For centuries, Brazil has been known for prolific deposits of gold, diamonds, and other gems including quartzes, tourmalines, beryls, and topazes (especially imperials). More recent discoveries include spodumenes (kunzites and hiddenites) and chrysoberyls (especially alexandrites).
The Brazil Gem Show, billed as the largest Latin American fair for precious stones, is the primary showcase for the country’s gemstone offerings. The 12th annual show took place in Governador Valadares, in the state of Minas Gerais, June 25–28. It hosted 180 local dealers of rough and finished gems and welcomed 9,190 buyers and visitors from 22 countries and 14 Brazilian states.
Imperial topaz was king of the show. The displays of natural-color, one-of-a-kind rough crystals and cut imperials were memorable. All imperial topaz comes from mines in and around a single locality, Ouro Prêto, approximately 250 km south southwest of Governador Valadares. The color of imperial topaz, as described by the Brazilians, is reddish to pinkish orange. Call it “ripe peach” if you prefer a consumer-oriented description, with the rarest colors moving toward a dark reddish peach hue. Imperial topaz is not, as some non-Brazilian suppliers might suggest, simply any yellow topaz.
If imperial topaz was king, beryl was queen, with fine-quality aquamarines (heated), goldens (irradiated), and morganites (pink, irradiated) in plentiful supply.
There were good selections of natural-color green and teal tourmalines (left) as well as dark pink and red tourmalines (in natural as well as irradiated colors).
Dilermando Rodrigues de Melo Neto, of Geometa, showed moderate to strong natural-color kunzites (pink spodumenes) from Geometa’s famous Urucum mine, in Galiléia, just upriver from Governador Valadares. He led a small group of international visitors on a short tour of his newly opened Itatiaia aquamarine mine on the second day of the show.
In the “seen everywhere” category, huge quantities of quartzes of all colors and qualities were on offer. Rock crystal—from eye clean to highly included as well as rutilated and dendritic—was readily available as was rock crystal with other unusual qualities.
If it was colored and gemmy, I considered it either heated or irradiated. Examples include citrine (heated amethyst), “green gold” (irradiated), “honey” (irradiated), amethyst (lightly natural colored or natural dark colored Uruguayan), and “lilac” (irradiated). There were plenty of examples of natural-color rose quartz, rutilated and tourmalinated (filled with black or rare blue tourmaline needles) quartz, “Paraíba” quartz (with copper-gilalite inclusions from Paraíba, north of Minas Gerais), as well as an unusual orangey-stained fractured rock crystal (shown by Daniel Ingalsbe of Pyramid Imports).
Large gemmy examples of a new find of citrine from the south were on offer. Solange Serafini at Sul Pedras showed two nice pieces of rough citrine (heated amethyst) from the Nova Brescia mine in Rio Grande do Sul, south of Minas Gerais. Other citrines (also heated amethyst) came from the state of Santa Catarina, next to Rio Grande do Sul.
A few exhibitors showed lightly colored gem-quality Brazilian emerald. If there were any top-quality emeralds, they were stashed in pockets, shown only as a special offer. Jihad Aboul Hosn, of Amazonas Gemas in Teófilo Otoni (just north of Governador Valadares), showed non-gemmy emerald crystals embedded in a dark gray matrix, material used for carving large sculptures. There were several displays of beautiful orangey Brazilian fire opal.
Brazil used to supply the world with amethyst, but Uruguayan amethyst was the only fine color seen here. And natural-color ametrine is really Bolivian. Fancy color diamonds are still found but were noticeably absent from the show, and only a handful of alexandrites were shown. These are so rare, they may be held back for special calls.
Tanner Diniz showed a large parcel of natural-color aquamarine rough crystals from Mozambique as well as preform pink and red tourmaline (both irradiated) from the last big production of the Namitil mine, near Nampula in northern Mozambique. With pink and red tourmaline, different hues are irradiated separately with different intensities of irradiation. This makes the color more uniform and, in most cases, makes lighter colors darker.
Unimpressive but still pretty Paraíba tourmalines in weak to moderate saturated colors were available, but nothing with strong or vivid saturation was shown. There were more nice-quality, strongly saturated Mozambique teal and green tourmalines than there were Paraíbas, but even these were in short supply compared with the quantities typically available at North American gem shows.
One supplier had both Brazilian and Mozambique tourmalines in the same case, with moderately saturated Mozambique tourmalines separated from local Paraíba material by other green and teal Brazilian tourmalines. The Mozambique tourmalines were labeled Paraíba. “The labs call it ‘elbaite with copper, also known in the trade as Paraíba,’” says Marcelo Bernardes, of Manoel Bernardes. “And this is how the trade perceives it.”
We asked other Brazilians if they believe it’s acceptable to label Mozambique and Nigerian cuprian tourmalines “Paraíba,” even though they’re not from Paraíba, Brazil. The attitude was mixed, with some feeling strongly that the African material has added to the popularity of the local material. Others are preparing to meet with the governor of Paraíba state in an attempt to persuade him to become more involved in the fight to keep the name Paraíba as a label-of-origin description only.
Captions:
Oval brilliant natural-color imperial topaz (54.75 cts.) is from Ben Sabbagh Bros., Governador Valadares, Minas Gerais, Brazil;
www.gemstones.com.br
.
Suite of natural-color imperial topaz (6.93, 12.96, and 19.70 cts.) is from Manoel Bernardes, Belo Horizonte, Minas Gerais, Brazil;
www.mbernardes.com.br
.
Natural-color bluish green cushion brilliant tourmaline (311.50 cts.), from Ben Sabbagh Bros., came from the Cruzeiro mine.
Brazilian natural-color oval brilliant fire opal (81.60 cts.) is from Ben Sabbagh Bros.
Natural-color hiddenite (48.85 cts.) is from Ben Sabbagh Bros.
Natural-color pear-shape kunzite spodumene (55.93 cts.) comes from the Urucum mine. (The rough crystal weighs 200 grams.) Geometa Ltd., Governador Valadares, Minas Gerais, Brazil; e-mail:
geometaltda@uol.com.br
.
Tricolor tourmalines (65.35 cts. and 61.30 cts.) are from Ben Sabbagh Bros.
Suite of mixed beryls, including aquamarine, morganite, and yellow beryl, is from Manoel Bernardes.
Kilo bags of irradiated quartzes include green (“prasiolite”), lemon, green gold, and honey. Cristais Minerais Preciosos do Brasil, Belo Horizonte, Minas Gerais, Brazil;
www.cmpbrasil.com
.
Pair of citrine rough crystals (heated amethyst) is from Sul Pedras, Porto Alegre, Rio Grande do Sul, Brazil; e-mail:
sulpedras@yahoo.com.br
.
Matching rutilated quartz cat’s-eyes are from Ben Sabbagh Bros.
This rock crystal has unusual inclusions. Pyramid Imports, Governador Valadares, Minas Gerais, Brazil; and Tucson, Ariz.; e-mail:
pyramidgem@hotmail.com
.
A very large citrine is offered here by Andre Santana Dos from Ben Sabbagh Bros.
Suite of green tourmaline is from Manoel Bernardes.
[Sidebar 1]
Radiation and Heat Treatment
Suppliers at the show were willing to fully disclose the history of their gems: which mine produced them, the original color, and what if any enhancement was used. But getting accurate disclosure information is still a challenge, even for the experienced buyer. On more than one occasion, rough and cut quartzes that were obviously irradiated (their unusual colors gave them away) were claimed to be natural color.
After a discussion with Mauricio Favacho at Embrarad it was obvious that hundreds of kilos are being irradiated, including bags of gem materials we had just been told were natural color.
Using ISO-certified cobalt-60 gamma radiation processors to alter the electron-created color centers, Embrarad Brasil creates cognac-, beer-, green gold–, and lilac-color quartzes; hot pink, yellow, and dark yellow beryls; hot pink and red tourmalines; dark blue topaz; dark rose kunzite; and green and dark blue fluorite. Embrarad has been irradiating gems for over 20 years.
Because cobalt-60 gamma irradiation does not affect the nucleus of an atom, it leaves no residual radioactivity. Embrarad also uses gamma irradiation to sterilize surgical tools, bottles, pharmaceutical products, cosmetics, and teas; in the processing of foods, spices, and seasonings; and to improve synthetic fibers and polymers.
Since gems must retain their original enhanced color to maintain the integrity of a piece of jewelry, Embrarad will not enhance gems with low color stability.
Cost for irradiation varies with the type and quantity of gem materials to be treated. The quantity can vary from grams up to several kilograms. It costs nothing to run a test batch.
Heat treatment can accomplish three things: eliminate brownish or grayish secondary hues, enhance the available inherent color, and alter the inherent color. Best examples of enhancement by heat were aquamarines and citrines. Aqua comes out of the ground in Brazil as mainly a grayish- to light bluish-green color. Heat enhances and alters the grayish and bluish secondary colors to a primary blue and reduces or eliminates the green. All citrine comes from heating poor-color amethyst.
[Sidebar 2]
Minas Gerais and Governador Valadares
The state of Minas Gerais is chock-full of gem-mining activity. Famous for the world’s only imperial topaz mines, Minas Gerais produces quartz (including rock crystal, amethyst, citrine, rose, agate, dendritic, rutilated, and chalcedony agates), beryl (morganite, heliodor, green, emerald, and goshenite), and spodumene (kunzite and hiddenite).
Belo Horizonte, the capital of Minas Gerais, is a jewelry-manufacturing center, and Ouro Prêto, the original capital city, is famous for its gold deposits (now depleted). Diamantina is known for its alluvial diamond deposits.
The Brazil Gem Show is held at the Garfo Clube (“fork club”), a modern tennis and water recreation venue located at the fork of the Rio Doce (“sweet river”) in Governador Valadares. Local gem materials are displayed inside and out, and attendees can meet those directly involved in mining and cutting. A spectacular view overlooks both the Rio Doce and the 3,000-foot Ibituruna Peak, famous for hang-gliding and paragliding free-flight events. Valadares, population 250,000, is a major trading center for the region. The surrounding countryside is still active in mining and exploration.
Not every available Brazilian gem is displayed at the show, and many buyers make appointments at private offices in downtown Governador Valadares to view additional material. We visited Clement Sabbagh, of Ben Sabbagh Bros., and photographed the gems shown here.
Top quality red-pink 32.56 ct. imperial topaz
Aquamarine weighs 623 cts.
This is one sample from a parcel of Brazilian fire opal rough.
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