The Brazilian constitution permits the extraction of raw materials from the reserves but a lack of regulation has resulted in widespread wildcat mining across the region.
But competition from a state-run monopoly, which gets its coal mines free, may stymie Prime Minister Narendra Modi’s efforts to attract more investments into the sector.
Venezuelan opposition leader Juan Guaido says the EU should use a label to limit the trade of Venezuelan gold, the way the "blood diamond" campaign of the 1990s targeted diamond sales in Africa.