In Segovia, Colombia, nearly 100 shops process the gold that prospectors bring down from the foothills of the Andes Mountains. The cheapest, easiest way for miners to refine gold is to mix it with mercury, aka quicksilver.

Photograph by Ronald deHommel for Bloomberg Businessweek

In Segovia, Colombia, nearly 100 shops process the gold that prospectors bring down from the foothills of the Andes Mountains. The cheapest, easiest way for miners to refine gold is to mix it with mercury, aka quicksilver.

Photograph by Ronald deHommel for Bloomberg Businessweek

Mercury Madness

Foothills
Foothills

In Segovia, Colombia, nearly 100 shops process the gold that prospectors bring down from the foothills of the Andes Mountains. The cheapest, easiest way for miners to refine gold is to mix it with mercury, aka quicksilver.

Photograph by Ronald deHommel for Bloomberg Businessweek
Polluted
Polluted

Gold made Segovia a boomtown. Mercury made it one of the most poisonous places in the world.

Photograph by Ronald deHommel for Bloomberg Businessweek
Miners
Miners

Workers at the 120-year-old Niemi Niemi mine still dig for ore by hand.

Photograph by Ronald deHommel for Bloomberg Businessweek
Shaft
Shaft

The Niemi Niemi mine.

Photograph by Ronald deHommel for Bloomberg Businessweek
Slush
Slush

Slush from gold extraction.

Photograph by Ronald deHommel for Bloomberg Businessweek
Supply
Supply

At a supply store, mercury is measured for sale to miners.

Photograph by Ronald deHommel for Bloomberg Businessweek
Processing
Processing

Processing centers mix water, mercury, and gold ore in tumblers.

Photograph by Ronald deHommel for Bloomberg Businessweek
Sale
Sale

Luis Arango travels two hours to Segovia to sell gold from his mine in Remedios.

Photograph by Ronald deHommel for Bloomberg Businessweek
Safer
Safer

Juan Camilo Hoyos chose a job buying gold over the dangers of processing it.

Downtown
Downtown

Bars in central Segovia.

Photograph by Ronald deHommel for Bloomberg Businessweek