The ancient landscape comprises various cratons, formed during the Precambrian period, the earliest part of the Earth's history. This unique geological landscape is rich in minerals, providing a diverse environment for gemstone formation.
Brazil is home to more than a hundred different varieties of gemstones; here are just a few that have shaped the gemmological history of the country.
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EMERALD |
| Discovered | 1500s |
| Mohs Hardness | 7.5 - 8 |
| First deposits discovered in Bahia |
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SANTA-MARIA AQUAMARINE |
| Discovered | 1900s |
| Mohs Hardness | 7.5 - 8 |
| First mined in Santa Maria de Itabira |
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PARAIBA TOURMALINE |
| Discovered | 1980s |
| Mohs Hardness | 7 - 7.5 |
| Discovered by Heitor Barbosa in Paraiba |
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IMPERIAL TOPAZ |
| Discovered | 1700s |
| Mohs Hardness | 8 |
| Discovered in the Ouro Preto region |
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Emerald
Brazil is a world-famous source of emerald gemstones, third only to neighbouring Colombia and Zambia in south-central Africa.
Emerald is the vibrant green variety of beryl that occurs in the biotite-schist deposits of the region as a reaction of pegmatitic veins within ultrabasic rocks that result in the formation of new minerals.
Emerald deposits were discovered in 1573 in the present-day Governador Valadares area. Emerald production now occurs across three states: Goiás, Bahia and Minas Gerais. In 2001, one of the world's largest emeralds was found in Brazil. It is called the Bahia Emerald and weighs more than 180,000 carats.
Santa-Maria Aquamarine
Another member of the beryl gemstone family is the highly prized Santa-Maria Aquamarine.
Aquamarine shares its basic chemical composition with emerald; however, it is coloured by iron impurities. Brazil has been a primary world source of aquamarine for more than 300 years, with aquamarines found across the Bahia, Espirito Santo, Paraiba, Rio Grande do Norte, Ceara, and Minas Gerais regions.
High-quality aquamarines are prized for their sky-blue colour and exceptional clarity. Vivid-blue varieties were discovered in the Santa Maria de Itabira mine in Brazil and are dubbed Santa-Maria aquamarine.
This unique hue made Santa Maria aquamarine highly valuable, and although supply from the Santa Maria de Itabira Mine is near exhaustion, demand for the variety remains high.
Hence, there are more aquamarines on the market called Santa Maria than have been mined!
Paraiba Tourmaline
Tourmaline comes in many colours, most of which can be found in Brazil.
With that said, none is as rare and sought-after as the neon blue to green Paraiba tourmaline.
This tourmaline variety was discovered in the 1980s by Heitor Dimas Barbosa, who had spent many years prospecting in the hills of the Paraiba region.
The vivid glow of the material was unlike any gemstone that had been seen before. Created by copper inclusions in the gemstone's structure, the variety is also called cuprian or copper-bearing elbaite.
Since the discovery of tourmaline deposits in Africa with Paraiba-like qualities, the debate over the definition of 'Paraiba' tourmalines has raged. However, true Paraiba tourmalines mined from the region continue to be some of the most coveted gemstones by collectors.
Imperial Topaz
Brazil's mining regions produce more topaz than any other country. Topaz has a diverse chemical composition. It forms as an aluminium fluorine-hydroxy silicate, and the presence of fluorine makes it an uncommon mineral.
However, the warm hues of the pinkish-orange, gold, and red stones are some of the most desired in the world.
They are referred to as imperial topaz, which has been associated with the Russian monarchy.
According to legend, the Tsar was presented with the gemstone when deposits were discovered in the Ural Mountain ranges during the 18th century. The Tsar prized the gemstone for its impressive colours and only allowed members of the royal family to wear it.
However, a second version of the tale attributes the name to Emperor Peter II. In 1881, he visited the town of Ouro Preto and, upon being presented with the gemstone by Professor Henry Gorceix, coined the term.
Whatever the case, imperial topaz is sought after by gemstone collectors worldwide, and the mines of Ouro Preto in the state of Minas Gerais remain the premier source.
Other gemstones
Brazil is one of the most important sources of gemstones used in jewellery. Although a wide array of gemstone varieties can be found throughout the country, Brazilian emeralds, Santa-Maria aquamarines, Paraiba tourmalines, and imperial topaz are some of the rarest gemstones ever discovered.
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