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

Bergman Jewelers family
IndependentsApr 01, 2025
Bergman Jewelers in Omaha Closing After 137 Years

The independent jeweler first opened its doors in 1888.

QVC Group Inc. logo
MajorsApr 01, 2025
QVC Group to Cut 900 Jobs in the U.S.

The layoffs come amid the TV shopping channel’s efforts to restructure and focus on live shopping through social media.

Coconut Grove Jewelry & Watch Show
Events & AwardsApr 01, 2025
U.S. Antique Shows Adds Fall Show in Florida

The debut event will take place in Miami’s Coconut Grove neighborhood this fall.

bench jeweler 1872x1052.png
Brought to you by
The Heart of the Industry: Giving Bench Jewelers the Recognition They Deserve

Bench jewelers spend years honing their skills, Jewelers of America’s Certification validates their talents.

The Jewelry Symposium (TJS)
Events & AwardsApr 01, 2025
TJS to Host Discussion on Jewelry Industry’s Labor Shortage

The roundtable will take place May 17 ahead of the trade show’s welcome dinner.

Weekly QuizMar 27, 2025
This Week’s Quiz
Test your jewelry news knowledge by answering these questions.
Take the Quiz
Peanuts x Monica Rich Kosann Collection Bracelets
CollectionsApr 01, 2025
Monica Rich Kosann Says ‘Good Grief’ in Peanuts Jewelry Collection

The “Peanuts x Monica Rich Kosann” collection features the comic strip’s classic vocabulary across 10 bracelet designs.

Graphic for What Do We Mean When We Say “Recycled” Gold webinar
Recorded WebinarsMar 31, 2025
Watch: What Do We Mean When We Say ‘Recycled’ Gold?

Three industry experts dive into the complexities of the material often marketed as an “ethical” alternative for metal in jewelry.

Facets-of-Fire-Difference-You-Can-See.jpg
Brought to you by
Natural Diamonds Should Mean More

Natural diamonds mean more than lab-grown, but when every cut is ideal, they all look the same. Customers want more—Facets of Fire delivers.

Mindi Mond Clarity Earrings
TrendsMar 31, 2025
Amanda’s Style File: Dripping in Diamonds

Diamonds are not only one of the most prominent gemstones, but the birthstone for those born in April.

Lashbrook ring
MajorsMar 31, 2025
Lashbrook Expands Into Luxury Golf Gifts With Acquisition

The Utah-based company known for making wedding bands has acquired Doubloon Golf.

Bulgari and LVMH Watches CEO Jean-Christophe Babin
WatchesMar 31, 2025
Bulgari CEO Jean-Christophe Babin Will Also Head LVMH Watches

The longtime luxury executive led one of LVMH’s watch brands, TAG Heuer, for 12 years before taking over Bulgari in 2013.

Surveillance footage of robbery
CrimeMar 28, 2025
2 Suspects Arrested in $1.7M Smash-and-Grab Robbery of NY Jewelry Store

Authorities said the robbers fled with jewelry and 70 Rolex watches, later taking pictures of themselves posing with big stacks of cash.

Nephrite and Jadeite by Heinrich Fischer, Richard W. Hughes
SourcingMar 28, 2025
19th-Century Jade Book Now Available in English

Lotus Gemology founder Richard W. Hughes has translated Heinrich Fischer’s 1880 book “Nephrit und Jadeit” from its original German.

LÖF The Valentine Ring
CollectionsMar 28, 2025
Piece of the Week: Löf’s ‘The Valentine’ Ring

The ring's design features contrasting lines influenced by work from architecture-inspired photographer Nikola Olic.

Eggs on a shelf
SurveysMar 27, 2025
Consumer Confidence Falls in March Amid ‘Gloomy’ Outlook

The Conference Board’s index fell as consumers continued to worry about the impact of tariffs, the labor market, and the price of eggs.

Richard Rainsford memorial ring
AuctionsMar 27, 2025
300-Year-Old Ring Linked to Witch Trial Judge Goes Unsold at Auction

However, two medieval jewels surpassed estimates at Noonans Mayfair’s recent jewelry auction in London.

Austin Butler
WatchesMar 27, 2025
Austin Butler Joins Breitling as Brand Ambassador

The Oscar-nominated actor debuted in the campaign for the new “Top Time B31” collection, which introduced Breitling’s Caliber B31.

ICA Congress Brazil 2025
SourcingMar 27, 2025
Susan Jacques, Gaetano Cavalieri to Headline 2025 ICA Congress

The Congress is scheduled to take place May 19-22 in Brasilia, Brazil.

Bailey’s Fine Jewelry storefront
IndependentsMar 26, 2025
Bailey’s Fine Jewelry Acquires Fellow NC Independent Jeweler

The family-owned retailer is the new owner of Morrison Smith Jewelers in Charlotte, North Carolina.

Bulova 150 Art Deco Miss America Watch, 150 Art Deco Pocket Watch
WatchesMar 26, 2025
Bulova Celebrates 150th Anniversary With Art Deco Watches

The “150 Art Deco” collection features a Miss America timepiece and a pocket watch from the brand’s Archive Series.

Alex Wellen
MajorsMar 26, 2025
QVC Group Appoints New President

Alex Wellen, formerly CEO and president of MotorTrend Group, has taken on the role.

Jewelers of America’s new logo
Events & AwardsMar 26, 2025
Jewelers of America Announces New Funding Initiative

The Impact Initiative is part of the nonprofit association’s new three-year strategic plan.

Christies regent kashmir sapphire and regal Burmese ruby
AuctionsMar 25, 2025
Christie’s To Auction 35-Carat Sapphire, 13-Carat Ruby

The ruby and the sapphire, which Christie’s calls a “once-in-a-generation masterpiece,” are part of the upcoming Hong Kong jewelry auction.

Diamond earrings held in gloved hand
CrimeMar 25, 2025
Tiffany & Co. Earrings Swallowed Following Grab-and-Run Theft Recovered

The two pairs of earrings, snatched from a Tiffany & Co. store in Orlando, Florida, are valued at a combined $769,500.

Emmanuel Raheb CEO of Smart Age Solutions
ColumnistsMar 25, 2025
The Smart Lab: Using Short-Form Videos to Sell More Jewelry

The time to start experimenting with video content is now, writes columnist Emmanuel Raheb.

Pomellato Nudo High Jewelry Campaign
CollectionsMar 24, 2025
Pomellato’s Latest ‘Nudo’ Collections Revamp its Classic Design

From striking high jewelry to miniature fine jewelry, the new chapter continues to highlight gemstones featuring its signature 57-facet cut.

Jamie Singleton, Bill Brace, Rebecca Wooters, Bill Luth
MajorsMar 24, 2025
4 Top Executives to Depart Signet Jewelers Amid Turnaround

The jewelry giant is reducing its senior leadership by 30 percent as part of its new turnaround strategy.

×

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