CORRELATION BETWEEN SPECTRAL, SEM/EDX AND ELECTROCHEMICAL PROPERTIES OF MAYA BLUE: A CHEMOMETRIC STUDY*

Visible spectra, composition from SEM/EDX and solid-state electrochemical data are correlated for a set of 12 Maya Blue samples from different archaeological sites of Campeche and Yucatan (Mexico). In addition to indigo and dehydroindigo, indirubin and other possibly indigo-type compounds can be detected in Maya Blue samples. Application of hierarchical cluster analysis techniques allows similarity relationships to be established between samples from different sites, confirming prior results which suggest that the preparation of Maya Blue pigment evolved with time during the Maya culture following a ramified scheme.