Forensic lab creates database of gold samples from across country
BRASILIA, Brazil — Brazil’s Federal Police are using a forensic technique known as gold fingerprinting to combat illegal mining in the Amazon. At the National Institute of Criminalistics in Brasilia, analysts maintain a reference collection of gold samples seized from across the country and neighboring regions, allowing them to compare and identify the origin of newly confiscated material.
The method relies on isotope analysis, which Federal Police officials said can reveal the unique chemical signature of each gold sample. “Nature has marked the gold with isotopes and we can read these unique fingerprints with radio-isotope scans,” Humberto Freire, director of the Federal Police’s Environment and Amazon Department, told Reuters. “With this tool we can trace illegal gold before it gets refined for export.”
Gustavo Geiser, a federal police forensics expert, stands beside the reference collection of gold samples at the laboratory, according to the Associated Press. The collection includes samples from different regions of Brazil and neighboring countries, creating a database that investigators can use to match seized gold to its source.
The forensic technique enables authorities to determine whether a sample originated from a protected area — meaning it was illegally mined — and to trace the gold’s origin with high precision, officials said.
Illegal gold mining in the Amazon has accelerated deforestation and driven mercury contamination to dangerous levels, according to the Associated Press report. The activity also endangers Indigenous groups and other communities in the region.
MSI previously reported that gold prices helped fuel a renewed illegal mining rush in the Brazilian Amazon in May, with a study finding that mining sites drove clear-cutting inside three conservation areas in the Xingu region. Officials described enforcement as a “cat-and-mouse game” at the time.