By Jon Sullivan for PCGS ……
When we hear the word “mule” we usually think of the animal that is the offspring of a horse and a donkey. However, in the world of mint errors, it refers to a coin struck with dies that were not intended to be used in combination with each other. The reason the term mule is used is because the die combination being used together is not correct.
A mule error’s die pair possibilities can include the obverse die, the reverse die, or even the collar die. It can occur using dies from the same coin series that were not intended to be used together (such as a pairing of two Roosevelt Dime reverse dies), or it can be dies from different coin series entirely (such as the famous 50 State Quarter obverse die and a Sacagawea Dollar reverse die).
In determining the denomination of a mule error (since frequently they are made up of differing denominations of coins, such as $1 and 25-cent coins, etc.), the coin’s denomination is considered to be whichever denomination’s planchet is used in the mule. So, for example, in the case of a $1 Sacagawea/50 State Quarter mule, because the mule is struck on a Sacagawea $1 planchet, it is considered to be a “$1 coin” and not a “25-cent coin”. If it had been on a quarter planchet, it would be described as a “25-cent coin”.
Below is a list of some of the more well-known mule errors:
- Washington Quarter struck with two 25-cent eagle reverse dies.
- Roosevelt Dime struck with two 10-cent reverse dies.
- (2000-P) Sacagawea Dollar reverse die paired with a 50 State Quarter obverse (unquestionably the most famous of the U.S. mules).
- 1993-D Lincoln Cent struck with dime reverse die.
- (1995) Roosevelt Dime struck with dime reverse and a 1995 Lincoln Cent obverse.
- 2014-D Sacagawea Dollar obverse paired with a Presidential Dollar reverse (a recent discovery coin).
- 2001-D Lincoln Cent obverse paired with a Roosevelt Dime reverse (new discovery).
- 2000-P Jefferson Nickel struck with two obverse Jefferson Nickel dies.
These are some of the more well-known examples, although others exist. Some of the above coins listed are unique, while for others there are just two or three known examples.
The most “common” mule of the group is also the most famous and the most valuable, namely the (2000-P) Sacagawea Dollar reverse paired with the 50 State Quarter obverse. For that particular mule, there are about 20 known examples, and they typically sell for around $100,000 to $125,000 USD. Most of the other mule types sell for between $25,000 and $100,000.
Counterfeits exist for mule errors, most of which are made by altering genuine coins to make them look like a mule. The most common would be what is referred to as a “magician’s coin”, which is when two coins are essentially cut or ground down and then glued together to form a single coin. They can be any number of various coin combinations, and countless thousands of them exist. These fake “mules” are easily detected but could convince a novice collector.
Because of their value, collecting mule errors as a set is really not within reach of the vast majority of collectors. However, acquiring just one example would be a crowning achievement for any error collector, as they are the rarest type of mint error, with probably less than 35 examples for all dates, types, and combinations of mules known for all series of U.S. coins combined. Mule errors are the king when it comes to rarity as an error type.
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