Gold Washington Quarter Mint Error Sells for $120,937.50 at GreatCollections

One of the strangest modern U.S. Mint errors has sold for $120,937.50 with buyer’s premium at GreatCollections. The coin looks like a gold Washington quarter, but that description only tells part of the story. It is a 1970-S Proof Washington Quarter struck over an already completed 1898 Liberty Head $5 Half Eagle, creating a dramatic overstrike that combines two coins separated by 72 years.

Instead of being struck on the normal copper-nickel clad planchet used for a 1970 quarter, the San Francisco Mint’s Proof dies came down on a genuine 90% gold Half Eagle. The result weighs 8.3 grams, essentially the original weight of the $5 gold coin. GreatCollections describes the piece as believed unique and one of the most extraordinary modern U.S. Mint errors. PCGS graded the coin Proof-66, with certification number 48183803.

The finished coin still shows evidence of both designs, with George Washington’s quarter imagery struck over the much older Liberty Head gold piece beneath it. That combination is what gives the error such an unusual appearance and explains the “Gold Washington Quarter” nickname used in the auction listing.

Errors involving the wrong planchet are well known in U.S. coin collecting, but this one is in a different category. Rather than a quarter being struck on a blank intended for another denomination, the dies were impressed over a finished U.S. gold coin that had already circulated or existed as a completed piece for decades.

The coin’s high grade adds another layer to the result. Despite the unusual overstrike, PCGS certified it Proof-66, placing it in a level of preservation rarely associated with a mint error this dramatic.

GreatCollections had already attracted heavy interest in the coin before the auction closed, with dozens of bids and more than 100 members tracking the lot during the sale. At $120,937.50, the result turns one of the Mint’s most bizarre known mistakes into a six-figure collectible.