Characterization of Pottery from Teotihuacan Using Laser-Induced Breakdown Spectroscopy and Inductively Coupled Plasma Optical Emission Spectroscopy

Abstract

Pottery sherds from Teotihuacan, Mexico, belonging to the Formative and Classic periods (150 BCE–700 CE) were investigated using laser-induced breakdown spectroscopy (LIBS) and inductively coupled plasma optical emission spectrometry (ICP-OES). LIBS results show that most of the investigated samples have primarily the same elemental composition. Nevertheless, there are also a few sherds that could be associated to foreign ceramic groups with characteristic concentrations of Na, K, Ca, Mn, Rb, and Sr. The relative elemental composition of red pigments applied on ceramic bodies was also analyzed through a LIBS depth profiling. Diverse hematite-based pigments were distinguished according to the detected iron content. Hematite was also combined with red soils with a high relative content of Mn, Sr, Ba, or Ti. The ICP-OES analysis of ceramic pastes is consistent with the emission intensities obtained using LIBS. Principal component analysis indicates that all samples identified as locals belong to a single chemical group. Moreover, locally made ceramics and the analyzed clays from the nearby area have the same elemental composition, which appears clearly differentiated from imported samples.