Laboratory investigation of a deformed 1834 William IV sixpence

Abstract Severe deformation in historic metal artefacts is not always resolvable by visual inspection alone. This study investigates a deformed 1834 William IV sixpence using scanning electron microscopy with energy-dispersive X-ray spectroscopy and optical surface profilometry. SEM-EDX spot analyses show an Ag-dominant silver-copper substrate in comparatively intact regions, while damaged regions show reduced Ag, elevated Cu, and C, O, Al, Si, P, S, Cl, K, Ca and Fe consistent with contamination and corrosion products trapped in mechanically disturbed depressions. Profilometry documents localised relief displacement, terraced deformation, steep-sided troughs, raised shoulders and overlapping compression structures, with vertical relief variation up to approximately 750 micrometres and damaged-zone roughness of Sa approximately 67 micrometres and Sq approximately 82 micrometres. The combined evidence is most consistent with a severe mint-stage striking anomaly involving constrained compressive deformation.