Chemical and mineralogical characterization of Aguada Portezuelo pottery from Catamarca, north‐western Argentina: PIXE, XRD and SEM‐EDS studies applied to surface pre‐ and post‐firing paints, slips and pastes

Abstract

Particle‐induced X‐ray emission (PIXE), X‐ray diffraction (XRD), electron microprobe analysis (EDS) and scanning electron microscopy (SEM) analytical techniques were used to characterize surface paints in pre‐ and post‐fired Aguada Portezuelo decorated pottery. Surface paintings in black, white, red, brown, burgundy and ochre were analysed. Major, minor and trace elements were detected by PIXE, whereas XRD and SEM‐EDS gave information on the main mineral phases and the characteristic morphology for each analysed pigment. The results obtained indicate that the main colour groups can be easily discriminated by PIXE, and they are characterized by only one pigment for each colour: hematite (red) and manganese mineral oxides (black), respectively, whereas white pigments are characterized by calcite, ghelenite and gypsum.

The Santa María pottery of El Bolsón valley (Catamarca, Argentina): Compositional characterization and implications on the elaboration processes, ca. 1000–1600 ce

“…Analysis of the paints focused on black and cream colours. This decision was based on previous studies of red paint in NWA, which had shown that the used chromophore has always been haematite (Fe 2 O 3 ); instead, cream and black paints were achieved through a variety of components (Bugliani et al, 2012; Centeno et al, 2011; De La Fuente et al, 2019; Puente et al, 2017; Ratto et al, 2020). The pastes of these samples were also studied by XRD and RS to compare their composition with respect to those of the painted surfaces.…”

A multi‐analytical approach to understand El Alto‐Ancasti's painted pottery (north‐western Argentina): Non‐invasive and micro‐invasive analyses of vessel's paintings from El Taco 19

“…This style is characterized by a diversity of decoration techniques and a great iconographic complexity (having motifs such as warriors, jaguars, birds, etc.) painted in various colours and hues, such as light red, dark red, purple red, brown/ochre, black, white and, in some cases, yellow (Figure 1, d: 1) (Baldini et al, 2005; Cremonte et al, 2003; De La Fuente et al, 2019; De la Fuente & Pérez Martínez, 2008; González, 1998; Kush, 1996; Nazar & De la Fuente, 2016). Besides, Aguada Portezuelo pottery combines pre‐ and post‐firing paintings, using negative or positive spaces to create motifs.…”

“…Besides, Aguada Portezuelo pottery combines pre‐ and post‐firing paintings, using negative or positive spaces to create motifs. Indeed, they have been manufactured in at least two firing steps (De La Fuente et al, 2019; De la Fuente & Pérez Martínez, 2008; González, 1998). The internal surface of the vessels usually shows an intense polished black colour attributed to a smoking technique called graffited , obtained by ancient potters throughout the inclusion of vegetable materials inside bowls charred in a reducing atmosphere during firing processes (De la Fuente & Pérez Martínez, 2018).…”

“…Many works were centred on the archaeometric study of Aguada Portezuelo pottery using a variety of technical approaches (XRD, SEM‐EDS, particle‐induced X‐ray emission (PIXE), RS and FT‐IR) to enquire about the elemental and molecular composition of motifs, splits and pastes (Baldini et al, 2005; Cremonte et al, 2003; De la Fuente et al, 2005, 2019, 2020; De la Fuente & Pérez Martínez, 2008, 2018). As result, it is known that some pigments (blacks and reds) were added to a clay colloid (alumino‐silicate mineral) to fix colours onto the surface of a ceramic matrix.…”

Jugando con colores y pigmentos: una aproximación experimental y arqueométrica a la alfarería Portezuelo (ca. 600-900 d.C.) (Catamarca, Argentina)

“…Por otra parte, diferentes autores han realizado análisis composicionales de los pigmentos utilizados para policromar la cerámica Portezuelo (Cremonte et al, 2003;Baldini et al, 2005;De La Fuente et al, 2005;Bertolino et al, 2008;De La Fuente y Pérez Martínez, 2008, 2018De La Fuente et al, 2020). La Tabla 1 resume los cromóforos (pigmentos) identificados en cada uno de los casos y las técnicas analíticas utilizadas.…”