The famous Panama Pacific Exposition half dollar without the "S" mintmark struck in gold. These strikings, before the mintmark was added, were probably deliberately struck to create a rarity. Pollock mentions a quote from Breen by Farran Zerbe which more or less describes them as pieces struck for the Secretary of the Treasury. Examples are known as follow: Gold J1960/P2031. This used to be J1793 in earlier editions. Only 2 are known including the Olsen, Farouk, Norweb, Queller, 2010 ANA sale coin and the Brand, 79 ANA, SRCA 6/81, Heritage 11/03, southern collection, Simpson collection example which is illustrated above. Silver J1961/P2029. This used to be J1791 in earlier editions. Fewer than 4 known are confirmed. Copper J1962/P2030. This used to be J1792 in earlier editions. Fewer than 4 known are confirmed. Photo courtesy of Heritage.