A pigment unknown to art historians has been identified on ancient Maya artefacts from Mexico. The blue-green colour of veszelyite seems to have been chosen to blend in with and even imitate jade, the most precious substance used by the Maya.

When the great Maya city of Calakmul in the centre of the Yucatán peninsula was excavated in the 1980s and 1990s, a number of royal tombs were found, notably within the colossal Structure 2, one of the largest temple-pyramids ever built in pre-Hispanic America. Tomb 4 was identified as that of the ruler Yuknoom Yich’aak K’ak’, “Smoking Jaguar Paw”, who was born in AD649 and reigned from 686 to 695, when he was apparently defeated by Jasaw Chan K’awiil I of Tikal, Calakmul’s rival to the south.

Whether Yuknoom was killed in this battle or died sublater is not known but he was buried with pomp in his capital city. Among his grave goods was a funerary mask of apple-green jade mosaic. The jade plaques were set into white lime stucco over a wooden base, and the stucco was painted green to match the jade.

In the adjacent Tomb 6 a woman presumed to be Yuknoom’s companion was buried with three more jade mosaics, including two masks, also with the stucco painted green. An earlier tomb in the Structure 3 palace nearby included a wooden vessel with green-painted supports.

The assumption was that the green was derived from malachite or chrysocolla, but analyses showed instead the use of veszelyite, the use of which as a pigment “had never been reported for any civilisation to our knowledge”, Dr. R. García Moreno and his colleagues report in Archaeometry.

Veszelyite, named after a mining engineer in 19th-century Romania, is found widely but rarely across the world; there are sources in Scotland, Greece, Japan, Africa and Mexico. The Mexican source is in the state of Puebla, southeast of Mexico City.

Samples from Calakmul were analysed using multiple methods, including X-ray diffraction (XRD), proton-induced X-ray emission (PIXE) and a scanning electron microscope; a mineral sample from Katanga in the Democratic Republic of Congo was used as a control.

The veszelyite had been used in a pure form, mixed with lime in the stucco. The mosaics from the coeval Tombs 4 and 6 had veszelyite from the same source, but the earlier Structure 3 tomb used a mineral of slightly different composition, perhaps from a different source. The limestone geology of the Calakmul region, and of the Maya lowlands generally, indicates that the green mineral must have been imported. Since the only currently known source lies in highland Mexico, an area that has historic links with the Maya area through the influence of the great city of Teotihuacan from the 4th to 7th centuries AD, this seems the most likely origin.

“This would imply that this mining zone was well known in pre-Hispanic times, and that it formed part of a precious materials trade route in the Classic period. It is possible that malachite (also found used at Calakmul), pseudomalachite and even chrysocolla might have been found in the same mine. Nevertheless, the purity of the pigment used shows its careful selection,” the team conclude.

Archaeometry vol 50: 658-667