Potosí Silver Mining Boom

Timeline

1. 1590–1599Potosí amalgamation works · Upper PeruAfter Viceroy Francisco de Toledo introduced the amalgamation process at Potosí in the 1570s, it became the dominant smelting technology by the 1590s. Silver-bearing ore was ground and mixed with mercury, salt, and copper vitriol, then spread out to dry in the open air, greatly improving silver recovery from low-grade ore and driving output to its colonial-era peak in the 1590s.
2. 1592–1599City of Potosí · Upper PeruIn the 1590s, Potosí's population exceeded 100,000, making it one of the largest cities in the Western Hemisphere. Spanish colonizers used the mita forced labor system to conscript workers from surrounding Indian communities to labor in the mines and amalgamation works under extremely harsh conditions with high mortality; African slaves were also imported to supplement the labor force.
3. 1590–1599Lima · PeruPotosí silver was smelted into bars at the Royal Mint; part was shipped via the Isthmus of Panama to Seville, Spain, paying the royal quinto tax; the rest flowed east to Asia via the Manila galleons from Acapulco. In the 1590s, Potosí produced about two million pesos of silver annually, over half of global output, forming a core pillar of the Spanish Empire's finances and the early modern global economy.