Potosí

city · earth

A silver city built above four thousand metres in the Bolivian Andes beneath the Cerro Rico, whose ore was registered in 1545 and which became the largest single source of silver in the early modern world. Two things made the scale possible and neither was the ore alone. The first was mercury amalgamation, introduced in the 1570s, which extracted silver from low-grade ore that smelting could not work, and which depended on mercury from Huancavelica in Peru — so the output of one mine was governed by the output of another a thousand kilometres away. The second was the mita, a rotational labour draft imposed under Viceroy Toledo that required highland communities across a vast catchment to send a fixed proportion of their adult men to the mountain. Potosí grew into one of the most populous cities in the world at its peak, in a place with no agriculture, no fuel and barely enough air, sustained entirely by imports paid for in silver. The phrase vale un Potosí entered Spanish as a measure of unimaginable wealth; the mortality in the mine and the refining mills is the other half of the record.