X-ray powder microdiffraction for routine analysis of paintings

Abstract

Laboratory powder X-ray microdiffraction with a focusing monocapillary and linear multichannel detector was applied to phase identification in fragments of painting layers of art works, canvas and wall paintings, and polychromes on wood. This method is useful in materials research of painting layers with complex stratigraphy, and it is indispensable in distinguishing inorganic pigments of different natural provenance and revealing degradation products. The advantage of X-ray microdiffraction is its nondestructive nature and no need of sample pretreatment. Samples after microdiffraction can hence be used for other analyses or archived. Another advantage is the possibility to work with samples smaller than 1 mm, which is particularly important in the analysis of artworks where the sample amount or size is a serious limit of using the laboratory techniques of materials research. The X-ray equipment used is more economical and more easily accessible than other microdiffraction techniques and is, hence, suitable for routine analytical work.

Transmission and Reflection Mode Macroscopic X-ray Powder Diffraction Imaging for the Noninvasive Visualization of Paint Degradation in Still Life Paintings by Jan Davidsz. de Heem

“…The mention of syngenite in oil paintings seems very limited in literature; it has been found as a secondary salt in a red-orange Baroque bole ground used for the altar piece Celebration of St. Roche. 49 Only rarely, syngenite has been mentioned as a possible raw material in the plaster of a Chinese wall painting, together with calcite, quartz, and gypsum. 50 Although gypsum can be an original material in oil paintings (e.g., as gesso ground in Southern European panel paintings, or mixed together with orpiment), 51 its presence at the surface of Still Life with Fruit and a Lobster seems to indicate its formation as a secondary product.…”

Combined Micro- and Macro scale X-ray powder diffraction mapping of degraded Orpiment paint in a 17th century still life painting by Martinus Nellius

“…Syngenite is a frequently encountered secondary salt, either as a weathering product in black crusts or as efflorescence layers on stone monuments, mural paintings and medieval (K-rich) glass [30][31][32][33][34][35][36]. In some cases it has been found below the surface of artworks, such as in a red-orange Baroque bole ground or as a raw material in the plaster of a Chinese wall painting [37,38]. On the other hand, palmierite is less commonly reported as a sulfate salt on stone sculptures, medieval glass windows and wall paintings [39][40][41].…”

X-ray powder diffraction investigation of green earth pigments

“…One of the main advantages of this technique is its nondestructive nature and there is also no need for special sample preparation. For these reasons this technique is used more and more often in the field of cultural heritage investigations (Simova et al , 2005; Bugoi et al , 2008).…”