With the extensive emerald discoveries in the Colombian mines, explorers and conquistadors were searching Brazil for emerald deposits as early as the 16th century. Eventually gem deposits were found, along with gold, diamonds, and many other gems.
As a note, any nice looking green gem before the 19th century was an “emerald”, including tourmaline. Brazil has far superior tourmaline resources than they do emeralds, including the rare electric blue Paraiba tourmaline.
Currently emeralds are mined in the states of Ceará, Bahia, Goiás, and Minas Gerais. Brazil also produces important beryl varieties in addition to emeralds.
According to Sinkankas (1981): “In respect to gem beryls, Minas Gerais is the world’s most important producer, surpassing all other countries both in terms of the largest production sustained over several centuries and in quality (with the notable exception of pink beryls, the finest of which stem from Madagascar).”
Since the 1970s, Brazil has served as one of the few consistent sources of gem-quality emeralds in the world. Due to Brazilian emeralds being referred to as green beryl until certification by the AGTA (American Gem Trade Association) in the 1960s, there are perceptions of them being lower quality than the Colombian emeralds. Emerald quality is not determined by source, but the individual gem. E1356 | medium | play | left | “Emerald ID: E1356 – Weight: 3.85 Carats – Origin: Brazil”
Colombia does supply the majority of all gem-quality emeralds on the world market, but the quality of emeralds they produce is a range. Some are so heavily included they are green rocks, and some are so clear that they go to auction. The range is applicable to every emerald source, though the percentages of emeralds that can be used in jewelry varies between them, and varies year to year. This is because the amount of time between large discoveries can be years.
With that being said, Brazil is capable of producing emeralds of equal or better quality than Colombia. Again, it depends on the individual gem. As an average evaluation of everything they export, Brazilian emeralds tend to be lighter in tone and saturation than Colombian emeralds.
Mining can have serious repercussions on the surrounding environment. If a large mining site is not properly cleaned up after closing, with the next rainfall could cause a landslide onto a nearby village.
At the less extreme end of the spectrum, a bunch of 10 foot deep pits may be littered around instead. Point being that the mining sites can be problematic to people and their environment if no one cleans up afterwards.
Working the mines is dangerous between taking preventative measures for cave-ins, and handling any equipment. As such, the importance of mandating safety measures and insurance is very important, albeit costly to the mine owner. This also leads to numerous legal battles between the government regulations and what is reasonable towards the mine owners or party leasing the mine.