Archeologists have made an intriguing discovery about the remains of two mummies found in a burial site in Northern Chile in 1976. The corpses of the two young women, victims of a human sacrifice ritual, had clothing colored red by a toxic dye. This, as well as several other elements, make the discovery an outlier in Inca findings in the region.
As reported in the journal Archeometry, the two young women, aged 9 and 18, were likely killed in what is known as a capacocha, a ritualistic sacrifice that was carried out by the Inca to commemorate either political and historical events or as a response to natural disasters. The site is located at Iquique, which is at a lower elevation compared to previously studied capacocha sites.
The team believes the location is of the utmost importance. They state “a special lower‐elevation capacocha burial, most probably undertaken to politically and symbolically incorporate the coastal people into the Tawantinsuyo Empire.” Tawantinsuyo is the name that the Inca gave to their empire.
The mummies were found wearing silver ornaments, surrounded by ceramic vessels, and with the aforementioned red robes. The red in Inca clothing was often obtained by using hematite or other iron oxides. But this particular dye contained cinnabar, a mineral rich in mercury. Cinnabar was used throughout the ancient world as pigment for make-up, clothing, and painting.
Handling cinnabar leads to mercury poisoning, which has a wide range of symptoms – from muscle weakness and loss of coordination to neurological effects like memory loss, speech impediments, and hearing loss. It is possible to partially or completely reverse the toxic effect, but only if caught quickly. The half-life of inorganic mercury in human brains is almost three decades.
Researchers believe that the toxicity of cinnabar was well known in ancient Peru, where it was not just used as a pigment but also refined into pure mercury. It was used to gild gold and silver to objects, and there are even testimonies of the consequences of mercury fumes in such processes. This raised the question of why they used it in the first place then. It's possible that the rituals were so important in their eyes that the handling of cinnabar was worth the risk. After all, the Incas used it in other prestigious social contexts.
It could also be possible that it was used again by grave robbers, who were aware of the danger of the bright red pigments. This is important for modern archeologists who handle the findings, as even though these mummies were discovered more than 40 years ago, we are only now finding out the danger.