TY - JOUR
T1 - Ochres and earths: Matrix and chromophores characterization of 19th and 20th century artist materials
AU - Vilarigues, Márcia Gomes
AU - Melo, Maria João
N1 - Sem PDF
PY - 2013/1/1
Y1 - 2013/1/1
N2 - The present paper describes the main results obtained from the characterization of a wide range of natural and synthetic ochre samples used in Portugal from the 19th to the 20th century, including powder and oil painting samples. The powder ochre samples came from several commercial distributors and from the collection of Joaquim Rodrigo (1912-1997), a leading Portuguese artist, particularly active during the sixties and seventies. The micro-samples of oil painting tubes came from the Museu Nacional de Arte Contemporanea-Museu do Chiado (National Museum of Contemporary Art-Chiado Museum) in Lisbon and were used by Columbano Bordalo Pinheiro (1857-1929), one of the most prominent naturalist Portuguese painters. These tubes were produced by the main 19th century colourmen: Winsor & Newton, Morin et Janet, Maison Merlin, and Lefranc. The samples have been studied using mu-Fourier Transform Infrared Spectroscopy (mu-FTIR), Raman microscopy, mu-Energy Dispersive X-ray fluorescence (mu-EDXRF), and X-ray diffraction (XRD). The analyzed ochres were found to be a mixture of several components: iron oxides and hydroxides in matrixes with kaolinite, gypsum and chalk. The results obtained allowed to identify and characterize the ochres according to their matrix and chromophores. The main chromophores where identified by Raman microscopy as being hematite, goethite and magnetite. The infrared analysis of the ochre samples allowed to divide them into groups, according to the composition of the matrix. It was possible to separate ochres containing kaolinite matrix and/or sulfate matrix from ochres where only iron oxides and/or hydroxides were detected. mu-EDXRF and Raman were the best techniques to identify umber, since the presence of elements such as manganese is characteristic of these pigments. mu-EDXRF also revealed the presence of significant amounts of arsenic in all Sienna tube paints.
AB - The present paper describes the main results obtained from the characterization of a wide range of natural and synthetic ochre samples used in Portugal from the 19th to the 20th century, including powder and oil painting samples. The powder ochre samples came from several commercial distributors and from the collection of Joaquim Rodrigo (1912-1997), a leading Portuguese artist, particularly active during the sixties and seventies. The micro-samples of oil painting tubes came from the Museu Nacional de Arte Contemporanea-Museu do Chiado (National Museum of Contemporary Art-Chiado Museum) in Lisbon and were used by Columbano Bordalo Pinheiro (1857-1929), one of the most prominent naturalist Portuguese painters. These tubes were produced by the main 19th century colourmen: Winsor & Newton, Morin et Janet, Maison Merlin, and Lefranc. The samples have been studied using mu-Fourier Transform Infrared Spectroscopy (mu-FTIR), Raman microscopy, mu-Energy Dispersive X-ray fluorescence (mu-EDXRF), and X-ray diffraction (XRD). The analyzed ochres were found to be a mixture of several components: iron oxides and hydroxides in matrixes with kaolinite, gypsum and chalk. The results obtained allowed to identify and characterize the ochres according to their matrix and chromophores. The main chromophores where identified by Raman microscopy as being hematite, goethite and magnetite. The infrared analysis of the ochre samples allowed to divide them into groups, according to the composition of the matrix. It was possible to separate ochres containing kaolinite matrix and/or sulfate matrix from ochres where only iron oxides and/or hydroxides were detected. mu-EDXRF and Raman were the best techniques to identify umber, since the presence of elements such as manganese is characteristic of these pigments. mu-EDXRF also revealed the presence of significant amounts of arsenic in all Sienna tube paints.
KW - Ochre
KW - Fourier Transform Infrared Spectroscopy
KW - Raman microscopy
U2 - 10.1016/j.saa.2012.10.064
DO - 10.1016/j.saa.2012.10.064
M3 - Article
C2 - 84871457900
SN - 1386-1425
VL - 103
SP - 409
EP - 416
JO - Spectrochimica Acta Part A-Molecular And Biomolecular Spectroscopy
JF - Spectrochimica Acta Part A-Molecular And Biomolecular Spectroscopy
IS - NA
ER -