One of the more interesting and expensive error coins is the
double-denomination error, where a normally struck coin ends up in the
blank bin for a different denomination.
In this case a 1963-D Jefferson 5-cent coin was overstruck with
1963-D Washington quarter dollar dies.
A struck coin is “work-hardened” by the striking process, so if a
struck coin is subsequently fed into another coin press, the second
striking will be weaker.
In most cases, the original coin’s details will not be completely
obliterated by the second strike, especially if the original coin is
smaller or thinner than a normal blank would be.
The characteristics of a double-denomination error become
complicated when a counterfeiter decides to get into the act.
This particular coin is a genuine 1963-D Jefferson 5-cent coin
that was overstruck with fake Washington quarter dollar dies that were
produced using the spark erosion method. This type of fake die
typically will have rough, ragged design elements and proof-like fields.
Note in the accompanying images how the raised devices of the
Washington quarter dollar design are rough and lumpy where the details
meet the fields.
While the surfaces and devices on a genuine error coin will often
exhibit some roughness and uneven striking, a fake error struck with
spark erosion dies will be exaggerated by comparison.
On the illustrated coin, the three areas shown in the images are
the eagle’s head, the eagle’s legs, and the letters in in god we trust.
Other parts of this fake error also exhibit unusual roughness, but
these areas show the diagnostic lumps and bumps better than the rest.
A number of fake error coins have been produced using spark
erosion dies over the last few decades, so this is something to watch
When in doubt, it is always best to consult with an error
specialist, someone who has had the opportunity to inspect both
genuine and fake errors in quantity.
Like so many other offerings in numismatics, if it seems too good
to be true, it probably is.
Michael Fahey is a senior numismatist at ANACS in Denver, Colo.