Maya Blue

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A warrior with Azul Maya on the background

Maya Blue (Spanish: Azul Maya) is a unique bright blue to greenish-blue pigment manufactured by cultures of pre-Columbian Mesoamerica, such as the Maya and Aztec. The pigment is a composite of organic and inorganic constituents, primarily indigo dyes derived from the leaves of añil (Indigofera suffruticosa) plants combined with palygorskite, a natural clay.^[1] Smaller trace amounts of other mineral additives have also been identified.^[2] The pigment was used as a colorant in pre-Columbian artworks, sculptures, murals, textiles (probably) and to illuminate Mesoamerican codices.

It first appeared around the 800 A.D. and it was still used in the XVI century in several Convents of Colonial Mexico, notably in the paintings of the Indian Juan Gerson in Tecamachalco and after that, the techniques for its production were lost in Mexico but in Cuba there are examples from 1830.^[3]

Seeds of Añil

Leaves of Añil

Despite time and the harsh weathering conditions, paintings coloured by Maya Blue have not faded over time. What is even more remarkable is that the colour has resisted chemical solvents and acids such as nitric acid. Recently, its resistance against chemical aggression (acids, alkalis, solvents, etc.) and biodegradation was tested, and it was shown that Maya blue is an extremely resistant pigment, but it can be destroyed using very intense acid treatment under reflux.^[4]

What is particularly surprising is that no known organic pigments show such stability. As a result, Maya Blue's chemical complexity and remarkable physical properties have attracted much scientific attention for over 50 years. There were many researchers interested in this pigment, among them were H. E. Merwin, R. Kleber, L. Masschelein-Kleiner and J. Thissen, H. Van Olphen, Rutherford J. Gettens, José María Cabrera Garrido, Arthur R. Littmann, Pedro A. Sánchez, Antonio de Yta and Luis Torres.

In 1993, a mexican Historian and Chemist, Constantino Reyes-Valerio[1], discovered the secret of the chemical composition of the compound, which was formed by a series of clays: paligorskita, atapulgita, sacalum, montmorillonita, together with the use of the leaves of a plant añil.

After the formula for the production was published in the book "De Bonampak al Templo Mayor: Historia del Azul Maya en Mesoamerica" (Siglo XXI Editores, 1993) there were many developments in the chemical analysis of the pigment in collaborations between Reyes-Valerio with European Scientists, notably, Giaccomo Chiari [2] and David Ajo from the University of Torino, and Manuel Sanchez del Rio [3] from ESRF [4] in France.

A sample of Palygorskite

[edit] Notes

^ Arnold (2005); Haude (1997).
^ Haude (1997); Reyes-Valerio (1993).
^ Chiari(2000)
^ Sanchez del Rio(2006)

[edit] References

Arnold, Dean E. (2005). "Maya Blue and Palygorskite:A second possible pre-Columbian source". Ancient Mesoamerica 16: pp.51–62. DOI:10.1017/S0956536105050078.

Arnold, Dean E.; and Bruce F. Bohor (1975). "Attapulgite and Maya Blue: an Ancient Mine Comes to Light". Archaeology 28 (1): pp.23–29.

Sanchez del Rio, Manuel; and P. Martinetto, C. Reyes-Valerio, E. Doriyee, M. Suarez (2006). "SYNTHESIS AND ACID RESISTANCE OF MAYA BLUE PIGMENT". Archaeometry 48 (1): pp.115.

Chiari, Giaccomo; and

R. Giustetto, C. Reyes-Valerio, G. Richiardi (2000). "Maya Blue Pigment: A Palygorskite-Indigo complex". XXX Congresso Associazione Italiana di Cristallografia 48 (1): pp.115.