Mercury, Cinnabar, and Honduran Archaeology

When the international press covered the news that researchers at Teotihuacan had encountered liquid mercury in their excavations of a tunnel associated with the Temple of the Feathered Serpent, I was called by a reporter interested in knowing whether similar finds existed elsewhere in Mesoamerica.

Luckily, I knew the answer: ancient Honduras (and adjacent Guatemala) were central locations for Mesoamerican use of liquid mercury. Here’s why.

Cinnabar, the red powdery mineral mercuric sulphide, was in use in Central America by the time when people in Formative Honduran sites like Puerto Escondido, Copan, Los Naranjos, and the Cuyamel Caves created pottery with deeply carved designs rubbed with red pigments. While red pigments on early pottery from Honduras have never (to my knowledge) been tested chemically, cinnabar has been reported from sites in Mexico, including La Venta, Chalcatzingo, and Izapa, and museums often describe the red pigment on ceramics similar to those from Honduras as cinnabar.

A long time later, liquid mercury appears in archaeological sites dating to the Classic Period (between 400 and 800 AD). The majority of reported finds are from the highlands of eastern Guatemala and western Honduras, at Lake Amatitlan, Kaminaljuyu, and Quirigua in Guatemala, and Copan and El Paraiso in western Honduras.

Outside of this area, two sites in Belize– Caracol and Lamanai— and now, Teotihuacan, in Mexico, have yielded liquid mercury dating to the Classic Period.

A major point of disagreement among archaeologists writing about finds of liquid mercury has been whether it was collected from naturally occurring deposits, or produced by processing cinnabar, burning it in closed vessels.

David Pendergast, excavator of a ballcourt cache at Lamanai, Belize described the liquid mercury there as likely collected in the highlands of Honduras or Guatemala as native drops of liquid mercury in cinnabar deposits.

USGS reports from the 1950s do describe some liquid mercury in Honduran cinnabar deposits near Tegucigalpa. Some of these deposits were exploited by Spanish colonial miners who used mercury in processing silver ore.

However, these geological resources are far from the zone where archaeological finds of liquid mercury are reported, and no archaeological sites in this area have produced evidence of contact with places like Copan or Quirigua, let alone sites in Belize.

Other cinnabar deposits are present in the Department of Santa Barbara, much closer to the archaeological locations where liquid mercury has been found. There are no reported incidences of native mercury in these deposits. But liquid mercury can be produced by burning cinnabar under certain conditions.

At Copan and Quirigua, there is evidence that this was how liquid mercury found there was actually produced.

A cache associated with carved stone Monument 21 at Quirigua contained a deposit burned in place. The excavator, Professor Wendy Ashmore of UC Riverside, argued that the burning of cinnabar in this cache produced the liquid mercury found there.

At Copan, a deposit in the Margarita tomb similarly includes signs of burning, with both unconverted cinnabar and liquid mercury present. Harriet Beaubien of the Smithsonian Institution commented that she

was involved in the excavation of a cache associated with the Margarita South Offering Platform at Copan in 1993, which produced a large quantity of liquid mercury. The stone “box” had, among other items, a large lidded ceramic bowl containing the remains of a turkey. Everything was very very heavily burned (blackened), and I believe that quantities of cinnabar were included in the deposit, transformed to liquid mercury in a reduction environment. Yellowish stains (not tested) suggest sulfur-rich products, the leftover component of cinnabar’s decomposition.

So, did the people of the ancient southeastern Maya area invent this process, and innovate the use of liquid mercury?

Dating of the Teotihuacan cache suggests not.

The deposits being explored by the current Teotihuacan project under the Temple of the Feathered Serpent predate 400 AD. Sergio Gomez, the lead archaeologist on the team slowly excavating the contents of the ancient tunnel below the pyramid, has suggested that the tunnel might have been sealed off as early as 200-250 AD.

That would make the presence of liquid mercury substantially earlier at Teotihuacan than in the caches from Copan, Quirigua, and other nearby sites. Only the cache from Caracol has similarly early dates.

With the new discovery at Teotihuacan, we can now say with certainty that mercury was used in ritual before 400 AD in Mexico. The technology required to produce mercury from cinnabar was entirely within the reach of people in this area as soon as they were able to fire pottery (long before 1000 BC).

In Honduras and bordering Guatemala, the practice of burning offerings was an important part of ritual. The red pigment cinnabar, locally available, may have originally been burned as a ritual gesture– producing a model of transformation in color and texture from red powder to silvery liquid.

It may be no accident that this practice became important at the same time, and in the same area, where other burial practices, cache and burial contents, and imagery suggest that Teotihuacan was an important point of reference in political and religious life.

Working at Home

HondMap BW Large Names4

People who lived in Honduras before the Spanish conquest made things at home. This was certainly true of the residents of the Ulúa River Valley where I have done research for many years. Farmers left home every morning to work in their fields. Traders traveled down rivers and across mountains.

Families made excursions to ballgames and other festivals hosted by their neighbors.

But when it came time to weave, pot, pound bark into paper, or shape stone, craftswomen and men gathered their materials, got out their tools, and set to work in their living spaces.

These living spaces varied in size and shape but combined buildings and outside areas.

D394_The Cerro_071102

Cerro Palenque is a large settlement built on a hilltop and associated ridges that sit above the Ulúa River. It was occupied from the 7th to the 11th centuries A.D. There is an impressive monumental center with a ballcourt. People lived in houses built of stone, wood, and clay. These houses were built on raised foundation platforms around central patios.

I excavated in one household compound very close to the monumental center of the city for several seasons.

During the first season of excavations, in 1998, my co-workers and I dug lines of shovel test pits around all the visible buildings and across the open space of the central patio. These were small holes, dug quickly but not carelessly, designed to give us some sense of the different kinds of deposits we might expect.

Near the southern mound the soil was bright red and burned looking. I chose the area as one to investigate more thoroughly with larger scale excavations. This is how we found not one, but three small kilns. One was in front of the large mound and two were on its west side.

Each kiln had a dome of clay built over a wood frame. The base was circular with a stone and gravel floor.

CP02 41K 26a kiln

CP00 42I,M kiln

The best preserved one had a square fire box underneath it with pipes to distribute the heat. Nearby we found a trench used to collect trash, including some of the molds used by the potters.

 CP00 42I h kiln

We also found the things made in these molds: bowls, other kinds of tableware, and figurines made from a fine grained clay. The quantity produced was not great, certainly not by modern expectations based on industrial production. It was the diversity of figures and vessels produced that made me think.


What were these items used for?

The vD615_41E8_figurine_1998essels were mostly small bowls and many of the figurines were whistles. The clay itself, used for more public or fancy kinds of objects, as well as what was made with it, led me to conclude that these kilns were being used to fire items to be used in rituals and celebrations held at home. In fact, I think that making the figurines may have been part of these rituals.

D784_41S11_Tacamiche Marmol_2002_062003


Crafting at Cerro Palenque was something embedded in the stream these people’s lives. Working outside would also have placed the crafter in the middle of things. Cooking, hauling water, minding children, gossiping, mending equipment, planning the next big family event – these were the kinds of activities that would have taken place as a matter of course. Better light and more room to spread out were practical advantages. But I think it was the sociable side of the location that was also attractive and is important to our understanding of how people structure the making of things as they do.