ocr: GOLCONDA The Portuguese first discovered the gemstone tourmaline in the Golconda district of Brazil in 1676. Tourmaline isi found in rocks called pegmatites, which sometimes contain large gemstone-quality crystals of a variety of minerals. The gemstone-bearing pegmatites at Golconda are about 490 million years old and contain many different colored tourmalines. The Golconda pegmatites are mined at the surface in open pits, as well as in highly mechanized underground mines.
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