Brazil’s second largest diamond discovered in MG

With this new discovery, Coromandel consolidates itself as the Brazilian municipality where the two largest diamonds ever recorded in the national territory were located. The largest of these, known as the Getúlio Vargas diamond, was discovered in 1938 and weighs 727 carats. The diamond identified in 2025 now occupies second place in the historical ranking.

Considering that one carat is equivalent to 0.2 grams, the newly discovered example has an estimated weight of approximately 129.36 grams. The volume and characteristics of the stone have attracted the attention of experts and authorities in the mining sector, who are following the regularization and certification process.

The diamond was discovered in May 2025 in an area authorized for small-scale mineral exploration, classified as Garimpeira Mining Permit (PLG). The zone title is in force, which indicates that the activity takes place within the legal parameters established by the ANM.

According to information from Coromandel town hall, the extraction took place on the banks of the Douradinho River. The stone has a brown color, a characteristic that directly influences its commercial valuation, as well as factors such as weight, purity and transparency.

Economic impact for the municipality

According to Coromandel Mayor Fernando Breno, the discovery of the diamond has a direct impact on municipal revenue. As part of the Financial Compensation for Mineral Exploration (CFEM), a rate of 2% is levied on the gross income from the sale of ore, already deducting the taxes paid during the sales.

Based on the estimated value of the stone, the revenue allocated to the federal government, with full transfer to the municipality, could reach approximately BRL 320,000. The amount must be applied in accordance with legal guidelines that govern the use of resources from mining activities.

After the discovery, the owner of the place – whose identity was not revealed – made the official declaration of the discovery in the Commercial Transaction Report (RTC). The procedure was carried out with the National Diamond Trade Register (CNCD) on May 29, in compliance with all legal requirements.

Once regularization is completed, the diamond can be sold both domestically and abroad, provided that the criteria and standards established by Brazilian regulatory bodies are met.

How is the value of a diamond defined?

The CEO of Fábrica do Ouro and specialist in high-end jewelry and precious stones, Igor Ferreira, explained that the carat weight is the first element analyzed when evaluating a diamond.

“In Brazil there is no specific table that determines the values, since other factors have a significant influence on the final value of the stone. But the transparency and the degree of purity of this stone are decisive, since they have a direct impact on the quality of the stone after cutting. In this case, its color is also considered an essential criterion, since diamonds can have different shades, some more appreciated than others on the international market.”

According to the ANM, any possible sale of the diamond, whether for the national market or for export, must follow the rules of the Kimberley Certification Process (CPK). Brazil is part of the international system that aims to prevent diamonds from being used to finance armed conflicts or illegal activities.

ANM is responsible for Brazilian representation in the process and carries out all stages of batch identification and characterization. This includes distribution by weight and carat, photographic records, value estimates, and detailed information on the mineral’s origin and destination.

After the technical conference, the batch is packaged and sealed by an agency inspector. Only after this step, and all requirements are met, is the Kimberley Certificate issued, an essential document for the legal circulation of diamonds in the international market.