Papers by Claire Rebekah Cohen
This thesis considers the technology employed to produce silver within the Porco-Potosí region, s... more This thesis considers the technology employed to produce silver within the Porco-Potosí region, southern Bolivia, providing archaeo-metallurgical data on indigenous and European silver production methods in Porco during the period AD 1500 to 2000. The research has been conducted as part of Proyecto Arqueológico Porco-Potosí (PAPP) set up by Dr Mary Van Buren (Colorado State University).
The region of Porco was home to an Inca mine already prior to the Spanish conquest in 1538. Five years later, Spanish rule was established at Potosí. Indigenous technology, such as wind blown furnaces, huayrachinas, continued to be used in the region until the introduction of mercury amalgamation from 1570 onwards meant that the indigenous methods of silver production were superseded. Huayrachina technology employed at Porco dates back to at least the mid 16th century, with historical indications for earlier usage. PAPP has documented ongoing huayrachina smelting near Porco as late as 2003, showing the continuing existence of this technology. In this thesis, different silver production techniques from the archaeological and ethnographic records have been assessed using analytical techniques: Energy Dispersive X-Ray Fluorescence, Optical Microscopy and Scanning Electron Microscopy, and including a historical, archaeological and theoretical review of the relevant data.
In Porco, a diverse range of metallurgical techniques was being used for both small and large scale production. From the early colonial periods onwards both European and indigenous methods were used simultaneously to produce silver. The Spanish influence is evident in the archaeological remains of European furnaces. The analyses of the European furnaces show that these were more efficient in extracting metal than the indigenous huayrachinas, at the expense of an increased fuel consumption. A comparison between the archaeological and recent huayrachina remains has shown differences in smelting capacity; the latter having a relatively low metal yield and reduced technical efficiency, and indicating a change in ore composition.
Recent silver production shows an environmental adaptation taking into account the difficulty and cost in obtaining fuel and ore. The continued use of the huayrachina over five centuries shows the persistence of indigenous technology, despite other production methods being available.
The results of this project contribute to a better understanding of the history of the Porco-Potosí region, and to Andean metallurgy.
Gold & silver smelting by Claire Rebekah Cohen
Este articulo se centra en el proceso metalurgico lIevado a cabo en las huayrachinas (pequenos ho... more Este articulo se centra en el proceso metalurgico lIevado a cabo en las huayrachinas (pequenos hornos de viento) de Porco-Potosi, en el sur de Bolivia. Para analizar la tecnologia de las huayrachinas, este estudio considera el proceso de produccion actual de plata tal y coma fue documentada por el Proyecto Arqueologico Porco-Potosi -PAPP. Se presentan los resultados de los analisis arqueo-metalurgicos deI metal producido en un contexto etnografico con el uso de las huayrachinas. A continuacion, estos resultados se comparan con muestras de metales arqueologicos provenientes de diferentes sitios con presencia de huayrachinas.
Uploads
Papers by Claire Rebekah Cohen
The region of Porco was home to an Inca mine already prior to the Spanish conquest in 1538. Five years later, Spanish rule was established at Potosí. Indigenous technology, such as wind blown furnaces, huayrachinas, continued to be used in the region until the introduction of mercury amalgamation from 1570 onwards meant that the indigenous methods of silver production were superseded. Huayrachina technology employed at Porco dates back to at least the mid 16th century, with historical indications for earlier usage. PAPP has documented ongoing huayrachina smelting near Porco as late as 2003, showing the continuing existence of this technology. In this thesis, different silver production techniques from the archaeological and ethnographic records have been assessed using analytical techniques: Energy Dispersive X-Ray Fluorescence, Optical Microscopy and Scanning Electron Microscopy, and including a historical, archaeological and theoretical review of the relevant data.
In Porco, a diverse range of metallurgical techniques was being used for both small and large scale production. From the early colonial periods onwards both European and indigenous methods were used simultaneously to produce silver. The Spanish influence is evident in the archaeological remains of European furnaces. The analyses of the European furnaces show that these were more efficient in extracting metal than the indigenous huayrachinas, at the expense of an increased fuel consumption. A comparison between the archaeological and recent huayrachina remains has shown differences in smelting capacity; the latter having a relatively low metal yield and reduced technical efficiency, and indicating a change in ore composition.
Recent silver production shows an environmental adaptation taking into account the difficulty and cost in obtaining fuel and ore. The continued use of the huayrachina over five centuries shows the persistence of indigenous technology, despite other production methods being available.
The results of this project contribute to a better understanding of the history of the Porco-Potosí region, and to Andean metallurgy.
Gold & silver smelting by Claire Rebekah Cohen
The region of Porco was home to an Inca mine already prior to the Spanish conquest in 1538. Five years later, Spanish rule was established at Potosí. Indigenous technology, such as wind blown furnaces, huayrachinas, continued to be used in the region until the introduction of mercury amalgamation from 1570 onwards meant that the indigenous methods of silver production were superseded. Huayrachina technology employed at Porco dates back to at least the mid 16th century, with historical indications for earlier usage. PAPP has documented ongoing huayrachina smelting near Porco as late as 2003, showing the continuing existence of this technology. In this thesis, different silver production techniques from the archaeological and ethnographic records have been assessed using analytical techniques: Energy Dispersive X-Ray Fluorescence, Optical Microscopy and Scanning Electron Microscopy, and including a historical, archaeological and theoretical review of the relevant data.
In Porco, a diverse range of metallurgical techniques was being used for both small and large scale production. From the early colonial periods onwards both European and indigenous methods were used simultaneously to produce silver. The Spanish influence is evident in the archaeological remains of European furnaces. The analyses of the European furnaces show that these were more efficient in extracting metal than the indigenous huayrachinas, at the expense of an increased fuel consumption. A comparison between the archaeological and recent huayrachina remains has shown differences in smelting capacity; the latter having a relatively low metal yield and reduced technical efficiency, and indicating a change in ore composition.
Recent silver production shows an environmental adaptation taking into account the difficulty and cost in obtaining fuel and ore. The continued use of the huayrachina over five centuries shows the persistence of indigenous technology, despite other production methods being available.
The results of this project contribute to a better understanding of the history of the Porco-Potosí region, and to Andean metallurgy.