Land of ever blossoming diamond mines. The Ribeirao do Inferno near Itaipaba ultimately yields more than 8000 carats of goods. Diamonds are found all over. River beds, high plateaus, deep mountain passes. Extraction is no easy task.
Slavery precludes the labor problem.
Slaves wash gravel in watercourses while overseers sit in seats without arms or backs, designed this way for the utmost discomfort and to keep the surveillance officer awake and alert. If a man found a diamond, he clapped his hands, holding the stone up between thumb and forefinger. It was then passed to the inspector who placed it in a pan half filled with water and suspended from a rafter till the end of the day. Each evening, the diamonds are counted and a register is kept. There were surely commensurate rewards for stones weighing between 10 and 17.f carats too, but I can't find any listed.