Editors

Precious and imperial topaz from Brazil

EditorsJan 25, 2013

Precious and imperial topaz from Brazil

Brazil produces more topaz than any other country in the world. Most of the production is colorless, which is irradiated and heated into various shades of blue. Precious and imperial topaz offer a rare and warmer alternative to the cool blue shades we are accustomed to seeing in jewelry stores. “Precious” topaz usually refers to yellow to orange colors while “imperial” topaz usually refers to pinkish-orange to pink to purple and even red colors (see figs. 1 and 6).  However, some dealers argue that all topaz in these warmer hues should be classified as imperial. Since the origin of the word topaz is most likely from the Sanskrit word “tapas,” meaning fire, this argument seems to have merit. Recent price increases are due to limited mining, renewed interest from designers in these warmer hues and strong domestic demand in Brazil.



Fig.1: Precious and imperial topaz from Ouro Prêto, Brazil (Gems from 5 carats to more than 62 carats)
Center: Classic orthorhombic crystal with prismatic termination (102g). Photo: E. Boehm, RareSource

No visit to Brazil would be complete without stopping by the famous gold mining region of Ouro Prêto, “Black Gold” in reference to the black rock in which gold was first discovered there during the Brazilian gold rush of the early 18th century. Today, this beautifully preserved colonial Portuguese city is a UNESCO World Heritage Site and the world’s only source for imperial topaz.

Ouro Prêto, while built on gold mining, is today more famous for precious and imperial topaz, which was also discovered here in the early 1700s. The topaz mines are located just a short drive outside the city so it is possible to visit them in a few days. Getting there is easier if one flies through the closest major airport in Belo Horizonte, which is only a two- to three-hour drive from Ouro Prêto.

The two main large-scale mines of Capão and Vermelhão produce the majority of all material on the market today but there are also several small-scale mines operated by independent artisanal miners known as Garimpeiros. Vermelhão is the Portuguese word for vermilion in reference to the reddish-orange to red topaz crystals found there. All the mines are open-pit operations that use water to separate the gem crystals from the weathered host rock.


                              

Fig.2: Washing grate (top left) used for the initial separation of host rock and gem-bearing ore, which flows down the slope to the rolling jig that further separates the gems from the ore. Capão Imperial Topaz Mine, Brazil.
Photo: E. Boehm, RareSource

Fig.3: Fine topaz crystals (top right) displaying the orange to sherry range of color found at the Capão mine in Ouro Prêto, Brazil. Photo: E. Boehm, RareSource


Fig.4: Topaz crystals ranging from golden yellow to vivid pink. Photo: E. Boehm, RareSource

Geology
Topaz is an alumina-silicate that typically forms in granitic pegmatites or rhyolitic igneous rocks.  Imagine a molten volcanic material that travels from the lithosphere deep in the earth through the asthenosphere and ultimately into the Earth’s crust. This molten material either migrates up as a large plutonic mass, or squeezes into weaker fractured areas within the earth’s crust creating pegmatites, or explodes out in the form of a volcanic rhyolite. Once it
hits the solid crust or is exposed to the surface, it cools and crystallizes. There are two parts to this crystallization process. The first is the pegmatitic phase, which may also involve the mixing of the surrounding crust’s minerals with the molten intrusive pegmatite. The second is the hydrothermal phase, which involves the introduction of mineral-rich fluids into the pegmatite. This is a very basic explanation of the extremely complex nature of how petrological forces effect the formation of various pegmatite minerals such as topaz.



Fig.5: Topaz crystals in host rock from the Vermelhão Mine in the Saramenha district of Ouro Prêto within the state of Minas Gerais, Brazil. Photo: E. Boehm, RareSource

Gemology
The basic chemical formula for topaz is Al2(SiO4)(F,OH)2.  Precious and imperial topaz gets its colors from trace amounts of chromium (Cr+3). It has a relatively high hardness of eight on the Mohs scale, which is the same as spinel. Like diamond, it has one direction of perfect cleavage so care must be taken to avoid hard blows. Its relatively high refractive index (1.61-1.63) and excellent transparency make topaz one of the most versatile and desirable gems. Like tanzanite and chrysoberyl, topaz is no-axial which means it has two optic axes and three optical directions through which light travels at different speeds. These three optical directions represent the three refraction indices of topaz. This also means that each direction has a different absorption producing different colors. Blending these colors in the faceting process is a true art and can produce amazingly varied results, particularly in precious and imperial topaz. Topaz typically contains two-phase inclusions (liquid and gas), three-phase inclusions (crystal, liquid and gas), or multi-phase inclusions (crystals, liquids and gas). These multi-phase inclusions are a result of the hydrothermal phase during which crystal growth occurs.


Fig.6: An extremely rare 17-carat imperial red topaz, square cushion, Ouro Prêto, Brazil Gem Courtesy RareSource, Photo by R. Weldon

Graduate Gemologist (G.G.) Edward Boehm is the owner of RareSource (formerly JOEB Enterprises), a Chattanooga, Tenn.-based gemstone supply and consultancy. RareSource travels to mines worldwide to bring customers the finest quality gemstones. Contact him at edward@raresource.com. For those attending the Tucson show next month, please feel free to drop by the RareSource booth #406 at the AGTA show.
Edward Boehmis a Graduate Gemologist and the owner of colored gemstone and supply consultancy RareSource.

The Latest

WFDB Moments campaign
SourcingJan 28, 2025
WFDB Joins Efforts to Promote Natural Diamonds With New Campaign

The “Moments” social media campaign emphasizes the emotional ties between natural diamonds and life’s special milestones.

Bliss Lau As We Are Collection Campaign
CollectionsJan 28, 2025
Bliss Lau Celebrates the Intricate Mosaic of Identity in New Collection

The versatile “As We Are” collection features 14 pieces with interlocking designs allowing for 27 different looks worn around the body.

Olympic gold medalist and De Beers ambassador Letsile Tebogo
SourcingJan 28, 2025
Botswana’s First Olympic Gold Medalist Is Now a De Beers Ambassador

Letsile Tebogo will help to promote natural diamonds and the good they have done for his country.

Resolutions - 2025.jpg
Brought to you by
3 New Year’s Resolutions for Jewelry Lovers

The new year feels like a clean slate, inspiring reflection, hope, and the motivation to become better versions of ourselves.

Hargreaves Stockholm NouvelleBox
Events & AwardsJan 28, 2025
NouvelleBox Show Returns to New York City

The showcase, in its second year, will feature more than 20 international brands at its curated event from Feb. 2-4.

Weekly QuizJan 23, 2025
This Week’s Quiz
Test your jewelry news knowledge by answering these questions.
Take the Quiz
Graphic for “Predictions for the Year Ahead” webinar
Recorded WebinarsJan 28, 2025
Watch: Fine Jewelry Market Predictions for 2025

“My Next Question” guests Sherry Smith and Edahn Golan share their 2025 forecasts, from sales and marketing to what retailers should stock.

AGTA Seminar Series
Events & AwardsJan 28, 2025
Here Is the 2025 AGTA GemFair Tucson Educational Lineup

The seminar series covers topics from market trends and colored stone terminology to working with museums and growing an Instagram profile.

ride_or_die_1872x1052.png
Brought to you by
A Diamond Is Forever Celebrates "Forever Present" Holiday Campaign

A Diamond is Forever hosted a holiday celebration in honor of their new marketing campaign, ‘Forever Present.’

A picture of the LeVian family including Larry LeVian
MajorsJan 27, 2025
Le Vian Corp. Chairman Larry LeVian, a Man of Faith and Family, Dies at 73

LeVian is remembered for his leadership in the jewelry industry and for being a selfless and compassionate person.

Stock image of gavel, books, and handcuffs
CrimeJan 27, 2025
New Jersey Jeweler Sentenced to 2 1/2 Years for Evading Customs

Monishkumar Kirankumar Doshi Shah pleaded guilty to evading customs on more than $13.5 million of jewelry imported into the U.S.

 Jemora Gemhouse
SourcingJan 27, 2025
Dev Shetty To Head New Auction House for Rare Colored Gems

Jemora Gemhouse’s inaugural auction, slated for March, will take place in Dubai and feature polished sapphires.

Rachel Quinn and Gemfields’ Crazy Love collection campaign
CollectionsJan 27, 2025
Rachel Quinn Embodies Feelings of Falling in Love in New Collection

Quinn partnered with Gemfields to create “Crazy Love,” which features Zambian emeralds and Mozambican rubies across 10 pieces.

Arch Crown 2025 Tag & Label catalog
MajorsJan 27, 2025
Arch Crown’s 2025 ‘Tag & Label’ Catalog Is Out Now

The catalog is 48 pages and features more than 100 styles.

Ashley Zhang Jewelry 2025 Lunar New Year Snake Necklace
CollectionsJan 24, 2025
Piece of the Week: Ashley Zhang Jewelry’s Lunar New Year Necklace

The one-of-a-kind necklace was designed in celebration of the Chinese New Year, as 2025 is the Year of the Snake.

Ethical Gem Fair Tucson Anza Gems
SourcingJan 24, 2025
Ethical Gem Fair Heads Back to Tucson

The gemstone show is slated to take place at the Scottish Rite Cathedral.

Ophelia Eve 15 mm yellow gold and diamond hoops
Policies & IssuesJan 24, 2025
These Designers and Retailers Are Raising Money for LA Wildfire Relief

From raffles to auctions to donations, the industry is working to aid charities in Los Angeles amid the raging wildfires.

Mugshots of Zacary Briggs, Aaron Hammond, Tre’von Anthony Neal, and Evan Puckett
CrimeJan 23, 2025
4 Men Arrested After Allegedly Plotting to Kidnap Jeweler

The suspects are accused of planning to kidnap a Miami jeweler and rob him of his cryptocurrency.

Loose diamonds from Namdia
CrimeJan 23, 2025
Security Guard Killed in Armed Robbery at Namibian Diamond Co.

Francis “Gosh” Eiseb, 58, was a senior protection officer for Namib Desert Diamonds, also known as Namdia, in Windhoek, Namibia.

Gemstone Trading Network by RapNet and AGTA
SourcingJan 23, 2025
RapNet, AGTA Partner to Launch Gemstone Trading Network

The online diamond and jewelry marketplace has expanded, introducing a new platform dedicated to colored gemstone trading.

Symposium 2025 Speakers
Events & AwardsJan 23, 2025
Plumb Club Announces Speaker Lineup for Symposium ‘25

The second annual learning forum for retailers is slated for March 13 at City Winery in Pier 57 in New York City.

Fancy Color Research Foundation
SourcingJan 23, 2025
Fancy Color Research Foundation Names New CEO

Roy Safit took over the role on Jan. 1.

National Jeweler columnist Sherry Smith
ColumnistsJan 22, 2025
On Data: How Did Independent Jewelers Fare in 2024?

Sherry Smith shares data on the year gone by, including the breakdown between natural and lab-grown diamond sales.

Los Angeles wildfires
Policies & IssuesJan 22, 2025
Jewelers Mutual Steps Up Aid for LA Jewelry Businesses

The company also is matching donations made to Jewelers of America and the Diamond Council of America’s Jewelers Relief Fund.

Jewelers of America 20 Under 40 graphic
Events & AwardsJan 22, 2025
JA Seeking Nominations for Its Next ‘20 Under 40’ Class

Now in its fourth year, the program is expanding to include a list of “20 Under 40” for jewelry suppliers.

Holiday wrapped gift boxes
SurveysJan 22, 2025
Holiday Sales Hit Record High, Says NRF

Core retail sales during the 2024 holiday season surpassed the National Retail Federation’s forecast.

Foundrae Reach for Life collection campaign
CollectionsJan 22, 2025
Foundrae’s New Collection Channels the Power of Now

The “Reach for Life” collection uses feather and arrow motifs to invite growth and inner curiosity.

National Jeweler columnist Peter Smith
ColumnistsJan 21, 2025
Peter Smith: Sales Training’s Dirty Little Secret

Peter Smith pulls back the curtain on the often misinterpreted, and sometimes maligned, world of sales training.

×

This site uses cookies to give you the best online experience. By continuing to use & browse this site, we assume you agree to our Privacy Policy