Discipline: Technology and Engineering
Subcategory: Materials Science
Krystal Cunningham - University of California, Los Angeles
Co-Author(s): Moupi Mukhopadhyay, Carolyn Carta, Michelle Flores, Mark Goorsky and Ioanna Kakoulli, Department of Materials Science and Engineering, University of California, Los Angeles
In this communication, preliminary results of our investigations in collaboration with special agents from the Department of Homeland Security (DHS) on the analysis of a metal sculpture of a male, suspected to be looted or forged artwork. This research presents data from the contributions of X-ray fluorescence (XRF) spectroscopy, X-ray diffraction (XRD) and Scanning Electron Microscopy – Energy Dispersive Spectroscopy (SEM – EDS) for trace evidence characterization of materials in the context of a forensic investigation in art and archaeology. Results suggested that the bulk was made of native copper (Cu) sheets, affected by corrosion denoted by the presence of three of the most common copper corrosion phases: cuprite (copper oxide Cu2O), malachite (basic copper carbonate Cu2CO3(OH)2) and atacamite (copper chloride hydroxide CuCl(OH)3), the latter being characteristic of the ‘bronze disease’. Bronze disease’ refers to the irreversible corrosion process that occurs when chlorides come into contact with copper or copper metal alloys. Other materials identified included surface deposits of calcite (CaCO3) and gypsum (CaSO4.2H2O), which could be associated with burial environments and weathering or deliberate additions to fake the authentication of the sculpture. The absence of elements such as arsenic (As) and tin (Sn), main components in bronzes, and the identification of copper sheets as the bulk material suggests that the object is not a cast bronze sculpture, typical of ancient production. However, the object shows small windows (holes in the sprueing system) implying a lost-wax bronze casting method. These may have been forged to imitate a bronze casting technology. Despite this evidence, further investigations using the SEM–EDS has been conducted to confirm that these data are representative of the entire object and that the copper sheets are not modern repairs. This research, at the interface of materials science and archaeology, provides a cross-disciplinary effort to better study physical evidence and changes it has undergone due to its age and environment and to aid law enforcement practioners in combatting crime of archaeological looting and forgery of ancient materials.
Funder Acknowledgement(s): Eugene Cota – Robles Scholarship; Bridges to Doctorate Fellowship by the National Science Foundation
Faculty Advisor: Ioanna Kakoulli, firstname.lastname@example.org
Role: I was involved in every aspect of the research with help from my coworkers.