Centre d'Analyses et de Recherche en Art et ArchéologiePigments are present everywhere in Art. They are found in prehistoric paintings on rock art, on stained-glass, on canvas and panel paintings, on statues, dyes on fabrics, glazed on terracotta, etc. They are everywhere and knowing their chemical structure is an undeniable asset for authentication, preservation and restoration. Understanding a work of art, an artist…
At CARAA we have a strong experience in the expertise of metals. We have to date made studies on statues (antique as well as modern), gilded bronzes from furniture, archaeological metallic artefacts, numismatic collections, etc. Our analyses aim to help in understanding and preserving the metal-based objects. The accuracy of physicochemical analyzes A physico-chemical analysis…
The analysis of metal sculptures correspond to an understanding of the technology used by the artist. To do this, one can determine the manufacturing process (lost wax casting, sand casting, molding …) and the alloy used. The manufacturing process is determined by optical observations or through imaging (X-rays, CT- Scan… ).The characterization of the alloy…
This category is also known under the classical term of “fire arts”. It includes glasses (coloured or not), stained-glass, porcelain, ceramic, terracotta, but also some siliceous materials which have not necessarily undergone intentional thermal metamorphosis: flint, obsidian, mosaics, … The study of the matrix and fillers The analyses that we conduct at CARAA on such…
The analysis of artworks made of ceramics or glass consist first in the study of the matrix: the distribution of the grains in a porcelain, in a clay preparation, etc. Elemental analyzes (e.g ICP-MS, ICP-AES, EDS, XRF, …) are mainly used to characterize the major elements (silica, fluxes, modifiers), minors (e.g. coloring oxides) and trace…
Etude et identification de fibres d’amiante dans une collection de livres du 18ème s. • Bouchard M. et al., 2008, at AIC’2008, Denver, USA. pdf Etude et identification de fibres d’amiante dans une « lanterne magique » (fin 19ème s.) (non publié) Identification d’uranium dans une photographie utilisant le procédé Uranotype. (non publié) Etude de…
Semi-precious stones, as well as rocks belong to the mineral world. Again, the role of CARAA is to determine the most efficient methods to scan an object according to its value, size, conservation state and, the sampling opportunities … or the non-invasive possibilities. Choosing the appropriate techniques Understanding a gem or a mineral might be…
The study of historical monuments concerns the study of some decorative art objects (tapestries, sculptures, paintings, etc.) as well the study of the architectural structure (murals, wall sculptures, railings, exterior coatings, etc.). The broad range of techniques available in conservation science can be applied to the study of these historical monuments in a goal of…
The wide variety of existing materials adds to the intrinsic complexity of some organic molecules. Organic artefacts generally relate to wood, leather, bacteria, plants, bones, solvents, fibers, etc. Only organic materials related to the fields of Arts are treated at CARAA (wood, ivory, bone, varnishes, binders, dyes, polymers and plastics, etc.). Understanding the organic material…
Archaeological objects concern all material remains that relate to Man from Prehistoric to all Historical periods and that sometimes is necessary to unearth (tools, bones, pottery, weapons, coins, jewellery , clothing, prints, traces, paintings, buildings, infrastructure, etc.).. The diversity of the materials encountered in archaeology, and the vast historical period concerned make the study of…
• Environmental scanning electron microscopy coupled with Energy dispersive spectroscopy (ESEM-EDS): Energy dispersion spectrometer (EDS) provides the elemental composition of pigments in a painting (e.g. Fe for iron oxides, Hg for cinnabar, As for realgar, Cu for azurite, etc..) or helps to determine the chemical content of the different chemical elements (e.g Si, Ca, K, Na,…
• Raman microscopy : Raman microscopy is a molecular and mineralogical technique that is very efficient for the characterization of metallic alteration products, dies, pigments or siliceous material. Raman microscopy or X-ray diffraction (DX) are often complementary to XRF and allow to obtain the molecular or mineral composition of pigments (e.g., hematite-Fe2O3, cinnabar-HgS-,-realgar As4S4-, malachite…
“Directly” datable materials are ceramics, terracotta, carbon-based materials (such as wood, ivory, textiles, etc.), and some rocks and minerals. The characterization of pigments or metal alloys also enables “indirect” dating of an object by correlating historical and technological knowledge with the analyzed material.
• Thermoluminescence (TL) correspond to the ability of certain crystals to accumulate the energy released by radioactive ionizing radiation and to restore this energy under the form of light when they are submitted to heat. TL dating in archeology applies to materials such as pottery, terracotta, clay core in sculptures, burned or heated flints and…
The experience at CARAA in the analysis of toxic products include to date: the detection of asbestos, mercury and lead in art objects, arsenic in ethnological objects and taxidermy. Less known than pigments, metal alloys or ceramics, toxic materials yet exist in art. It is therefore imperative to remove or replace them with more stable…