Archaeometric Study of the Colorants in the Finds From the 4th Century BC Cist Tomb at Lakkoma, Chalcidice

The analytical findings concerning the red pigments used on various decorative features originating from a Macedonian, as well as the purple dye from the deceased's attire, are presented. The cist tomb, discovered in 1987 at the area of Lakkoma Chalcidice (Macedonia, Greece), dated to the 4th century bc and featured a wooden funeral couch with intricate ornaments, such as clay “eyes,” colored plaster, and clay gorgoneions. Vermilion and red ochre served as the main pigments of these decorative features. The pigments were applied in various combinations to produce a range of red hues, from deep to bright red. Furthermore, the precious vermilion was also used in every element of the couch. The stucco on the decoration was gypsum, whereas the preparation layers over clay and stucco elements consisted of calcite and lead white, respectively. The cloth covering the deceased was dyed with the most expensive organic dye of antiquity, the Tyrian (shellfish) purple. In this research, the preliminary identification of the chromophoric minerals in the colors of the samples was carried out with the examination of their optical characteristics in thin sections using polarizing light microscope (PLM) and with portable XRF. Physicochemical techniques, Raman and HPLC, were also used to definitively identify the pigments. Portable Raman spectrometer was used for the in situ analysis of the inorganic colorants of the decorative materials, whereas laboratory Raman spectrometer served for the identification of inorganic and organic colorants of the grain samples and the dye. High-pressure liquid chromatography with diode array detector (HPLC-DAD) was applied for the identification of the coloring components of the purple organic dye from the deceased's clothes. The samples examined (0.5- to 1.5-mm diameter) were collected during the initial cleaning of the surface.