In the fall of 2009, the UCLA/Getty Conservation Program offered the course “Introduction to Archaeological Materials Science: Scientific Techniques, Methodologies and Interpretation” (CAEM M210) that focused on basic scientific techniques employed for the examination of archaeological and cultural artifacts to answer questions of anthropological significance and their state of preservation. Among the techniques covered were UV/VIS/NIR spectrophotometry, X-ray fluorescence (XRF), X-ray diffraction (XRD), scanning electron microscopy and energy dispersive spectroscopy (SEM-EDS), and Fourier Transform Infrared Spectroscopy (FTIR). Students were assigned small research projects in which they would apply these techniques, in addition to others discussed in this and other courses, to the investigation of various materials to answer questions about technology and condition.
The four groups of artifacts studied were:
- samples of a Byzantine wall painting from St. Neophytos, Cyprus
- samples of fibers associated with a mummy bundle excavated by the Tarapaca Valley Archaeological Project in Chile
- glazed ceramic sherds from the American Southwest
- 2 Balinese paintings on canvas belonging to the Fowler Museum at UCLA
At the end of the term, the students presented their poster, which was displayed at the Cotsen Institute of Archaeology. Below are two of the posters produced as the final project for the class.
Make sure to stay tuned to this blog for upcoming posts on the other posters presented, as well as future student projects.
Investigation of Pigment Alteration in the Wall Paintings at the Enkleistra of St. Neophytos, Paphos, Cyprus
Steven Brightup, Sara Kiani, Nicole Ledoux, James Ma, Saurabh Sharma
A series of 5 blue and 5 red pigment samples from the Enkleistra of St. Neophytos, the place of reclusion, in Paphos, Cyprus were analyzed to determine the pigments identity and possible alteration products. Fourier Transform Infrared Spectroscopy (FTIR), Variable Pressure Scanning Electron Microscopy – Energy Dispersive X-ray Spectroscopy (VPSEM-EDS), Polarized Light Microscope (PLM), and Binocular (stereo) Microscope (BM) were used to analyze the samples and due to the limitations of the techniques, only inconclusive assignments can be made on the pigments’ identity.
From elemental analysis it is suspected that the blue pigment is lapis lazuli and that there are two different red pigments which are cinnabar HgS and red lead (Pb3O4). However, without phase analysis of these samples, a positive identification cannot be made. Alteration of red to black and dark blue to light blue were observed for the samples analyzed. A possible alteration of Cinnabar is to metacinnabar. Documented alteration products of red lead are to plattnerite [β-PbO2] and anglesite [PbSO4]. Fading of lapis lazuli has been attributed to the breakdown of the Al-O-Si in the literature. However, it was not possible to verify if these are the alteration products with the available tools.
The Identification of Fibers from a Mummy Bundle, Tarapaca Valley, Chile
Tessa de Alarcon, Elizabeth Drolet, Robin O’Hern and Cindy Lee Scott
Fiber samples from a formative period mummy bundle from Tarapaca 40 in the Atacama desert of Chile were examined in an attempt to identify
them. Standards of human hair and alpaca were used for comparison. Fourier transform infrared spectroscopy (FT-IR) spectra were collected on the samples and standards. The morphology of the fibers and standards were examined using polarized light microscopy (PLM), scale casts and cross-sections. The spectra from the FT-IR analysis could not be used to differentiation between human and alpaca hair. Based on morphology, three samples were identified as camelid and two were tentatively identified as human.