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RESEARCH PROFILE
Johannes Vermeer, the 17th-century Dutch artist, was recently catapulted into mainstream attention by Tracy Chevalier’s novel Girl with a Pearl Earring and the subsequent film starring Scarlett Johansson and Colin Firth. The painting that inspired the book is a genuine Vermeer masterpiece. However, a different painting, Young Woman Seated at a Virginal, has had its Vermeer credit questioned. The painting was rejected as a forgery in the mid-1940s after an expert forger admitted that he had sold fake Vermeers to museums and collectors. But art historical evidence gathered over the past decade suggests that the previously disgraced Young Woman Seated at a Virginal is probably not the forgery it was once thought to be. In this issue of Analytical Chemistry (pp 1261–1267), Robin Clark and colleagues at University College London (U.K.) provide scientific evidence to support the notion that the 25 20 cm painting, which in 2004 was sold by Sotheby’s to an anonymous bidder for ~$30 million, is a genuine Vermeer. The investigators analyzed a series of pigments from the painting and found that the pigments were all typical of Vermeer’s palette and period. Clark and colleagues used a series of experimental approaches to study the painting. In addition to cross-section and polarized light microscopy, surface microscopy, and energy dispersive X-ray analysis, the investigators relied heavily on Raman microscopy. Clark says, “Raman [microscopy], I think, is probably the best single technique to use for every kind of art work analysis, whether it’s of paintings, manuscripts, papyri, icons, you name it.” Clark points out that Raman microscopy can be carried out in situ and obviates the need to remove samples, a procedure that could damage the artwork. In addition, Raman microscopy has high spatial and spectral resolution, which is critical for the unambiguous
COURTESY OF ROBIN CLARK
It looks like a Vermeer . . .
Spectroscopic analyses of the painting Young Woman Seated at a Virginal show its pigments to be typical of Johannes Vermeer’s palette.
identification of pigments, especially in mixtures. From their analyses, Clark and colleagues demonstrated that the blue pigment from Young Woman Seated at a Virginal was lazurite, a pigment extracted from the semiprecious mineral lapis lazuli. The discovery of lazurite helped to date the painting. “Lazurite is rare [but] is also the most brilliant and most stable of the blue pigments, so every artist wanted to use it,” explains Clark. “It used to come from the Hindu Kush mountains in Afghanistan, but there was never enough of it to satisfy the needs or wishes of artists, or more especially, the patrons who were paying for the paintings.” The demand for lazurite was so intense that in about 1826, the French government offered a large award to any chemist who could synthesize this blue pigment. Clark says that people “knew you would have to start with something like kaolin and sulfur and cook them up with a few other things such as pitch, clay, and silica [to] get the
pigment. They did discover that in 1828.” The synthetic form of the blue pigment is known as ultramarine blue and has been readily available ever since its recipe became known. Ultramarine blue is chemically identical to lazurite, but their physical appearances differ. The synthetic material consists of small, uniform, rounded particles. By contrast, the pigment particles extracted from lapis lazuli have sharp edges and range in size and shape. The discovery of lazurite on the painting, instead of ultramarine blue, suggests it was created before 1828. Vermeer’s works date between 1654 and 1673. Lead tin yellow type I was also discovered in the painting. This synthetic pigment fell out of use at about the beginning of the 18th century, putting a likely latest date for Young Woman Seated at a Virginal at around 1700. Other pigments that Clark and colleagues identified on the work included vermilion, calcite, and green earth, all of which are consistent with pigments found on different Vermeer paintings and on works of other 17th-century Dutch artists. Clark emphasizes that his group’s analyses do not authenticate Young Woman Seated at a Virginal as a Vermeer. He subscribes to the late Sir Karl Popper’s view that positive evidence is impossible to achieve. “In science, you can disprove something, but you can’t absolutely prove it,” says Clark. “Art historians have gone through and said that the artwork and canvas look to be correct for the period. . . . We’ve come along and shown that the pigments are genuine pigments that would have been around in 1685. Vermeer would have had access to them, and we know that he used them on genuine Vermeer paintings, ones for which there is no query. One has done the best one can. The results are completely consistent with this painting’s being by Vermeer, but they cannot possibly prove it.” a —Rajendrani Mukhopadhyay
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