Underground mining in Potosí was a male sphere. Nevertheless, women were actively involved in the early stages of silver mining in Potosí, when traditional technologies were still in use. They also played an important role in the local ore market. After the introduction of new technology and the reorganization of the labour force, the process of refining ore was much more complicated. Women then participated in some stages of the process: in selecting the ores and sieving. This implies that mining is a complex process with a labour and gender division that has been underrated and underestimated. More importantly, women became owners of rudimentary mills (trapiches) where the ore was processed, selling different amounts of silver to the Spanish authorities, making their living in this way.