Ken Potter's Educational Series ...

Examining ...
"Contaminated Die Design Transfers"
by Ken Potter, NLG
Ken Potter 2002

    Probably one of the least seen error types in the hobby is one that I refer to as Contaminated Die Design Transfer.   This type of error occurs when the dies strike an already struck coin for a second time and pick up some of the design image from that coin via contaminants that are on it's surface which are then transferred as a ghostly image of that strike, (or a portion of it), to the next coin (or series of coins) struck.
    These contaminants may be in the form of plain old-fashioned oxidation, environmental contaminants, lubricants, etc., that the planchets may have picked up before or while being struck.   An extreme example of this error type is illustrated by the photos below.
    The first pair of photos are of a circulated 1953 Franklin Half Dollar that was struck by the Gallery Mint (GM), (a private Mint that produces rare coin reproductions), by their 1793 Wreath Cents dies.
    As one can see by the pair of photos that follow -- GM then took a circulated Walking Liberty Half Dollar and immediately struck it with the same die pair that had just struck the 1953 Franklin Half Dollar.  Well circulated "dark" host coins were purposely chosen for this project so that the understrikes would show well through the overstrikes.
   The result was that residue in the form of dirt and grime that was present on the Franklin Half Dollar was picked up by the dies as a mirror image, (of the date in particular), and then transferred as a normal-reading image to the surface of the Walking Liberty Half as it was struck into one of GM's 1793 Cents.
    Since we could not ascertain the date of the host coin it was ironic that we still ended up with two dates on this coin.  When was the last time you saw a 1953 Walking Liberty Half?

Here is the 1953 Franklin Half Struck
By GM's 1793 Wreath Cent Dies

Here is the Walking Liberty Half  Dollar
Struck by GM's "Contaminated" 1793 Wreath Cent Dies.
Notice the date "1953" showing below Liberty's chin.

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