The term “unauthorized strike” is generally applied to coins that
carry a date earlier than the intended start of a particular design or
a date later than the official retirement of a particular design. It
can also be applied to any coin that carries a date or Mint mark for
which there is no official record.
The best known example among U.S. coins is the 1913 Liberty Head
5-cent coin. Widely regarded as the product of a clandestine effort,
the five known examples postdate by one year the last officially
authorized representatives of this series.
A number of other domestic rarities may fall into the same
category, as Mint records indicate that none were struck.
All of these U.S. coins cost a fortune. But if you expand your
search beyond our borders, you can obtain unauthorized strikes for
very modest sums.
A particularly abundant example of an unauthorized strike is the
small-size 1954 Mexico 5-centavo piece. This brass coin, which
features the right-facing bust of Josefa Dominguez, was not supposed
to be struck until 1955. Nevertheless, an unknown but substantial
number of these coins were struck in 1954 and placed into circulation.
The government-authorized version of the 1954 5-centavo coin is a
considerably larger bronze coin with a left-facing bust of Josefa that
was first issued in 1942 and was last issued in 1955.
As a result, you can find both small and large 5-centavo coins
bearing the dates 1954 and 1955. While circulated examples of the
small-size 1954 5-centavo coin are very inexpensive, Uncirculated
examples are quite scarce and can cost more than $100.
The Panama 1985 tenth balboa exists only in Proof form and was
struck by the Franklin Mint without authorization from the government
of Panama. These Proof pieces were also struck with medal rotation
instead of the normal coin rotation.
Sources differ as to whether 765 or 785 Proof sets containing this
denomination were produced. Many of these same sources concede that
additional examples were probably struck. Despite the small mintage,
they’re not very expensive, with values hovering around $20.
It is important to distinguish between unauthorized strikes and
temporal or temporal/transitional mules. These types of mules also can
feature an incorrect date, but only because the wrong die was
inadvertently installed in a press. A temporal mule can carry an
earlier-than-expected date if a die fabricated in preparation for the
next year’s production is prematurely taken out of storage. A
later-than-expected date can occur if a die left over from the
previous year’s production is mistakenly grabbed.
The illustrated 2000 Macedonia 1-denar piece is a one-year issue
that commemorates 2,000 years of Christianity. The reverse face should
show the image of a Byzantine copper folis. Instead, this coin
displays the reverse design that was used in 1997 and again in 2001.
I don’t know whether the obverse die or the reverse die is the
incorrect die, since that would depend on exactly when these mules
were struck. This qualifies as a temporal mule because there is a
temporal (time-related) mismatch between the obverse design (and date)
and the reverse design.
Our last coin is a Russian 1993 ringed-bimetallic 50-ruble piece
that resides in a 1992 St. Petersburg Mint set. The 1992 and 1993
50-ruble coins share the same design, but the normal 1992 50-ruble
piece is a ringed-bimetallic coin while the normal 1993 50-ruble coin
is composed of a solid aluminum-bronze alloy. In this case, a reverse
die bearing the date 1993 was prematurely installed in a press
striking 1992 50-ruble coins.
This is both a temporal and a transitional mule because a change
in composition occurred along with the date.
It is believed that perhaps 100 St. Petersburg Mint sets contain
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