2006 Atypical Die Clash ADC-25C-2006-01CO

Description

Documented by the MadDieClashes catalog as ADC-25c-2006-01CO, this 2006 Colorado State Quarter displays an unabraded die clash — a die clash where the transferred design elements were not subsequently polished away during die maintenance, leaving the clash marks in their original, undiminished state on all coins struck from the affected dies. The clash marks visible on the obverse originate from the lines in the mountain range on the Colorado reverse design, producing what collectors have aptly named the "extra mountain" effect — an unintended repetition of the Rocky Mountain topography appearing on Washington's portrait side. When comparing the obverse to the reverse, the obverse retains the more pronounced clash marks, while the only clash mark visible on the reverse was left by Washington's hair, specifically the area just above the knot in his queue (ponytail). A die clash occurs when the obverse and reverse dies strike each other without a planchet between them, transferring elements of each die's design as incuse impressions onto the opposing die face. The "unabraded" classification is significant because most die clashes undergo abrading — light polishing of the die face to remove or reduce the transferred design elements before the die returns to production. The Colorado State Quarter, part of the 50 State Quarters Program (1999-2008), features a reverse designed by Norman E. Nemeth depicting the Rocky Mountains with a banner reading "Colorful Colorado." Struck in copper-nickel clad composition weighing 5.67 grams at 24.26 mm diameter, the 2006 Colorado quarter's mountain-range reverse creates particularly recognizable and visually appealing clash marks because the bold topographic lines transfer clearly onto the obverse portrait area.

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