The Colombian government says it will seize and close a mine run by FARC guerrillas that has supplied tungsten to some of world’s leading multinational companies. Colombian security forces are...preparing an assault on Tiger Hill, the mine in a remote part of the Amazon jungle run by FARC...One of the biggest importers of the Colombian tungsten was a U.S. unit of Plansee..., a Reutte, Austria-based metals processor...That division, Towanda, Pennsylvania-based Global Tungsten & Powders, stopped buying the metal from Colombia...Plansee, the parent company, processes tungsten products and sells them to...BMW, Ferrari, Porsche and Volkswagen, Siemens and BIC...These companies said they conducted investigations...They all now say they are confident their supply lines are free of minerals mined for the FARC. Apple and Samsung...had also purchased materials that came from the same sellers of Colombian tungsten. Both companies opened investigations into their suppliers...They now say that all of their products no longer have any tie to FARC tungsten.