Diamantina The native inhabitants of the town named Arraial do Tijuco used to play with shiny stones found in the mud of a neighbouring river. What they didn't know is that they were playing with diamonds. The town was renamed to Vila de Diamantina in 1831, and it was the main source of diamonds for the Portuguese crown until Brazil's independence. Diamantina produced more than 3 million carats of precious diamonds in 100 years.