A noninvasive complementary study of an Egyptian polychrome cartonnage pigments using SEM, EPMA, and Raman spectroscopy

Abstract

Raman spectroscopy, optical microscopy, scanning electron microscopy (SEM), and electron probe microanalysis (EPMA) were used to study pigments on an Egyptian cartonnage from the Ptolemaic period (305-30 BC). The surface morphology of each color region was examined using backscattering (BS) and secondary electron imaging. SEM X-ray energy dispersive spectrometry and EPMA wavelength dispersive spectroscopy provided semiquantitative chemical analysis of each pigment. Raman spectroscopy was used to identify the minerals associated with the pigments. This technique confirmed the presence of cinnabar (α-HgS) in the red part of the fragments. A mixture of orpiment (As 2 S 3) and bonazziite (β-As 4 S 4) and/or alacránite (As 8 S 9) was detected in the yellow regions of the fragments. The orange pigment was confirmed to be a mixture of orpiment, uzonite (χ-As 4 S 5), and pararealgar (As 4 S 4). Egyptian blue (CaCuSi 4 O 10) and Egyptian green ((Cu,Ca)SiO 3) pigments were detected from blue/green dark-colored regions of the fragments.

Pigments — Mercury-based red (cinnabar-vermilion) and white (calomel) and their degradation products

“…Other copper-based pigments such as atacamite have been found less frequently; conversely, the presence of azurite, Prussian blue and lead white are generally attributed to retouches and restorations of a later period. The study performed by Gard et al (2020aGard et al ( , 2020b on a Ptolemaic cartonnage (305-30 BC) deserves a special mention because-besides the typical pigments-pararealgar, bonazziite and/or alacránite, uzonite and Egyptian green ((Cu,Ca)SiO 3 ) were also found (for the As-containing phases 2 Table 3 Cinnabar in funerary contexts -Meso and South America (the numbers in the second column refer to Fig. 7) Mexico 1.…”

A Multi-Method Analysis of a Color Painting on Ancient Architecture from Anyuan Temple in Chengde, China

“…Historically, mineral pigments were predominantly used, being favored for their varied colors, accessibility, diverse types, and stable physical and chemical properties. Common mineral pigments include cinnabar [8,9], lead red [10], iron oxide [11], carbon black [12,13], ultramarine [14], lead white [15], and azurite. Binders [16] also play a vital role in securing pigments to mortar surfaces.…”