How to Identify the 1950-S/D Washington Quarter Overmintmark

What the Coin Is

The 1950-S/D is a mintmark variety of the regular-issue Washington quarter, not a separate date or design. At the San Francisco Mint, a working die intended for Denver (already punched with a "D") was mistakenly repunched with an "S" mintmark before being put into service. The result is a quarter that shows traces of both letters overlapping, a memorable example of a mid-century Mint production error that slipped into circulation unnoticed at the time.

Obverse Design & Inscriptions

The obverse is the standard Washington quarter portrait: George Washington facing left, designed by John Flanagan and adapted from a marble bust by Jean-Antoine Houdon. Inscriptions read "LIBERTY" above, "IN GOD WE TRUST" to the left of the portrait, and the date "1950" below. There is nothing unusual on the obverse for this variety, so any identification work must focus entirely on the reverse mintmark.

Reverse Design & Inscriptions

The reverse shows an eagle with wings spread, perched on a bundle of arrows with olive branches beneath, flanked by "UNITED STATES OF AMERICA" above and "QUARTER DOLLAR" below, with "E PLURIBUS UNUM" in a small banner near the eagle's head. The mintmark sits just below the wreath, above "QUARTER DOLLAR," in a fairly small and easily overlooked spot on a worn coin.

Where to Find the Overmintmark

Look closely at the mintmark position with a loupe. On a genuine 1950-S/D, you should see the outline of a "D" peeking out from underneath or beside a bolder "S" — often visible as an extra loop or serif that does not belong to a clean "S." Comparing the suspect coin against a normal 1950-S quarter mintmark under magnification helps reveal the doubling, and tilting the coin under a raking light source can make the underlying shape stand out more clearly.

Size, Weight, Metal, Edge

Like all pre-1965 Washington quarters, this coin is 90% silver and 10% copper, weighs 6.25 grams, measures 24.3 mm in diameter, and has a reeded edge. These physical specifications match every other business-strike Washington quarter from this era, so they will not help separate this variety from a normal coin — only the mintmark detail matters here.

Telling It Apart From Similar Coins

Do not confuse this with a plain 1950-D (struck in Denver) or plain 1950-S quarter, both of which show a single, clean mintmark. Also distinguish it from the reverse-punched 1950-D/S variety, where a "D" was punched over an "S" instead — the underlying letter runs the opposite direction, so careful side-by-side comparison of both varieties helps avoid mixing them up.

Judging Condition at a Glance

Grade this coin the same way as any circulated Washington quarter: check the hairlines above Washington's ear and the feather detail on the eagle's breast for wear. Because the variety's value depends on visibility of the overmintmark, coins with heavy wear that obscures the doubling are harder to identify with confidence, so a coin retaining sharper mintmark detail is generally easier to confirm than one that has circulated extensively.

Authenticity Red Flags

Beware of mintmarks that have been artificially altered or added with a tool, which typically show file marks, an unnatural shine, or a mintmark sitting slightly off the correct position. A genuine doubled mintmark results from the mint's own die-punching process and blends smoothly into the coin's surface with no tool marks, so any suspicious roughness or inconsistency around the letter warrants a second, closer look before drawing conclusions.