First insights into the archaeometric analysis of the Los Amores Mosaic in Cástulo (Linares, Spain): the Judgement of Paris

Abstract

This paper discusses results obtained from in situ analysis of the tesserae of the Roman mosaic of Los Amores (Cástulo site, Linares, Spain) dating back to the turn of the 1st to the 2nd century AD. Specifically, it focuses on the scene The Judgment of Paris. In view of the exceptional state of preservation of the mosaic, from which very few tesserae had fallen off, non-invasive methods with portable Micro Raman Spectroscopy (MRS) and hand-held X-ray fluorescence (hXRF) and data assessment by use of principal component analysis and binary representations were selected. The results obtained allow to evaluate both the analytical method and the portable equipment used, as well as to classify the raw materials, the colouring agents and the opacifiers used. MRS analysis proved crucial for the identification of stone tesserae (ironstones, carbonate and siliciclastic rocks) and for the identification of the type of glasses used (soda-lime-silicate and lead type glasses) based on the analysis of two detached tesserae. hXRF analysis of the glass tesserae identified both colouring agents (Co, Cu, Pb, Zn) and opacifiers (calcium antimonate). The data obtained lend themselves to an assessment of the degradation process that threaten the integrity of the mosaic. The identification of tessera made of specific stone materials (especially ironstone) and of lead glass tesserae suggest the existence of a mosaic workshop in the Upper Guadalquivir (Eastern Andalusia, Spain).

Non-Invasive Approach to Investigate the Mineralogy and Production Technology of the Mosaic Tesserae from the Roman Domus of Villa San Pancrazio (Taormina, Italy)

“…The only red opaque glass sample investigated, 15117RV (Figure 5, Table 2), was featured by a surface golden layer, as well as small spherical holes and craters, indicating the occurrence of a macroscopic alteration quite common in archaeological glass [99]. The core piece displayed as its main elements, found by EDXRF, Si, Pb and Na (with amounts of Furthermore, rutile (TiO 2 , signals at 143, 241, 445 and 610 cm −1 ), and different Si-O bonds of the glassy phase (at 550 and 1093 cm −1 , and also at 480 and 1065 cm −1 ) were identified, together with some calcium and/or aluminum-silicate, incorporating cobalt ions or some alkali sulfate [80,101] as indicated by the signals collected at 459, 616, 637, 996, 1076, 1130 and 1198 cm −1 .…”

“…The only red opaque glass sample investigated, 15117RV (Figure 5, Table 2), was featured by a surface golden layer, as well as small spherical holes and craters, indicating the occurrence of a macroscopic alteration quite common in archaeological glass [99]. The core piece displayed as its main elements, found by EDXRF, Si, Pb and Na (with amounts of 34, 29 and 14 wt.%, respectively) and, as the minor elements, Ca, Fe, Cu, Sb, K and Al, i.e., 7, 5, 4, 2, 1 and 1 wt.%, respectively.…”

“…14117BV, 17117BV and 18117BV samples (Figure 5, Table 2) are blue glass tesserae found in a secondary context close to the niche of the rear wall, so that it is very likely that they belonged to the mosaic decoration of the niche itself (Table 1, Figure 3). Among them, the surface of 17117BV is the only one characterized by small spherical holes and iridescent areas strongly suggesting glass degradation processes [77,99]. The EDXRF analysis evidenced high amounts of silicon, between 55-61 wt.%, followed by significant concentrations of calcium, sodium, antimony and aluminum, i.e., between 11-14 wt.%, 4-12 wt.%, 6-12 wt.% and 2-7 wt.%, respectively.…”

Correction to: First insights into the archaeometric analysis of the Los Amores Mosaic in Cástulo (Linares, Spain): the Judgement of Paris

“…The correct author name is: Anastasia Rousaki. The author group has been updated above and the original article [1] has been corrected.…”