Analysis of clay smoking pipes from archeological sites in the region of the Guanabara Bay (Rio de Janeiro, Brazil) by FT-IR.

In this study, twenty samples of clay smoking pipes excavated in an 18km(2) area between the Macacu and Caceribu rivers, in the municipality of Itaboraí, Rio de Janeiro, Brazil were analyzed by FT-IR technique. The samples, excavated in different archeological sites of the region, are dated between the seventeenth and the nineteenth centuries and are part of the material culture left by Africans and African descendants that lived in the complex. FT-IR analyses and complementary SEM-EDS studies showed that the clay paste used in the manufacture of smoking pipes, mostly handcrafted, is composed of quartz, feldspar, phyllosilicates and iron oxides. Multivariate statistical tests (PCA) were applied to FT-IR data to assess the interactions between the archeological sites. The results indicated that one archeological site - Macacu IV - is greatly related to the other sites. The results obtained have helped archeologists and anthropologists in better understanding the manufacturing process employed in ancient ceramic artifacts produced during the period of colonial Brazil.

Analysis of a Brazilian baroque sculpture using Raman spectroscopy and FT-IR.

In this study, samples were taken from the sculpture of Our Lady of Sorrows and analyzed by Raman spectroscopy and FT-IR. This sculpture has been dated to the early eighteenth century. Samples were also examined using optical microscopy and Energy Dispersive Spectroscopy (EDS). Based on chemical analysis, the pigments vermilion [HgS], massicot [PbO] and azurite [Cu3(CO3)2(OH)2]were found in the sculpture polychrome. The results indicate that the green polychrome of the sculpture's mantle comes from the blending of massicot and azurite. Because the literature reports that the mantle of the Our Lady of Sorrows sculpture is blue, the mixing of these pigments results from a production error. The results also indicate the presence of Au in the sculpture, which indicates the originality of the piece. The results from this study helped restorers to choose the appropriate procedures for intervening in the sculpture and contributed to the knowledge about the manufacturing process of Brazilian baroque sculptures.

Characterization of Brazilian artists' palette from the XIX century using EDXRF portable system.

In this work were characterized the palettes of some of the most representative Brazilian painters from the XIX century: Eliseu Visconti, Almeida Junior, Rodolfo Amoedo, Henrique Bernardelli, Rafael Frederico, Modesto Brocos, Augusto Rodrigues Duarte and Pedro Peres. EDXRF measurements were carried out with a portable system consisting of an X-ray tube Oxford TF3005 and a Si-PIN XR-100CR detector from Amptek. Some pigments identified were: zinc and lead white, ochre, umber, vermilion, Prussian blue, cobalt blue, cadmium yellow, black iron oxide, etc.

Analysis of the painting "Gioventú" (Eliseu Visconti) using EDXRF and computed radiography.

In this work, the painting "Gioventú" (Eliseu Visconti, 1898) was analyzed by means of energy dispersive X-ray fluorescence and computed radiography. A portable EDXRF system was employed to identify the pigments used by the artist: yellow, red and brown ocher; umber; vermilion; cobalt blue; lead white and viridian (or chromium oxide). The CR analysis revealed that the painting was in a good state of conservation and also a previous composition hidden under the painting.