Raman and FT-IR spectroscopy of prefiring paintings and slips in pre-Hispanic South American pottery?the case of Diaguita Inca pottery: an initial glazing-painting process? (Tinogasta, Catamarca, Argentina)

DE LA FUENTE GUILLERMO A.; MARTE, FERNANDO; MASTRANGELO, NOEMÍ; MARTÍNEZ CARRICONDO, MARINA; ROZAS, GUILLERMO; VERA, SERGIO D.; NAZAR, CARLOS D.; TASCÓN, MARCOS

Archaeological and Anthropological Sciences

Springer Nature

Año: 2021 vol. 13

1866-9557

Prefiring paintings of Diaguita Inca pottery from Costa de Reyes N° 5 archaeological site (Tinogasta, Catamarca, Argentina) were investigated through a multianalytical approach. Micro-Raman, FT-IR and EDS analyses were carried out on microstratigraphical transversal sections of the sherds as well as on the painted surfaces. Results obtained preliminary indicate that a complex technological process is involved to decorate these vessels. Red and black paints are characterised by hematite (α F2O3) + quartz (α quartz) and tenorite (CuO) compounds, respectively. White slip, is characterised by the presence of anatase (TiO2), and crystalline and glassy phases such as quartz (α quartz), mullite (2Al2O3.3SiO2) and cristobalite (SiO2), and in some cases calcium silicates (wollastonite, ghelenite) have been detected. The presence of quartz, calcium silicates and baryte in this slip, together with a specific lustrous visual colouring effect, suggest the presence of an initial sintering and glazing process. Whether this glazing-painting process was done intentionally by ancient potters requires further future research in this area. Additionally, the presence of CaO in the white slip as a natural flux is explored and discussed in detail.