What the GIA research team learned in Brazil
July 09, 2014
The GIA sent a team of field researchers to the top gemstone mining areas of Brazil this spring, including the Cruzeiro mine, which produces the color-gradient tourmalines pictured here.
Carlsbad, Calif.--Field researchers with the Gemological Institute of America recently took a trip to Brazil to visit the most important gem mines in the country, and also were given the chance to interview the man who discovered Paraiba tourmaline.
The team, which included field gemologist Andrew Lucas, the GIA’s Director of West Coast Identification Shane McClure, video producer Pedro Padua and Gems & Gemology Editor-in-Chief Duncan Pay, traveled to Brazil from March 31 to April 17. Geologist and co-owner of Nature’s Geometry and Stone World President Sergio Martins also participated.
They visited the most important gemstone mining areas of the country, including Minas Gerais, Rio Grande do Norte and Paraíba, to gather information and document the current state of colored stone mines, particularly emerald and tourmaline.
The team also had the opportunity to interview Heitor Dimas Barbosa, the first discoverer of Paraiba tourmaline, in the original mine tunnel in Batalha where the gem was found.
On their trip to the Belmont mine in Minas Gerais, they found that it’s moving to new open pits while also continuing to develop its underground mining. The mine also is building a new state-of-the-art rough processing and sorting facility, and cutting around 60 percent of their own production, with a focus on higher quality stones.
In Nova Era, meanwhile, production at mines such as Monte Belo is yielding high-quality emerald from pockets.
The Cruzeiro tourmaline mine has produced great quantities of the stone from large pegmatites, which are intrusive igneous rocks with very large crystals that form in the later stages of a magma chamber’s crystallization, and all of its rubellite tourmaline goes to Shenzhen, China, for cutting and sale.
“We’ve never seen a mine produce the amount and quality of material as the tourmaline we saw coming from the massive pegmatites at the Cruzeiro mine,” Lucas said, adding that, “the value of Paraíba tourmaline has risen unbelievably and the passion to find more material at the mines was contagious.”
The GIA noted that mining and prospecting remains very strong in Paraíba and Rio Grande do Norte for the highly valuable Paraiba tourmaline.
Findings from the trip and a more in-depth look at the interview with Heitor Dimas Barbosa will be featured in an article in the upcoming issue of GIA’s scientific journal Gems & Gemology, as well as in field reports and video documentaries hosted on the GIA website.
The GIA regularly conducts research field trips to important gem and jewelry centers around the world, incorporating its findings into research practices and education practices as well as informing the trade of the new information through various channels.