The census of identified Washington quarter dollar/Sacagawea dollar double-denomination mule error coins appears to have climbed to 14.
An example certified Mint State 65 by Professional Coin Grading Service is being offered Jan. 10 in Orlando, Fla., by Heritage Auctions as part of its Platinum Night.
The auction will be held in conjunction with the Florida United Numismatists convention.
The piece does not appear to be part of the census compiled by researchers within the numismatic community.
The mule errors pair a State quarter dollar obverse die, depicting George Washington, and a Sacagawea dollar reverse die, depicting the eagle. The errors were struck on manganese-brass clad dollar planchets in a coinage press at the Philadelphia Mint dedicated to dollar coin production.
The mules were struck in 2000, but the coins bear no date (the date for 2000 quarter dollars was applied by their reverse dies, and for the dollar coins, by their obverse dies). The mule obverses bear, in the field to the right of Washington’s bust, the Philadelphia Mint’s P Mint mark.
Three different die pairs have been identified by specialists for the double-denomination mule. The example being offered Jan. 10 is from Die Pair 1.
Neither PCGS nor Numismatic Guaranty Corp., which combined have certified all of the publicly known examples, maintains a separate registry for error coins.
The Heritage cataloger speculates in the auction lot description that the error example being offered Jan. 10 could possibly be the “Fred Weinberg” specimen or the “Tommy Bolack 1” example.
Tommy Bolack, a New Mexico collector who owns eight of the now 14 known examples, said Dec. 10 the piece being offered by Heritage Auctions is not his. He said he has no plans to sell any of the eight that he owns. In fact, he’d like to increase that number.