Deep in the heart of the Brazilian state of Minas Gerais, along the banks of the Rio Jequitinhonha, rural miners explore the massive open pit mines left behind by giant mining companies in search of diamonds. They try out their luck with artisanal techniques used a hundred years ago such as wooden knives, metal pans, and large water pumps. It’s a difficult process that takes weeks to accomplish with no guarantee of results. Working in groups of ten or less, these miners first excavates the soil down to a layer of gravel of up to 50 meters deep. Rocks are extracted with the help of small pumps powered by old truck engines. The miners then use their hands to go through the small rocks. If they're lucky, they'll find some diamonds.