sentences:  The appearance of slavery in Brazil dramatically changed with the discovery of gold and diamond deposits in the mountains of Minas Gerais in the 1690s Slaves started being imported from Central Africa and the Mina coast to mining camps in enormous numbers.Over the next century the population boomed from immigration and Rio de Janeiro exploded as a global export center.Urban slavery in new city centers like Rio, Recife and Salvador also heightened demand for slaves.