One of the most intriguing -- and mysterious -- pattern coins ever produced by the United States is now in a Professional Coin Grading Service (www.PCGS.com) holder: the unique 1814 platinum Capped Bust half dollar with nearly three dozen "P" punch marks. It is graded PCGS Secure Plus XF40.

PCGS will use a "new" Judd reference number, Judd-44a, to differentiate it from any other known platinum 1814 half dollar patterns assigned J-44 that do not have punch marks or the word, "Platina," engraved on the reverse. This particular coin was pictured in the original edition of the reference book, Pattern, Experimental & Trial Coins, authored by J. Hewitt Judd, MD, and the PCGS insert label identifies it as "Judd Plate Coin."

The coin is owned by Midwest collector Charles Link who describes himself as a "Bust half dollar and early American pattern enthusiast." He says "the platinum half is my favorite coin in my Bust half dollar collection. I never expected that I would have the honor of being a steward of this important part of American history, if only for a small snippet of its history."

Previous owners of this coin include notable numismatists George Woodside, Virgil M. Brand and Dr. Judd. Link acquired the coin for $138,000 at the Heritage Auctions Chicago auction in August 2011. It was displayed on his behalf by Harry Laibstain Rare Coins at the recent American Numismatic Association World's Fair of Money convention in Philadelphia, and will be displayed by Laibstain (booth #354) at the upcoming Whitman Coin & Collectibles Baltimore Expo, November 15 - 18, 2012.

PCGS CoinFacts notes that there may be two other examples of the 1814 platinum pattern half dollar without the punch marks and engraving. One such coin is part of the National Numismatic Collection at the Smithsonian Institution, and it has an obvious test cut. Another example is rumored to exist based on a mention of it by researcher Walter Breen in a 1974 auction catalogue; however, that coin has not been confirmed or seen in the 38 years since then.

The full PCGS CoinFacts description and an illustration of the J-44a pattern are online at www.pcgscoinfacts.com/Coin/Detail/515721.