1950-S S/D

The 1950-S S/D over-mintmark is the San Francisco companion to the famous 1950-D D/S variety, attributed by PCGS, the Professional Coin Grading Service, and NGC, the Numismatic Guaranty Company, as FS-501 in the Cherrypickers' Guide reference system. The variety occurred when a San Francisco working die received an initial D punch in error, then was corrected with an S punch over the top, leaving the underlying D visible as a horizontal ghost beneath the dominant S on the reverse below the wreath. The San Francisco mintage for 1950 totaled 10,284,004 pieces across all dies; only a small portion came off the over-mintmark dies, and survival in collector hands is correspondingly limited. The two 1950 over-mintmark quarters are the most prominent twin-variety pair of the postwar Washington run.

Authentication centers on the mintmark itself. Examine the S under five-to-ten-power magnification: genuine S/D coins show clear traces of straight horizontal D-bar lines inside the upper and lower loops of the S, plus occasional vertical D-leg traces extending below the S where the underlying letter exceeded the S silhouette. Machine doubling on the mintmark, which is not collectible variety material, shows as a flat shelf-like effect rather than the structured remnants of an underlying D shape. The distinction matters: raw "1950-S S/D" listings include many machine-doubled coins that do not meet the variety standard. Buy the issue certified by PCGS or NGC with the FS-501 designation noted on the holder, and verify the diagnostic photos match. Strike on the variety follows the typical 1950 San Francisco pattern, with most certified examples concentrated in the MS63 to MS65 range.

The 1950-S S/D has been a Cherrypickers' staple for decades, and the certified market remains thin enough to support strong premiums in every grade. Realistic acquisition is a PCGS or NGC slabbed MS63 to MS65 sourced through a major auction, with prices considerably above the standard 1950-S in matching grades and Gem MS66 examples reaching into strong four-figure territory. Variety set collectors pursuing the Washington quarter run treat this coin as the natural pair to the 1950-D D/S and one of the cornerstone entries alongside the 1942-D and 1943 doubled dies. For the broader story of John Flanagan's design and the series' production arc, see the Washington Quarter series history.