By Bill
Fivaz, NLG
Upon occasion,
either in print or in a seminar, I have noted that reference has
been made to the “roughness” or not-fully-struck-up
portions of a coin as being the result of “die abrasion”.
This is really
not a proper term to describe this characteristic, as “die
abrasion” would indicate that something had abraided or scratched
the die, thereby imparting a raised aberration on the coin. This
is not what is in question.
A more accurate
description would be “planchet abrasion”, and even this
is somewhat misleading. I thought is might help everyone understand
a little bit better if we examine precisely what causes this roughness
on various coins, so let’s take a quick look at the appropriate
sections of the minting process.
In order for
any coin to be fully struck up so that all the design details are
sharp and distinct, there must be: (1) properly designed dies that
are not worn or damaged in any way, (2) a properly annealed (heated
and cooled) planchet, and (3) adequate striking pressure from the
dies applied to that planchet.
Coins struck
from worn dies exhibit a weakness in areas of low relief on the
coin, usually where the design meets the field (the lower furl of
the flag on a Walking Liberty Half Dollar, for example). A coin
struck with inadequate striking pressure (a weak strike), will show
weakness and design loss in the areas of high relief (center of
coin, areas where first wear shows, etc.). The hair over the ear
or the eagle’s breast on a Morgan Dollar are good examples
of this.
Many times a
worn die strike, or one struck on an improperly annealed planchet,
will exhibit a “rippled” effect on the coin, similar
in appearance to the skin of an orange. Understandably then, we
refer to this as the “orange peel effect”. However,
it is the second of these two problems, the weak strike, that we
are concerned with in this article.
Before a planchet
is struck, it has passed through several stages of preparation,
constantly hitting and banging against other planchets in tumblers,
tote bins, etc. This metal-against-metal contact creates various
degrees of dings, dents, and scratches on the planchet as illustrated
in the photo below.
(Contact
Marks on a planchet)
When a heavily
marked up (abraded) planchet enters the striking chamber (resting
on the lower die within the collar), and is struck by the two dies,
if the striking pressure is inadequate for any reason, the metal
from the planchet fails to flow into the deepest cavities of the
die’s design. If the particular area that is not fully struck
contains some of the more prominent planchet marks, they will not
be obliterated by the strike and show as nicks and abrasions on
the coin. This is planchet abrasion.
Here are three
examples of planchet abrasion on a Buffalo 5¢, Walking Liberty
50¢ and a Morgan $1:
Planchet
Abrasions on weakly struck 1935-S Nickel - Obverse
Planchet
Abrasions on weakly struck 1935-S Nickel - Reverse
Planchet
Abrasions on weakly struck 1940-S Half Dollar - Obverse center of
gown
Planchet
Abrasions on weakly struck 1940-S Half Dollar - Reverse eagles breast/wing
Planchet
Striations on 1883-O Morgan Dollar Obverse
Planchet
Striations on 1883-O Reverse
The important
thing to remember is that these planchet abrasions “go with
the territory”, and unless severe, usually do not affect the
price of a coin other than considering the degree of weakness of
the strike.
To differentiate
between planchet abrasions and post-striking nicks, contact marks
and mis-handling, examine the area closely to make certain there
is still planchet luster (a whitish, frosty appearance) in the are
of question. Also, zero in on some of the nicks, etc. (a 10X or
16X power loupe may be necessary) to see if they have the same color
(luster), which would indicate they were there prior to striking,
or if they are shiny, telling you that they were made by coming
in contact with another coin (metal-against-metal).
Another good
indication of planchet abrasion is that the small marks, under high
magnification, will exhibit rather rounded edges where the striking
process muted the original defect.
I hope you will
now be able to understand what planchet abrasions are and be able
to tell them from post-striking contact marks.
Bill Fivaz is
the author of Helpful
Hints for Enjoying Coin Collecting and co-author of The
Cherrypickers' Guide to Rare Die Varities.
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