Non-invasive and micro-destructive investigation of the Domus Aurea wall painting decorations

Abstract

The paper reports on the exploitation of an educated multi-technique analytical approach based on a wide non invasive step followed by a focused micro-destructive step, aimed at the minimally invasive identification of the pigments decorating the ceiling of the Gilded Vault of the Domus Aurea in Rome. The combination of elemental analysis with molecular characterization provided by X-ray fluorescence and UV-vis spectroscopies, respectively, allowed for the in situ non-invasive identification of a remarkable number of pigments, namely Egyptian blue, green earth, cinnabar, red ochre and an anthraquinonic lake. The study was completed with the Raman analysis of two bulk samples, in particular, SERS measurements allowed for the speciation of the anthraquinonic pigment. Elemental mapping by scanning electron microscopy-energy dispersive spectrometer combined with micro-fluorimetry on cross-section gave an insight into both the distribution of different blend of pigments and on the nature of the inorganic support of the red dye.

Raman spectroscopy of minerals and mineral pigments in archaeometry

“…In 2010/2011, a lot of Raman studies dealing with mineral pigments were published: the complex gilt stucco surfaces of different monuments in Lombardia (Sansonetti et al); Pompeian wall paintings using EDS and SR‐HRPD and micro‐Raman (Duran et al); pigments in 15th century mediaeval and 16th century renaissance vault paintings in the Our Lady's Cathedral in Antwerp, Belgium (Deneckere et al); mural paintings from the Pyrenean Church of Saint Eulàlia of Unha (Clark et al); the wall painting ‘Historia de Concepcion’ by Gregorio De La Fuente in Concepcion, Chile (Aguayo et al); wall painting by Romans and Arabs (Garofano et al); fresco fragments at the Coriglia, Castel Viscardo, Orvieto, excavation site (Donais et al); wall paintings by Masolino da Panicale in the Baptistery of Castiglione Olona, Italy (Comelli et al); pigments from the Mortuary Temple of Seti I, El‐Qurna at Luxor, Egypt (Mahmoud); Roman and Arabic wall paintings in the Patio de Banderas of Reales Alcazares’ Palace (Duran et al); and the ceiling of the Gilded Vault of the Domus Aurea in Rome (Clementi et al).…”

Raman microspectroscopic analysis of decorative pigments from the Roman villa of El Ruedo (Almedinilla, Spain)

“…Roman pigments have been found on highly diverse supports including wall paintings, plaster casts, mosaics and mortars, and characterised with various analytical techniques [8][9][10][11][12][13][14] including Raman spectroscopy [15][16][17][18][19][20]. Determining the particular decorative pigments used by a population can be useful to identify the specific materials available at a local, regional or even more extensive level; also, it can help better understand the basic colour preparation and application techniques used in its day.…”

Microanalysis of clay‐based pigments in painted artworks by the means of Raman spectroscopy

“…Mobile variations of instruments are currently available, enabling non–invasive analysis of works of fine art in situ , i.e. there is no need to take samples …”