS63 and MS64 examples exist, but the best is a single PCGS MS65 sold way back in 2003 for $43,700.
On this date, the central details are usually well-defined, but the denticles can often be soft or downright weak.