Archaeo-mineralogical study of Prehispanic copper ores in Collahuasi, northern Chile

Abstract

Northern Chile is known for its large-scale contemporary copper exploitation. Archaeological evidence indicates that such exploitation is not only a modern occurrence but has been ongoing since at least the Late Archaic Period. In order to identify the raw mineral materials used in pre-Hispanic mining and metallurgical production processes we performed an automated mineralogy analysis (QEMSCAN). The samples are from the Collahuasi mining-metallurgical district, in the Tarapaca region. It was determined that the primary mineralogy of the ore in the pre-Hispanic smelting sites of the Collahuasi District was brochantite, malachite and chrysocolla, and in turn, it has been possible to determine what the “Collahuasi metal” was, that circulated in late prehispanic times.