The Great Gold Scramble
The Serra Pelada gold rush began with a 6-gram gold nugget found by a child swimming in a local river in January 1980. The find occurred on a farm owned by Genésio Ferreira da Silva, confirming rumors that the land held one of the world's largest gold deposits. Within five weeks, 10,000 prospectors, known as garimpeiros, had descended on the property, and another 12,000 were nearby. At its peak in 1983, the site swarmed with an estimated 100,000 miners.
The mine was entirely manual. The garimpeiros, dubbed "mud hogs", worked on precarious claims, often just 2 meters by 3 meters. They dug into the earth, filling sacks that weighed between 30 and 60 kilograms. These workers, called formigas (ants), then had to carry the heavy sacks up a treacherous 400-meter network of wooden and rope ladders to have the contents sifted for gold. For this backbreaking labor, a worker might earn just 20 cents per sack, with a bonus if gold was found. The chaotic conditions prompted Brazil's military government to take control, appointing Major Sebastião Rodrigues de Moura to oversee the operation. To impose order, he banned women and alcohol from the immediate mining area.
A Pit of Chaos and Mercury
The collective labor of the garimpeiros transformed the area, carving a massive hand-dug open pit into the earth. The town that emerged nearby was rife with violence; at the rush's height, 60–80 unsolved murders occurred there every month. The government established an office to buy all the gold at 75 percent of the London Metal Exchange price, but it's estimated that as much as 90 percent of the gold was smuggled out. Officially, 44.5 tons of gold were extracted.
The mining process had a severe environmental cost. To separate the gold, miners used mercury to form an amalgam. This amalgam was then heated, which burned off the mercury as a toxic vapor and left the gold behind. This process released large quantities of mercury into the soil and water. The mine officially ceased operations in 1986 and was deliberately flooded in 1992 to prevent further mining. Today, the pit is a polluted lake roughly 140 meters deep, heavily contaminated with mercury. Geological surveys suggest that 20 to 50 tons of gold may remain buried beneath the toxic water.