Each side of this mule carries the denomination — QUARTER DOLLAR on the obverse and ONE DOLLAR on the reverse — making the coin a $1.25 piece
The Mint has never purposefully struck 11-cent coins or $1.25 pieces, but they exist nonetheless and are avidly collected.
On rare occasions, perhaps by accident, perhaps on purpose, dies are mismatched when they’re placed in coinage presses — an obverse die for one denomination is paired with the reverse die of a different denomination.
For this to happen the coins must be similar in size, limiting the possibilities to 11-cent coins — coins from paired dime and cent dies — and $1.25 coins — coins from paired quarter dollar and dollar dies.
The errors, called mules by collectors, are extraordinary scarce and sell for $50,000 and up.
In 2010, Heritage Auctions sold a pair of cent-dime mules — a 1993-D cent obverse paired with a dime reverse on a cent planchet and a 1995 cent obverse with a dime reverse on a dime planchet.
Heritage’s listing for the 1995 coin notes, “An astounding mint error that prior to the 1990s was believed impossible to occur. Only the narrow difference in die diameter between the cent and dime makes it plausible that a busy mint worker could erroneously pair dies of different denominations. Most likely, a press run was made from this die pairing and detected by an inspector, possibly the operator of the mint press. Perhaps the entire batch was melted, aside from the present coin.”
In 2000 the collecting world was startled to learn that the Mint had produced mules that married the obverse of a State quarter dollar with the Soaring Eagle reverse of the just-released golden Sacagawea dollar. Each side of this mule carries the denomination — QUARTER DOLLAR on the obverse and ONE DOLLAR on the reverse — making the coin a $1.25 piece.
The error was first reported to the numismatic community in May 2000 by Frank Wallis from Mountain View, Arkansas, who found an example in a 25-coin roll of Uncirculated Sacagawea dollars from First National Bank & Trust.
While collectors across the country checked their change for the coins, only 15 have been found to date. New Mexico collector Tommy Bolack has gobbled up most of the coins as they came on the market, currently owning 11 of the 15 pieces. He has paid as much as $117,500 for a coin in 2014. (Bolack was an under-bidder on the same coin when it went on the auction block in 2012. Bolack dropped out at $100,000 as the piece soared to $155,250.)
The various $1.25 pieces are believed to have been struck from three different pairs of dies. Coin World has reported, “The presence of more than a single die pair would suggest that production of the errors was prolonged and the initial mintages sizeable.”
It’s interesting to speculate if any more or out there, lying in unsearched rolls or bags of the millennium dollars.