In June, , a man began digging into the soft red earth in the back yard of his house, on the outskirts of Kolwezi, a city in the southern Democratic Republic of the Congo. As the man later told neighbors, he had intended to create a pit for a new toilet. About eight feet into the soil, his shovel hit a slab of gray rock that was streaked with black and punctuated with what looked like blobs of bright-turquoise mold. He had struck a seam of heterogenite, an ore that can be refined into cobalt, one of the elements used in lithium-ion batteries.
Among other things, cobalt keeps the batteries, which power everything from cell phones to electric cars, from catching fire. As global demand for lithium-ion batteries has grown, so has the price of cobalt. The man suspected that his discovery would make him wealthyβif he could get it out of the ground before others did.
Southern Congo sits atop an estimated 3. In recent decades, hundreds of thousands of Congolese have moved to the formerly remote area. Kolwezi now has more than half a million residents. Some creuseurs secure permits to work freelance at officially licensed pits, but many more sneak onto the sites at night or dig their own holes and tunnels, risking cave-ins and other dangers in pursuit of buried treasure. The man took some samples to one of the mineral traders who had established themselves around Kolwezi.
At the time, the road into the city was lined with corrugated-iron shacks, known as comptoirs , where traders bought cobalt or copper, which is also plentiful in the region. In the rainy season, the earth occasionally turns green, as a result of the copper oxides beneath it. Many of the traders were Chinese, Lebanese, and Indian expats, though a few Congolese had used their mining profits to set up shops.
The man returned to his district, Kasulo, determined to keep his find secret. Hitzman, who teaches at University College Dublin, explained that the rich deposits of cobalt and copper in the area started life around eight hundred million years ago, on the bed of a shallow ancient sea. Over time, the sedimentary rocks were buried beneath rolling hills, and salty fluid containing metals seeped into the earth, mineralizing the rocks.
