Investigation of a metallic green Tara Buddhist statue using neutron tomography and multiple techniques

This study presents a comprehensive investigation of a sealed metallic Buddhist statue using neutron computed tomography (CT) combined with X-ray CT, Raman spectroscopy, and X-ray fluorescence (XRF). The results revealed that the statue is hollow with multiple ritual deposits, consistent with the Buddhist consecration practice known as zhuangzang (装藏) . Furthermore, the manufacturing technique was identified as lost-wax casting. Specifically, the forearms were separately cast and welded to the main body, most likely with a tin- and/or lead-based solder and borax as a flux. Additionally, organic adhesives used for the external gem inlays and restoration materials (likely organic) at the back of the pedestal were indicated. This work establishes an integrated analytical protocol for investigating historical metallic artifacts, elucidating their manufacturing techniques, cultural significance, and conservation history. It highlights the pivotal role of neutron CT, in combination with complementary techniques, in advancing the scientific study of cultural heritage.