Composition and Color of Maya Blue: Reexamination of Literature Data Based On the Dehydroindigo Model

[EN] An analysis of literature data studying the composition and color of Maya blue (MB) type materials prepared from indigo, dehydroindigo, and different aluminosilicates, accompanied by new spectral data, is presented. After thermal treatment at above 100 degrees C, indigo-based specimens displayed Raman and UV-vis spectroscopic features common to those of equivalent dehydroindigo-based replicants, thus supporting the socalled dehydroindigo model (J. Phys. Chem. B 2006, 110, 6027-6039) in which the dehydroindigo/indigo ratio, increasing with temperature, is crucial to determine the color of MB and its variability. The current analysis supports the view of MB as a polyfunctional hybrid mat…