Spectroscopic examination of Red Queen's funerary mask and her green stone offering from the Mayan site of Palenque, Mexico

This work presents a non-invasive material study of the Red Queen's funerary offering via in situ infrared (FTIR) and Raman spectroscopies for mineral identification, and X-ray fluorescence spectroscopy (XRF) for elemental characterization. A second non-destructive laboratory stage on the main mask of the offering only was carried out by particle induced X-ray emission (PIXE) for further elemental analysis. The main FTIR results indicate that all of the tesserae of the main mask are composed of malachite, identified by their nu(Cu-O),nu(Cu-OH),nu(1)-nu(4)(CO32-) and delta(CO32-) infrared and T(CO32-) Raman vibrational modes. Moreover, the pupils are composed of obsidian (delta(Si-O-Si) and nu(Si-O) infrared vibrational modes), and remarkably, jadeite was identified in the sclera of the eyes. Most of the accompanying mask's tesserae are green quartz and chalcedony (delta(Si-O-Si) and nu(Si-O) infrared and Raman vibrational modes). The pendants are made of jadeite, while the headdress tesserae were identified as omphacite. The diadem and necklace's green beads were mostly jadeite, omphacite and albite. Jadeite, albite and omphacite were identified through their characteristic infrared and Raman vibrational modes: nu(Si-O-Si), delta(Si-O-Si), tau(SiO4) and Al-SiO4 interactions. Yellow-orange beads in the diadem and in the pectoral are quartz. Green and blue pectoral beads are jadeite, omphacite and quartz. Limestones and shells identified in the figurine, valve and in some of the headdress and accompanying mask's tesserae, were properly classified by Raman spectroscopy, using their characteristic nu(1) and nu(4) (CO32-) vibrational modes for aragonite and beta-carotenes characteristic Raman shifts for Spondylus valves. These results indicate a special selection and the use of unique raw materials for the royal burial of the Red Queen, different to those used for other rulers of Palenque and other contemporary Mayan sites. (C) 2020 Elsevier B.V. All rights reserved.