The population of certified George Washington State quarter dollar obverse/Sacagawea dollar reverse double-denomination mules has grown by one, to 15. Professional Coin Grading Service has graded and encapsulated as Mint State 66 what is now the 15th known example of the dateless Philadelphia Mint error.

It bears the George Washington obverse from the State quarter dollar series and Soaring Eagle reverse of a Sacagawea dollar.

Full video transcript:

Good morning. This is the Monday Morning Brief for July 25, 2016. I’m Coin World Senior Editor Paul Gilkes.

The population of certified George Washington State quarter dollar obverse/Sacagawea dollar reverse double-denomination mules has grown by one, to 15 coins.

Connect with Coin World:  

• Sign up for our free eNewsletter
• Like us on Facebook  
• Follow us on Twitter

Professional Coin Grading Service has graded and encapsulated as Mint State 66 what is now the 15th known example of the dateless Philadelphia Mint error.

It bears the George Washington obverse from the State quarter dollar series and Soaring Eagle reverse of a Sacagawea dollar.

This newly certified piece is identified as an example struck from Die Pair 1 from three known die pairs used to strike the errors.

The newest piece reported has been acquired by New Mexico collector Tommy Bolack. With his latest purchase, Bolack now owns 11 of the 15 publicly identified examples of the mule.

The name of the seller, the price paid, and details of where the 15th error was found were not disclosed.

What is a mule?

A mule is a coin, medal or token struck from dies not normally intended to be paired together. It derives its name from the animal that is the offspring of a male donkey and a female horse.

The double-denomination mule error pairs the George Washington obverse from the State quarter dollar series with the Soaring Eagle reverse of the Sacagawea dollar.

Each side bears a denomination and the coin is sometimes called a $1.25 piece.

The Washington obverse bears the "P" Mint mark but the 2000 date is missing; it would have been found on the correct mate for either of the mismatched pieces.

On the State quarter dollar series, while the Mint mark is on the obverse, the date of issue appears on the reverse bearing each commemorative State quarter design. For the Sacagawea dollar, the date would appear on the obverse.

The mules were struck at the Philadelphia Mint on manganese-brass clad dollar planchets between dies fitted into a coinage press dedicated to Sacagawea dollar production.

The error type was first discovered in May 2000 in Mountain Home, Ark., by Frank Wallis, in an Uncirculated 25-coin roll of Sacagawea dollars from First National Bank & Trust.

How many more examples of the mule error may still be extant is anybody's guess. It’s taken 16 years for 15 examples to publicly surface.

Initial Treasury reports suggest that possibly several hundreds of thousands of the mule errors were struck and shipped out of the Philadelphia Mint, but were subsequently tracked to a contracted armored carrier coin terminal for the Federal Reserve in the Philadelphia area, and the production recovered.

That is, except for at least 15 examples.

For the full story, visit www.CoinWorld.com. For Coin World, I’m Paul Gilkes.