Federal police have set up a gold lab at the National Institute of Criminalistics in Brasilia to trace whether seized gold came from protected areas and was illegally mined in the Amazon, where illegal extraction has accelerated deforestation and pushed mercury contamination to dangerous levels.
Who Holds the Samples
Tiny, coin-shaped vessels at the Brasilia lab hold gold flakes that investigators say can expose the route from rainforest to market. The work centers on a simple question with a hard edge: “Where did this gold come from?” Gustavo Geiser, a federal police forensics expert, said the method has been developed since 2019 in collaboration with Brazilian universities. The investigators use X-ray fluorescence spectrometry, scanning electron microscopy and laser ablation mass spectrometry.
The lab’s samples come from across the country. Their value isn’t in the metal alone. It’s in the data. Each speck absorbs particles from the area where it formed, including traces of silver and copper, and that lets investigators compare a seized sample with stored data from protected areas. If the gold matches a national forest or Indigenous land, police say it can show the metal was illegally sourced, even if someone claims it came from a legal mine.
Geiser said that as the work advanced, the forensic examinations became increasingly complex, but the question stayed the same. The answer can help police build a case and move toward further investigations and possibly charges. That’s the machinery of enforcement: a lab in the capital, a database, and a chain that turns a speck of gold into evidence.
Who Pays for the Rush
The people at the bottom of this extraction economy are the ones living with the damage. Illegal gold mining is a top threat to the rainforest, Indigenous groups and other communities there. It has driven mercury contamination to dangerous levels, and it has helped cut down rainforest on a massive scale.
Amazon Mining Watch, a platform that uses satellite imagery to track mining, estimates that about 496,000 hectares (1.2 million acres) of rainforest have been cut down for mining since 2023, including some 223,000 hectares (551,000 acres) in the Brazilian Amazon. Those numbers sit behind the polished language of supply chains and reserves. They’re the cost of a market that keeps pulling gold out of the ground and pushing poison into rivers.
Those involved in environmental crimes in the Amazon frequently resort to fraud to introduce their goods into legal markets, not just for gold but also for cattle and timber. A worldwide surge in gold prices has only spurred on the mining rush in the Amazon rainforest. Brazil’s Federal Court of Accounts, the country’s top audit institution, said last year there was evidence indicating that mining permits granted by the National Mining Agency to small-scale miners were being used to pawn off gold extracted from protected areas in the Amazon.
Greenpeace, in an independent report in May based on publicly available records, satellite imagery and aerial surveillance, described how the scheme works. On paper, an owner of a legally authorized mine in the Amazon would declare that tons of gold had been extracted at that mine. Satellite and aerial imagery would show that there had not been any activity at the site of the legal mine. Meanwhile, images of bordering Indigenous lands, where mining is banned, would reveal large-scale mining operations. Greenpeace calls it a ghost mine scam.
What They Call Control
A federal court in Para, a northern state severely impacted by illegal mining, issued an order this month for institutions like the Central Bank and the National Mining Agency to enact effective control and traceability of all gold, from the mines to the markets. Brazil’s federal prosecutors also filed a lawsuit against the National Mining Agency, seeking better oversight of mining permits.
Prosecutor André Porreca, who is leading the case, said the permits have become a front used “to launder gold extracted by criminal organizations from Indigenous territories and protected areas.” That’s the language of the system trying to clean itself up after the fact, with courts, agencies and prosecutors all moving through the same channels that failed to stop the extraction in the first place.
Geiser said the Brasilia gold lab is an important piece of the puzzle that helps battle crime and strengthen global gold supply chains. “Being able to state that it (gold) has a legitimate origin and therefore is valid for inclusion in a country’s or a bank’s financial reserves, I believe provides solidity not only to the market but also to the countries’ financial bonds,” he said.
There is no data on how many criminals the lab has helped put behind bars, but Geiser said crime networks have recently begun exploiting neighboring countries such as Venezuela, French Guiana and Suriname to launder illegally mined gold. Samples from abroad have made it to his lab, where they have joined the constantly growing database, he said. The growing crime has also forced regional countries to strengthen collaboration through the Amazon International Police Cooperation Center, headquartered in the Brazilian city of Manaus.
Illegal gold mining also causes devastating mercury contamination. The Amazon is the world’s largest rainforest and a key regulator of global climate, so anything that degrades it could accelerate global warming, researchers say. A 2023 analysis by MapBiomas, a nonprofit that monitors land use, said that over 90% of Brazil’s mining is taking place in the Amazon region, with nearly 40% of it illegal, in protected areas.
The harm is nearly impossible to reverse, especially because of the use of mercury to extract gold. Once the gold is separated, the mercury is released into the rivers, contaminating water sources and fish essential to Indigenous life. A 2023 study by Fiocruz, a Brazilian science institute, said 21.3% of fish in Amazonian markets exceeded the World Health Organization’s safety limits for mercury levels, with children between 2 and 4 years old consuming mercury at levels up to 31 times the recommended maximum.
Brazil signed the U.N. agreement known as the Minamata Convention on Mercury, which commits it to eliminate mercury use in gold mining. The Ministry of Mines and Energy published a draft this month on easing out mercury that’s up for debate until Aug. 7. Federal prosecutors have urged that Indigenous groups, the ones most affected by the contamination, be consulted, but that has not yet happened.
Geiser said a total ban on mercury would both curb environmental contamination and bolster forensic investigations because the federal police lab can detect any traces of mercury in its samples. “It will make it even clearer that any mining using mercury ... is illegal,” he added.