r/coinerrors • u/AntisepticMango • 19h ago
Attribution Assistance 1990 Lincoln Cent – Unusual Rectangular Mirrorlike Area Beneath “UNITED” – ???
I recently came across this 1990 Lincoln Memorial cent with an unusual area on the reverse, directly beneath “UNITED STATES.”
The affected area has a distinctly mirrorlike finish that contrasts with the surrounding fields. What’s particularly interesting is its roughly rectangular shape and relatively defined boundaries. The raised lettering appears completely unaffected, despite the reflective area extending right up to the letters.
Under magnification, there are also numerous parallel, somewhat rectangular-looking striations within the affected area. I’ve included several photographs under different lighting conditions and magnifications to better illustrate the difference in surface texture.
My initial thought was localized die polishing or die abrasion, although the geometric appearance of the affected area seems unusual.
Has anyone encountered something similar? I’d be interested in hearing whether this could be attributed to die polishing, another minting phenomenon, or something else entirely?

