Insights into the Maya Blue Technology: Greenish Pellets from the Ancient City of La Blanca

Facile preparation of stable palygorskite/methyl violet@SiO2 “Maya Violet” pigment

“…Schematic illustration of preparation of the PAL/MV@SiO 2 ''Maya Violet'' pigment and the corresponding digital images. of organic dye or pigment is less than 3.0% in most cases [5,7,12,31,32]. In contrast, the MV content in the as-prepared PAL/MV pigment can be as high as 10%, substantially higher than all of the state-of-the-art Maya Blue pigments [21] and nearly equal to the Maya Blue-like pigments prepared by Fan et al [24] and Zhang et al [25].…”

“…The marvelous merits of Maya Blue are highlighted by the excellent resistance against acidic, alkaline and organic corrosions and biodegradation, which prevents discolor in harsh environments. It is believed that the ancient Maya Blue was a hybrid of palygorskite (PAL) and indigo from the leaves of an~il plant [3][4][5][6][7][8].…”

Electroanalytical chemistry for the analysis of solids: Characterization and classification (IUPAC Technical Report)

“…The characteristic peaks of indigo, corresponding to the reduction and oxidation of this compound to leucoindigo and dehydroindigo, respectively, can be clearly seen in the voltammogram of the archaeological sample, in spite of large background current. Further, analysis of fine details of voltammetric data permitted the idea to be proposed that different types of preparation were used by the ancient Mayas [195] and that yellow and green pigments [196] and decorative plasters [197] using indigoid plus clay associations were prepared by this people.…”

Application of solid-state electrochemistry techniques to polyfunctional organic–inorganic hybrid materials: The Maya Blue problem

“…In the archaeometric domain, VMP permitted to document the most ancient use of MB (Substructure IIC of Calakmul, Late Postclassical period) whereas chemometric analysis of Maya Blue samples from different sites suggested that the preparation procedure of Maya Blue probably changed along time following a ramified pattern [29,30]. More recently, it has been characterized the presence of 'Maya Yellow' analogs to MB [31] and characterized the use of indigo plus palygorskite plasters evidencing the use of such materials in non-ritual context [32]. The use of VMP also permitted to characterize the coexistence of different topological redox isomers of dye molecules and to model the possible distribution of such species in the palygroskite grains [33,34] thus providing a more complex view of the MB as a polyfunctional nanostructured material [34,35].…”