A Multi-Analytical Investigation of Roman Frescoes from Rapoltu Mare (Romania)

Abstract

(1) Background: Due to the precarious situation of many monuments or archeological sites, analytical investigations are necessary to obtain information about the used materials, as well as to identify the most appropriate solutions for their conservation/restoration. This paper addresses the characterization of mural painting fragments collected during the excavation in 2018 in Rapoltu Mare (La vie), Deva. (2) Methods: Specific analytical techniques were used, as follows: X-ray diffractometry (XRD), wavelength dispersive X-ray fluorescence (WDXRF), optical microscopy (OM), zoom microscopy and scanning electron microscopy (SEM), spectroscopic techniques (UV–Vis, FTIR, Raman), porosity and thermal analysis, all of which provide information about the structure, chemical composition, morphology and topography of pigments and their deterioration as well. (3) Results: Up to seven different pigments were identified: Egyptian blue, carbon, calcite, gypsum, hematite, goethite and green earth. Egyptian Blue is identified in all the other color areas, except the white area: in the green zone (as degradation product with beeswax) and in the red zone (in mixture with ochre) too. In addition, carbon and beeswax were highlighted as toner and binder for pigments, respectively. In the presence of the organic beeswax binding environment, the Egyptian blue pigment particles darkened or turned yellow significantly, changing the blue to a greenish color. It is also possible to identify wollastonite (CaSiO3) in the blue pigment, which indicates that the temperature used in the manufacturing of Egyptian blue was higher than 950 °C from thermal analysis. The presence of apatite, hematite and gypsum deposits in the Hunedoara region certifies that these pigments could have been of local origin, as demonstrated by the presence of analytically identified elements (Fe, P, S, Ca). (4) Conclusions: The analytical techniques used for such investigations have highlighted the main pigments used in Roman times for various Roman murals.

Unveiling Hidden Insights of Ancient Roman wall paintings in Cremona: In-Depth Knowledge Beyond the Surface with Spectroscopic Analysis

“…In this case, the presence of iron compounds was interpreted as intentionally added in little portion to calcium carbonate to achieve a slightly pale pink color. These results, however, are consistent with other studies of white pigments used in ancient Roman wall paintings [12].…”

Diagnosis, Photogrammetry and Conservation Treatment with Nanomaterials of Sacidava Fortress

“…Except the visible surface cracks, thermographic inspection put into evidence further cracking, difficult to be detected through visual testing (Figure 3). The physicochemical analysis, absolutely necessary in such experiments [17], was performed in this paper using WDXRF, XRD and FTIR. WDXRF allowed to see the elemental composition of mortar samples taken from the bricks existing in the fortress, It can be found that, on the same stone component, there can be differences of about 10-15 • C, which give the organisms associated with these surfaces' adequate ecological adaptations and allow them to survive in this type of microhabitat.…”

“…Except the visible surface cracks, thermographic inspection put into evidence further cracking, difficult to be detected through visual testing (Figure 3). The physicochemical analysis, absolutely necessary in such experiments [17], was performed in this paper using WDXRF, XRD and FTIR. WDXRF allowed to see the elemental composition of mortar samples taken from the bricks existing in the fortress, The physicochemical analysis, absolutely necessary in such experiments [17], was performed in this paper using WDXRF, XRD and FTIR.…”

“…The physicochemical analysis, absolutely necessary in such experiments [17], was performed in this paper using WDXRF, XRD and FTIR. WDXRF allowed to see the elemental composition of mortar samples taken from the bricks existing in the fortress, The physicochemical analysis, absolutely necessary in such experiments [17], was performed in this paper using WDXRF, XRD and FTIR. WDXRF allowed to see the elemental composition of mortar samples taken from the bricks existing in the fortress, revealing the presence of CaO, SiO 2 , Al 2 O 3 , and Fe 2 O 3 (Table 1).…”

“…Currently, the fortress is in an advanced state of deterioration, with only a few walls excavated through partial archaeological works, which led to a significant loss for this monument of cultural heritage. Physico-chemical environmental factors and biological factors participate synergistically or antagonistically in the process of deterioration of the remaining walls of this monument [2][3][4]. The degree of stone deterioration depends on the physico-chemical environmental factors, the composition and nature of the stone material itself, and biological factors.…”