First let’s understand the name, Mule…

In nature, a mule is the offspring of a male donkey and a female horse. Horses and

donkeys are different species, with different numbers of chromosomes. I know redonkulous, right?  

What Is a Mule Coin?

Well, numismatists, excuse the pun,  “coined this term”, for coins struck with mismatched “dies”, i.e., the side of one coin applied intentionally/accidentally to the side of another.

Now, as mentioned, some mules are purely accidental, and their release sometimes goes unnoticed until after thousands enter circulation.  The obverse mistakenly carries a Bahamas 5 cent design. Current estimates suggest at least 30,000 were released before red-faced mint officials realized what happened.

Other mules are unauthorized but are intentionally produced under clandestine situations where mint employees sometimes strike these hybrids for sale to collectors.

 Three dies are involved in striking a coin - the hammer die, the anvil die, and the collar. A mismatch between any of those three dies should qualify as a mule. All are the result of various combinations of Planchet, Hammer, Anvil, and Collar influences.

PCGS Certifies Unique “Two Headed” Coin

This is one of five known U.S. or World coins struck by two obverse dies Certified by PCGS as authentic Mint Errors.

HOW WAS THIS MADE?

A number of different mule errors have appeared over the last several years; however, with questionable authenticity.  Many mule circulating are "Pseudo Mules". 

For example, The 2005 Malaysian 1 sen, shown in Figure 1 displays the obverse design on each face. It would appear to have been struck by two hammer dies (one retro-fitted to function as the anvil die, of course). But take a closer look. A clever mint employee started the process by stacking two 1 sen planchets in a 1 sen collar and striking them with a normal set of dies. The result was two in-collar, uniface strikes (full indents). The bottom coin (carrying a drum motif on the reverse face) was then discarded. The top coin, with a featureless reverse, was flipped over and placed on top of another planchet. The two discs were then struck again. The originally featureless reverse face of the top coin received a fresh, die-struck obverse design, while the original die-struck obverse design was flattened against the underlying planchet.

On the Contrary, for this coin, this particular mule/error was struck with two actual hammer dies.  The neck on hammer dies are normally shorter than the neck on anvil dies.  This explains why some of the funerary mask on both faces of the coin were not fully struck  

(excessive space between striking dies).  This is not fully struck feature is also exhibited by the recent Jefferson two-headed nickel certified last year.

In the Mint's own words...

Our coins are minted by embossing a seal or image in relief on a metal “blank.” Each coin is struck by the dyes on both sides at the same time, generating an image on each face. The dyes are made of tempered steel and are capable of producing hundreds of thousands of coins.

This Chilean specimen was certified as dateless; however, further examination strongly suggests through comparisons of the remaining portrait of Bernardo's bobbles, Braiding, and No signature, the piece's date should land on 2010.  Shortly, it shall be resubmitted with the supporting data to confirm with a third-party grader.

It is a Chile 10 Pesos struck with two obverse dies on what seems to be a 2010 by uniform and raids.  Even though has similar markings, the 2011 isn't likely due to their change in production and processes that year.  In Aug 2011 they bought new state of the art production machinery. Accompanied way beforehand new adopted procedures to ensure quality..

in the mint's own words...

During 2011 and 2013, Casa de Moneda purchased the new production line, with the best technology available on the market for banknotes production. In addition, the Chilean company implemented new procedures and processes to its daily operation.

This phase, known as Phase A concluded launching the new line on 2013.  So a two headed coin date 2011 would be unlikely at best due to the attention of the new processes to prepare for the August installation.  Before 2011 would be more likely... The best guess, as dies are made way before the actual year to be used - so 2010 it is.

HOW RARE IS THIS COIN?

Only four other unique coins are known to have been struck by two obverse dies that have been authenticated by PCGS or NGC.

• The First, an 1859 Indian cent with a dual obverse mule strike was certified as MS62 after submission to PCGS at the October Long Beach show. The pedigree of the coin can be traced to the 1930s, but it disappeared from the market for over 60 years before resurfacing at a Chicago coin show in June 2000. The 1859 dual obverse mule is considered to be a Mint error rather than a pattern. Noted Indian cent expert Rick Snow has traced both obverse dies used to make the coin to other business strike coins.

• The second is a unique two headed 1971 Great Britain ½ Pence struck with two obverse dies on a nickel-copper planchet and is certified by NGC. 

• Third, is It is a Chile 10 Pesos struck with two obverse dies on a 1997 Bolivian 10 Cent copper plated steel planchet and weighs 2.22 grams certified by PCGS. 

• Fourth, the only known U.S. regular issued nickel certified by PCGS (Also exhibiting weak obverse impressions, from two hammer dies) See above explanation) .

As for the US, there are three known U.S. regular issued coins struck with two reverse dies.

Fred Weinberg sold a two-tailed Washington Quarter for $75,000 and
A two-tailed Roosevelt Dime for $45,000.

The third known two-tailed was a Washington Quarter that sold in a Heritage Auction for $41,975.

BACKGROUND

Up to recently, most enthusiast, less those in the field of error coins, firmly believed that one specific mule coin could never be possible, i.e., the Two-Headed /Tailed coin. It was argued that production processes in the United States Mint, and many other Mints around the world, make it virtually impossible for a two-headed (or two-tailed) coin to be manufactured by the mint.

The coining presses that are used to produce United States coins have two different shaped receptacles for the coin dies. When coin dies are manufactured, the shank of the coin die for the obverse is a different shape than the shank of the coin die for the reverse. This manufacturing process design makes it virtually impossible for a coin press operator to load two obverse (or two reverse) dies into the coin press.

                                       - 
“Uh, nature will find a way…”Dr. Ian Malcom (Jurassic Park)   

THE TWO-HEADED COIN

Thus, in June 2017 Coin Week reported a United States 2000-P Jefferson nickel struck with two obverse dies was discovered in 2016 and certified by PCGS.  The in Experts are puzzled as to how this can happen, but the professional authenticators at PCGS agree that the coin is a genuine mint product.

It’s actually, one of the more “popular” stories, the “Mint Error” experts have known for years that these coins exist.  In fact, there are approximately thirty known genuine two-headed or two-tailed coins that have been authenticated and certified by ANACS, PCGS and NGC. There are only four known "Two Tailed" U.S. coins: three Quarters and one Dime. One of the Quarters recently sold for $80,000.

Most of these world coins that were struck with either two obverse or two reverse dies have been handled by Mike Byers of Byers Numismatic Corp. Two of these are Canadian Copper Cents that were struck with two reverse dies and authenticated by PCGS. A few others from this collection of two headed and two tailed coins are featured below.

In speaking with Jon Sullivan, Sullivan Numismatics, when dealing with two-headed / tailed – or any mule coin, for that matter, these things are known truths…

• Regardless of what you read on the internet, Mints try new things – things happen.  Whether intentional or by accident, the origins of these coins are not definite, some were helped, but many were done by accident – and were probably were meant to be destroyed, but as evidenced some slip through’s a two-headed, foreign planchet or otherwise – a new metal was switched, an experimental process was in place, outsourced crew, etc… We just don’t know, and with the legalities associated with it, we won’t know. They are all mysteries.

• Even though recent certifications of these items are getting notoriety, these Dime(s) and the Quarter(s) were known in the 1960s especially by those numismatist that were in the error coin discipline.

• For those who may think that the graders that certify these coins may be mistaken by the coin authenticity, just know, these graders use a small number of the most knowledgeable people in the respective coin’s category; in addition, the testing and expertise thrown at these pieces is exhaustive, so for every certified coin there are literally thousands that are rejected using the very same processes and expertise.

• Only way to truly authenticate a two headed coin is to Certify with one of the top graders who have the expertise and processes in place, i.e., NGC or PCGS As for the mules only getting “popularity” now? (1) The collector probably had his mule kept secret – known but probably confidential for security reasons. (2) Coin grading / certification really didn’t kick in until 1977, and even then was in its infancy – before that it was Sheldon Grading Scale used by coin dealer’s subjective appraisals.

• Value may be subject to popularity, but usually a US two headed coin can run up to $25,000.00 to $150,000.00 where their world counterparts range from five hundred to $25,000.00. 

Phenomena with mules – curb appeal – popularity is king.

Those in the business that cry “fakes” are people that aren’t familiar space – the true argument of interest is whether the coin in question is intentionally or accident.  Either way, if proven authentic, really rare, and really valuable. ​​​​​​​