Elbaite Tourmaline, Ouro Preto, Beryl (Morganite) on Quartz Image Credits - CC Robert M. Lavinsky CC-BY-SA-3.0, Adelano Lázaro CC BY-SA 4.0, Robert M. Lavinsky CC-BY-SA-3.0
The state of Minas Gerais in Brazil is one of the most celebrated mining regions in the world, renowned for both its extraordinary mineral wealth and its deep influence on the nation’s history. To date, the region has produced more than 600 individual mineral species, serving as the type location for 55 of these.
Mining activity in the area began in the late 17th century, when Portuguese explorers discovered gold deposits in the mountains. The ensuing gold rush transformed the landscape and society of colonial Brazil, attracting settlers, enslaved labourers, and fortune seekers from across the Atlantic. By the 18th century, Minas Gerais had become the heart of the Portuguese Empire’s mining economy, supplying gold to Europe and shaping the development of towns such as Ouro Preto, Mariana, and Sabará, which still bear the architectural legacy of this boom period.
The key factor behind the region's extraordinary mineral wealth and diversity is its unique geology. Much of Minas Gerais sits on the ancient Brazilian Shield, a stable block of 2.5 billion-year-old Precambrian rock that has undergone aeons of tectonic, volcanic, metamorphic and hydrothermal activity.
Specifically, the state’s famous pegmatite fields in the northwest formed when granitic intrusions into these rocks cooled slowly, concentrating rare elements and producing large, well-formed crystals of beryl, tourmaline, and spodumene. Faulting and later hydrothermal activity enriched these with gold, topaz, and emeralds, ensuring a unique diversity of mineral deposits unmatched in most parts of the world.
In the south, vast beds of banded iron deposits were laid down on top of the shield rocks from the erosion of metamorphosed, iron-rich rock called itabirite. These formed the world-class iron ore deposits of the Quadrilátero Ferrífero, producing some spectacular crystal specimens of hematite and countless tonnes of massive lapidary-grade material. The area is also known for diamonds, mined in the 18th century.
Finally, the sandstone formations in the northwest of Minas Gerais are rich in spectacular quartz specimens, being a prolific producer of varied and often enormous crystals. The town of Corinto serves as the central hub for their sale and distribution.
When the gold fields declined, attention shifted toward gemstone minerals, ushering in a new era of mining that cemented Minas Gerais’ global reputation as a source of world-class gems. The region became a leading source of aquamarine, tourmaline, emerald, and quartz, with crystals of remarkable size and quality. Among its treasures, the rare and vivid orange-pink imperial topaz, found near Ouro Preto, is especially prized by collectors and jewellers alike. The various pegmatite fields scattered across the state have also produced world-class beryl, spodumene, and other minerals, many of which are now housed in prestigious museums around the world.
Beyond gemstones and gold, Minas Gerais is also synonymous with iron ore. The Quadrilátero Ferrífero, or 'Iron Quadrangle', holds some of the largest and richest iron deposits on Earth. This vast resource played a crucial role in Brazil’s 20th-century industrial development and continues to make the state one of the leading iron producers globally. Other significant resources mined here include manganese, niobium, and tantalum, all of which are vital to modern technologies.
Today, Minas Gerais stands as a cornerstone of Brazil’s mineral economy while also holding legendary status among collectors and geologists. Its mines continue to yield specimens of breathtaking beauty, from gem crystals to massive iron formations, making the region a place where natural history, cultural heritage, and economic power are uniquely intertwined.
If you are interested in mineral specimens from Minas Gerais and Brazil for your collection, click HERE