On page 197 of World’s Greatest Mint Errors (Zyrus Press,
2009), author Mike Byers features a multi-struck 1978 Canadian cent
with the reverse design on both faces. The extra strike(s) transformed
the coin into a die cap with impressively high walls (see photos).
These details are beyond dispute. What can be questioned is the
coin’s status as a two-tailed mule. A mule is a coin struck by
mismatched dies. Both Byers and Professional Coin Grading Service
state that the coin was struck by two reverse dies, one acting as
hammer die and one as the anvil die.
It’s important to note that ordinary Canadian cents are invariably
struck with the reverse die acting as the hammer die (the hammer die
delivers the impact while the anvil die receives the impact).
Possible pseudo mule?
There’s another, equally plausible diagnosis — that this is a
two-tailed pseudo-mule (false mule). Despite carrying the same design
on each face, a pseudo-mule is struck using a conventional die setup.
The 1978 Canadian cent’s current owner, Chef Ito, sent it to me after
I mentioned this possibility.
A pseudo-mule incorporating the maple leaf design on each face can
be created in several ways.
(1) A cent is struck normally, flips over, and lands on top of
another planchet. A second strike flattens the original Maple Leaf
design while the queen’s bust is obliterated. The double thickness,
and the associated increase in effective striking pressure,
facilitates complete erasure of the bust.
(2) Two planchets are struck together within the collar, creating
two in-collar uniface strikes. In other words, each coin has a blank
face. The bottom coin is ejected, while the top coin flips over and
lands on another planchet. The original Maple Leaf design is
flattened, while the original featureless surface is struck by the
(3) A cent sporting an in-collar first-strike brockage of the
Maple Leaf design on its bottom face flips over (a brockage is an
incuse, mirror-image version of the design). Another planchet is fed
on top of the brockaged coin and is struck into it. The bottom face of
that newly-struck coin carries a first-strike counterbrockage of the
Maple Leaf design.
These events can occur spontaneously or with human assistance.
Regardless of its etiology, I strongly suspect that Ito’s coin had
help. In 1978 a flood of highly improbable errors emerged from the
Royal Canadian Mint, many bearing the cent design.
Despite careful study, I was unable to determine if Ito’s coin is
a mule or a pseudo-mule. Based on appearance alone, both scenarios
seem equally plausible. But from the standpoint of process, a
pseudo-mule would seem more likely.
Chris Pilliod explained why in an Oct. 2, 2000, Coin
World article on a two-headed 1859 Indian Head cent. In most
presses, the anvil die has a longer neck than the hammer die. This
allows the anvil die to move up and down within the collar and bring
the newly-struck coin into the path of the ejection finger. A hammer
die installed in the anvil die’s position could not perform this
function and, more importantly, could not bring a planchet within
range of the properly installed hammer die for a strike.
For a hammer die to act as an anvil die, you need to machine a
longer neck. That requires time, equipment, expertise and most
problematically, a wider conspiracy. One press operator, working
quickly, can create an intentional pseudo-mule. This is probably why
all Malaysian double-obverse 1-sen coins show the diagnostic
characteristics of a double-struck pseudo-mule (see Feb. 8, 2010 and
April 25, 2011, issues of Coin World).
Other Canadian rarities
Two other double-reverse Canadian cents (1980) have been reported
(Coin World, Oct. 1, 2001). Both were described and
encapsulated as mules. However, both coins show features consistent
with a pseudo-mule (see photos of one of the examples, to the left).
(1) One face (“side A”) is sharply struck while the other (“side
B”) shows flatter relief and softer details. PCGS reported side B as
being “rougher in appearance” while Superior Galleries described a
“frosty” surface texture. Both organizations thought Side B was struck
by a worn die. However, these attributes are wholly consistent with a
second strike against a planchet. Such impacts not only flatten the
design, but they often cause a coarsening of the metal crystallites,
leaving a matte texture.
(2) Side A has a finned rim. Abnormally high striking pressure
caused coin metal to squeeze into the gap between die neck and collar.
Two stacked discs could easily have been responsible for an increase
in effective striking pressure.
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