Die Polishing is the process of cleaning the dies used to strike a coin. Over the course of the life of a working die, dirt and grime may accumulate on the die itself. In addition, the die may acquire clash marks or other imperfections that a mint worker might try to polish away in an attempt to strike "cleaner" coins.
In the VAM world, die polishing is associated with many interesting variety features, including prooflike surfaces, "disconnected" wreath leaves (e.g. 1878-P VAM-79), and "washed out" devices (e.g. 1878-P VAM-223).
Die polishing lines are also noteworthy. These "hairlines" are sometimes confused with abrasions on the coin or even whizzing. However, die polishing lines are distinctive features that come from the die itself, and they are often used to distinguish different varieties or even different stages of the same variety. Die polishing lines are raised and are often found on Morgans within the bow of the wreath, on either side of the eagle's neck, within the letters of LIBERTY, and in the band of the Phrygian cap. An extreme example of die polishing can be found on the 1921-S VAM-1i. The 1921-P VAM-41 late die state, pictured below, also shows major die polishing lines:
Die polishing has nothing to do with the "polishing" of a minted coin, which is a form of cleaning.
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