Bonampak Mural with Maya Blue background. Image: Nick Leonard (Flickr, used under a CC BY-NC-SA 3.0)
Maya blue is the brilliant long-lasting pigment that coloured the Maya world and is one of just a handful of man-made pigments known to the ancient world. It had special significance to the Maya , and was associated with sacrifice and Maya deities, including the rain god Chaak.
Impervious to the effects of chemical or physical weathering, the pigment was applied to pottery, sculpture and murals of Mesoamerica largely during the Classic and Postclassic periods (AD 250-1520), playing a central role in ancient Maya religious practice. This unusual blue paint was also used to coat the victims of human sacrifice and the altars on which they were dispatched.
Mural detail of warrior on Maya Blue background at Bonampak. Image: Constantino Reyes (www.creativecommons.org/licenses/by/3.0), via Wikimedia Commons
Finding the source
Scientists have already discovered that it is produced by chemically binding indigo to the clay mineral palygorskite by carefully controlled heating, though it is still not absolutely clear exactly how the Maya actually made it. However, science and anthropology teamed up to solve another question concerning the brilliantly hued pigment and the researchers have established a link between contemporary indigenous knowledge and the ancient sources of the mineral.
In a paper published online in the Journal of Archaeological Science on March 16, 2012, it was demonstrated that the palygorskite component in some of the Maya Blue samples came from mines in two locations in Mexico’s northern Yucatan Peninsula
Research on sources for palygorskite has been ongoing since the late 1960′s. Through a combination of ethnographic research and mineralogical analyses, Dean E. Arnold, Professor of Anthropology at Wheaton College, and now Adjunct Curator of Anthropology at The Field Museum, discovered that palygorskite was well known among indigenous potters of Ticul, Yucatán.
These contemporary Maya used palygorskite as a key component of their own pottery production as a temper and is also prescribed the mineral for medicinal purposes for intestinal problems. Indigenous knowledge provided the sources of the palygorskite: potters extracted the mineral from two mines in Yucatán – one in Sacalum and the other near the city of Ticul at a location called Yo’ Sah Kab.
Palygorskite, otherwise known as attapulgite, fuller’s earth, or Mountain Leather. Image: University of Waterloo
Confirming the mines
As part of his research, Arnold noted Terminal Classic (800-1000 AD) pottery and other signs of ancient site occupation at both of the modern sources. This suggested that the mines were used by the Maya as sources for the palygorskite used in Maya Blue. However, further tests were needed to convincingly link the present-day mines with the ancient Maya.
Between 1965 and 1997, Dean Arnold and Bruce E. Bohor of the United States Geological Survey collected 33 samples of the mineral from the Yucatán region. After mineralogical analysis, it was possible to differentiate between samples of palygorskite based on composition, which meant the mineral clay within specific samples of Maya Blue could be traced to specific locations.
Arnold and Bohor collected an additional 167 samples from five different sites in Yucatan in 2008. These samples were then compared to analyses of the Maya Blue pigment found on pottery originally taken from Chichén Itzá and Palenque, Yucatán by E. H. Thompson and J. E. S. Thompson in the late 19th and early 20th century and now curated at The Field Museum.
The analysis confirmed that all the samples of Maya Blue from the ancient Maya site of Chichén Itzá were created with palygorskite derived from Sacalum, while the Maya Blue samples from Palenque could have been from Sacalum, Yo’ Sah Kab, or another unknown source.
Unlocking the data
| Fact File |
| Maya Blue requires the combination of ingredients–the indigo plant and palygorskite ore–at temperatures between 150 and 200 degrees centigrade.
Such heat is necessary to get molecules of indigo incorporated into the white palygorskite clay. The process of embedding (intercalcating) indigo into the clay makes the color stable, even under exposure to harsh climate. |
“Utilizing ground-breaking chemical sourcing techniques, we have unlocked data from collections held in The Field Museum for more than 100 years,” reported , Ryan Williams the Curator and Chair of Anthropology at the Field Museum
“The data resulting from this study provides definitive evidence that Sacalum was the source for palygorskite used in Maya Blue from Chichén Itzá,” Williams added.
Noting that the ancient Maya would have been limited by available technology and using this new data, senior author Arnold and his colleagues argue that sources of palygorskite for the ancient Maya were limited by available technology and the ancient landscape. Thus, Sacalum and Yo’ Sah Kab, because of their accessibility and size, would have been prime sources of palygorskite used by the ancient Maya.
“Overall this study illustrates the key benefits of scientific teamwork to unravel the mysteries of a key ancient technology,” said study participant and Field Museum curator, Gary Feinman.
Field Museum Video on the research into Maya Blue
Dr. Gary Feinman, Professor Dean Arnold (Wheaton College) and museum colleagues used elemental analysis to unlock some of the secrets to the productions of Maya Blue – a pigment that the Mayans used to decorate objects, such as murals and ceramics, and paint human sacrifices at Chichén Itza.
Source: EurekAlert
More information:
Arnold, D.E., et al., The first direct evidence of pre-columbian sources of palygorskite for Maya Blue, Journal of Archaeological Science (2012), doi:10.1016/j.jas.2012.02.036
Arnold D.E. , MAYA BLUE AND PALYGORSKITE: A second possible pre-Columbian source, Ancient Mesoamerica (2005), 16 : pp 51-62 Cambridge University Press DOI: 10.1017/S0956536105050078
The Field Museum, Chicago