Unique Proof 1973-S Kennedy Half Dollar Double Struck
on Washington Quarter Double Denomination
This unique proof Kennedy Half Dollar mint error combines several major errors at once. It was double struck on a Washington Quarter that had already been struck. There is one known proof Kennedy Half Dollar on a struck quarter but this one offered here was double struck on a struck quarter. It is a unique double struck double denomination and belongs in a world-class mint error collection.
It was just authenticated and certified by NGC as Proof 68 Cameo and is an amazing and unique proof mint error. Some of the original detail from the quarter design is evident on both the obverse and reverse.
Proof double denomination mint errors are so rare that there are only a few known. There are three proof 1976-S Bicentennial Quarters that are struck on struck U.S. coins. One is double struck on a struck dime, another is struck on a 1967 struck dime (dual date), and the third was struck on a struck Lincoln cent with a Denver Mint Mark. There are also four known proof Jefferson Nickels struck over struck dimes.
Proof coins are struck by technicians who hand feed the blanks into special presses. They are produced, examined and packaged using extreme quality control. It is very unusual to find major proof errors. A few broadstrikes, off-centers, double strikes (in collar) and off-metals have been known to be found in sealed proof sets. Proof errors are aggressively sought after by many error collectors.
A very small group of Proof errors recently came from a collection that was auctioned by the State of California. The U.S. Secret Service inspected and released this collection to the State of California determining that it was legal to own. The State of California then auctioned the collection and it has been dispersed since the sale.
This is the other recently discovered and certified Proof Kennedy Half Dollar on a struck Washington Quarter. These two Kennedy Half Dollars are the only known double denominations.
Proof Errors are featured in chapter 21 of the
NLG award winning book, World's Greatest Mint Errors.