Edited Reality: What I Learned from Filming Eaten Alive

In the lowlands of Amazonia, at the foot of the Andes Mountains, gold comes in the form of small particles among the sediment in the Amazonian clay, almost naked to the human eye. To extract the gold, chainsaw crews level and burn huge swaths of forest. Then they use motorized pumps to suck earth through great hoses, leaving enormous empty pits where jungle once stood. Finally, mercury (Hg) is poured into the sediment, where it binds to the gold. This mercury-gold amalgam is heavier than other particles in the sediment mix, and falls to the bottom. Thus, the miner is able to extract his yellow prize. 
http://news.mongabay.com/2014/1222-rosolie-rps-eaten-alive.html