A gold mask made around 1000 C.E. by people from the Sicán culture living along Peru’s northern coast was painted with human blood, a new study suggests.
Archeologists first discovered the mask, which was colored using a red pigment, in the 1990s during the excavation of the tomb of what appears to be an elite leader, Yasemin Saplakoglu reports for Live Science. The mask was placed on a detached skull of a 40- to 50-year-old man, with the rest of the skeleton found nearby, upside-down and also painted red. The grave also contained four other skeletons, including two positioned in a tableau apparently representing a midwife and a woman giving birth, as well as more than a ton of grave goods including many gold alloy objects.
At the time of the discovery, researchers identified the red pigment as the mineral cinnabar, which was used for its bright red color across many cultures. But they didn’t know how the thick paint had stayed on the mask for 1,000 years.
“The identity of the binding material, that had been so effective in the red paint, remained a mystery,” the authors of the new study write in an American Chemical Society paper published in the Journal of Proteome.
The team, led by University of Oxford chemist Elisabete Pires, identified proteins including six found in human blood, as well as others that probably came from the eggs of the Muscovy duck, Science Alert’s Tessa Koumoundouros reports.
This finding, together with “the unique inverted placement of the skeleton next to the two young adult women in parturition and midwifing poses suggests that the desired effect was the rebirth of the deceased leader,” the team writes.
The Sicán culture lasted from the eighth through 14th centuries C.E., predating the rise of the Inca empire, per Encyclopedia.com. At its height between 900 and 1050, its people built monumental temples, created elaborate gold objects and controlled trade routes that reached what’s now the upper Amazon, southern Colombia and northern Chile.
The researchers couldn’t definitively verify that the proteins came from human blood, or that it was included in the paint intentionally. But they say it’s likely that blood was used to represent life force. They cite previous research finding that the Sicán people performed human sacrifices using a method of cutting into the neck and chest designed to maximize bleeding.
Study co-author Luciana da Costa Carvalho, an archaeologist at Oxford, tells Vice’s Jordan Pearson that Spanish colonial documents describe prehispanic beliefs that societal elites were born from stars or eggs and were totally different from everyday people.
“Those myths also speak of how these elites upon death transform into the mythical deities or powerful ancestors who should be worshipped,” Carvalho says. “We may think of the use of human blood as a binder is an extension of the religious dogma that the Sicán elite promulgated so that they could attain the transformation to become deified ancestors.”
The researchers plan to investigate whether other funeral masks from the Sicán culture also contain traces of blood, which could help reveal whether the practice was only for elite funerals. Carvalho tells Vice they may also be able to extract genetic information from the blood.