Ancient Roman wall paintings mapped nondestructively by portable NMR

Abstract

The stratigraphies of decorated walls in ancient Herculaneum, Italy, were analyzed by single-sided (1)H NMR. A large version of the NMR-MOUSE® with a maximum penetration depth of 25 mm was used to map proton density profiles at different positions of the Mosaic of Neptune and Amphitrite showing considerable differences between different tesserae and the mortar bed at different times of the year. In the House of the Black Room, different mortar layers were observed on painted walls as well as different proton content in different areas due to different moisture levels and different conservation treatments. The proton density profiles of the differently treated areas indicated that one method leads to higher moisture content than the other. Untreated wall paintings from different times were profiled in a recently excavated room at the Villa of the Papyri showing two different types of mortar layer structures which identify two different techniques of preparing the walls for painting. Reflectance Fourier mid-infrared spectroscopy and in situ X-ray fluorescence measurements complemented the NMR measurements and provided additional insight into the identification of organic coatings as well as the nature of the pigments used, respectively. The information acquired nondestructively by NMR is valued for elaborating conservation strategies and for identifying different schools of craftsmen who prepared the mortar supports of the wall paintings.

Mahi:A Unique Traditional Herbal Ink of Early Assam

“…STUDY of ancient ink and paint may help retrieve useful information regarding traditional practices in addition to unfolding historical mysteries [1][2][3] . Modern ink is a complex mixture of pigments, dyes, solvents, resins, lubricants, solubilizers, surfactants, particulate matter, fluorescents and other materials 4 .…”

“…LONG-TERM observations, experiments and modelling studies have demonstrated significant changes in patterns of global biodiversity in response to climate change [1][2][3][4] . In particular, mountainous regions are predicted to be more vulnerable for biodiversity loss due to fragmented ecosystems 5 .…”

Nuclear Magnetic Resonance, a Powerful Tool in Cultural Heritage

“…The presence of CO2 in the sodalite cage of natural Afghan ultramarine was confirmed by 13 C MAS NMR spectroscopy.…”

“…It has been shown that 13 C NMR may be successfully used to characterize the motion of molecules adsorbed on molecular sieves [74]. In particular, the 13 C NMR spectrum has been successfully used to investigate the local structure and dynamics of absorbed CO2 in porous materials such as zeolites with micro-or mesopores [73].…”

“…In particular, the 13 C NMR spectrum has been successfully used to investigate the local structure and dynamics of absorbed CO2 in porous materials such as zeolites with micro-or mesopores [73]. We exploited 13 C MAS NMR spectroscopy to ascertain the presence of CO2 in natural abundance included into the structure of a sample of Afghan lapis lazuli. In Figure 13 the 13 C MAS NMR spectra of a sample of Afghan lapis lazuli (bottom) and a sample of synthetic ultramarine (top) are compared.…”