Tarascan Copper Metallurgy at the Site of Itziparátzico, Michoacán, México

Laboratory Analysis

The main goal of the slag analysis is to examine the technology and social context of copper metallurgy at Itziparátzico, by determining the type of ore, smelting temperature, manufacturing processes and the level of mastery that the smelters exercised over their craft. Optical microscopic examination of microstructures has been carried out to determine the mineralogical structure of the slag. Scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM/EDS) is being used to perform phase and elemental analysis of the samples, as well as for confirmation of the minerals detected by optical microscopy. The samples are also being examined by X-ray fluorescence spectroscopy (XRF) to determine the bulk chemical composition of the slags and assist the microscopic examination of mineral phases within samples.

Preliminary results indicate the use of chalcopyrite (CuFeS₂), a sulfidic ore, for copper extraction at the site. In addition, the partial mixing of iron with copper observed in metal prills, indicates the production of a high smelting temperature, and points towards a very efficient, highly-reductive environment. A high reduction environment requires a well-developed and sophisticated smelting method. This rules out the possibility of the use of crucibles and lung-powered blow pipes, and suggests instead, the use of a formal furnace operated by bellows. Alternatively, this high-oxygen environment could have been the result of the use of some type of wind-powered furnace.

Previous Page  |  Table of Contents  |  Next Page

Return to top of page