Locations of Cinnabar-Mercury Occurrences in Peru: Implications for Pre-Contact Gold Production

The Huancavelica cinnabar-mercury occurrence is the most well-known, but not the only, cinnabar-mercury occurrence in Peru. Therefore, a compilation of the approximately 20 other cinnabar-mercury occurrences is important in assessing the regional availability of this important mineral and its industrial uses in pre-contact Peru. These include: 1) cinnabar use as an ancient red pigment and, 2) more importantly, retorting cinnabar was an important source of mercury that was used for pre-contact alluvial gold amalgamation and, later Colonial silver amalgamation. Geochemical sampling of the lesser-known Chonta occurrence also indicates Ag, Pb-Zn, or Au exploration targets. Retorting cinnabar has been widely documented and dates to 8000 years ago in ancient Turkey; during Roman time; in ancient Mexico; medieval Europe; the western US; and Indonesia. Using only cinnabar, clay for the ceramic retorts, and charcoal, coal, or other fuels, this artisanal process provided the mercury that was essential to the small-scale gold mining technology that produced tons of gold from alluvial sources before the arrival of the Spanish explorers in ancient South America. In present-day Peru, mercury is used to produce tons of gold from small-scale mines, and by analogy, the tons of gold produced in pre-contact Peru are hard evidence that is consistent with small-scale gold mining and mercury amalgamation in the past.