Tungsten is a mineral used in manufacturing everything from auto parts to pens to cell phones and computers. Some of the tungsten purchased by some of the world's most well-known companies is illegally mined and used to enrich FARC, a Colombian rebel army.

An excellent new story by Michael Smith in Bloomberg Markets shows in fine detail exactly how international corporations end up helping to fund murderous guerilla warfare that has been going on in Colombia for decades. Briefly: most of the world's tungsten comes from China. But China likes to hoard tungsten for itself, so there is always a search for new supply lines. In Colombia, there is one tungsten mine. That mine is illegal and unsanctioned. It operates, however, because it is in remote territory controlled by FARC, the Marxist guerilla army that has been waging war against the Colombian government for nearly 50 years. (We will not delve into a deep discussion here of the rightness or wrongness of FARC's cause; suffice it to say that whatever your opinion on their political stance, it is a fact that they are major drug traffickers, kidnappers, employers of child soldiers, and are considered to be a terrorist organization by the US and the EU, meaning that they are not the sort of outfit than any multinational corporation would admit to supporting.)

The tungsten produced by the FARC-controlled mine often has its origin purposely obscured during its trip through the supply chain. The mine, Smith writes, is "illegal in three ways: It’s inside a forest preserve, it’s banned by Colombian law because it’s on an Indian reservation, and it’s run by the FARC." Nevertheless, the tungsten it produces makes its way to companies including BMW, Ferrari, Porsche, Volkswagen, Siemens, Apple, HP, and Samsung, among others.

Companies that have bought parts from a supply chain that included tungsten ore from Colombia say they had been unaware of any possible links to the FARC before they were contacted by Bloomberg Markets. Apple, BIC, BMW, Ferrari, Samsung and Volkswagen say they’re opening investigations to secure their supply lines.

“Apple is committed to using conflict-free minerals, and we are one of the first electronics companies to map our supply chain for conflict minerals,” spokeswoman Kristin Huguet says.

Please, Volkswagen-driving cell phone users, read the story for a full accounting of the Colombian tungsten trade and its implications. No iPhone exists in a vacuum.

[Bloomberg Markets. Image by Jim Cooke]