Feature Gems & Gemology, Summer 1984, Vol. 20, No. 2

Gem Pegmatites of Minas Gerais, Brazil: Exploration, Occurrence, and Aquamarine Deposits

The northeastern portion of the state of Minas Gerais, Brazil, contains the world's greatest concentration of complex granitic pegmatites, which are especially noted for the production of gem beryl, chrysoberyl, topaz, tourmaline, and kunzite. Pegmatite gemstones were first found in this region over 400 years ago; in the last 100 years, Brazil has supplied most of the world market for these five gemstones. As the first of a series of articles on this region and these gem materials, this article reviews the early exploration for gemstones, their occurrence, and the mining methods and miners responsible for the development of the deposits. Focus is then given to some of the major deposits of aquamarine and other beryls, especially in the Teofilo Otoni-Marambaia and Jequitinhonha River valley districts.