Overview

• MoMA conservation scientist Abed Haddad sampled blue paint from the back of the canvas and used Raman spectroscopy to conclusively identify manganese blue.
• Stanford researchers Edward I. Solomon and Alexander J. Heyer applied resonance Raman, magnetic circular dichroism, and density functional theory to probe the pigment’s electronic structure.
• The team reports that manganate(VI) centers within a barium sulfate lattice create two absorption bands whose trough is perceived as blue.
• The findings appear in the Proceedings of the National Academy of Sciences in September 2025 (DOI: 10.1073/pnas.2513166122).
• Manganese blue was widely used before being phased out by the 1990s for environmental and health reasons, and the confirmation informs display, treatment, and ongoing surveys of artists’ palettes whose breadth of use remains uncertain.