Proof Coin Reveals One Style of Mintmark Punched over Another
Numismatic Guaranty Corporation® (NGC®) has certified a newly discovered variety for the popular Kennedy Half Dollar series. Submitted for attribution under NGC’s VarietyPlus Service by Florida dealer Bob Ryan, it was at first suspected to be a normal “S” mintmark punched over an inverted impression of the same letter, but the 1968-S Proof Half turned out to be so much more.
Enlarged photographs of the mintmark area revealed two oddities.
The first was that the mintmark is of a style not seen on other 1968-S Half Dollars nor, for that matter, on other San Francisco Mint coins of the period. In fact, NGC Research Director David W. Lange was not able to place it on any other coin. Thinking that it may have been used on a foreign coin struck by the San Francisco Mint, Lange showed the coin to colleague David J. Camire, an NGC Finalizer and error coin specialist. Camire consulted an extensive database of world coins made by the US Mint, but was also unable to find a match for the mintmark style.
The second peculiar feature of the mintmark is that a knob projects to the side of each serif, hinting at another, underlying style of mintmark. Lange sent photos of the mystery coin to several experts in the variety/error field for opinions. Bill Fivaz, co-author of The Cherrypickers’ Guide to Rare Die Varieties of United States Coins, suggested that the underlying letter is similar to the Knob-Tail “S” (mintmark) last used on San Francisco Mint coins in the late 1940s. Fivaz also speculated that the primary mintmark was itself inverted, though its nearly symmetrical shape makes this hard to determine with certainty.
Variety/error specialist Ken Potter revealed that he’d seen a box full of different puncheons while taking a 1998 tour of the Philadelphia Mint. These were preserved by the Engraving Department’s Edgar Steever, who’d been at the Mint for decades and was reportedly the main applier of mintmarks before this feature began to be sculpted into the master dies starting in the 1980s. It was thus possible that any number of different mintmark styles remained on hand in 1968. Retired numismatist and respected researcher Tom DeLorey agreed that two different mintmarks had been applied.
NGC has assigned its own VarietyPlus number of VP-003 to this remarkable variety, labeling the Ryan specimen as SERIF S/KNOB S, indicating the application of one mintmark style over another. The coin is a particularly attractive piece and was certified as NGC PF 67★. The NGC Star Designation was included to denote its superior eye appeal as a one-sided cameo coin (the reverse does not possess frosted devices).
Illustrated here are close-ups of the new variety, VP-003, and also an example of the style of mintmark usually seen on the 1968-S Half Dollar. This normal style has a serif at top and a knob end at the bottom.
It’s anticipated that the rush will be on to find additional examples of this fascinating new variety. Such coins may be submitted to NGC for grading and encapsulation at the normal tier rate, with an additional $15 fee for variety attribution. Coins already certified by NGC may have a variety added for the same $15 fee, which includes the cost of reholdering.
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