Van Gogh's chemical error

Although a great painter, Van Gogh was certainly not a chemist otherwise he would have avoided adding degrading white pigments to the yellow of his "Sunflowers." New studies reveal how in using the bright pigment, chrome yellow, which contains lead chromates together with white pigments containing barium sulfate or aluminum silicate, Van Gogh was dooming his paintings to dullness. A large European team used X-ray techniques as well as Raman and infrared spectroscopy to demonstrate how the white additives cause degradation of lead chromate to viridian green (hydrated chromium(III) oxide).