On‐and off‐site Raman study of rock‐shelter paintings at world‐heritage site of Bhimbetka

Abstract

Rock-shelter paintings of Bhimbetka world-heritage site near Bhopal, India have been investigated using a portable Raman spectrometer. These paintings in the rock shelters belong to periods starting from pre-historic to the 19th century AD (Gond period). In addition, tiny fragments of pigments (100-200 mm in size) extracted from some of the artworks were also studied in laboratory using a micro-Raman spectrometer and analyzed using energy-dispersive X-ray analysis for elemental composition. Based on the Raman spectra and the elemental analysis mineral-based pigments such as calcite, gypsum, hematite, whewellite, and goethite could be identified. A comparison of the spectra recorded on-site using a light-weight portable spectrometer with those using laboratory equipment is also made and discussed.

μ‐Raman spectroscopy of prehistoric paintings from the Abrigo Remacha rock shelter (Villaseca, Segovia, Spain)

“…Crusts of whewellite and weddellite are frequently found on the surface of rocks, monuments and walls as the results of the metabolic activity of lichens, fungi, bacteria and microbes inhabiting their outer layers . Therefore, crusts of these hydrated forms of calcium oxalate are often detected on the walls of open‐air rock shelters with prehistoric paintings . These oxalates could remain on the rock surface up to 45 000 years .…”

“…Techniques used to prepare the pigments, pictorial recipes, relationships among pictographs, prospective radiocarbon dates, deterioration processes and possible forgeries may be determined from this data. Micro‐Raman (μ‐Raman) spectroscopy is a powerful tool to achieve this information …”

Raman microscopy of prehistoric paintings in French megalithic monuments

“…S1 (Supporting Information). Raman spectra from a large number of points may be obtained in situ with portable micro‐Raman spectroscopy ( μ ‐RS) instruments, thereby avoiding numerous extractions of specimens . Orthostats with possible rests of paintings are usually in tumulus chambers without light and wind, two advantages for in situ μ ‐RS .…”

Recent advances in linear and nonlinear Raman spectroscopy. Part VIII

“…used on‐site and off‐site Raman to study rock‐shelter paintings at the world‐heritage site of Bhimbetka near Bhopal, India. Based on the Raman spectra and the elemental analysis, mineral‐based pigments such as calcite, gypsum, hematite, whewellite, and goethite could be identified . Schmid and Dariz imaged and determined binder remnants and aggregates in historic cement stone by Raman microscopy.…”