The "Brazilian Gold Rush" was a gold rush that started in the 1700s, in the then Portuguese colony of Brazil. The rush opened up the major gold-producing area of Ouro Preto (Portuguese for black gold), then the aptly named Vila Rica (Rich Town).
The rush began when bandeirantes discovered large gold deposits in the mountains of Minas Gerais. The bandeirantes were adventurers who organized themselves into small groups to explore the interior of Brazil. Many bandeirantes were of mixed indigenous and European background who adopted the ways of the natives, which permitted them to survive in the interior rain forest. While the bandeirantes searched for indigenous captives, they also searched for mineral wealth, which led to the gold being discovered.
More than 400,000 Portuguese and half a million African slaves came to the gold region to mine. Many people abandoned the sugar plantations and towns in the northeast coast to go to the gold region. By 1725, half the population of Brazil was living in southeastern Brazil.