UCLA

Maya Blue is considered a significant organic-inorganic hybrid pigment and the oldest known nanostructured material, produced in Mesoamerica during the Pre-Hispanic period. Experimental and theoretical research conducted on its manufacturing technique and composition indicated that its hue and unique stability comes from the intercalation between the organic indigo dye (C16H10N2O2) and the inorganic fibrous clay palygorskite [(Mg,Al)4(Si)8(O,OH,H2O)26•nH2O]. Maya blue is known particularly for its resistance against chemical corrosion and biodegradation; however, there is still an ongoing debate on how the indigo's interaction with the clay helps achieve the stability of the pigment. In this research, we investigate the variability in composition, microstructure and properties of ancient Maya blue pigment, decorating a set of funerary Jaina-style figurines now at the collection of Fowler Museum at the University of California, Los Angeles (UCLA) and San Miguel Museum in Campeche, Mexico. For the analysis, we employed a multiscale and multianalytical approach from the macro to the micron length scale using forensic imaging combined with optical microscopy, fiber optics reflectance spectroscopy, scanning electron microscopy-coupled with energy dispersive X-ray spectroscopy and Raman spectromicroscopy.