Cutting the Presidente Vargas was an act of destruction as much as craft. The rough stone had flaws running through it, and the only way to get clean gems out was to cleave it apart. What emerged was a set of twenty-nine finished diamonds totaling 411.06 carats - sixteen emerald cuts, a pear, a marquise, ten trillions, a baguette. The largest of them, an emerald cut of 48.26 carats, kept the name. Harry Winston bought that stone back in 1958, recut it to a flawless 44.17 carats, and sold it again in 1961. The two men who found it in the riverbed had been working by hand in water, sorting gravel, the way garimpeiros in this region have worked for two centuries. The stone's later career in New York and its earlier life in a Minas creek belong to almost entirely separate worlds.

Diamonds form under enormous pressure deep in the mantle and reach the surface only when a particular kind of volcanic eruption carries them up, freezing them into pipes of rock called kimberlite. The Coromandel district is riddled with them - hundreds of kimberlite bodies scattered across a municipality of 3,313 square kilometers. Erosion has done the rest of the work over millions of years, stripping the pipes and washing their contents into the drainage. That is why the finds here come out of streambeds rather than mine shafts: the Santo Antonio do Bonito, the Douradinho, and their neighbors are natural sorting machines, concentrating heavy stones in gravel bars where a patient person with a pan can reach them. It is also why the National Mining Agency licenses roughly eighty companies and cooperatives to work claims on private farmland, under Kimberley Process certification.

The year after the Presidente Vargas came the Darcy Vargas, 460 carats, also from Coromandel. Then decades of smaller stones, steady enough that residents here talk about diamonds the way people elsewhere talk about the harvest. And then, in May 2025, on the banks of the Rio Douradinho, a rough diamond of 646.78 carats - the second largest ever recorded in Brazil, valued at around sixteen million reais, registered with the mining agency from a legally permitted claim. Eighty-seven years separate the two finds and perhaps a few kilometers of cerrado. Coromandel has fewer than thirty thousand residents, and it has produced both the largest diamond in Brazilian history and the second largest.

Nobody in town agrees on where the name came from. The older explanation, still repeated locally, ties it to the Coromandel Coast of southeastern India and to ships that carried enslaved people from there - though this is difficult to sustain, since the people enslaved in Brazil were taken overwhelmingly from West and Central Africa rather than the Indian Ocean. A different connection suggests itself, and it is at least as tidy. Before Brazil's strikes upended the trade in the eighteenth century, the Coromandel Coast was the shore from which the world's diamonds left for Europe - the Golconda stones, shipped out through its ports. A Brazilian diamond district borrowing the name of the place it displaced would be a fitting piece of history. It remains speculation.

For all the attention the stones attract, the everyday economy of Coromandel rests on agriculture. This is cerrado coffee country, growing beans for export on the corrected red soils of the plateau, alongside broad plantations of soybeans and corn. Dairy farms supply processing plants in town; cattle go to the meat industry. Limestone quarries feed a market created by the soil itself - the cerrado is acidic, and every hectare brought into production needs calcareous rock ground and spread across it. The municipality runs 495 kilometers from Belo Horizonte, borders Goias on the north, and contains six districts scattered across its considerable territory. Nearly 29,000 people live here. A few of them, on any given weekend, are down at the river with a pan.