Non-destructive in situ spectroscopic analysis of greenstone objects from royal burial offerings of the Mayan site of Palenque, Mexico

Abstract

One of the most important Mayan cities of the Classic period (A.D. 200-900) of Mesoamerica is Palenque, in Chiapas. The Mayan civilization attributed great importance to greenstone minerals, in particular jadeite. This study covers the analysis of greenstones found in royal tombs of several temples corresponding to the Classic period: the Temple of the Skull, Temple of the Cross and Temples XVIII and XVIII-A. The aim of this research is to determine the use of greenstone minerals and the raw materials' sources as a first step in understanding the development of Palenque and its relationships to other sites in the Maya region. Here, we present a non-destructive in situ study of lithic objects carried out by means of a several spectroscopic techniques, such as Raman, Fourier transform infrared (FTIR), X-ray fluorescence (XRF) and color measurements, at the Palenque site museum. FTIR and Raman allowed for the identification of minerals including jadeite, omphacite, amazonite, albite, muscovite and green quartz. Moreover, XRF was effective for in situ analysis of the elemental composition of the artifacts. This information was essential for sourcing the raw materials, in particular, jadeite. It was possible to infer the exploitation of an unknown source of jadeite for the earlier burial (A.D. 250-450). During this period the exploitation of the Verapaz and Motagua jadeite deposits also began. These sources were the primary deposits used for the manufacture of the artifacts studied from the period of A.D. 600-850. Also, a greater diversity of minerals is observed during the zenith of Palenque during this period, corresponding to the reign of Pakal. Although, between burials, the color of the artifacts is diverse, the color measurements indicated similarity in color among artifacts within individual burials.

A multi-technique approach, based on mobile/portable laser instruments, for the in situ pigment characterization of stone sculptures on the island of Crete dating from Venetian and Ottoman period

“…Typical exposure time for each scan on the CCD was 20 s, and spectra reported correspond to an average of 5-20 consecutive scans on the same point. For transportation, the whole instrument is packaged in two carrying cases, a medium-sized one, housing the 3 , weight 28 kg), containing the laser and its power supply unit, the sample illumination source, the spectrograph and the detector, all attached firmly onto a light-weight aluminium frame.…”

“…Collecting microsamples is often an alternative for bypassing the above limitations, but current trends, concerning protection and preservation of cultural heritage objects, impose non-sampling policies or strict controls in performing sampling for further analysis in the laboratory. Obviously the option to use mobile analytical equipment, which can be operated on site, emerges as an important prospect [1][2][3][4][5].…”

Molecular and X-ray Spectroscopies for Noninvasive Characterization of Mayan Green Stones from Bonampak, Chiapas

“…However, such objects may be composed of a wide range of green minerals. 21,22 In this research, we were able to identify the main mineral component in many objects using FT-IR (typical spectra acquired are shown in Fig. 2).…”

“…In Mexico, a combination of portable Fourier transform infrared (FT-IR), Raman, and XRF devices has been previously used for the study of Mesoamerican objects. 19–22 Raman and FT-IR spectroscopies detect vibrational modes of molecular bonds, identifying different composites. X-ray fluorescence is useful for elemental identification and the information obtained helps prove hypothesis about manufacture, origin, or conservation of archaeological objects.…”

“…The characterization of the green stone funerary objects may provide insights about the person sacrificed in the burial, as well as new data about the use of raw materials for the manufacturing of artifacts and the offering. Their composition can be compared with pieces discovered in other sites of the region and with other important contemporary Mayan sites, such as Palenque, 21 in order to establish possible relationships between them and the exploitation of similar raw sources.…”