Color and Casta in the Andean Silver Industry

Amalgamation technologies allowed refiners throughout colonial Latin America to profitably extract silver from a wider variety of metals, including even the most refractory ores. These expanded processing capabilities meant that mineral classification and sorting became even more important, as metallurgists had to identify which silver metals to treat with traditional methods and which ones to refine by amalgamation. The vocabularies used to classify metals provide critical evidence of Indigenous contributions to silver refining in the seventeenth century. By tracing the incorporation and removal of Andean color and spatial vocabularies, this chapter shows how scientific writers and translators replaced Indigenous classifications of matter with a racialized language of metallic “castas” that included “pacos,” “mulatos,” and “negrillos.” The chapter concludes by suggesting how a reading of color signatures in khipus might shed light on Andean miners’ experiences in ways that traditional historiographic methods have not yet allowed.