Degradation process of lead chromate in paintings by Vincent van Gogh studied by means of spectromicroscopic methods. 3. Synthesis, characterization, and detection of different crystal forms of the chrome yellow pigment.
The painter, Vincent van Gogh, and some of his contemporaries frequently made use of the pigment chrome yellow that is known to show a tendency toward darkening. This pigment may correspond to various chemical compounds such as PbCrO(4) and PbCr(1-x)S(x)O(4), that may each be present in various crystallographic forms with different tendencies toward degradation. Investigations by X-ray diffraction (XRD), mid-Fourier Transform infrared (FTIR), and Raman instruments (benchtop and portable) and synchrotron radiation-based micro-XRD and X-ray absorption near edge structure spectroscopy performed on oil-paint models, prepared with in-house synthesized PbCrO(4) and PbCr(1-x)S(x)O(4), permitted us to characterize the spectroscopic features of the various forms. On the basis of these results, an extended study has been carried out on historic paint tubes and on embedded paint microsamples taken from yellow-orange/pale yellow areas of 12 Van Gogh paintings, demonstrating that Van Gogh effectively made use of different chrome yellow types. This conclusion was also confirmed by in situ mid-FTIR investigations on Van Gogh's Portrait of Gauguin (Van Gogh Museum, Amsterdam).
Centre SMAArt and Dipartimento di Chimica, Università degli Studi di Perugia, via Elce di Sotto 8, I-06123 Perugia, Italy.
Letizia
L
Monico
Koen
K
Janssens
Costanza
C
Miliani
Brunetto Giovanni
BG
Brunetti
Manuela
M
Vagnini
Frederik
F
Vanmeert
Gerald
G
Falkenberg
Artem
A
Abakumov
Yinggang
Y
Lu
He
H
Tian
Johan
J
Verbeeck
Marie
M
Radepont
Marine
M
Cotte
Ella
E
Hendriks
Muriel
M
Geldof
Luuk
L
van der Loeff
Johanna
J
Salvant
Michel
M
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D000965:Antimony / Q000032:analysis*; D002840:Chromates / Q000032:analysis*; D017608:Chromium Compounds / Q000032:analysis* / Q000138:chemical synthesis; D003460:Crystallization; D007854:Lead / Q000032:analysis*; D010151:Paintings; D017550:Spectroscopy, Fourier Transform Infrared; D013059:Spectrum Analysis, Raman; D014025:Titanium / Q000032:analysis*; D014961:X-Ray Diffraction
D002840:Chromates; D017608:Chromium Compounds; D007854:Lead; C037326:chrome rutile yellow; D000965:Antimony; C031895:lead chromate; D014025:Titanium