Investigation of Ancient Wall Painting Fragments Discovered in the Roman Baths from Alburnus Maior by Complementary Non-Destructive Techniques

Abstract

In this study, several wall painting fragments discovered in the Roman baths from the archeological site Alburnus Maior (Roşia Montană, Romania) were analyzed with the aim to investigate the material composition of both plasters and pictorial layers. Dated from the beginning of the second century AD, these rare findings stand among the oldest examples of preserved decorative polychrome paintings on plaster excavated thus far in the former territory of the Roman province of Dacia. A non-destructive multi-analytical approach based on complementary techniques was considered: Fourier transform infrared (FTIR) spectroscopy, X-ray fluorescence (XRF), X-ray diffraction (XRD), UV fluorescence, and hyperspectral imaging (HSI). The obtained results highlight a common Roman color palette mainly based on naturally occurring earth pigments. Red ochre, yellow ochre, manganese-rich ochres/wads, carbon black, and calcite were identified. A traditional two-layer sequence of plasters was found—arriccio (based on lime and siliceous sands), and intonaco (pure lime). The presence of an organic protein binder, identified via FTIR analysis, and sustained by combined imaging documentation, indicates that the pigments were applied a secco. The obtained results are discussed in relation to previous published data, and they can be considered as valuable archeological indicators that contribute to the understanding of the painting techniques and the materials used in the Roman provinces.

Minerva in Colours: First Results on a Polychrome Roman Sculpture from Carnuntum (Pannonia)

“…A similar picture emerges regarding the materiality of polychromy on monuments of the Roman provinces. Isolated studies of the pigments used on sculptures, reliefs or architecture are available, e.g., [13][14][15], but most of the relevant literature concerning the Roman provinces, and particularly the Danubian provinces, is still based on studies of mural paintings, e.g., [16][17][18][19][20][21]. In addition, occasional findings of dyes are documented, which must be included in further studies, e.g., [22][23][24].…”

Assessment of Easily Accessible Spectroscopic Techniques Coupled with Multivariate Analysis for the Qualitative Characterization and Differentiation of Earth Pigments of Various Provenance

“…A peak at 396 cm −1 can also be observed in most of the samples (except PK40490 and PK116431). Frequently found in ochers or earth-based pigments [18], this band is thought to be due to SiO4-SiO4 coupling in silicate [48], while other studies assign this band to Fe-O vibrations [64]. The shoulder band around 1165 cm −1 , observed in some of the spectra, can be linked to quartz.…”

“…Given the fact that earth pigments are ubiquitous in archaeological contexts, as well as in works of art from ancient times up to the modern period, their precise characterization is of great importance for understanding the archeological and art historical record, such as: raw material selection and use, provenance (geological origin) and the technology of paint production. Important information, especially in terms of use, have been obtained via the numerous case studies performed over time on a large variety of artifacts: prehistoric rock art [6,15,16], ancient wall paintings [17][18][19][20], religious art [8,21,22], easel paintings [23][24][25][26] and so on. However, within these case studies, the analyses are often limited to the identification of the generic class of earth pigment used (e.g., red ocher), without any specific characterization of the mineralogical species present or of the geological sources.…”

The “Restoration of the Restoration”: Investigation of a Complex Surface and Interface Pattern in the Roman Wall Paintings of Volsinii Novi (Bolsena, Central Italy)

“…The first step of the diagnostic campaign was conducted by means of UVF photography, a non-invasive technique widely used in the field of restoration of cultural heritage as it revealed the state of conservation of the surfaces [33][34][35][36]. This technique showed a bad state of preservation of the paintings characterized by several grouting, lacunae, and differences due to the past interventions, e.g., the ones that started in 2012 and were never completed.…”