Like mayflies, the average coinage die lasts about a day. In that time, it can suffer damage that is serious enough to warrant repair, but not so severe as to require permanent removal. The most common type of superficial damage occurs when dies collide in the absence of a planchet.
In the case of a relatively light die clash, the clash marks can be removed by abrasion. Intentional die abrasion has in the past been called “die polishing,” “lapping,” and “stoning,” the assorted names perhaps reflecting different techniques used over the years.
One frequent hallmark of intentional die abrasion is the presence of fine die scratches. Usually these run in many different directions, but swathes of parallel scratches are not unknown.
Shown here is a 1986 Lincoln cent with profuse die scratches that cover the reverse face. The abrasion was undertaken after the dies clashed in a slightly rotated position. For some reason, little or no effort was made to erase the clash marks on the obverse die.
Not all cases of intentional die abrasion will show die scratches, however. The scratches can slowly disappear after the die is reinstalled and strikes thousands of additional planchets.
Some abrasive techniques seem to use a much finer grit that produces a smooth surface. For example, Sacagawea dollars in which the right iris and pupil are lost to abrasion (creating the so-called “cat’s eye” effect) typically show a smooth surface.
Overzealous intentional die abrasion can lower the field portion of the die to such an extent that recessed design elements become shallower, thinner, and may even disappear. The illustrated 1972-D Lincoln cent shows the results of such an assault. Low-lying portions of Lincoln’s nose, mouth, temple, cheek, and neck have been erased. The letters of IN GOD WE TRUST become progressively thinner as they approach the design rim with some pinching out.
Intentional die abrasion can affect an entire die face or can be quite localized. The reverse face of the illustrated 1982 cent shows only scattered, light die scratches. The design shows no loss of detail or strength except in the area containing the letters ERIC, which grow thinner and pinch out as they approach the design rim. Why special attention should have been paid to this area is unclear. Perhaps some peripheral die damage needed to be repaired. Interestingly, no die scratches appear in this area, suggesting that a very fine abrasive was used.
Design elements can also be lost to accidental die abrasion. Machine parts like a feeder can rake across the die face and wear away its surface. The resulting drag marks are typically both coarse and unidirectional. They are usually referred to as scrapes rather than scratches.
The illustrated 1996-P Washington quarter dollar shows heavy die scrapes that appear most prominently in front of Washington’s face but which continue for a short distance behind his head. The low-lying area between Washington’s eye and the root of his nose has been abraded away.