" Enter tantalum, niobium, and cellular technology. Now, I don’t mean to impute direct blame. Clearly, cell phones didn’t cause the war—hatred and grudges did. But just as clearly, the infusion of cash perpetuated the brawl. Congo has 60 percent of the world’s supply of the two metals, which blend together in the ground in a mineral called coltan. Once cell phones caught on—sales rose from virtually zero in 1991 to more than a billion by 2001—the West’s hunger proved as strong as Tantalus’s, and coltan’s price grew tenfold. People purchasing ore for cell phone makers didn’t ask and didn’t care where the coltan came from, and Congolese miners had no idea what the mineral was used for, knowing only that white people paid for it and that they could use the profits to support their favorite militias. Oddly, "

― Sam Kean , The Disappearing Spoon: And Other True Tales of Madness, Love, and the History of the World from the Periodic Table of the Elements