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

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

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

WatchesMay 23, 2022
Steven Kaiser, Watch Industry Veteran and Beloved Mentor, Dies at 68

Kaiser, whose illustrious career spanned decades, died suddenly on Friday.

IndependentsMay 23, 2022
Long’s Jewelers to Open New Location

The family-owned jeweler is relocating its Braintree, Massachusetts, store to a new space.

IndependentsMay 23, 2022
Luxury Goods Veteran Olivier Stip Joins Chicago Jeweler CD Peacock

He will step into the retailer’s newly created role of chief development officer.

Brought to you by
Dive into GIA’s Pearl Expertise

When it comes to knowing the identity and quality of your pearls, count on GIA as your independent pearl experts.

GradingMay 23, 2022
Gem-A Launches Digital Entry-Level Gemology Course

GemIntro is meant to give a broad introduction to gems and gemology.

Weekly QuizMay 19, 2022
This Week’s Quiz
Test your knowledge of the latest jewelry news with this quick test.
Take the Quiz
Recorded WebinarsMay 20, 2022
Watch: Responsible Sourcing and the Gold Supply Chain

Three industry experts discuss “recycled” gold vs. mined, their challenges and benefits, and how jewelers can navigate the area.

FinancialsMay 20, 2022
Richemont’s 2022 Jewelry Sales in the Americas Nearly Double

Cartier, Van Cleef & Arpels, and Buccellati put on stellar performances.

Brought to you by
A.I. Grading is Changing Conversations at the Retail Counter

Advanced technology levels the playing field, helping jewelers give customers what they want.

AuctionsMay 20, 2022
Piece of the Week: ‘Birds in Flight’ by Oscar Heyman

The New York jeweler made this incredible, colorful Art Deco bracelet featuring tropical birds in 1927.

SurveysMay 19, 2022
5 Predictions for Jewelry Retail in the Second Half of 2022

From a slowdown in sales growth to rising costs, Fruchtman Marketing outlines its expectations for the second half of the year.

MajorsMay 19, 2022
As It Nears 75, Here’s How Grandview Klein Stays Competitive

Once a part of Julius Klein Group, the diamond company combines its direct supply and cutting expertise with a keen eye to the future.

SourcingMay 19, 2022
De Beers’ Rough Sales Up 21% So Far This Year

One analyst cited rising diamond prices and the sanctions on Alrosa as contributing factors.

CollectionsMay 19, 2022
Brilliant Earth Collaborates with Jade Trau

The two have partnered on a capsule collection.

MajorsMay 19, 2022
Jewelers Mutual Adds 2 Industry Veterans to Its Board

John A. Green of retailer Lux Bond & Green and Niveet Nagpal of Omi Privé have joined the board of directors as of May 18.

FinancialsMay 18, 2022
Watches of Switzerland’s Jewelry Sales More Than Doubled in Q4

The retailer also said demand for Rolex, Patek Philippe, and Audemars Piguet watches continues to exceed its supply.

AuctionsMay 18, 2022
Jewels from Bette Midler Are Headed to Bonhams

The auction house’s upcoming sale also includes collections from American heiresses.

IndependentsMay 18, 2022
Jeweler Lewis Baribault Celebrates 50th Work Anniversary

The Connecticut jeweler reflected on five decades in the industry and what the future holds for the family business.

Events & AwardsMay 18, 2022
Visit A Mine in New Jersey With WJA New York Metro

The chapter has organized a day trip to the Sterling Hill Mine and Museum in Ogdensburg on Saturday, May 21.

SourcingMay 17, 2022
A New Source in Tanzania Is Producing Cobalt-Blue Spinel

The stones come from a deposit close to Mahenge and have been on the market for several months.

SourcingMay 17, 2022
‘Pop’ the Question With Stephanie Gottlieb’s New Diamond Cut

The jewelry designer is partnering with popcorn brand Angie’s Boomchickapop on a whimsical diamond cut.

ColumnistsMay 17, 2022
What You Need to Know About the Google Analytics 4 Rollout

In the latest article from The Smart Lab, Emmanuel Raheb outlines the website changes jewelers can expect with this new software.

TechnologyMay 17, 2022
Virtual Diamond Boutique Uncorks the ‘Sales Genie’

The new app allows salespeople to quickly and easily access a lot of inventory.

Events & AwardsMay 17, 2022
‘Cartier and Islamic Art’ Exhibition Opens in Dallas

Following its Paris debut, “Cartier and Islamic Art: In Search of Modernity” has landed at the Dallas Museum of Art.

IndependentsMay 16, 2022
Mejuri Plans to Triple Its Store Count This Year

The fine jewelry brand expects to open 17 new locations, mostly in North America.

IndependentsMay 16, 2022
Karats Jewelers Plans Expansion Into 30,000-Square-Foot Store

The Kansas retailer is aiming for a fall 2023 opening.

MajorsMay 16, 2022
Pandora Announces Plans to Build Third Factory, First Outside Thailand

It will be located in Vietnam’s Binh Duong Province, and construction is slated to start early next year.

IndependentsMay 16, 2022
MJSA Has Released its 2022 Buyer’s Guide

It’s full of hundreds of contacts for jewelry-making supplies and services.


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