This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility: A severely deformed 1834 British silver sixpence preserves physical evidence most consistent with an unusual minting anomaly, according to an IA STUDIO study published in npj Heritage Science. The coin was individually marked £8 in a mixed coin album at a flea market in Greater Manchester.
The album was later acquired as a bulk lot, rather than the sixpence being purchased separately for £8. The study examined a William IV sixpence whose extraordinary deformation could not be confidently explained through visual examination alone. The investigation used scanning electron microscopy, chemical analysis and three-dimensional surface measurements to test competing explanations for the deformation.
The measurements revealed severe disruption concentrated in the central fields of the coin, while substantial portions of the rim and edge milling remained comparatively well preserved. Three-dimensional measurements identified steep-sided troughs, raised shoulders, terraced deformation and overlapping displacement structures. The damaged obverse region showed approximately 0.75 millimeters of vertical relief variation.
Taken together, the chemical, microscopic and topographic findings are most consistent with severe localized deformation involving repeated high-pressure loading under at least partial lateral constraint. The study favors a mint-stage striking anomaly over ordinary wear, corrosion or a single unconstrained later impact. The investigation combined scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDX) and optical surface profilometry.
SEM-EDX identified a silver-copper substrate in comparatively intact regions of the coin. Damaged areas showed lower measured silver levels, elevated copper and additional chemical signatures consistent with corrosion products and surface contamination concentrated within mechanically disturbed depressions. These chemical findings primarily describe changes to the coin's surface.
Although corrosion and contamination are present, neither adequately explains the extent or geometry of the deformation. Optical surface profilometry provided a detailed three-dimensional record of the damaged surface. It revealed abrupt changes in relief, steep-sided troughs, raised shoulders, terraced structures and overlapping displacement across the most severely affected areas.
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