Some 90% of emeralds sold worldwide come from Colombia. On the fringes of the official market, a clandestine sector has developed and escapes all control. It generates more profitable business than that of gold or diamonds. The journalist leads the investigation in Bogota, where the "esmeralderos", emerald traders sell their cargo on the sidewalk. Their stones come mainly from Muzo, in the north of the country. The ten mines that surround the city provide 75% of world production. The miners extract the purest stones on the planet there.Director: Thierry Gaytán - Follow us on the networks: Facebook: https://www.facebook.com/InvestigationsEnquetes