Comparative Study of Two Blue Pigments from the Maya Region of Yucatan

A comparative study of two blue pigment found in separate megalithic structures in Yucatan Mexico is presented. The first sample (Ml) is a piece of turquoise stucco discovered at the top of a building known as Structure-2 in the town of Dzilam Gonzalez. The second sample (M2) is a residual blue powder that was contained in a Oxcum Cafe type ceramic vessel recovered in the rubble of the Kabul building in Izamal city. The interest in characterizing these samples increases with the possibility of finding in them evidence of Maya Blue, a dye created in the eighth century by the Maya people, whose extraordinary physical and chemical prope ries have been studied in laboratories around the world. Maya Blue was a tailored technology used for several centuries, even during the Spanish occupation, throughout Mesoamerica. Despite 80 years of study, the mysteries of its composition, traditional preparation and obsolescence have not yet been fully resolved. Using different spectroscopic techniques (SEM, EDX, XRD, FTIR, UV-Vis DR) we have studied and compared the blue colorants in Ml and M2. Results indicate that Ml is Maya Blue. Despite some similarities in the infrarred vibrational spectra of the two samples, we have determinated that M2 is not Maya Blue but a non-Mesoamerican mineral pigment known as Ultramarine which was probably introduced to America by Europeans.