DIAMANTINO, a small town of the State of Matto Grosso, Brazil, near the Diamantino river, about 6m. above its junction with the Paraguay, in 33" S., 56° 8' 3o" W. Population of the municipality (1920) 4,475, mostly Indians. It stands in a broken sterile region 1,83 7f t. above sea-level and at the foot of the great Matto Grosso plateau. The first mining settlement dates from i 73o, when gold was found in the vicinity. On the discovery of diamonds in 1746 the settlement drew a large population and for a time was very prosperous. The mines failed to meet expecta tions, however, and the population declined ; it has grown slowly since 1880. Ipecacuanha and vanilla beans are now the principal articles of export.