Chemistry of Art Forgery: How Analytical Techniques Verify Masterpieces

On Life Scientific, chemist Jehan Ragaee describes how chemistry helps separate truth from imitation in art. She recalls a career spanning the Great Sphinx project in Cairo, the analysis of pigments, mortars, and dating materials, and her fascination with art forgery. The conversation outlines how modern techniques—Raman spectroscopy, infrared reflectography, X-ray fluorescence, and ultraviolet fluorescence—reveal pigment choices, underpaintings, or retouching that can expose fakes. They discuss famous cases such as Han van Meegeren, Chagall, and Van Gogh, and how committees and galleries balance scientific findings with connoisseurship. Ragaee's work sits at the intersection of chemistry, archaeology, and culture, and she emphasizes teaching and collaboration as essential to preserving cultural heritage while advancing science.

Introduction

The Life Scientific conversation centers on Jehan Ragaee, a chemist whose work sits at the intersection of chemistry, archaeology, and art conservation. Her career runs from the Great Sphinx project in Egypt, where she analyzed mortars and pigments, to the modern art world, where scientific analysis helps verify works and expose forgeries. The interview also reveals her personal journey, including a long-standing connection between Cambridge and Cairo and her role as a mentor and public figure championing women in science.

Authentication techniques: surface science and spectroscopy

Ragaee explains how authentication combines surface study, imaging and analytical chemistry. Visual inspection and provenance are supported by tools such as stereomicroscopy to study cracks, ultraviolet fluorescence to reveal retouching, infrared reflectography to uncover underpaintings, and X-ray fluorescence to identify inorganic pigments. Raman spectroscopy is highlighted for identifying organic pigments that XRF cannot detect, enabling detection of pigment that would be anachronistic for a painting's era.

"The cracks are normally deep. They have a special pattern, and if they're not organized in particular manner, they suggest actually that they are forged." - Jehan Ragai, Professor of Chemistry

Case studies: Van Meegeren, Chagall, Van Gogh

Examples include the 1930s Van Meegeren forgeries, where on the spot painting was used to reveal the deception and embarrass critics. The Chagall painting Nude was exposed as a forgery using Raman spectroscopy, which detected two pigments that did not exist during Chagall's era, prompting a ruling that the work was a fake. The discussion also touches on how French law requires that paintings attributed to famous painters be destroyed if forged, underscoring the ethical dimensions of authentication.

"there are two anachronistic pigments, which did not exist during the time of Chagall." - Jehan Ragai, Professor of Chemistry

The Sphinx project and ancient chemistry

The episode highlights Ragaee's Sphinx work, including analyses of mortars and pigments that revealed Egyptian mortar choices and color usage, such as gypsum mortars and the presence of Egyptian blue, a manufactured pigment. The findings suggested clever material choices by ancient Egyptians and demonstrated quantitative chemistry in early technology, including pigment preparation and pigment composition.

Biographical journey: science, family and leadership

Ragaee discusses her upbringing in Cairo, the influence of her feminist mother Doria Shafik, and how she balanced family life with scientific ambition. Her path included chemistry studies at the American University in Cairo, a remote PhD through Brunel University, and a long engagement with the Sphinx project. She describes her later marriage to John Marag Thomas and how his encouragement helped turn her lectures into a published book, The Scientist and the Forger (2015). The interview emphasizes that following one’s passions, rather than fixating on a final product, is central to a productive scientific life.

"for me, it's always been about following my two passions, science and arts, and I love teaching my students that lesson." - Jehan Ragai, Professor of Chemistry

Future directions and advice for young scientists

The discussion looks ahead to new technologies such as laser ablation coupled with plasma mass spectrometry, which can pinpoint the geographic origins of pigments and strengthen attribution with isotopic fingerprints. Ragaee also reflects on her life in Cambridge and Cairo, the value of collaboration between scientists and art professionals, and her ongoing commitment to mentoring young scientists and supporting women in science. Her advice centers on pursuing passion and enjoying the journey, even if it does not always lead to the intended end.

"What matter is the journey." - Jehan Ragai, Professor of Chemistry

She concludes with a hopeful note about continued collaboration between science and art, the potential for new analytical breakthroughs, and the importance of contextual understanding in interpreting data and safeguarding cultural heritage.