Argentinean prehistoric pigments’ study by combined SEM/EDX and molecular spectroscopy

E-Preservation …, 2009

key words: Prehistory pigments, child bones, red and yellow ochre, micro-Raman, SEM/EDX e-PS, 2009, 6, 112-117 ISSN: 1581 web edition ISSN: 1854-3928 print edition www.Morana-rtd.com © by M O R A N A RTD d.o.o. M O R A N A RTD d.o.o.

We studied the composition, colour chromaticity and form of application of red pigments in human bone samples from seven Classic period Lowland Maya sites. The samples were analysed by X-ray diffraction, scanning electron microscopy (SEM) and X-ray energydispersive spectroscopy (EDS). Colour was measured using conventional colour identification standards (Munsell) and reflectance spectroscopy. Cinnabar and hematite were identified as the pigments used. We conclude that the reflectance method has advantages over conventional visual results, as it provides precise, objective and quantifiable optical data to distinguish the chromaticity, colour saturation and brightness of the pigments.

Samples of prehispanic rock art from Oyola's archaeological site, near the city of Catamarca, Argentina have been analyzed using micro-Raman spectroscopy, SEM-EDS and BSD, and optical microscopy. These samples are representative of diverse figures and non-painted surface of one of the caves at the site: Oyola 7. The pigments employed in the rock art were fully characterized. The red colors are confirmed to be red ochre (hematite) and clay. White areas of the painting have been identified as gypsum whereas black pigment is attributed to graphite. In addition, it was demonstrated that all the samples analyzed, including underlying strata, contain large amounts of calcium oxalate as the mineral whewellite. Because of the distribution along the sample, it was conclude that the presence of this compound is due to biodeterioration produced by microorganisms, fungi, algae or lichens. Moreover, a methodology to differentiate black painting layers from carbon deposition layers from bonfires and to characterize them is presented. These results have a great impact in both chemical and archaeological sciences because allow an interdisciplinary approach bringing relevant information about relative and absolute dating. Finally , the information collected with this methodology establish a sound basis to develop complementary studies between the wall and painting stratigraphies with archaeological excavations resulting in a new and fundamental tool henceforth.

Archaeometry, 2020

We present the results of analysis of pigments used in slips and designs deployed in ceramic assemblages recovered from archaeological sites located in different environments, expressing the socio-historical process developed in the regions of Fiambalá and Chaschuil during the last 1500 years (Catamarca, Argentina). The sample, formed by fragments of different ceramic styles and natural pigments, was analysed via Raman spectroscopy and Xray diffraction. Results indicate the continuity in the use of certain pigments (mainly hematite for the red hues, and manganese oxides in combination with magnetite for the black paints), within the different socio-political organizations that inhabited the region from I to XVI centuries, in spite of the diverse shades of colour, which suggests an intentional search linked with their cultural conventions. For the Inca Period, this scenery of continuities in minerals employed for reds and blacks is complemented by the use of new compounds (titanium oxide, apatite, and gypsum) in order to generate the "cream" tones applied as slips, all of which have not been identified for previous moments.

Heritage, 2024

The study seeks to unravel the intricate operational sequence involved in preparing prehistoric pigments for rock art within the Puerto Roque rock art shelter. Sixteen pigment samples were meticulously collected from specific figurative representations. Additionally, three ochre samples were sourced from the shelter's soil. Employing a comprehensive multi-analytical approach, including Raman microspectroscopy, X-ray microfluorescence (EDxrf), Fourier-transform infrared spectroscopy (ATR-FTIR), and scanning electron microscopy (SEM-EDS), all nineteen samples underwent thorough analysis. Notably, darker pigments revealed a composition of hematite with the added presence of carbon. Meanwhile, one sample exhibited an orange hue primarily composed of goethite and bright red pigments predominantly characterised by hematite, as confirmed by Raman analysis. EDxrf analysis demonstrated an elemental composition akin to the three ochre pieces examined. Furthermore, ATR-FTIR spectroscopy suggested the potential influence of a heating process in enhancing red coloration, corroborated by spectral results from specific samples. This finding aligns with prior research, underscoring the technological sophistication embedded in early artistic endeavours.

Journal of Raman Spectroscopy, 2015

In Northwestern Patagonia, many archaeological sites can be found that testify human occupation by hunter-gatherer groups during the Holocene period. The general purpose of archaeological research in this area is to obtain information on the movements of these groups between the dry steppe and the different sectors in the forests. This paper reports on the results of the first spectroscopic analysis of samples from the archaeological excavation of two hunter-gatherer regions in Northern Patagonia (Traful Lake and Manso River areas). Thirty samples of rock art fragments, grinding tools, shell, raw pigment material, as well as painted ceramics and beads were examined with micro-Raman spectroscopy, complemented with X-ray fluorescence (XRF) analysis. Micro-Raman analysis revealed mostly the use of haematite (Fe 2 O 3 ) as the red chromophore. The presence of associated minerals and silicates indicated that clay-like material (ochre) was used, instead of pure haematite. Although not fully conclusive, Raman spectroscopic results tend to indicate that in some samples haematite might be formed by heating iron-containing ochres.

Materials Issues in Art & Archaeology VII, Vol. 852 (eds. P.B. Vandiver, J. L. Mass & A. Murray), 2005

The ancient technology involved in the application of pigments and paintings used by potters to decorate ceramic vessels is one of the most interesting aspects of ceramic technology in the past. Potters have used in the past several sources (e.g. inorganic and organic) to decorate the vessels in order to achieve the colours desired and fix them in the vessels throughout the firing process. In this paper, we present the results of a technological and chemical characterisation of pigments and paintings through the application of Scanning Electron Microscopy-Energy Dispersive Spectroscopy (SEM-EDS) analytical technique to ceramics from the Middle Period (ca. 650 AD – 900 AD) at Northwestern Argentine region.

Journal of Raman Spectroscopy, 2015

In Northwestern Patagonia, many archaeological sites can be found that testify human occupation by hunter-gatherer groups during the Holocene period. The general purpose of archaeological research in this area is to obtain information on the movements of these groups between the dry steppe and the different sectors in the forests. This paper reports on the results of the first spectroscopic analysis of samples from the archaeological excavation of two hunter-gatherer regions in Northern Patagonia (Traful Lake and Manso River areas). Thirty samples of rock art fragments, grinding tools, shell, raw pigment material, as well as painted ceramics and beads were examined with micro-Raman spectroscopy, complemented with X-ray fluorescence (XRF) analysis. Micro-Raman analysis revealed mostly the use of haematite (Fe 2 O 3 ) as the red chromophore. The presence of associated minerals and silicates indicated that clay-like material (ochre) was used, instead of pure haematite. Although not fully conclusive, Raman spectroscopic results tend to indicate that in some samples haematite might be formed by heating iron-containing ochres.

Journal of Heritage Science

This article presents the results of physical-chemical characterization of the layers of coating covering the bodies, faces and stuffed of four mummified human bodies and seven grave goods from the Chinchorro Archaic funerary tradition that inhabited the Atacama Desert of the far northern coast of Chile. Using Scanning Electron Microscopy with Energy-Dispersive X-Rays (SEM-EDX) and X-Ray Diffraction (μDRX), the study identified the use of different pigments including iron, manganese and copper oxides that were combined into different preparations or pictorial recipes for paste and coating bodies and faces. The results indicate that the Chinchorro, an archaic hunting, gathering and fishing society (7000-3500 B.P.) managed a complex color technology for their mortuary practices.

Summary In recent years chemical analysis has been established as a significant contributor to science-based archaeology. The present work is a first approach to the study of chemical and mineralogical composition of pigments used in archaeological rupestrian arts of Vão Grande site, included in Lajeado Complex in Tocatins State, Brazil. Representative pigments micro-samples were removed from rock paintings and substrate rock. The characterization of the pigments was carried out by micro X-ray diffraction (μ-XRD) and Fourier transform infrared microspectroscopy (μ-FTIR). Riassunto Questo lavoro è un primo approccio allo studio della composizione chimica e mineralogica dei pigmenti utilizzati nel sito archeologico di arte rupestre di Vão Grande, facente parte del complesso di Lajeado nello Stato di Tocatins, Brasile. Micro-campioni dei pigmenti sono stati rilevanti dalle pitture rupestri e dal substrato di roccia. La caratterizzazione dei pigmenti è stata condotta con microdiffrazione dei raggi-X (μ-XRD) e microspettroscopia a infrarossi a trasformata di Fourier (μ-FTIR).

Heritage Science, 2014

This article presents the results of physical-chemical characterization of the layers of coating covering the bodies, faces and stuffed of four mummified human bodies and seven grave goods from the Chinchorro Archaic funerary tradition that inhabited the Atacama Desert of the far northern coast of Chile. Using Scanning Electron Microscopy with Energy-Dispersive X-Rays (SEM-EDX) and X-Ray Diffraction (μDRX), the study identified the use of different pigments including iron, manganese and copper oxides that were combined into different preparations or pictorial recipes for paste and coating bodies and faces. The results indicate that the Chinchorro, an archaic hunting, gathering and fishing society (7000-3500 B.P.) managed a complex color technology for their mortuary practices.

A collaborative project, Documentación y Preservación del Arte Rupestre Argentino, was initiated by the Instituto Nacional de Antropología y Pensamiento Latinoamericano in 1994. This report describes the project generally and then focuses on analyses of samples from two rock painting sites in Patagonia, Argentina: Cueva de las Manos (a World Heritage Site) and Cerro de los Indios. Representative microsamples were removed from rock paintings and substrate rock to investigate pigments, substrate preparation, mineral accretions, and other physical aspects of the sites. Analyses were done using light microscopy, x-ray microanalysis (scanning electron microscopy), x-ray microdiffraction, and Fourier transform infrared spectroscopy. Pigments identified were red earth (hematite: α-Fe2O3), yellow earth (goethite: (α-FeOOH), manganese oxide black (pyrolusite: β-MnO2), green earth (celadonite or glauconite), maghemite (γ-Fe2O3), as well as gypsum, kaolin, quartz, and other minor ancillary minerals. Colored material excavated at an archaeological site at Cerro de los Indios was also analyzed for comparison.

Chemical and microscopical analyses were undertaken of samples from the rock painting sites Azcona (El Bolsón) in Río Negro Province and Campo Moncado 1 (Valle de Piedra Parada) and Cerro Pintado (Cholila) in Chubut Province, Argentina, by the Canadian Conservation Institute. Representative microsamples were removed from rock paintings and substrate rock to investigate the pigments and any mineral accretions present. Analysis by x-ray microanalysis (scanning electron microscopy) and x-ray microdiffraction revealed the presence of hematite, lepidocrocite, and green earth (celadonite or glauconite) pigments as well as calcium oxalates (whewellite structure). (AATA Nos: 2006-108423 and 40-2592; Abstractor: Ian N.M. Wainwright)

Rock Art Research, 2019

Pigments from several preHistoric rock art painting samples were analysed through a multiproxy archaeometric approach. Sampling occurred in two rockshelters within the National Park of Serra da Capivara National Park area (a UNESCO World Heritage Site): Toca do Paraguaio and Toca do Boqueirão da Pedra Furada. Five complementary techniques x-ray micro-fluorescence, Raman spectroscopy, scanning electron microscopy, stereomicro-scope observation and high temperature-gas chromatography (HT-GC) were combined to identify and characterise the inorganic and organic material. In particular, gas-chromatography analyses revealed the presence of binders, hardly recognised in rock art preHistoric pigments. These binder substances (plant fatty acids) could be included in the pigment process 'chain-opératoire'.

This paper presents the first studies on the compositional characterization of the pigments used on Belén-style prehispanic pottery from El Bolsón valley (Catamarca, northwestern Argentina). The integrated analyses using micro-Raman spectroscopy and XRD revealed variability in the precursors used to generate the black paints: manganese oxides, magnetite, titanomagnetite, carbon and calcined bone. This variability of compounds, and their use in various combinations, had not been previously documented for a particular ceramic style, and provides evidence of the coexistence of different recipes for the elaboration of paints. It is also noted that this is the first case in which the use of calcined bone as a component in black paint is registered. From these results, and those previously obtained from ceramic pastes, it is proposed that the Belén-style pottery manufacture from El Bolsón valley was not standardized, but developed with low intensity in small-scale workshops.