On the Colombia-Venezuela border, the illegal mining of strategic minerals such as tantalum, niobium, and rare earth elements is fueling a transnational illicit economy involving guerrillas, armed organizations, and criminal networks. Colombia’s Orinoquía Naval Force has seized dozens of tons of these so-called "black sands." However, the complexity of trafficking networks and the lack of a solid legal framework have made it impossible to curb the extraction and illicit flow of these materials. The absence of state control and the manipulation of mining titles allow the laundering of these minerals, while legal loopholes facilitate an illegal mining industry that could become one of the region’s main sources of conflict.
Brigadier General Rafael Olaya, commander of the Orinoquía Naval Force, has fought drug traffickers on Colombia’s southwestern Pacific coast and sat at the verification table of President Gustavo Petro’s ambitious peace agenda with the National Liberation Army (ELN), the country’s largest guerrilla group. Now he faces a new adversary: the absence of legal frameworks regulating critical mineral extraction and commercialization, which could become a major driver of conflict on the Colombia-Venezuela border.
“We’re the only state presence in the territory. The only public trying to exercise authority under this fragmented legal framework, and we’ve run into countless gaps, including the absence of those who should be regulating mining in Colombia,” Olaya said at his office in Puerto Carreño, a Venezuelan border city and the capital of Colombia’s Vichada department.
The stern and seasoned naval officer is months away from rising to major general of the Marine Infantry, one of the highest ranks in the Navy. Despite his modesty, Olaya has overseen the largest seizures of black sands in Colombia’s history, as the Orinoquía Naval Force has captured 60 tons in recent months. These heavy sacks of minerals, containing tin, tantalum, and rare earth elements, move through the Orinoquía and Amazon regions along the Guiana Shield.
“The Ministry of Mines and the National Mining Agency should pay more attention to this region,” Olaya said. “This is not just about Colombia. Rare earth elements are now influencing international conflicts and global trade. We’re talking about the biggest trader, which is China.”
But the seizures reveal a troubling paradox.
Police and intelligence sources, along with those involved in illegal extraction and transportation, confirmed to Amazon Underworld that most of these minerals come from illegal mining sites controlled by guerrillas in Venezuela.
Yet a significant portion of the seized material has been returned to the mineral traders.
Why? Because the trafficking schemes are cleverly designed to appear fully compliant with the law.
“Unfortunately, that legal weakness prevents prosecution,” General Olaya explained, noting the high quality of the seized concentrates: “We’re talking about material so pure that it can only come from industrialized, specialized exploitation, not artisanal mining.”
Despite frequent flyovers, the Navy has been unable to locate the actual mines within its territory. “If you fly over the area assigned to me, you don’t see the pits or environmental damage that would correspond to that level of industrial production. It’s very hard to determine if the mining is happening directly in our rivers or if material is being brought in from another country.”
The answer lies in document manipulation. To avoid legal scrutiny, illegally sourced minerals are paired with documentation from existing Colombian mining titles, which are often incomplete or fraudulent. “These titles are also used to legalize minerals from other regions, making it look as though extraction occurred under an existing title. All they need to do is attach the documentation to formalize large quantities of material.”
Indigenous miners interviewed by Amazon Underworld, speaking on condition of anonymity, said information about upcoming inspections routinely leaks to criminal networks controlling mining equipment: “They warn people in Inírida about five days before the government arrives,” one miner said. “That gives us time to hide the dredges, fuel, and equipment, everything.”
Hiding the machinery requires enormous effort: “When I was there, we had to hide the raft four times,” another miner recalled. “We dug a huge ditch about 500 meters away and planted bushes on top to make it look natural.”
There’s a perfect legal vacuum within an imperfect legal framework, one that allows tons of Venezuelan minerals to flow through Colombia under the guise of legality.
In Amanavén, a riverside town in Vichada facing the Venezuelan town of San Fernando de Atabapo — a main departure point to the mines in the Yapacana National Park — fewer than a dozen vessels are docked. Shops named “La Cuñada,” “La Cariñosa,” and “Las Toninas,” sell basic supplies and food products. According to the Colombian Navy, these floating houses double as storage hubs for black sands, a mix of heavy, high-value minerals essential for modern technology, including tantalum, niobium, tin, tungsten and even rare earth elements.
This is one of the key collection points. “In some places, we’ve found this type of sand, carried out inspections, and seized material when there’s no documentation,” said Colonel Higuera, a young officer of the Orinoquía Naval Force wearing a bulletproof vest and helmet. “It’s very likely that there are armed group members here at this moment.”
In December 2024, the Navy raided one of those boats and seized 13 tons of black sand concentrate, belonging to a mineral trading company, Gracor. But in April, a municipal judge in Cumaribo, Vichada, Ximena Ramírez Zambrano, ordered the return of the seized minerals to Gracor, citing irregularities in the process, despite objections from prosecutors and the Navy.
Amazon Underworld visited Amanavén in May 2025 together with a Colombian Navy team, in a tense atmosphere where locals began filming and questioning the team’s presence at the location. Colonel Higuera approached three nervous Venezuelan men dressed in black at the hamlet’s restaurant to shake their hands. “These three work with the ELN,” Higuera said afterward, citing naval intelligence, but arguing he couldn’t act without arrest warrants.
In a strange mix of Venezuelan state forces, mineral traders, and Colombian guerrillas, Amanavén exemplifies the inability to act against this growing illicit economy while the legal framework lags behind and the technical capacity to identify critical minerals remains limited.
General Olaya estimates that around 80 tons of black sands move through Colombia’s Guainía and Vichada departments monthly, although this figure probably represents the lower end of actual volumes. “They’re extracting rare earths left and right,” he noted.
The movement of minerals from Venezuelan extraction sites into Colombian territory depends on a network of intermediaries and collection points strategically positioned along the border.
Indigenous buyers and other collectors act as links between miners and Colombian traders, facilitating frequent cross-border mineral flows.
These hubs are deliberately positioned to exploit the porous border. When Venezuelan state forces threaten trafficking activities, operators quickly move the minerals across the river to Colombia, and back again when needed. Some stash minerals on Colombian riverbanks to prevent theft by Venezuelan National Guard units, whose involvement in the trade — from personal resale to cooperation with armed groups — is widely documented.
Directly across from Amanavén, Venezuelan National Guard boats are moored on the opposite bank. In February 2025, members of the military organization reportedly tried to kidnap personnel from Gracor, the Colombian trading company. The crew jumped into the river to escape, and the soldiers stole over 400 kilograms of black sands, according to a company representative.
At collection centers in locations like Amanavén, Puerto Inírida, and Carlos Lata, the minerals undergo basic processing and quality checks. Amazon Underworld obtained a video showing buyers transferring minerals from sacks into buckets for weighing — a process designed to prevent fraud by mixing valuable minerals with low-quality dark sand. Sacks are marked with colored tape to indicate ownership, and sometimes spectrometers are used to verify material quality.
Armed groups control key smuggling routes, charging “tolls” in places such as Isla Ratón on the Venezuelan side of the Orinoco River and Carlos Lata, where the ELN operates. These extortion schemes show how armed actors profit from their territorial control.
“You have to be very careful because obviously they’re going to link you to us,” said Colonel Higuera, before leaving Amanavén. “We’re working to provide security support, but you shouldn’t let your guard down because unfortunately armed groups are active in the area.”
Click here to read the full special report The Price of Progress: The Dark Side of Critical Minerals in the Amazon
Researcher
Bram Ebus
Researchers
Daniela Castro, María de los Ángeles Ramírez, Emily Costa, Fábio Bispo, Hyury Potter, Isabela Granados, Natalie Barusso.
Cover and infographics
Laura Alcina
Maps
Natalie Barusso
