DIAMANTINA (formerly called Tejuco)  , a mining town of the state of Minas Geraes, Brasil, in the N.E. part of the state, 3710 ft. above sea-level . Pop . (189o) 17,980 . Diamantina is built partly on a steep hillside overlooking a small tributary of the Rio Jequitinhonha (where diamond-washing was once carried on), and partly on the level plain above . The town is roughly but substantially built, with broad streets and large squares . It is the seat of a bishopric, with an episcopal seminary, and has many churches . Its public buildings are inconspicuous; they include a theatre, military barracks, hospitals, a lunatic asylum and a secondary school . There are several small manufactures, including cotton-weaving, and diamond-cutting is carried on . The surrounding region, lying on the eastern slopes of one of the lateral ranges of the Serra do Espinhaco, is rough and barren, but rich in minerals, principally gold and diamonds . Diamantina is the commercial centre of an extensive region, and has long been noted for its wealth . The date of the discovery of diamonds, upon which its wealth and importance chiefly depend, isuncertain, but the official announcement was made in 1729, and in the following year the mines were declared crown property, with a crown reservation, known as the " forbidden district," 42 leagues in circumference and 8 to 16 leagues in diameter . Gold-mining was forbidden within its limits and diamond-washing was placed under severe restrictions .

There are no trustworthy returns of the value of the output, but in 1849 the

total was estimated up to that date at 300,000,000 francs (see DIAMOND) . The present name of the town was assumed (instead of Tejuco) in 1838, when it was made a cidade .