Conserving Nayarit Ceramics

Last quarter we both had the opportunity to treat pre-Columbian Nayarit ceramic figurines from Mexico, on loan from the Southwest Museum of the American Indian Collection, Autry National Center. At first glance we thought the treatment would be pretty straightforward, but after a closer look it appeared to be anything but!

The surface and structure of the figurines are deceptively highly restored, which can be common for artifacts passing through the art market. In addition to reassembling the fragmented figurines, our goal is to document and identify old from new, and shed light onto the unknown pasts of these objects. We’re approaching the project with a range of tools including X-ray imaging, UV-induced visible fluorescence imaging, X-ray diffraction (XRD) analysis, and X-ray fluorescence (XRF) spectrometry. XRF analysis indicates the presence of lead and zinc on the surface of both figurines, which are common in modern pigments, though typically not found in pre-Columbian ceramics. Using XRF and XRD, we also detected the presence of plaster in some areas, a common restoration material for ceramics. While we work to try to piece our puzzles together, take a look at our projects!

Female Nayarit figurine before treatment. Southwest Museum of the American Indian Collection, Autry National Center, Los Angeles; 2232.G.33

Female Nayarit figurine during treatment: after reconstruction (left) and after gap-filling of the joins to stabilize fragments on the nose and lower section of the body (right). Southwest Museum of the American Indian Collection, Autry National Center, Los Angeles; 2232.G.33

Female Nayarit figurine after treatment. Southwest Museum of the American Indian Collection, Autry National Center, Los Angeles; 2232.G.33

Figure 5: Male Nayarit figurine, imaged under visible light (left), 415 λ induced visible fluorescence (center) and B&W image of UV induced visible fluorescence (right). Fluorescence imaging can help distinguish difference in material that cannot be detected under normal lighting conditions. It is common for restoration materials to fluoresce distinctly from original material. Southwest Museum of the American Indian Collection, Autry National Center, Los Angeles; 2232.G.28

X-ray image of Male Nayarit figurine taken from the back of the object at 45 kV. This imaging technique reveals that the body is composed of many fragments that have been previously restored. Southwest Museum of the American Indian Collection, Autry National Center, Los Angeles; 2232.G.28

XRF analysis was conducted on the rear supports at the bottom of the figurine. The spectrum shows presence of gypsum-based plaster due to the high calcium peak (CaKa1) and presence of a sulfur peak (S Ka1) indicating this is an area of restoration. The significant amounts of titanium (Ti Ka1) and manganese (Mn Ka1) may be from modern pigments used to paint the plaster surface. Southwest Museum of the American Indian Collection, Autry National Center, Los Angeles; 2232.G.28

Colette Khanaferov and Betsy Burr (’16)