Crystallography in the studies of art and historical artefacts
Philippe Walter
Laboratoire d’archéologie moléculaire et structurale – UMR 8220 Université Pierre et Marie Curie / CNRS
College de France, Chair of Technological Innovation
INTERNATIONAL YEAR OF CRYSTALLOGRAPHY Opening Ceremony Paris, UNESCO, January 21th, 2013
Giorgio Vasari painting himself and the Virgin (1565, Florence)
Describe the list of pigments used on the palette of the artists :
History of techniques
Find relevant impurities to identify material sources:
Trade of pigments
Understanding the physical properties of the paint matter:
The artist’s gesture
Understanding the chemical modifications through times Conservation purposes
Describe the list of pigments used on the palette of the artists :
History of techniques
Understanding the physical properties of the paint matter:
The artist’s gesture
Combining XRD and XRF
XRD peak profile analysis Transmission electron microscopy
Qualitative powder X-ray diffraction
RT 300°C, 2h 500°C, 2h
Defects, size and shape of the crystals
Understanding the chemical modifications through times Conservation purposes
Galena
Find relevant impurities to identify material sources:
Trade of pigments
low stability to photochemical processes and atmospheric gases.
Sunflowers, fourth version: yellow background, National Gallery, London, England
Sunflowers, repetition of the 4th version (yellow background), Van Gogh Museum, Amsterdam, Netherlands.
Chrome Yellow PbCrO4
Chrome Yellow - PbCrO4 Synthetic pigment commonly used by artists of the 19th C, such as V. Van Gogh, J. Ensor, G. Seurat, P. Cezanne
Cr(VI) → Cr(III)
This pigment tends to gradually acquire a darker aspect, causing the original bright yellow color to become brown
Monico et al., Anal.Chem., 2011, 83, 1224–1231
About 15 to 20 glaze layers for the shadows, as thin as 2µm
In the glaze layers, 1.4% of manganese oxide crystals
Calculations with PyMCA L. De Viguerie et al., Angewandte Chemie Int. Ed., 2010, 49: 6125–6128
Drawing an oil mill, the "molino della doccia di Vinci" turned into a machine to grind colors
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Walter, European review, 21(2), pp 175-189, 2013
Specificities of painting materials • Precious materials • Highly heterogeneous (need of local and overall information) • Two trends : - Synchrotron XRD on samples if a sampling is
possible - Portable XRD devices, directly on the painting
Cross-section of samples embedded in resin
- Superimposition of layers (different colors)
- Mixtures of ingredients in the layers
Preliminary analyses with conventional analytical techniques in the lab, like SEM-EDX, Raman spectroscopy, …
Mathias Grünewald - Isenheim Altarpiece (1512- 1516), Colmar
ESRF – D2AM French CRG Beamline (coll. Institut Néel, J.L. Hodeau et al.)
Small sample (30-200µm) in a glass capillary
SDD Detector
CCD Detector
XRD and XRF with Synchrotron radiation (ESRF)
g
00-025-0322 (N) - Copper Zinc - (Cu,Zn) - Y: 17.64 % - d x by: 1. - WL: 0.6888 - 0 - 00-036-0432 (D) - Gypsum - CaSO4.2H2O - Y: 20.04 % - d x by: 1. - WL: 0.6888 - 0 - I/Ic PDF 1.7 - 00-013-0131 (I) - Hydrocerussite syn - Pb3(CO3)2(OH)2 - Y: 45.93 % - d x by: 1. - WL: 0.6888 - 0 - Operations: Enh. Background 1.778,0.100 | Import\\psf\Home\Desktop\2012ESRF\Data_XRD\WNERO1_good_pour_1048_5Converted from UXD format to RAW for Dif [...] - File: hod302dg.RAW - Type: 2Th/Th locked - Start: 3.509 ° - End: 32.395 ° - Step: 0.026 ° - St
Lin
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2-Theta - Scale4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29
WNERO1 Hydrocerussite Gypsum
Synchrotron de Grenoble - ESRF- Ligne de lumière ID22
Sample
Embedded in resin
XRD camera
XRF detector
µXRD on painting samples (ESRF, ID22)
µXRD on painting samples (ESRF, ID22)
Argon
XRF Si(Li) detector(Gresham)
PhotonicsScience Camera
I0
Microscope
θ=10°
sampleembedded
in resin
B.S.
Focalized beam : 1x3µm & XZ mapping
ROI Stibnite
ROI hydrocérusite
hydrocerussite <015> stibnite <202> stibnite <302>
2θ=12.06 2θ=9.93 2θ=12.06
0102030405060708090
100110120130140150160170180190200210
2-Theta - Scale4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27
B A
The resurrection of the Christ
XRD mapping on a sample cross-section
Stibnite Sb2S3 Hydrocerrusite 2PbCO3. Pb(OH)2 Cerussite PbCO3
Weight %
White layer (II):
- Hydrocerusite 44%
- Cerusite 56%
Grey layer (I):
- Hydrocerusite 72%
- Cerusite 17%
- Stibnite (S2Sb3) 11%
Quantitative analysis of lead white in the two layers Rietveld refinement analysis
G4
MGN7
White gound layer(imprimatura) Layers with pigments
Cerussite
Hydrocerussite
MGN12
MGN10
MGN2
MGN3
Classification of lead white pigments : 2 processes of synthesis / 2 origins ?
Welcomme et al., Applied Physics A, 2007
Various lead white pigments during the XVth and XVIth centuries: - List of pigments sold in the Frankfurt market: cerussa from Venise, cerussa from Antwerp, plain white pigment. - Rules for painters and glassmakers from Tournay, Belgium (1480), « blancq de plonc, chéruse, blanc commun » - chéruse : cerussa, probably with adding of chalk. - Traktaat om kleuren te bereiden (XVIe siècle, Anvers) : two types of pigments (lead white and cerussa) differentiated by their more or less refined preparation : the finest lead white is obtained by collecting the supernatant powder after several days in water.
Martinetto et al. Acta Crystallographica C, 58, 182–184.
P. Bleuet at al., Nature Materials, 7, 468 – 472, 2008.
XRF-XRD tomography (ESRF, ID22 and D2AM) to get a multi-modal local chemical & structural analysis.
Towards in situ analysis with mobile instruments
Portable XRF/XRD characteristics -X-ray, microfocus air cooled tube, -maximum 30 W power 50 kV, 600 µA -Cu Kα ; E=8.047 keV; λ=0.154 nm -polycapillary optics, 4 mm diameter parallel beam (slits) -XRD : image plates + scanner Gendex Denoptix - XRF: Amptek SDD 450 µm, resolution 135eV; 8 µm Be, Weight of measuring head: 22 kg Total weight about 50 kg
Gianoncelli et al., Analytical & Bioanalytical Chemistry, 395 (2009) pp. 1997-2004
Portable X-ray diffraction for Art
Consortium européen MOLAB Programmes européens CHARISMA (2009-2013) et Eu-ARTECH (2005-2009)
XRD-XRF on The virgin and the Child, with St. Anne
Jacques Castaing, Hélène Rousselière, Philippe Walter, CNRS-LAMS, UPMC
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2-Theta - Scale18 20 30 40 50
Cinnabar (HgS) Hematite (Fe2O3) Calcite (CaCO3). Hydrocerussite (PbCO3,Pb(OH)2) Cerussite (PbCO3)
Lead white analysis : less hydrocerussite in the flesh tones
Two types of lead white = purchase in two places or deliberate choices ? temporality in the painting realization or technical choice ?
Walter, European review, 21(2), pp 175-189, 2013
Black painting of a Mammouth - Rouffignac, Dordogne, 15000 BP X-ray diffraction identification of Manganese oxides Time of measurement : 10 minutes
Beck et al, Revue d’archéométrie, 2012
