X-ray diffraction and Raman spectroscopy study of white decorations on tricolored ceramics from Northwestern Argentina

Abstract

White virgules, commas, and dot designs on tricolored ceramics are sporadically found in different archaeological sites located in Northwestern Argentina area, as Puna and Quebrada de Humahuaca. This decorating style has been reported in several articles, but few previous archaeometric studies have been carried out on the pigment composition. Fragments from Puna and Quebrada archaeological sites, belonging to Regional Development Period (900–1430 AD), were analyzed by X-ray diffraction and Raman spectroscopy in order to characterize the pigments employed. Red and black pigments are based on iron and manganese oxides, as it has been extensively reported for the NW Argentina area. White pigments from white virgules, comma, and dot designs have shown different composition. Hydroxyapatite was found in samples from Doncellas site (North Puna region), and calcium and calcium–magnesium containing compounds, as vaterite and dolomite, along with titanium containing compounds were detected on samples from Abralaite (Central Puna region) and Gasoducto (Quebrada de Humahuaca region). It has been concluded that pigment composition is not characteristic of a unique region.