1971-S Proof Silver Ike Dollar
15% Straight Clip
NGC PF 66 Cameo
This unique discovery is the only known 15% Straight Clip on a silver proof Ike dollar. It was struck on the end of the planchet strip. It weighs 20.9 grams instead of the normal 24.5 grams.
Recently, a 40 year old U.S. proof mint error collection was sold. It is amazing that this mint error survived the minting process and was just certified by NGC.
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.
Proof Errors are featured in chapter 21 of my
NLG Award winning book, World's Greatest Mint Errors: