In pre‐Hispanic Mesoamerica, pigments and dyes were used in the elaboration of a large variety of colored objects. Obtaining information regarding the objects' material composition is useful in ...restoration and preservation processes, as well as for recovering knowledge of its production technology and the context and history of the object. Yellow colors have been obtained from a large variety of Mexican natural resources. Although mineral yellow pigments, such as orpiment and oxides, are relatively easy to identify by nondestructive and noninvasive techniques (X‐ray fluorescence, Raman spectroscopy, fiber optics reflectance spectroscopy, and Fourier transform infrared spectroscopy), organic yellow colorants are difficult to analyze by these techniques. Therefore, most works dealing with the identification of yellow dyes use destructive methods such as liquid chromatography–mass spectrometry. The aim of this work is to elaborate a methodology based on Raman spectroscopy and surface‐enhanced Raman spectroscopy for the study of yellow colorants used in pre‐Hispanic and colonial Mexico, in order to aid in their identification by spectroscopic techniques. The yellow colorants selected for this work were extracted from local plants: zacatlaxcalli (Cuscuta tinctoria), old fustic (Maclura tinctoria), weld (Reseda luteola), marigold (Tagetes erecta), and xochipalli (Cosmos sulphureus).
Yellow colorants are difficult to analyze with nondestructive methods. The aim of this work is to elaborate a methodology based on Raman and surface‐enhanced Raman spectroscopy for the study of yellow colorants used in pre‐Hispanic and colonial Mexico, in order to aid in their identification by spectroscopic techniques. The yellow colorants selected for this work were extracted from local plants: zacatlaxcalli (Cuscuta tinctoria), old fustic (Maclura tinctoria), weld (Reseda luteola), marigold (Tagetes erecta), and xochipalli (Cosmos sulphureus).
In 1952, contemporary artist Federico Silva (Mexico City, 1923–2022) carried out the first outdoor mural painting: The technique at the service of peace. At the end of 2021, the project for the study ...and conservation of this mural began with a diagnosis of its conservation, which was done through a multi‐technique study based on the experience acquired in research projects from other contemporary mural paintings. This included the proposal of an adequate conservation strategy to resolve the stability of the painting, since the behavior of the synthetic paints exposed to the different effects of the outdoor environment has altered the perception, form and meaning of the mural. Main results from this approach by documentation and global examination with Visible Imaging and Digital Microscopy, allowed us to describe the color palette and its alterations. Additional examination of cross sections acquired from this mural, allowed a material characterization by means of optical microscopy (OM), micro‐hyperspectral imaging, Fourier transformed infrared spectroscopy and X‐ray fluorescence spectroscopies.
Non invasive study of mural painting.
Desde la antigüedad, los artefactos de pizarra fueron utilizados por sociedades asentadas en diversos puntos del continente americano; su uso abarcó diferentes temporalidades y múltiples formas. En ...el caso particular de Teotihuacán, ubicado en el centro de México, los artefactos en cuestión se reportan dentro y fuera de esta ciudad, depositados como ofrenda y asociados directamente al fuego, al agua y al inframundo. Aunque la pizarra fue una materia prima con una presencia constante en Teotihuacán, sólo se reconoce cuando aparece asociada a los espejos, cuando presenta diseños iconográficos, o con evidencia de decoración. Al respecto, en este texto señalamos la importancia de la pizarra en Teotihuacán, su cronología y contexto. De acuerdo con los resultados de los análisis tipológicos, geológicos y de caracterización, proponemos el aprovechamiento de diversas materias primas dentro de un mismo yacimiento, así como la identificación de las áreas de extracción de la pizarra utilizada por los teotihuacanos a través del tiempo. Estos datos nos permiten inferir las funciones rituales, simbólicas y jerárquicas de esta materia prima dentro de la metrópoli teotihuacana.
Techinantitla building complex, in the Amanalco neighborhood of the ancient city of Teotihuacan, is famous for the iconography and quality of the mural paintings found in this site. A significant ...part of this heritage has been lost due to looting. In recent years, an interdisciplinary research project was developed to study the limited patrimony that was left. As part of this study, we first employed geophysical techniques to reconstruct the architectural pattern of the compound’s remaining walls, where other paintings may still be found. Then, we applied a non-invasive methodology to characterize a large set of fragments recovered in the 1980s and to gain information on their pigments and manufacturing techniques. This methodology included False Color Infrared Imaging, X-ray Fluorescence and Fiber-Optics Reflectance Spectroscopy, and led to the identification of hematite, calcite, malachite, azurite and an unidentified blue pigment. The results were compared with a previous study performed on a set of Techinantitla mural paintings looted in the 1960s. A broader comparison with contemporary mural paintings from other Teotihuacan complexes shows good agreement in the materials used. These results may suggest a standardization in the making of Teotihuacan mural painting during the Xolapan period (350 to 550 AD).
This work concerns the study of colors and dyes identified on archaeological textiles from the Atacama Desert. The different garments and ornaments come from the excavation of two important ...pre-Columbian cemeteries of the Tarapacá region: Tarapacá-40 attributed to the Formative period (1100 BC–660 AD) and Pica-8 to the Late Intermediate period (900–1450 AD). For the first time, a multi-analytical approach with non-invasive techniques using FORS and SERS was applied on samples of less than 2 cm of length for physicochemical characterization of the raw materials and the dyes employed in the textile production of northern Chile. The fibers are from animal origin. Blue, green, and yellow are identified as indigo, but we cannot discard a mixture with other dyes to vary hue and shade; while carminic acid and alizarin—to a lesser extent—are found on red, orange, and brown samples. This research provides new elements for the discussion about the textile technology developed in this desertic region, its changes, and continuities along the history. Our results are compared to recent findings on neighboring regions from South-Central Andes, to improve the current knowledge and discuss the existence of dyeing textile cultural traditions.
Alegoría de la construcción and Alegoría del trabajo were the first mural paintings commissioned to Saturnino Herrán (1887–1918), and they occupied a significant place in one of the most important ...schools in Mexico. The non-invasive methodology employed included different documentation phases and in situ multi-technique analyses. Hyperspectral imaging and digital radiography were used for a general characterization of the materials and were complemented with localized analyses by portable microscopy, and XRF and FORS spectroscopies. A complete identification of the original and the restoration palettes was achieved. Results from this work allowed us to understand the production context, painting technique, and conservation state, thus providing insights for the proper conservation of these murals, while also unveiling a new perception of the artist and his historical place among the muralist movement.
Purísima Concepción, a large-format and unusual panel painting attributed to the 18th century, based on style and the common aspect of the visual tradition of the Virgin Mary found in the Viceroyalty ...of New Spain, is sheltered at the Museo Ex-convento San Agustín Acolman-INAH, México, an institution opened in late 1920, and one of the oldest museums in México. In this work, we present the material characterization of the surface layer of the painting by means of a non-invasive methodology, resulting from the combination of imaging and spectroscopic techniques. Analysis of hyperspectral images employing methods such as spectral angle mapper and principal component analysis allowed us to describe spatial distribution of the pigments and manufacturing methods, while XRF and FORS allowed us to record the complex and diverse color palette employed to achieve effects such as brightness, hue, saturation, and even the covering power of this painting.
•Taguchi model was used to optimize conditions of water under subcritical treatment.•Subcritical water was used for recovery of chitin from shrimp wastes.•Deproteinization was achieved along with the ...crystallization of minerals.•The crystalline phases identified were α-chitin, calcite, hydroxyapatite, quartz.•Subcritical water treatment produces calcite and hydroxyapatite crystallization.
The extraction of calcareous chitin from shrimp cephalothorax was successfully achieved using a subcritical water treatment to attain a deproteinization up to 96%. The treatments also increased the crystalline domain size in the α-chitin fibers. An experimental design of Taguchi allowed the optimization of experiments. The macroelements identified in all samples were Ca, P, S, K, Cl and Al, whereas Cr, Mn, Fe, Ni, Cu, Zn, Br and Sr were also detected as microelements. The assigned crystalline phases by XRD were α-chitin, calcite, HAP and traces of quartz. The presence of these phases was corroborated by ATR-FTIR and SEM-EDS analyses. The highest content of α-chitin (82.2wt%) was obtained for the 0.17 chitin:dH2O (wt/wt) ratio for 30min treatment at 260°C. Noteworthy, this treatment promotes the crystallization of both minerals as microcrystals of calcite and nanocrystals of hydroxyapatite with needle and flake shapes as well as intermediate morphologies.
Jadeite was greatly appreciated by pre-Hispanic cultures in Mesoamerica. Despite its
importance, knowledge of its mining sources was lost after the Spanish conquest. In
the 1950s the only confirmed ...jadeite deposits in Mesoamerica were found in the
Motagua River Fault (MRF), Guatemala. The aim of this study is to present a
methodology that is appropriate for the study of archeological jadeite objects using
non-destructive spectroscopic and micro-ion beam analysis techniques. This
methodology has been applied to perform mineral, elemental, and luminescence
characterization of five jadeite samples from the MRF, with white, lilac, and green
colors. Fourier-transformed infrared spectroscopy and X-ray diffraction analysis
confirmed the presence of jadeite, albite, and omphacite as the main mineral phases
in the samples. Elemental maps using particle-induced X-ray emission (PIXE) with a
nuclear microprobe and elemental concentration analysis from individual mineral
grains using micro-PIXE coupled with micro-ionoluminescence (IL) allowed the
detection of minor feldspar, titanite, and grossular mineral contents. Distinctive
features from the mineral, elemental, and luminescence characterization have been
found that allow the identification of these five jadeite samples.
Los niños de San Bernardo Alejandra Quintanar Isaías , Alma Montero Alarcón , Daniel Ramírez Miranda , José Luis Criales Cortés , José Luis Ruvalcaba Sil , José Sepúlveda Sánchez , Judith Katia Perdigón Castañeda , María Eugenia Marín Benito , Mayra Dafne Manrique Ortega , Pablo Francisco Amador Marrero , Sor Beatriz Alceda
2022
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