Scientific investigation to look into the conservation history of a Tang Dynasty terracotta Dancing Horse

A terracotta Dancing Horse sculpture dating to the Tang Dynasty (China) and owned by the Cincinnati Art Museum (US) is the topic of the present investigation. Besides its intrinsic artistic and historical values, the peculiarity of this horse concerns its conservation history; it shows extensive breakage signs and restoration and above all, the presence of an odd tassel on the frontal part of the head. Nine tassels are present on the two sides of the body, which is very common for these kinds of sculptures. Here, a scientifc survey of this masterpiece is proposed aimed at looking into its conservation history, shedding light into the condition of the body and the tassels and the presence of residual conservation products applied during its troubled history. A comparative molecular, chemical and mineralogical study of the tassels is carried out focused on the identifcation of original and non-original materials, eventually added during restoration works. The multi-analytical protocol has been optimized for achieving as much information as possible from the available samples, a few mg of powders. X-ray powder difraction and Raman Spectroscopy techniques have been followed by Fourier Transformed Infrared Spectroscopy and Ionic Chromatography, using the same small aliquot of powders. Scientifc investigations highlighted that the odd tassel on the head and other two tassels on the body are not original, but replaced or added in subsequent time. Their composition includes both organic (polyester resin and/or phthalate) and inorganic compounds (sulphates and carbonates). Further data on original terracotta composition, decay substances and applied conservation products, provided new knowledge on past restoration treatments and cultural value. Importantly, the outcomes achieved with X-ray powder difraction to identify the tassels authenticity were matched by Raman Spectroscopy, a technique that can be also used in situ with portable instruments, paving the way to non-invasive in situ authenticity studies as future perspective.