Unique Proof Kennedy Half Dollar Double Denomination
This newly discovered and certified Proof Kennedy Half Dollar on a struck Washington Quarter is the only known Kennedy Half Double Denomination on any proof U.S. coin.
It was just authenticated and certified by NGC as Proof 67 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. It has full reeding from the quarter strike and shows the copper core along the edge. The 1973-S date from the quarter is visible below the 1973-S date from the Kennedy Half.
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 discovery mint error is fascinating since it combines rarity (unique), quality (Proof 67 Cameo) and intrigue (the only known proof U.S. Kennedy Half Dollar struck on any U.S. coin). This unique U.S. proof mint error belongs in a major collection of the finest error coins or in a collection of Kennedy Half Dollars.
The 1973-S date from the quarter is visible
below the 1973-S date from the Kennedy Half:
Overstrikes are featured in the NLG award
winning book, World's Greatest Mint Errors.