The non-destructive characterization of a rare Liao silver reliquary from the Museum of oriental art in Turin (Italy)

• Technical and scientific study of a peculiar Chinese silver artefact. • Non-destructive techniques to get insight into the conservation state. • Investigation of the silver embrittlement and yellowing phenomena. The present research study focuses on the archaeometric investigation of a delicate silver object. The artefact may be stylistically attributed to the Chinese Liao dynasty (907–1125 AD) and exhibits some peculiar aspects. It is made up of five overlapping and untied silver foil components, which may have been taken from unrelated artefacts and reassembled in ancient times. However, very little provenance information is available, and its manufacturing process is unknown. In addition, the reliquary was found in a highly fragmentary state, with advanced corrosion, extensive yellowing of the silver foils and severe embrittlement, which highly compromised its structural integrity and the legibility of its decorative features. Thus, a non-destructive and multi-analytical approach, based on surface spectroscopic techniques and structural characterization, was carried out on micro-fragments detached spontaneously from the reliquary. This study investigates the materials and manufacturing techniques, the conservation history, and the coherence of the five assembled components of this unique reliquary. Moreover, the investigation allowed us to gain insight into the silver microstructure and the possible causes of the observed alteration phenomena The results provide new knowledge on the metalworking practices of the Liao dynasty and might be valuable for developing and optimising strategies to restore the structural integrity of brittle ancient silver artefacts.