A few months ago, I tackled the issue of wobbly half dollars —
coins that would rock or spin when placed on a flat surface.
In that column, I noted that some cases — like the 2001-P Kennedy
half dollars that led off the discussion — were clearly caused by a
sunken reverse die that produced a corresponding bulge on the reverse
face of the coin. In a second case — a 1972-D half dollar provided by
Steve Rodriguez — I was not able to establish the source of the
instability. A few weeks after the column came out, Rodriguez sent me
a second 1972-D half dollar that was struck by a different die pair.
Like the first coin, it rocked when the reverse was placed on a flat
surface. In both coins, the highest point on the reverse was the
As with the earlier piece, identifying the cause of the
instability was made difficult by the fact that there was only one
example and there were no associated defects such as die cracks or
centralized design weakness that might have pointed to a sunken die. I
had to leave the coin in the suspense account, with respect to both
the cause of the instability and whether the coin represented a Mint
error (as opposed to post-strike damage).
Recent developments have left me more confident that both 1972-D
half dollars represent Mint errors of a minor sort. The reason for my
optimism is a large shipment of wobbly half dollars recently sent to
me by Jon Leese. The shipment includes 13 2001-D Kennedy half dollars
that rock when placed on the reverse face. Die markers show that at
least two die pairs are represented. Not surprisingly, the point of
instability is the center of the shield.
A second sample consisted of seven 1997-P half dollars, almost
evenly divided between two different die pairs. Unlike the previous
pieces, these rock when placed on the obverse face.
Rounding out the shipment were a single 1998-P Kennedy half dollar
and a single 2000-D half dollar, each of which rocked when placed on
the obverse face.
I didn’t have to look very far for the cause of instability in
these coins. In each sample, the instability appears to have been
caused by a very common and prosaic event — a failure for the design
rim to exceed the height of the interior design. One of the primary
functions of the design rim is to protect the interior design and
permit coins to stack neatly. If the design rim is too low, a wobbly
coin may result.
Further evidence in support of this conjecture is provided by a
“lipstick test.” I smeared a thin, uniform layer of red lipstick on a
piece of paper and placed the paper on a hard countertop. I then
pressed several of Leese’s coins into the lipstick, making sure that
the center of the coin and all points along the rim made contact with
the paper. Each coin was then carefully lifted off the paper. Areas
coated with lipstick represent the highest design points.
The reverse of one of the 2001-D half dollars shows a large
deposit of lipstick on the eagle’s shield. This is the highest point
of the design in normal half dollars. Lipstick has also stuck to some
of the peripheral letters.
Patches of lipstick are rather dispersed on a 1997-P half dollar.
Affected areas include Kennedy’s cheek, eyebrow, base of neck and two
spots in his hair. These are the highest points of a normal design.
Sunken die (die subsidence) errors will alter the normal array of high
points and concentrate them in one area.
A similar lipstick pattern is seen on the obverse face of the
1998-P and 2000-D coins.
The lesson from this exercise is that, when one is confronted by a
wobbly coin, one should first eliminate the prosaic explanation.
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