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Seated Liberty Half Dollar Struck on a Quarter Planchet

The following is released on behalf of Numismatic Guaranty Corporation®

Numismatic Guaranty Corporation® (NGC®) has certified an incredible error coin: a Seated Liberty Half Dollar struck on a quarter planchet. This stunning error is believed to be unique for the Seated Liberty Half Dollar series.

The coin was recently discovered in an old collection that had been held by the Wheeler Family of New Jersey for decades. After the current owner inherited the collection, they were unsure of its authenticity and decided to submit it to NGC for certification. NGC graded the coin NGC Mint Error AU-50 and pedigreed it to the Wheeler Family.

Although the date of the coin is missing because it could not fit on the smaller quarter planchet, NGC was able to identify the date range as 1871-75 because of the size and shape of the “S” mintmark that appears on the reverse. The “S” mintmark also indicated that this coin was struck at the legendary San Francisco Mint.


“This is an extremely exciting error,” said Mark Salzberg, NGC Chairman, and Grading Finalizer. “It is even more amazing that this coin was struck nearly 150 years ago yet remained unknown to specialists until now.”


At the time this coin was struck, the same Seated Liberty design was used on half dimes, dimes, quarters, half-dollars and dollars. In this case, a 24.3mm quarter planchet was mistakenly used in the half dollar minting process instead of the usual 30.6mm half dollar planchet. The extreme rarity of this coin indicates that such errors virtually never occurred.

After learning of this coin’s rarity, its owner contacted Ian Russell, president of GreatCollections, a well-known U.S. auction company. The owner selected GreatCollections to sell this extraordinary mint error.

“This is undoubtedly the most interesting error coin I have ever handled,” he said. “I am thrilled to be able to offer this important NGC-certified rarity.”

The Seated Liberty Half Dollar Struck on a Quarter Planchet Error will be sold without reserve by GreatCollections on Sunday, Sept. 29. Bidding is already over $1,000 with three weeks left to bid.

To learn more and bid, visit the GreatCollections website or telephone 1-800-442-6467.

About Numismatic Guaranty Corporation® (NGC®):

NGC is the world’s largest and most trusted third-party grading service for coins, tokens, and medals, with more than 44 million collectibles certified. Founded in 1987, NGC provides an accurate, consistent and impartial assessment of authenticity and grade. Every coin NGC certifies is backed by the comprehensive NGC Guarantee of authenticity and grade, which gives buyers greater confidence. This results in higher prices realized and greater liquidity for NGC-certified coins. To learn more, visit

All images courtesy of Numismatic Guaranty Corporation®.