Publication Year: - Title: Jadeite Manufacturing and Trading Hubs in Guangdong, China Abstract: China’s Guangdong Province is famous for the manufacture and trading of jadeite jewelry items such as bangle bracelets. – Photo by Eric Welch

                      Guangzhou, Jieyang, Sihui, and Pingzhou are mainland China’s well-known jadeite manufacturing and trading centers. Each specializes in a different aspect of the industry. In 2013, GIA visited Sihui and Pingzhou to gain deeper insights into China’s jade industry.

	Guangzhou, Jieyang, Sihui, and Pingzhou are the four jadeite manufacturing and trading centers in Guangdong Province, China.

	Guangzhou and Jieyang
Guangzhou has been the hub of the jadeite trade since the 1660s. By about the 1880s, the industry’s division of labor was already well established in this major port city, with specific groups of people trading rough, cutting, and selling the finished products.

Yangmei, a village located in the city of Jieyang, boasts the titles of “Jade Capital of China” and “Jade Capital of Asia.” Yangmei specializes in the manufacturing and trading of medium- to high-quality jadeite products, 90% of which come from here.

	Sihui
Sihui is world famous for jadeite manufacturing and trading. More than 200,000 people are involved in the industry in this city alone. During our visit to Sihui, we observed shops as well as carving and jewelry manufacturers. We also interviewed Tang Xiaodong, secretary-general of the Sihui Jade Trade Association.

China’s jadeite industry developed during the Qing Dynasty, under the reign of Empress Dowager Cixi (1861–1908). During that time, a jadeite carving center was developed in Guangzhou, with many of the artisans coming from Sihui. After economic reforms were implemented in the 1980s, many artisans returned to Sihui and started jadeite carving cooperatives, passing the trade down to future generations and enabling it to flourish locally. The industry in Sihui developed rapidly after 2005 and has now reached sales of more than 100 billion yuan each year.

	Some of the high-end stores in Sihui offer fine-quality imperial green jadeite jewelry. – Photo by Eric Welch, courtesy Hanwuyuting

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	Sihui Jadeite Industry

	Pingzhou
In Pingzhou, the modern jadeite industry began in the 1980s and has matured rapidly since 2000. As with Sihui, its growth accelerated after 2005, particularly in the last few years. Where there were 1,000 stores a decade ago, there are now more than 3,000. There are about 100 manufacturing businesses on Pingzhou’s Jade Street, and merchants from Jieyang and Sihui have also established a presence there. One very large jadeite trading center in Pingzhou is called Cui Bao Yuan (“a garden full of precious jadeite”). The buildings were designed to combine trading with tourism. A merchant from Yunnan built it to resemble the ancient city of Dali. This market features a garden built specially to display the work of the great carving artisans.

	There are thousands of jadeite shops in Pingzhou. Some have beautiful interiors to match the jadeite masterpieces in their window displays. – Photo by Eric Welch, courtesy Mazu Jade Co.
The Pingzhou Gemstone & Jade Association was founded in 2001. The association protects the interests of its members and regulates the industry. The association established a Myanmar jadeite bidding fair in 2003 to provide an open public platform for Chinese and Burmese traders.

	Pingzhou is an important center for jadeite bangle bracelets. Disks are cut from flat jadeite slabs using a drill press and a circular saw bit. – Photo by Eric Welch

	Jadeite Bangle Factory

	Visit to a Jadeite Bangle Factory in Pingzhou
Pingzhou is well known as a producing and trading center for jadeite bangles. During our stay, we visited a factory devoted to bangle bracelet production. In the past eight years, the factory has grown from an area of ten square meters to more than 2,000 square meters. There we witnessed the entire manufacturing process.

	In Pingzhou, jadeite bangles can be found in a wide variety of styles, including ones with color zoning. – Photo by Eric Welch, courtesy Mazu Jade Co.
First, flat slabs are cut from jadeite boulders. Outlines for various bracelet sizes are drawn onto the jadeite slabs. A drilling machine cuts the initial round shapes. Once the jadeite disks are formed, smaller circular saw bits are used to cut the bangles’ inside diameters. Factory workers use saw bits in various sizes to create inside dimensions for different wrist sizes.

At this point, a variety of bangle bracelet styles can be created from the initial forms, including rounded tops and engraving. A bangle might be recut thinner to remove fractures, which can diminish the value. Once the shape and style of the bangle is complete, it is polished.

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	Pingzhou Bangle Bracelet Manufacturing

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	Pingzhou Jadeite

	Jadeite Evaluation
During an interview in Pingzhou, Mr. Liang Huanglin, president of the Pingzhou Jewelry and Jade Association, described the association and the industry it serves. He also discussed the evaluation of jadeite products and the importance of Guangshen jade objects. “Guangshen” refers to jadeite that has not been carved but has a smooth, high-luster surface. Pingzhou is famous for the quality of its Guangshen bangles and other objects.

	Jadeite occupies a unique gemstone market that has its own evaluation considerations. – Photo by Eric Welch, courtesy Yu Tian Shan Fang
Mr. Liang began his description of the evaluation process and quality factors by talking about a jade quality characteristic that might be difficult for Westerners to understand. It’s called “Zhong,” and it refers to the completeness of metamorphism a piece of jadeite experienced. Jadeite that experienced more complete metamorphism tends to be of higher quality. “Shuitou” refers to transparency, which can range between “shuiduan” and “shuichang” (higher transparency).

Texture is another quality factor: The finer the texture, the higher the quality. Fine-textured jadeite generally takes on a better polish, which gives it higher luster.

According to Mr. Liang, the most precious jadeite color is green, followed by purple, colorless, yellow, and red. Transparency and color can affect each other directly when it comes to jadeite value. This is especially true for colorless jadeite, which has become very popular, especially with women in their twenties and thirties. Colorless, near-transparent jadeite cost only 30,000 yuan per kilo in 1991, when Mr. Huanglin first entered the industry. It reached its peak value in 2010, at 10 million yuan per kilo. Color zoning can also greatly affect jadeite value, depending on the pattern and the colors.

	On the Outside Looking In

	Jade experts in China’s Guangdong Province were extremely welcoming to the GIA team and generously shared their knowledge of this fascinating industry. – Photo by Eric Welch
While often hidden to the West, China’s jade market is a thriving one. It sometimes has dramatic ups and downs, but it has risen continually over the long term. It has its own language, evaluation criteria, complexities, and expertise. This industry is really its own niche market, separate from the colored gemstone market and focused on the Chinese people, who share a special cultural bond with jadeite that’s unequaled by any other gem. @chapter:25


Publication Year: 2019 Title: Dive Into Summer: Mozambique Ruby, Madagascar Sapphire, and Black Nephrite from China, Plus an Opal Inclusions Chart Abstract: With 2019 already past the halfway mark, we are very pleased to present our Summer edition. Inside you’ll find new insights into a variety of gem materials.
The issue leads with a review of the past decade of ruby from Mozambique. Since 2009, Mozambique has become the world’s leading supplier of ruby, transforming the market in the process. GIA has been visiting these deposits since the initial discoveries, and now Wim Vertriest and Sudarat Saeseaw from the Bangkok laboratory add a new chapter to this story with an overview of production and distribution, as well as a comprehensive gemological characterization and a discussion of the most common treatment processes applied to material from this important locality.

“Since 2009, Mozambique has become the world’s leading supplier of ruby, transforming the market in the process.”

Next, Billie Hughes from Lotus Gemology and Rosey Perkins with Fura Gems present the results of low-temperature heat treatment experiments on sapphire from Madagascar. Increasing numbers of these stones are being heated to relatively low temperatures (below 1350°C) to lighten their color. The authors show the changes in these goods, providing a means of separating unheated and heated Madagascar sapphire.
Moving from Africa to Asia, the issue continues with a study of black nephrite from a deposit in southern China. Qian Zhong, a PhD student of mineralogy at Tongji University in Shanghai, leads a team of professors from that university in characterizing 12 nephrite samples from the Guangxi region.
In the fourth article, Jean-Pierre Gauthier from the Gemological Research Center of Nantes and his coauthors characterize “flame structure” in 37 pearls from bivalves of the Tridacnidae family. Careful observation revealed evidence of rotation during growth, a feature also seen in numerous pearls from Pinctada margaritifera.
The next article, also on pearls, presents an unusual identification challenge that confronted researchers at the Max Planck Institute for Chemistry, Johannes Gutenberg University, and GIA’s New York and Bangkok laboratories. Two pearls were examined by the team of authors, who were unable to positively identify their origin (natural or cultured), their growth environment (freshwater versus saltwater), or the mollusk that produced the pearls.
In our last article, Nathan Renfro and coauthors present an opal inclusions chart, the fifth in their series on micro-features in gemstones. Laminated versions of all of these large, colorful wall charts are also available at store.gia.edu.
Highlights from the Lab Notes column include a rough diamond with a coating of fake green “radiation stains,” a study on the separation of kornerupine and prismatine, and the first report of a color-change spessartine garnet examined by GIA. Gem News International features brief but thorough studies on the gemological characteristics of jadeite from the Polar Urals of Russia, more than 800 natural freshwater pearls from the Mississippi River system, and rubies from the Rock Creek deposit in Montana. As always, Micro-World reveals a fascinating gallery of inclusion scenes, while the Diamonds from the Deep section (now a year old) outlines the basic geological and practical features of kimberlites, the earth’s diamond delivery system.
We hope you enjoy the Summer 2019 edition of Gems & Gemology! @chapter:3


Publication Year: 2023 Title: Cricket Bat Diamond Abstract: Figure 1. A 1.04 ct diamond in the shape of a cricket bat, measuring 14.20 mm long. Photo by Priyanka Kadam.
As early as the seventeenth century, the British introduced the sport of cricket to the Indian subcontinent, where it is now the most popular sport. Recently, a diamond shaped like a cricket bat (figure 1) was submitted to GIA’s Mumbai laboratory for testing. In cricket, a bat is a wooden piece of equipment with a long handle attached to a flat-fronted blade, used to hit the ball. This diamond weighed 1.04 ct and measured 14.20 × 4.12 × 2.13 mm. It had a Light brown color. The bat-shaped diamond was partially polished with a rough texture retained on the tip of the handle and the front part of the bat. According to the diamond manufacturer, the original rough skin is intentionally kept in a few parts to authenticate its natural origin.
Based on spectroscopic features, it was confirmed to be type IIa with a very weak peak at 3107 cm–1 (hydrogen-related infrared absorption peak). Photoluminescence spectra collected at liquid nitrogen temperature with varying laser excitations revealed its natural origin; no color treatment was detected. A crosshatched “tatami” strain pattern was clearly observed between crossed polarizers when viewed under a microscope.
In photoluminescence spectra collected at room temperature with 405 nm excitation, this diamond also showed the presence of N3, a defect wherein a vacancy is surrounded by three nitrogen atoms.

Figure 2. The cricketer’s name and signature inscribed on the diamond.
As shown in figure 2, this special diamond is inscribed with the name and signature of Virat Kohli, who is widely regarded as one of the greatest players in the history of the sport. The owner of the diamond intends to gift it to Kohli. @chapter:11


Publication Year: 1993 Title: Two Treated-Color Synthetic Red Diamonds Seen in the Trade Abstract: Two dark brownish red faceted stones, recently submitted to the GIA Gem Trade Laboratory for standard origin-of-color reports, were found to be treated synthetic diamonds. This conclusion was based on observations of: patterns of zoned color, U. V. luminescence, and graining; metallic inclusions; and certain bands in the visible- and infrared-range absorption spectra. We believe that this is one of the first published reports of treated-color synthetic diamonds seen as faceted gems. For some of the gemological features described here, such as visible-range spectra with sharp absorption bands, this is one of the first reported occurrences in gem-quality synthetic diamonds. @chapter:32


Publication Year: 1982 Title: Sri Lanka: The Gem Island Abstract: Sri Lanka, formerly Ceylon, remains one of the single most important sources for fine gemstones. Especially notable are blue sapphire, pink sapphire or ruby, and yellow sapphire; alexandrite and cat's-eye chrysoberyl; and almandine and hessonite garnet. Spinel, tourmaline, zircon, moonstone, and quartz are also relatively common; they share their country of origin with several rarer gemstones as well. Most of the gem-quality material is found in alluvial deposits throughout the island, which are mined by primitive methods. In many instances, the Sri Lankan origin of the gemstone can be determined by characteristic inclusions, several of which are also discussed in this article. @chapter:37


Publication Year: - Title: Report from Jewelry Camp 2013 Abstract: Auctioneer Joseph DuMouchelle shows a jewelry item to attendees during a session at Jewelry Camp.

                      If you were to wear more than three gold rings on your hand, you could be breaking the law—that is, if you were a woman during the Italian Renaissance. Sumptuary laws in Europe during the 14th and 15th centuries dictated what finery people of certain classes could legally wear, said Jan Krulick-Belin in a presentation at the 2013 Antique Jewelry and Art Conference in Atlanta. An art and jewelry historian, she has studied paintings as a glimpse into jewelry of the past, since few pieces from before the 18th century have survived. Bridal portraits, for instance, show young women dressed in fine gowns and expensive jewelry, which they were only allowed to wear for a brief period without being considered immodest.

	Historians study the styles of the past from portraits like that of Lucina Brembati (left), whose hair, dress, and jewelry indicate a person of upper class. One of her rings bears the coat of arms of the Brembati family, another clue to her noble heritage. Painting by Lorenzo Lotto, circa 1518-1523, from the collection of the Accademia Carrara, Bergamo. The portrait on the right of Bianca Maria Sforza was painted at the request of her husband, Maximilian I, as a condition of marriage, prior to her appointment as Empress of the Holy Roman Empire. Painting by Giovanni Ambrogio de Predis, circa 1493, from the collection of the National Gallery of Art.
Krulick-Belin’s talk was one of many at the 36th annual conference known as “Jewelry Camp.” Held in Atlanta for the first time in 2013, the event was started in Maine by art nouveau jewelry expert Dr. Joseph Sataloff but later moved to New York and changed hands. Joyce Jonas ran the event until 2006, when jewelry appraiser and educator Edward Lewand took over with his wife, Sandy.

We had the opportunity to attend this year’s conference, which took place August 1–3 at the Cobb Galleria Centre, in conjunction with the Atlanta Jewelry Show. About 80 jewelry professionals and collectors attended three days of lectures on various aspects of antique jewelry.

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Among the experts presenting at this year’s conference were William Drucker of Drucker Antiques, who spoke on the Danish jewelry company Georg Jensen; author and museum consultant Janet Zapata, on Tiffany & Co. jewelry; Ezriel Rapaport of The Rapaport Group, on the secondary diamond market; Joseph DuMouchelle, on selling jewelry at auction; and Tina Joseff, on the costume jewelry designer Joseff of Hollywood. We also attended lectures on identifying Georgian and Victorian jewelry, famous women jewelers, Gothic Revival jewelry in France and England, 150 years of jewelry styles, and internet research for identification and pricing, as well as an accelerated, hands-on assessment of antique jewelry.

	George Jensen’s Rare Designs
Over its more than 100-year history, Georg Jensen jewelry has maintained value and is still handmade, said Drucker, a recognized authority on the company’s silver jewelry. Georg Jensen (1866–1935) was trained as a sculptor and began making jewelry in a small workshop in Copenhagen. He worked in art nouveau, a style that still influences the company’s designs. Other Jensen designers brought their own aesthetic and modern influences to their designs. One designer, Arno Malinowski, developed a metalsmithing technique using iron and silver during World War II, when metals were scarce. The product was similar to shakudo, a gold-copper alloy traditionally used in Japan to decorate sword fittings. Malinowski used this technique for only a short time, so these Georg Jensen pieces are rare and highly sought after.

	Diamond Recycling
Everything old is new again, and diamonds are no exception. Ezriel Rapaport, director of global trading at the Rapaport Group, pointed out that more diamonds are actually coming out of the U.S. than South Africa today, thanks to the secondary market. This is being driven by “diamond recycling” on the part of the baby boomer generation. The generation is either selling off its diamonds or trading up. About $1.5 billion in diamonds are recycled annually, offering jewelers excellent profit margins.

	Ezriel Rapaport, director of global trading at the Rapaport Group, talks about the state of the secondary diamond market. Photo courtesy of ASK Media/The Antique Jewelry and Art Conference.

	A Jeweler to the Stars
Tina Joseff, president and CEO of Joseff of Hollywood, gave an engrossing account of the company started by her father-in-law in 1928. Eugene Joseff worked in advertising in Chicago before moving to Los Angeles and starting a business designing and manufacturing jewelry for the burgeoning movie industry. He worked with famous costume designers, including Walter Plunkett (“Gone With the Wind” and “An American in Paris”) and Adrian Adolf Greenberg, also known as Adrian Gilbert (“The Wizard of Oz”). Joseff’s jewelry used silver, gold, platinum, plastic, wood and other materials, including natural gemstones. He also developed a secret plating technique so the jewelry wouldn’t reflect the camera lights.

Many of the big Hollywood stars were bejeweled in Joseff creations, both on screen and off. Some of the most memorable pieces include Vivien Leigh’s swag necklace in “Gone with the Wind” (1939), Shirley Temple’s crown and scepter in “The Little Princess” (1939), and Judy Garland’s lariat necklace in “Ziegfeld Follies” (1944). When Joseff died in a plane crash in 1948, his wife, Joan Castle Joseff, continued the business and created jewelry for the likes of Marilyn Monroe in “Gentlemen Prefer Blondes” (1953) and “Some Like It Hot” (1959), and Grace Kelly in “High Society” (1956).

	This still from the movie "Gone with the Wind," featuring Vivien Leigh and Clark Gable, is composited with the necklace worn by Leigh, which features Austrian amethysts and white sapphires set in sterling silver. Photo courtesy of Joseff-Hollywood.

Actress Grace Kelly (left) wore faux pearl earrings (right) for the movie “High Society.” The piece was designed by Joseff of Hollywood, known at one time as the “Jeweler to the Stars.” Photos courtesy of Joseff-Hollywood.
Today, Joseff-Hollywood mostly produces precision investment castings for the aerospace industry, but the company still manufactures a line of retail costume jewelry using original findings purchased in mass quantities shortly before Joseff’s death. The vintage retail costume jewelry and studio pieces are still highly sought after by collectors.

	Hands-On Purchasing Simulation
Another session was led by Louis Scholz, a gemologist and founder of Fine Jewelry by Louis, a wholesale antique jewelry company, and Brixton & Gill English-made cufflinks. This hands-on session involved the lightning-fast examination of 25 jewelry items. Using only a loupe, with one minute per piece, participants determined each item’s age and gem and metal content and assessed its marks. The experience was humbling but beneficial, as purchasing estate jewelry often requires quick evaluation, along with a keen eye, experience, and good instincts.

	A Jewelry Camp attendee examines a hat pin during the conference’s hands-on purchasing simulation, led by antique jeweler Louis Scholz. Photo courtesy of ASK Media/The Antique Jewelry and Art Conference. @chapter:16


Publication Year: 2019 Title: Greenland Ruby Update Abstract: Greenland Ruby update

Greenland Ruby has been mining ruby and pink sapphire in southwestern Greenland since mid-2017. The mine is located near the town of Aappaluttoq, about 150 km (93 mi) from the country’s capital, Nuuk. During the AGTA show, we had the opportunity to talk to Hayley Henning, Greenland Ruby’s vice president of sales and marketing. She offered updates on the development of the mine and the market for their gemstones. Over the last year, the company has refined their extraction techniques. The deposit is challenging to work, and the miners improve their skills and knowledge by mining daily. The main difficulty in working this deposit is its isolated location. The remote area, though close to the coast, is covered in ice and snow most the year. And for most of the year, the only way to reach the mine is by helicopter.
Local residents make up the majority of Greenland Ruby’s staff. Around 40 people work and live on-site. The mine is highly mechanized, and heavy equipment and blasting are used to retrieve gems. The on-site sorting house is also very sophisticated. Because of this high degree of mechanization, most of the staff operates the equipment, whereas other colored stone mines often rely heavily on manual labor. Once material is mined and sorted at the plant where ruby is separated from host rock, the ruby concentrate is sent to Nuuk to be cleaned with hydrofluoric acid and sorted by color, clarity, and size. Most of the goods require treatment, which takes place in Chanthaburi, Thailand. Cutting is done in Chanthaburi and India, and then the material is sorted in Bangkok, based on the characteristics of the finished rubies. In order to apply the highest safety, environmental, human rights, and security standards at the mine and the treatment and cutting plants, Greenland Ruby works within this closed system. They feel this is the only way to guarantee the quality and disclosure of the product, and it is their main argument for not selling rough.
Greenland Ruby is experimenting with various cutting styles but sees the greatest potential in cabochons. They can produce a consistent supply of large, fine-colored cabochons. Faceted goods are much rarer. The quality of their gems varies, though most of the goods are lower-end. The material ranges in color from light pink to deep red.
In December 2018, the first collection with Greenlandic rubies was launched by Hartmann’s Jewellery, a luxury brand based in Copenhagen. This strategic decision arose from the longstanding connection between Denmark and Greenland. The collection sold out in a matter of weeks. Hartmann’s clientele was drawn to the combination of the traditional ruby with an exciting new source that speaks to the imagination. Another aspect that appeals to consumers is the transparent supply chain. Greenlandic rubies are controlled by one company from the moment they leave the ground until the gemstones are finished. This ensures a level of traceability that is rarely seen in the colored stone industry.
Greenland Ruby works with preferred partners rather than selling goods directly to the public. These partners are jewelry brands that want access to a reliable supplier operating with a transparent supply chain, something many clients currently demand.
The Pink Polar Bear Foundation is Greenland Ruby’s corporate social responsibility project, which is involved in various research in the Arctic region covering the impact of climate change on local communities and wildlife. The foundation is currently educating locals and supporting the local community.
The mine currently has a projected life of 10 years. At least two other ruby deposits have been identified and studied, though many more can be found in southwestern Greenland. @chapter:18


Publication Year: - Title: Winter 2023 G&G Available Now Abstract: The Winter issue of Gems & Gemology is bursting with exciting new content! In addition to three feature articles, it offers a field report, a new inclusions chart, the latest installment of Colored Stones Unearthed, and as always, our regular quarterly sections.
TOPAZ FROM MASON COUNTY, TEXAS
A team led by Dr. Roy Bassoo reports on Texas topaz, covering the gem’s mining history in Mason County, followed by a study of its gemological and compositional characteristics. The authors also use machine learning and statistical modeling of trace element data from worldwide topaz sources to provide a basis for determining geographic provenance.
BOHEMIAN GARNETS AS DECORATIVE MATERIALS FOR GLASS VESSELS FROM THE LATE SIXTEENTH TO EARLY EIGHTEENTH CENTURIES
Dr. Karl Schmetzer and fellow authors research a method of setting cut garnets on glass objects, examining vessels at two museums in Germany. The article begins with the historical and legal context of the technique, invented by Claudius vom Creutz in Nuremberg circa 1591, followed by the results of their study.
A UNIQUE PETRIFIED TREE FERN FROM NORTHEAST CHINA
A petrified tree fern fossil from the Cretaceous period has drawn attention since its discovery in northeast China in 2010. Ying Yan and coauthors share their study of six samples displaying golden yellow to brown colors and distinct plant structure patterns, identifying chalcedony as the primary mineral component in the material.
SLOVAK OPAL: A NEW LIFE FOR A HISTORICAL GEM
This field report by Dr. Peter Semrád follows the resurgence of opal mining in Slovakia, which yields both precious and common varieties. Historical, geological, and mineralogical details are followed by accounts of recent mining and production based on the author’s visit to the locality and interviews with heads of the country’s two main opal producers.
MICRO-FEATURES OF BERYL CHART
Nathan Renfro, John Koivula, and coauthors add to the G&G series of micro-feature charts with this display of inclusions found in natural beryl. The wall chart, which presents 30 superb photomicrographs, is included in every printed copy of this issue, and a laminated version is available for sale in the GIA Store.

LAB NOTES
GIA’s global laboratory staff present their latest findings in the Lab Notes section, including a unique bicolor natural diamond exhibiting two distinctly different colors, a natural saltwater pearl containing a pair of foraminifera-like spheres, and a rare encounter with a large faceted orange-yellow sodalite.
MICRO-WORLD
The Micro-World section, which showcases the inner beauty of gemstones, features a stunning “sun spangle” in amber, a cross pattern visible in a natural diamond, remarkable hollandite crystals in a Brazilian amethyst, and more.
COLORED STONES UNEARTHED
Colored Stones Unearthed returns to explore the formation of sedimentary rocks, gems formed in sedimentary environments, and gems found in sedimentary environments that formed elsewhere. The column also covers the alluvial mining of these gems.
GEM NEWS INTERNATIONAL
Finally, Gem News International contributors report on a variety of topics, including a Vietnamese garnet displaying 14 trapiche patterns, an update on Virtu Gem’s ethical supply chain practices, and a summary of the fall 2023 auction season, which was marked by several surprising twists. @chapter:18


Publication Year: - Title: Fall 2020 G&G Available Now Abstract: This issue features a unique glimpse into the overwhelming majority of diamonds submitted to GIA: those on the D-to-Z color scale. It also includes a detailed study of emeralds from Pakistan, a fascinating historical look at auctions of gems and jewels of Europe’s royal families, analysis of a rare raindrop pattern in Chinese turquoise, and a firsthand account of shell nuclei production and pearl farming in Vietnam.
Natural-Color D-to-Z Diamonds: A Crystal-Clear Perspective
The lead article, by Sally Eaton-Magaña and co-authors, examines a large dataset of colorless to near-colorless diamonds from GIA’s 2017 intake. The statistical evaluation of grading quality factors and diamond type properties has never been presented in such comprehensive detail for natural-color D-to-Z diamonds.
Inclusion and Trace Element Characteristics of Emeralds from Swat Valley, Pakistan
Hongshu Guo and coauthors provide a detailed study characterizing the various properties and chemistry of emeralds from Swat Valley, Pakistan. The researchers analyze regular and trapiche-type emeralds separately and posit that their distinct properties can be useful for geographic origin determination.
A History of European Royal Jewel Sales, Including Sotheby’s 2018 Auction of Marie Antoinette’s Jewels
Russell Shor delivers a fascinating retrospective on the accumulation of gems and jewels by the most prominent European royal houses, culminating with Sotheby’s historic Bourbon-Parma auction in 2018. This remarkable sale garnered worldwide attention as 10 lots featuring items that once belonged to Marie Antoinette faced the auction gavel.
Unique Raindrop Pattern of Turquoise from Hubei, China
Hubei Province in China produces about 70% of the turquoise available in the Chinese gem market. Hubei turquoise possessing blue and blue-green spots resembling raindrops is very popular in China and very rare. Ling Liu and coauthors use an array of spectroscopic techniques to analyze the differences in the raindrops, veins, and substrates while identifying the formation mechanism of this unique pattern in turquoise.
Vietnam: Shell Nuclei, Pearl Hatcheries, and Pearl Farming
A team from GIA’s Bangkok laboratory was granted behind-the-scenes access to two pearl farms and a shell nucleus manufacturing factory in Vietnam. In this field report, Nicholas Sturman and coauthors detail how high-quality bead nuclei are produced from raw shell and subsequently used to culture pearls on a commercial scale.
Lab Notes
GIA laboratory staff members present their latest findings in the Lab Notes section, including “fire and ice” fluorescence in a novelty cut diamond, color-change cat’s-eye diaspore, the discovery of a 15.53 ct pearl in an edible oyster, and magnetite inclusions in star peridot.
Micro-World
The Micro-World section, dedicated to the inner world of gemstones, features several creatively manufactured inclusions, epigenetic residue mimicking an “egg,” a beautiful tuft of blue needles, and metal sulfide “tree” patterns, all found within their quartz hosts.
Gem News International
Finally, GNI correspondents from around the world report on bead cultured pearls embedded with near-field-communication technology, Maxixe beryl with an unusual violet color, oiled spinel, and an overview of the research presentations at the annual Geological Society of America meeting.
The Fall issue also contains the list of winners from the 2020 Gems & Gemology Challenge. @chapter:29


Publication Year: 2018 Title: Rex Guo: The Science and Art of Recutting Fine Gemstones Abstract: Figure 1. The Geometeer, a synthetic ruby cut in a hybrid Portuguese-brilliant design, is dedicated to Rex Guo's mathematics professor and mentor, Dr. Timothy Poston. Photo by Rex Guo.

Deciding how to cut a gemstone is inevitably one of the most difficult decisions when transforming a piece of rough into a fine faceted gem. The three main factors to consider are final carat weight, color, and light performance (a general term describing the brilliance and scintillation of a faceted stone). In most cases, optimizing one of these factors comes only by sacrificing something else. This is especially true for light performance, which often suffers at the expense of carat weight. The colored stone market has historically demanded that cutters produce goods with the highest possible weight in the finished stone. This often leads to cuts that are not designed to optimize light performance. In recent years, however, there has been an increasing demand in the high-end colored stone market for precision cuts and optimized light performance. This year at Tucson we had the chance to sit down with Rex Guo, whose Singapore-based Sutra Gems focuses on sourcing and systematically recutting faceted stones to unlock their inner beauty.

Guo is a self-taught gem cutter who came into this profession after spending 20 years working with computer graphics and video editing software. In 2015, he decided to take a sabbatical from software to pursue his passion for gemstones. The seed of his passion was planted during childhood, when he discovered an amethyst geode among a pile of sand in his schoolyard. This inspiration stuck with him and was fueled by years of formal engineering studies, which now serve as the backbone of his lapidary art. This technical foundation led to his realization in 2016 that optimizing the interaction of light with a faceted gemstone was exactly the sort of problem he had been working on for 20 years in 3D graphics software. Guo’s mathematical mentor, the late Professor Timothy “Geometeer” Poston, was the inspiration for one of his latest creations, currently featured in the Somewhere In The Rainbow exhibit at the University of Arizona Gem and Mineral Museum. The Geometeer (figure 1), dedicated to Poston, is a precision-cut synthetic ruby in an innovative hybrid brilliant-Portuguese cut designed with Guo’s proprietary gem design and optical simulation software, Axiom.

Rex Guo’s Gem Cutting JourneyRex Guo reflects on how his previous career as a software editor impacts his current work as a self-taught gem cutter who recuts faceted stones.
While Guo enjoys the privilege of cutting from fine gem rough, about 80% of his work is in recuts. Given the ever-increasing price of rough material, recutting provides an opportunity to work with very fine material that would otherwise be difficult to obtain. He starts with excruciatingly accurate measurements of the geometry of the original faceted stone. Every angle of every facet must be recorded for input into Axiom. This software allows him to experiment with many possible recut designs to see how changing any single facet will affect the appearance of the final stone. Guo works very closely with his clients in this stage of the process to ensure they are getting what they want out of the recut. There are multiple paths that can be taken. The stone can be recut with an emphasis on saving weight, or a bolder design can be chosen with better light performance to bring out the stone’s inner beauty, but with more significant weight loss. At this point Guo finds he has to walk a fine line between presenting himself as a master craftsman and as a scientist. While diagrams from his software are useful to show clients various options, he avoids coming across as overly technical so as not to detract from the emotional and romantic aspect of his craft. He quips, “Machines and software don’t understand beauty—humans do.”

Figure 2. Guo's light performance-optimized unheated blue sapphire. Photo by Rex Guo.
Guo is very much on a journey through the world of gemstone faceting. He started with round patterns, as most cutters do. Once he understood rounds, he moved on to optimizing trilliant and oval cuts. In the future, he plans to experiment with squares, rectangles, and more. The light performance–optimized cuts in which he specializes are best exhibited in high-RI materials. For this reason, he has set a minimum refractive index of 1.72 for stones he works with, a playing field that includes spinel, zircon, garnet, ruby, and sapphire (figure 2). Test cuts are often used before recutting important stones.

Spinels are one of his favorite stones to cut. The high RI and rich color of fine spinel produce stones that are “just divine.” Zircons are another favorite, as they have a much higher RI than most other natural stones. With such a cornucopia of gem materials in front of him, Rex Guo’s lapidary journey has just begun. @chapter:24


Publication Year: 2011 Title: A History of Diamonds through Philately: The Frank Friedman Collection Abstract: South African jeweler Frank Friedman’s collection of diamond-themed stamps and other postal material offers an illuminating visual record of diamond history. Comprising approximately 2,000 pieces, these items chronicle diamond formation, the history of mining and manufacturing, and the evolution of a science and an industry built around this remarkable gemstone. @chapter:28


Publication Year: - Title: Spring 2009 Gem News International Abstract: Tucson 2009
            New Play-of-Color Opal from Welo, Ethiopia
            Gem-Quality Rhodochrosite from China
GNI Regular Features
Colored Stones and Organic Materials
            Gem-Quality Amethyst from Tata, Morocco
            Anahí’s “New” Ametrine
            Azurite/Malachite from Sonora, Mexico
            Light Yellow-Green Grossular from Kenya
            Kornerupine (Prismatine) from Tanzania
            Transparent Labradorite from Ketchikan, Alaska
            Gem News from Myanmar
            Interesting Natural and Synthetic Spinels
            Zoisite from Afghanistan
Inclusions in Gems
            Australian Chrysoprase with Dendritic Inclusions
            Ankangite and Celsian Inclusions in Quartz from Brazil
            “Paraíba” Quartz with Copper Inclusions from Brazil
Synthetics and Simulants
            Artificial Glass Showing Color Change When Exposed to Light
            Some Unusual Dyed Imitations
Conference Reports
            International Kimberlite Conference

To view the full section, download the PDF above. @chapter:0


Publication Year: 2006 Title: Spring 2006 G&G Lab Notes Abstract: Unusual Multicolored Assembled Stone
Diamond with “Fingerprint” Inclusions
Pink Diamond with Etch Channels at the Intersections of Glide Planes
Two Diamonds from the Same Octahedron
Unusual Translucent Brown-Orange Diamond
Inscriptions inside Emerald Crystals
Color-Coated Star Quartz
Variscite, Resembling Turquoise

To view the full section, download the PDF above. @chapter:32


Publication Year: 2018 Title: Prismatic Rutile in Quartz Abstract: Figure 1. Left: Depending on the viewing angle, these two rutile crystals in rock crystal quartz seem to be touching each other. In the foreground is a black-silver prismatic crystal, and below on the right is a shadowed, fragmented piece, seen in diffuse/fiber-optic illumination. Right: The use of Rheinberg illumination gives warmer colors to the rutile crystals and the background. Photomicrographs by Jonathan Muyal; field of view 14.52 mm.
Rutile, a mineral composed mainly of titanium dioxide (TiO₂), is a common inclusion in quartz in the form of profuse acicular hair-like crystals (E.J. Gübelin and J.I. Koivula, Photoatlas of Inclusions in Gemstones, Vol. 1, ABC Edition, Zurich, 1986). These golden needle inclusions are appreciated as a pleasing feature, giving their name to the variety known as rutilated quartz.
However, prismatic single rutile crystal inclusions in quartz remain an underappreciated feature, often synonymous with “flaws.” They are rarely showcased by the lapidary. Nevertheless, we observed a 21.27 ct cushion-cut rock crystal quartz that displayed a large, well-formed rutile crystal inclusion (see above) under the table.
The protogenetic inclusion showed a black-silver color with adamantine to submetallic luster, a well-formed tetragonal (“stubby”/blocky) prismatic crystal habit with fine striation along its length (parallel to the c-axis), and smooth pyramidal termination faces. Cyclical twinning such as twin knee/sharply angled twins on [011] and parallel twinning crystal growth along the length were also observed (again, see above).
Very close below, in the background, was another rutile crystal inclusion, this one a fragmented piece. At first glance, it could be mistaken for part of the main crystal inclusion described above. Nevertheless, this rutile fragment adds details to the overall visual composition.
Rheinberg illumination (Fall 2015 Micro-World, pp. 328–329) using blue and yellow filters provided additional contrast. Lighting technique is critical in photomicrography. Here it dramatically enhanced the inclusion scene, offering alternative vibrant colors for aesthetic purposes.
This rock crystal quartz had preserved and beautifully highlighted a prismatic rutile crystal inclusion, like a collector mineral specimen in a display window. Such a large inclusion specimen also provides valuable mineralogical information for the gemologist. @chapter:19


Publication Year: 2022 Title: In Memoriam: Andrew Cody Abstract: Andrew Cody was one of Australia’s leading opal authorities and made numerous contributions to the industry. Photo by Tao Hsu.
Australian opal leader Andrew Cody (see above) passed away on September 12, 2022, at the age of 71. Internationally regarded as one of Australia’s foremost opal wholesalers, cutters, and exporters, Cody was instrumental in the establishment of opal as Australia’s national gemstone and the development of standard opal nomenclature.
Collecting fossils, gemstones, and minerals since the age of 12, Cody began cutting opal in 1964 after a class trip to the famous deposit at Coober Pedy. In 1971, at the age of 20, he established Cody Opal, a wholesale opal and gem cutting business, which later began exporting worldwide. Cody was the joint founder of the National Opal Collection, an Australian opal and opal jewelry supplier with showrooms and museums located in Sydney and Melbourne.
Over the course of his career, Cody served in a number of leadership positions, including president of the Australian Gem Industry Association and president of the International Colored Gemstone Association. He was awarded honorary fellowships from the Australian Gemmological Association and the Gemmological Association of Great Britain. Also an author, Cody published two books. Australian Precious Opal – A Guide Book for Professionals (1991) was followed by The Opal Story: A Guidebook (2010), written with his brother Damien and published in six languages.
For more than 50 years, Cody worked tirelessly to promote Australian opal across the global gem industry, leaving an enduring legacy. We extend our condolences to his family and friends. @chapter:18


Publication Year: 1991 Title: Emeralds of the Panjshir Valley, Afghanistan Abstract: With the withdrawal of Soviet troops from Afghanistan, villagers in the Panjshir Valley are turning their attention to the emerald riches of the nearby Hindu Kush Mountains. Large, dark green crystals have been found in the hundreds of tunnels and shafts dug there. Teams of miners use explosives and drills to remove the limestone that hosts the emerald-bearing quartz and ankerite veins. The gemological properties of Panjshir emeralds are consistent with those of emeralds from other localities; chemically, they are most similar to emeralds from the Muzo mine in Colombia. "Nodules," previously reported only in tourmaline and morganite, have been found in Panjshir emeralds as well. Approximately $10 million in emeralds were produced in 1990; future prospects are excellent. @chapter:0


Publication Year: - Title: Eunice Miles (1917–1997) Abstract: Shortly after Eunice Miles became the first female gemologist at GIA’s New York lab in 1953, two dealers brought in an important diamond they wanted “the boys” to see. After examining it under the microscope, the gentlemen invited Miles to take a look. She did—and immediately spotted a pinpoint inclusion they had missed. After that, she became known as the “Pinpoint Girl.”

Miles’s fascination with gemstones began early, when she played with her grandmother’s gem and mineral collection as a child. She studied geology in college during the 1930s and approached Dr. Edward Wigglesworth, then director of Boston’s New England Museum of Natural History and later head of GIA’s East Coast office, to learn more. Although women “simply were not accepted in the field,” as she recalled, Wigglesworth took her on as an assistant and taught her mineralogy and gem testing.

During the 1950s, Miles helped establish GIA’s reputation with the New York diamond trade, and clients came to recognize her initials on diamond grading reports. Identification became her area of expertise as the flow of diamonds to the lab increased. In response to sophisticated new diamond coatings, she developed an optical technique for detecting them with magnification. Miles was cited in the U.S. Department of Mines’ 1963 annual report for her work, and the Federal Bureau of Investigation later used her data to arrest a major dealer of fraudulently coated diamonds.

The Manhattan chapter of the GIA Alumni Association honored the pioneering “Grande Dame of Gemology” in 1989 when it created a scholarship in her name. @chapter:24


Publication Year: - Title: Kunzite Quality Factors Abstract: This kunzite crystal is accompanied by faceted kunzites ranging in weight from 12.47 to 19.32 carats. - Robert Weldon

                      Kunzite can be found in a wide variety of jewelry styles to suit every buyer. Always attractive, it suffers somewhat from a lack of consumer recognition. However, this can translate to reasonable prices at the counter. In its largest sizes and finest colors, kunzite appeals to discriminating collectors.

Color
Kunzite is the pink-to-violet variety of the mineral spodumene, and gets its color from manganese. It’s most often found in shades of pale pink, but more vivid colors are possible and it can achieve rare hues of vivid violet to purple.

	The color of kunzite can range from very pale to medium shades of pink and violet. In rare cases, kunzite is found in more intense hues. - Robert Weldon, courtesy Pala International
Kunzite’s color can be enhanced by irradiation followed by heating. Whether natural or enhanced, the color can fade when exposed to heat and intense light. It’s a good idea to store kunzite jewelry in a closed jewelry box or case when it’s not being worn.

	These kunzites show the gem’s lovely shades of pink. - Robert Weldon
Kunzite is pleochroic, which means it can display different colors in different crystal directions. Kunzite displays its best, most intense color down the length of its crystals.

	Kunzite’s color is most concentrated down the length of its crystal. This crystal from the Oceanview mine in Pala, California, displays a vivid purple. - Brendan Laurs
Clarity
Kunzite crystals often have relatively few inclusions, so “clean” finished gems in jewelry are common.

	This kunzite’s cut shows off its inclusion-free nature. - Robert Weldon

	The cutter of this kunzite made creative use of the needle-like inclusions by making them into a design element. - Orasa Weldon
Cut
Kunzite can present problems for cutters. It has two directions of cleavage, which means that the gem can split cleanly along those directions. As a result, kunzite has been known to simply fall apart from the pressure applied during faceting. In addition, kunzite’s color is usually concentrated down its length, or C-axis. Cutters must factor these properties into their plans when fashioning gems.

Kunzite appears in a wide variety of shapes and cutting styles. Because many crystals are relatively inclusion-free, step-cut stones are fairly common.

	This kunzite is a modified step cut. - Maha Tannous, courtesy Roland Reed

	This round kunzite displays a lovely, lively brilliant cut.
Skilled cutters have fashioned kunzite into every imaginable shape and style. Some have even carved the gem. Also, many kunzites are cut deep to maximize the color.

	These gems were carved by Dalan Hargrave. The gem in the center is a kunzite. The others are varieties of quartz: #2 is a citrine and #4 is an ametrine. - Eric Welch, courtesy Dalan Hargrave
Carat Weight
Kunzite is often found in large sizes. The Smithsonian Institution houses a faceted 880-carat heart-shaped example.

	This kunzite from Minas Gerais, Brazil, weighs 648.10 carats. It’s shown next to a dime to demonstrate scale. - Robert Weldon, courtesy M. Meienhalder @chapter:2


Publication Year: 2007 Title: Summer 2007 Gem News International Abstract: Diamonds
	            Bar Code Technology Applied to Diamonds
	            U.S. Supreme Court Ruling may Affect Viability of Some Diamond Cut Patents
Colored Stones and Organic Materials
	            First Discovery of Amazonite in Mexico
	            Astorite: A Rhodonite-Rich Rock from Colorado
	            Color-Change Bastnäsite-(Ce) from Pakistan
	            Citrine with Pyrite Inclusions
	            Unusual Danburite Pair
	            Fluorite from Ethiopia
	            Heliodor and Other Beryls from Connecticut
	            Cat’s-Eye K-Feldspar and other Chatoyant Gems from Tanzania
	            Green Opal
	            Chinese Akoya Cultured Pearls
	            Pyrope-Almandine from Tanzania
	            Pink-to-Red Tourmaline from Myanmar
Synthetics and Simulants
	            Glass Object with Circular Bands
	            Heat-Treated Kashan Flux-Grown Synthetic Ruby
	            Synthetic Star Sapphire with Hexagonal Features
	            Pink Synthetic Spinel Colored by Iron
	            A New Imitation of Imperial Topaz
Miscellaneous
	            KPMG Report Predicts Growth for the Global Jewelry Industry
Conference Reports
	            Sinkankas Symposium: The Jades
Announcements
	            New CIBJO Blue Book Available
	            AGTA Spectrum Awards Competition
Exhibits
	            Exhibits at the GIA Museum in Carlsbad
	            Gold at AMNH
	            Wine and Gems in Dijon
	            Jewelry of Ben Nighthorse
	            Gems! Colors of Light and Stone at the Bowers Museum

To view the full section, download the PDF above.

	DATA DEPOSITORY

Additional Figures
	Submitted by Laurent Massi
	July 30, 2007 @chapter:7


Publication Year: - Title: Update on Ametrine from the Yuruty Mine, Bolivia Abstract: This ametrine (6.46–35.59 ct) was recently mined from the Yuruty deposit in Bolivia. Photo by Robert Weldon.

              During the Tucson gem shows, Hugo Marancenbau (Steinmar Ltd., Santa Cruz, Bolivia) provided an update on ametrine from the Yuruty mine in Bolivia (see Summer 2000 Gem News, p. 163). This deposit was initially claimed in the mid-1990s and is located ~50 km north of the famous Anahí ametrine mine. Mining at Yuruty has been intermittent, although commercial production was resumed during the past two years. The deposit is exploited by ~100 people in underground workings consisting of a 90 m shaft and four horizontal tunnels up to 200 m long. The mine produces an average of ~40 tonnes/month of mixed-grade material, approximately 3% of which is facetable. Although Mr. Marancenbau’s company plans to sell the ametrine in the rough form only, they have test faceted a few thousand carats (weighing 3–30 ct each) that were sold at the JOGS show. He indicated that it was the first time ametrine from this mine was sold in Tucson.

Mr. Marancenbau kindly donated several rough and cut pieces of ametrine to the GIA Collection. The faceted stones (figure 2) contained varying amounts of purple and yellow, with a sharp color boundary visible face-up in one of the samples. None of them had the distinctive smoky layers seen previously in Yuruty material (see the Summer 2000 Gem News entry).

With several tonnes of rough material stockpiled and good reserves that are inferred to remain underground, the Yuruty deposit appears poised to become an important supplier of ametrine. @chapter:0


Publication Year: 1986 Title: The Elahera Gem Field in Central Sri Lanka Abstract: Commercially important quantities of gem-quality sapphire, spinel, garnet, chrysoberyl, zircon, tourmaline, and many other gemstones are being recovered from deep gem pits and surface excavations in the Elahera gem field, a region in central Sri Lanka about 115 km northeast of the capital city of Colombo. Large-scale mining is being conducted in this highly metamorphosed sedimentary deposit by the State Gem Corporation in collaboration with the private sector. The chemistry and gemological characteristics of these gem materials are discussed; in many instances, characteristic inclusions were identified by microscopy, microprobe analysis, and X-ray powder diffraction analysis. It is estimated that the Elahera gem field currently provides approximately 35% of the gemstones exported from Sri Lanka. The continued steady production of good-quality gems is anticipated for the future. @chapter:3


Publication Year: 2023 Title: Changing Preferences for Gold Jewelry in Bahrain. Abstract: Consumer preferences for jewelry in Bahrain have shifted from the modern-looking designs to traditional gold jewelry designs. According to a report from www.gulf-insider.com, the buying behavior for jewelry in Bahrain has changed significantly, leading jewelry stores to design more Arab-style jewelry to meet the increasing demand from the local market. This shift comes after the impact of COVID-19, where these jewelry stores primarily sold to foreign buyers residing in the country, mainly from Southeast Asian countries, especially before Bahrain started imposing a 5% value-added tax in December 2022, which was later increased to 10%.

Many jewelry stores, including renowned brands, have started targeting local Arab buyers more, as gold has become the latest investment trend among Bahrainis. Shaji C.K, the manager of Devji stores with multiple retail outlets in Bahrain, mentioned, "The decline in gold prices during the pandemic partly contributed to this shift, but our company's market remained stable as we focused on trading with local Bahrainis, including designing products in Arab style to meet the demand from customers who mostly buy gold for investment, especially when prices are low. Therefore, the demand for gold jewelry has increased following the changes in gold prices. Some of our branches have increased the design of Arab-style jewelry
Another jewelry trader commented that their company did not expect an increase in sales after the pandemic hit hard. However, it was fortunate that Bahrainis began to revert to buying gold, which helped boost jewelry sales. Furthermore, this trend also promoted the value of the jewelry business in Bahrain. In addition to the increasing demand for gold jewelry, there is also an opportunity for the expansion of silver jewelry in Bahrain. This view is supported by a report from the Department of Internal Trade and Foreign Trade under the Ministry of Industry, Commerce, and Tourism, which stated that there were more than 9.9 tons of gold jewelry certified with the Hallmark standard in the past year. This quantity is considered historically high and aligns with Shaikh Hamad bin Salman Al Khalifa, the Minister of Industry, Commerce, and Tourism, stating that in 2023, the quality certification for valuable metal jewelry and gold in Bahrain increased significantly under various measures to enhance the quality of valuable metal and gold jewelry in Bahrain. Additionally, as part of proactive measures, the ministry has sent officials to inspect more than 3,400 jewelry stores in the past two years, marking an expansion of 38%, to ensure compliance with Bahrain's regulations regarding the use of pearls and valuable metals. This effort aims to build consumer trust and elevate standards to international levels.
Bahrain is currently a potential producer and exporter of gold jewelry in the Middle East. The jewelry produced caters directly to the preferences and interests of people in the Middle East. However, Bahrain also imports jewelry such as pearls, gold, and diamonds from foreign countries for resale and incorporation into products. Key import sources for Bahrain in 2022 included the UAE, Switzerland, India, Italy, France, China, Thailand, and Hong Kong.

Significant buyers of jewelry in Bahrain include Saudi Arabians who prefer to travel for leisure, purchase goods, and use services in Bahrain, especially through the causeway bridge between Saudi Arabia and Bahrain. Currently, there is a VAT rate difference of 5%, which motivates people from Saudi Arabia to travel to Bahrain to shop. In 2023, Thailand exported jewelry worth a total of 790 million Baht to Bahrain, marking a 282% increase compared to the previous year. The highest exported products from Thailand to Bahrain in this category were genuine jewelry, with a value of 785 million Baht, accounting for 99%. Other products included loose gems and decorative gemstone jewelry, albeit in smaller values. @chapter:27


Publication Year: - Title: Ekati + Diavik = A Revived CanadaMark Abstract: An aerial view of the Ekati diamond mine. Photo courtesy of Dominion Diamond Corp.

                      Sometime soon a celebrity may be posing for the paparazzi wearing suites of diamond jewelry hallmarked “Mined in Canada.” The merging of the two largest Canadian diamond mines has given the new owner, Dominion Diamond Corporation, the opportunity to relaunch and expand globally the CanadaMark, which was originally a brand commissioned by Rio Tinto for locally polished diamonds from its Diavik mine.

Dominion is no stranger to brands. The company owned a majority interest in Harry Winston, the jeweler synonymous with mega-diamonds, and carried its name for more than six years; it also owned a 40% stake in the Diavik mine. The company sold the Winston luxury stores and watch brand to Swatch Group of Switzerland for $750 million in 2013, changed its name to Dominion Diamond Corporation and acquired the Ekati mine from BHP Billiton later that year. The price was $553 million, leaving the company with nearly $200 million in surplus cash.

“We were always very keen to take over Ekati,” said James Pounds, president of Dominion Diamond. “The acquisition of Ekati provided the opportunity to revive a Canadian hallmark,” he added, noting that the combination of the two mines will produce sufficient quantities of “eligible” goods to sustain such a program.

James Pounds, president of Dominion Diamond Corp said the merger of the two largest Canadian mines offers an excellent opportunity to revive the CanadaMark brand. Photo by Russell Shor.
The CanadaMark will be used on polished diamonds with a cut grade of Very Good or above, L color or higher and I2 clarity or higher. The clarity range is lower because demand for I2 goods is growing, said Pounds. About 20% of both mines’ total production would polish out to such goods.
Dominion is just beginning a test marketing campaign for CanadaMark, but Pounds is confident the demand will be there.

“We’ve done our research. Consumers today have a growing awareness of the origins of their diamonds, so our brand can offer them the assurance of responsibly sourced, fully audited chain of custody,” he said.

The amount of cooperative advertising funds that will be available and which celebrity will carry the CanadaMark is still under consideration, Pounds said.

Previous attempts to establish a Canadian diamond brand were difficult because all of the larger mines were in the hands of different producers. Although there was no specific requirement that the diamonds be polished in the Northwest Territories, BHP did develop CanadaMark in tandem with efforts to start manufacturing there. Most cutting operations closed after a few years, however, because the high costs were not competitive with other diamond centers.

Approved manufacturers of CanadaMark diamonds are based in India, Canada and Belgium and have agreed to maintain the audited chain of custody. These operations, appointed by Dominion, are able to produce CanadaMark diamonds, assuring their provenance and origin at a competitive price, Pounds noted.

Ekati, commissioned in 1998, was Canada’s first diamond mine. Its discovery seven years earlier touched off a diamond rush not seen since the gaudy days of South Africa’s boom of the 1870s. This time, the prospectors flew aircraft with specially equipped sensors to detect potential kimberlites. BHP Billiton, which acquired a majority interest in Ekati, also staked claims to a number of kimberlites in the surrounding area.

At least one of the pipes will secure the future of Ekati for some years to come; mining at the original pipes, Misery and Koala, will likely end in 2019. Mining at the Fox pipe ended earlier this year because the costs of redeveloping it as an underground operation were too high. The large Jay pipe, however, has yet to be developed. Its production consists of mainly smaller stones, but is fairly rich at approximately two carats per ton. Jay, which lies under a shallow lake, could extend the life of the mine for another 10 to 20 years, Pounds said.

Diavik, discovered by Aber Resources during the mid-1990s diamond rush, started production in 2003 with a 40-60 partnership between Aber and Rio Tinto. Aber later acquired Harry Winston and took on the name of the New York–based retailer.

Pounds thinks there are eight to 10 years of production remaining from Diavik’s three main pipes. The mine transitioned to all-underground operation in 2012. One pipe, A-21, has yet to be developed.

BHP shook up the rough diamond market six years ago by becoming the first major producer to sell its production (from Ekati) by auction instead of selling at set prices by the “sight” system of set-price contracts. But as Pounds noted, Dominion has gone back to the sight system to ensure consistency of supply.

“Supply consistency is very important,” he said. “Manufacturers have to know what they are getting.” Accurate pricing is also important, he added, so Dominion will continue to auction a portion of its production every six months to accurately gauge market price levels.

Analysts expect Dominion sales to top $800 million this year, up about 6% from 2013’s total of $751.9 million, due mainly to increased volume, not price increases. @chapter:38


Publication Year: 2016 Title: Sphalerite Inclusions in Namibian Demantoid Abstract: Figure 1. A brownish orange sphalerite inclusion in Namibian demantoid with a spheroidal diopside aggregate along its upper left side. Based on its morphology, the rhombohedral crystal on the upper right could be a calcite inclusion. Photomicrograph by Aaron Palke; field of view 0.72 mm.

The inclusion scene of skarn-related demantoid garnets from Namibia and Madagascar is dramatically different from that of serpentinite-hosted demantoid found in the classic locality of the Russian Urals. Reported inclusions in Namibian demantoid include diopside, wollastonite, quartz, calcite, fluid inclusions, and sphalerite (F. Koller et al., “The demantoid garnets of the Green Dragon mine (Tubussi, Erongo Region, Namibia),” Joint 5th Mineral Sciences in the Carpathians Conference and 3rd Central-European Mineralogical Conference, April 19–21, Miskolc, Hungary, 2012). Demantoid from Madagascar is reported to contain inclusions of diopside, wollastonite, fluid inclusions, and growth tubes (F. Pezzotta et al., “Demantoid and topazolite from Antetezambato, northern Madagascar: Review and new data,” Spring 2011 G&G, pp. 2–14). There has been little photomicrographic documentation of these inclusion suites, however.

In this contribution we document relatively rare sphalerite inclusions in a Namibian demantoid crystal. Figure 1 shows a translucent brownish orange sphalerite inclusion with a spheroidal diopside aggregate adhering to it (both identified by Raman spectroscopy). While a clear Raman signal could not be obtained on a nearby crystal, its rhombohedral morphology leads the author to speculate that it is a calcite inclusion. The two sphalerite inclusions seen in figure 2 are larger, so their color is a much darker orangy brown. The oblique fiber-optic illumination used in this photo highlights the highly lustrous surface of these sphalerite inclusions. Further photomicrographic documentation of the inclusion suites in demantoid from Namibia and Madagascar may help to identify inclusion scenes unique to these skarn deposits.

Figure 2. Oblique fiber-optic light illuminates the surface luster of these sphalerite crystals within a Namibian demantoid. Photomicrograph by Aaron Palke; field of view 0.84 mm. @chapter:5


Publication Year: 2015 Title: Exhibition Review: Glitterati: Portraits and Jewelry from Colonial Latin America Abstract: Figure 1. Tiara, Colombia or Ecuador, circa 1690. Silver gilt, emeralds, and pearls. Denver Art Museum, Gift of Robert J. Stroessner; 1992.74

In Glitterati: Portraits and Jewelry from Colonial Latin America, the Denver Art Museum (DAM) displays jewelry and portraiture, as well as furniture and other personal objects (figure 1), that reflect personal adornment traditions in all classes and walks of life during the Spanish colonization period in Mexico and South America (1521–1800). Various indigenous tribes have a long tradition of metalworking, and the land is abundant in natural resources. Gold and silver, along with emeralds and diamonds and organic materials such as pearls and coral, are plentiful in the regions covered by the exhibition. The fusion of old and new is a major theme of the exhibition and is expressed through materials, techniques, and design. The talents of the native people and the European jewelers meshed, resulting in glorious creations such as the ones on display.

The exhibit, from the DAM’s Spanish Colonial collection, features a wall of 19th century portraits of Incan rulers from Peru. The rulers use lovely stamped stickpins, called tupu, with flat, round heads to fasten their cloaks; two of these pins are on display nearby. The hammered gold of the pins uses a stamped and chased design to draw out themes of the sun and heavens on these lovely ornaments. A beautiful gold filigree crucifix filial, dating from the 17th century (figure 2), features cabochon emeralds. Close examination reveals tool marks indicating that these gems were recycled from other, older jewelry, perhaps from the pre-Columbian era. The stone’s rough cabochon shaping contrasts with the delicate metalwork. Filigree has roots in both the Spanish and regional cultures, and is used to great effect in this piece.

Figure 2. Cross finial, Colombia or Ecuador, circa 1600. Gold, emeralds, pearls. Denver
Art Museum, Gift of the Stapleton Foundation of Latin American Colonial Art made possible
by the Renchard family; 1990.526.
Pearls and coral are present in almost every piece shown. Records from Columbus’ landing in present-day Venezuela in 1498 indicate that the native women were adorned in pearl and coral beads. Nueva Cadiz was settled in part because of the rich pearl beds nearby. Pearls and coral were available to all members of this society. This is demonstrated in Manuel de Arrellano’s portrait “Rendering of a Mulatto,” which depicts a woman of African and Spanish descent draped in pearls (including a six-strand necklace), earrings and coral rings. These materials were still sought by the upper class, and the intricate tiara in figure 1, with its lustrous white pearls and large, angular emeralds in an intricate gilt setting, is testimony to this.  Even the clergy wore status symbols; priests wore rosaries, badges and rings, not to mention the richly chased silver and silver plate used to glorify God during mass. A collection of handpainted nuns’ badges, worn as brooches by women who devoted themselves to Christ, feature saints and the Virgin Mary. Not all pieces were so opulent, and you can also see examples of the blue glass beads that were brought to South America by the Spanish. In fact, the Philippine trade ships that brought new exotic gemstones and ivory also carried paste stones and other materials for the equivalent of modern-day costume jewelry.

Figure 3. Diego de Borgraf, Portrait of Saint Catherine of Alexandria (detail), Mexico, 1656.
Oil on canvas. Denver Art Museum, Gift of Frederick and Jan Mayer; 2011.426.
Portraiture featuring members of the upper class makes up a large portion of the exhibit. Intended to display the sitter at the height of their finery, military medals and heraldic symbols decorate the men while the woman drip with diamonds, pearls, and other precious gems set in tiaras, brooches, bracelets, rings, and necklaces.  Even religious figures were not exempt; St. Catherine of Alexandria, seen in figure 3, is shown with a gold and pearl diadem, drop earrings, ruby shoulder clips and a large ruby brooch, as well as the pearls sewn to her neckline. Much of the jewelry follows the European fashions of the time, including trends of the courts. Aside from these surface implications, it is fascinating to see how many of the artists used primary colors and simple dabs of gold, silver, and white highlights capture the sparkle and richness of the stones. While the exhibit could draw more parallels between the art of the native people and the society that developed after colonization, on the whole it is a glimpse into the opulent costuming traditions of the time.

Glitteratti: Portraits and Jewelry from Colonial Latin America will be on display through November 22nd, 2016, on the fifth floor of the Denver Art Museum, in the Spanish Colonial collection. Admission is included in the $10 fee for nonmember Colorado residents ($8 for seniors and college students). The museum is open 10 to 5 Saturday through Thursday, and 10 to 8 on Fridays. @chapter:21


Publication Year: 2013 Title: Black Diamond with Unusual Color Origin Abstract: Figure 1. A face-up view of the black diamond. Photo by Robison McMurtry.

              A 1.75 ct Fancy black round brilliant diamond (figure 1) was submitted to the Carlsbad laboratory for color origin determination. Natural black diamonds are usually colored by inclusions of sulfides, graphite or other mineral inclusions or, in rare cases, hydrogen-related clouds thatextend throughout the stone. Treated black diamonds are generally heavily fractured stones that are subjected to high-temperature, low-pressure treatment, which graphitizes the fractures, turning them black. Artificial irradiation can also produce a dark enough color so as to appear black, but this is less common (H. Kitawaki, “Gem diamonds: Causes and colors,” New Diamond and Frontier Carbon Technology, Vol. 17, No. 3, 2007, pp. 119–126).

Upon initial examination, the stone was noted to be covered in large, deeply penetrating fractures; therefore, high-pressure, low-temperature treatment was suspected. Yet closer examination revealed that the fractures were surrounded by dark brown radiation stains. Patches of non-fractured surface on the pavilion showed the normal transparency of diamond, causing the radiation staining to stand out in relief. Because radiation stains in diamond are inert to short-wave ultraviolet light, we placed the stone in a DTC DiamondView to confirm their identity. Figure 2 shows numerous fractures surrounded by dark bands, which are the radiation stains.

	Figure 2. A DiamondView image showing the pattern of inert radiation stains following the fractures in the stone. Image by Troy Ardon.

	Figure 3. This image of the pavilion shows the patchwork nature of the radiation staining. Photomicrograph by Troy Ardon; magnified 55×.
Natural radiation stains provide an important clue to the color origin of a diamond. Diamonds that have been naturally colored by radiation can have stains associated with that color, though this is not a definitive criterion. In this case, the stains are so numerous and thick that they cause the diamond color. A close-up view of the pavilion (figure 3) shows the relative transparency of the diamond contrasted with the highly saturated color of the radiation staining of the fractures. The coverage of the stains is so complete that only a few transparent areas canbe seen in the face-up view. Some of the color was due to the presence of small black inclusions, but most was due solely to the natural radiation stains, an unusual cause of color. @chapter:11


Publication Year: 1998 Title: Summer 1998 G&G Lab Notes Abstract: Calcite Colored by Inclusions
Diffusion Treated Corundum
Diamond Colored by Pink Coating
Diamond with Different Color Appearances Depending on Viewing Position
Manufactured Glass Represented as “Green Obsidian”
Cultured Pearls with Dolomite Beads
Cultured Pearls with Treated Black Color
Quartzite Dyed to Imitate Sugilite
An Unusual Sapphirine

To view the full section, download the PDF above. @chapter:17


Publication Year: - Title: Titanium-Coated Tanzanite Abstract: These five tanzanite samples (0.39–0.82 ct) proved to be color-coated with titanium. Photo by Don Mengason.

                      Five faceted violetish blue stones, ranging from 0.39 to 0.82 ct (figure 1), were recently submitted to the Carlsbad laboratory for identification service. Standard gemological testing revealed a refractive index of 1.689–1.70 for all five samples. When observed using polarized light, each displayed a medium pleochroism. Specific gravity, measured using the hydrostatic method, was 3.37. These properties were consistent with tanzanite.

	Figure 2. This upper portion of a pavilion facet, examined in reflected light, shows a much higher luster than the lower, uncoated portion. Photomicrograph by Nathan Renfro; field of view 1.22 mm.
Microscopic examination showed that the material was relatively free of inclusions, but showed areas of abrasion along pavilion facet junctions. Observed using reflected light, the pavilion of each stone showed a significantly higher luster than the crown. Some individual facets even showed a variation in luster due to an incomplete distribution of the color coating (figure 2). When the samples were examined using diffuse transmitted light, the facet junctions and several chipped spots appeared much less saturated, which was consistent with a color coating (figure 3).

	Figure 3. The coating on this tanzanite’s pavilion has been worn away along the facet junctions and in some small chipped areas, revealing the less-saturated violet color of the tanzanite underneath. Photomicrograph by Nathan Renfro; field of view 2.90 mm.
Because tanzanite with a cobalt coating has previously been reported, all tanzanites submitted to the lab are routinely checked by energy-dispersive X-ray fluorescence (EDXRF) and microscopic examination. These five stones were also checked by EDXRF, but no cobalt was detected; however, all five showed a significant signal for titanium on their pavilions. No titanium was detected on the crowns. LA-ICP-MS was also used to confirm that the coated area contained significant titanium.

While color-enhancing coatings on tanzanite are occasionally seen at GIA’s laboratory, this is the first time we have examined tanzanite that has been color coated with titanium. @chapter:4


Publication Year: 2016 Title: “Punsiri”-type FTIR Spectral Features in Natural Yellow Sapphires Abstract: Figure 1. Ten of the 38 basalt-related yellow sapphires from this study. The specimens on the left, weighing 0.22–0.41 ct, are from the Anakie area in Queensland, Australia. The material on the right, ranging from 0.41 to 1.40 ct, comes from the Khao Ploi Waen area of Chanthaburi, Thailand. Photo by Nuttapol Kitdee.

	Recently, a yellow sapphire from Chanthaburi, Thailand, showed a spectrum associated with “Punsiri” high-temperature heat treatment of blue sapphire. In response, GIA’s Bangkok lab performed FTIR spectroscopy on 38 untreated natural basalt-related yellow sapphires (figure 1). Twenty-two of the samples were from the Anakie Gem Fields area in Queensland, Australia, and the remaining 16 from the Khao Ploi Waen area of Chanthaburi. All were collected from the mines by GIA field gemologists.

	Standard gemological testing of the Australian sapphires showed RI (nω) = 1.774 ± 0.001 and RI (ne) = 1.765 ± 0.001, with a birefringence of 0.009 ± 0.001. For the Thai sapphires, RI (nω) = 1.773 ± 0.001 and RI (ne) = 1.764 ± 0.001, with a birefringence of 0.009 ± 0.001. All the stones were inert under long-wave and short-wave UV radiation due to their very high iron content.

	Most of the Australian sapphires were yellow, whereas the Thai sapphires appeared greenish yellow. Only homogeneous yellow areas were analyzed by FTIR. Many of the stones (about 45% of the Australian stones and about 38% of the Thai stones) showed a characteristic Punsiri FTIR spectrum, consisting of a multiple band structure positioned around 2000−3300 cm−1 with peaks at 2025, 2137, 2258, 2413, 2463, 2627, 2990, 3032, and 3220 cm−1 (figure 2). These features have traditionally been considered indicative of heat treatment, since this pattern has only been observed in Punsiri-type heated blue sapphires (G. DuToit et al., “Beryllium treated blue sapphires: continuing market observations and update including the emergence of larger size stones,” GIA Research News, June 2009) that display multiband FTIR spectra around 3000 cm−1. This FTIR feature is attributed to the stretching vibration of the OH bond formed by the incorporation of hydrogen and host oxide ion in a publication about “magnesium-doped α-alumina” grown by the Verneuil method, where the IR absorption results are affected by the incorporation of hydrogen into a Mg-doped α-alumina (N. Fukatsu et al., “Incorporation of hydrogen into magnesium-doped α-alumina,” Solid State Ionics, Vol. 162, 2003, pp. 147−159). Since the samples were all collected in the field, it is extremely interesting to document that Punsiri-type FTIR spectra may be found in natural unheated yellow sapphires.

	Figure 2. FTIR spectra of natural yellow sapphires from Australia and Thailand in the 1800–3600 cm–1 range. The peaks shown here are similar to those observed in Punsiri heat-treated blue sapphire (black spectrum). Peaks at 2360 and 2340 cm–1 are related to CO2. Please note that the absorption coefficient of the Punsiri heat-treated blue sapphire (black spectrum) at the y-axis was divided by two.

	LA-ICP-MS showed trace elements of Mg, Ti, V, and Ga, with very high ppm levels of Fe (3000 ppma on average). Mg content (about 23 ppma) was higher than Ti content (approximately 16 ppma); thus, blue coloration is not seen in these stones. Since Be was not detected, there are no concerns about beryllium diffusion treatment, which is not surprising since these specimens were collected in the field.

	It appears as though the incorporation of hydrogen in corundum may form characteristic Punsiri-like FTIR features. Since these features were observed in natural basalt-related yellow sapphires from Australia and Thailand, careful consideration must be exercised when using FTIR to identify heat treatment in corundum. @chapter:12


Publication Year: 2020 Title: A Fossilized Shell Blister and Blister Pearl Abstract: Figure 1. Two fossilized specimens, a shell blister (left) and a blister pearl (right), both with their associated shell. Photo by Sood Oil (Judy) Chia; courtesy of Gina Latendresse, American Pearl Company, Inc.

Fossils are the remains or impressions of prehistoric organisms preserved from past geological ages. Some of the most common fossils are shells of various marine mollusks and, occasionally, their associated pearls (Winter 2015 Lab Notes, pp. 432–434). Recently two interesting fossilized specimens were studied by staff of GIA’s New York laboratory. One resembled a shell blister and the other a blister pearl, both with associated shell (figure 1).

Figure 2. Left: Clear striations are visible on the back of the shell blister (measuring approximately 24.4 × 18.6 × 6.5 mm). Photo by Sood Oil (Judy) Chia. Center: Cellular crystal growth patterns are evident on the back of the shell blister. Right: Columnar growth structures are prominent with the cross section of the shell fragment. Photomicrographs by Chunhui Zhou (center and right).
The smaller sample appeared to be a shell fragment measuring approximately 24.4 × 18.6 × 6.5 mm and weighing 12.62 ct. The back of the shell showed even striations and a cellular crystal growth pattern, while the cross section showed a columnar structure (figure 2). A shallow “bump” noted on the face side could be best described as a shell blister, according to a recent study (“Natural shell blisters and blister pearls: What’s the difference?” GIA Research News, https://www.gia.edu/gia-news-research/natural-shell-blisters-and-blister-pearls). No additional information was provided about this specimen.

Figure 3. A near-round blister pearl seen lightly attached to its host shell. Photo by Sood Oil (Judy) Chia.

Figure 4. Map of North America highlighting the shallow inland seaways present during the mid-Cretaceous period. The arrow indicates the present-day state of Kansas. © Colorado Plateau Geosystems Inc.
The second sample measured approximately 37 × 25 mm and weighed 32.63 ct. Its form resembled a concave shell fragment, and a near-round blister pearl was clearly attached to its inner surface (figure 3). According to our source, this specimen was found in Ellis County, Kansas, and formed within an Inoceramus mollusk genus (an extinct marine bivalve resembling the related winged pearly oysters of the extant genus Pteria). Fossils of the Inoceramus are commonly found in the Pierre Shale of the Western Interior Seaway in North America, where the state of Kansas lies today (figure 4). The specimen is reportedly estimated to be as much as 86 million years old.
EDXRF analysis detected low concentrations of manganese and high concentrations of strontium, typical of marine mollusks. Iron was also detected in both specimens, probably introduced through infiltration from the surrounding environment over millions of years. Microradiography did not reveal any clear internal growth structures. These two intriguing specimens created by Mother Nature and preserved by her until their discovery provide unique insights into ancient mollusks and their associated pearl or pearl-like companions. @chapter:14


Publication Year: - Title: From Brazil to China: The Journey of Rubellite Tourmaline Abstract: After witnessing the mining of rubellite tourmaline at the Cruzeiro mine in Brazil, our representative was able to visit the factory in China where the mine’s stones are cut. Photo by Andrew Lucas/GIA, courtesy Cruzeiro mine.

                      In April 2014, a team from GIA traveled to Brazil to document some of the country’s most important emerald and tourmaline mines. One of the mines the group visited was the Cruzeiro, owned by Nevestones, a family company. The Cruzeiro is a prolific Brazilian tourmaline mine that produces about eight tons of tourmaline each year, 20 percent of which is rubellite.

	Cutting in China

	This video takes you through the cutting factory and headquarters of a company that fashions large quantities of tourmaline and other colored gemstones for China and the global market. You’ll also witness the creation of a faceted colored stone.
In June 2014, a member of the GIA team, Andrew Lucas, traveled to Asia to attend Gemfields’ first Mozambique ruby auction in Singapore and to teach a two-week GIA law enforcement gemology seminar in Hong Kong. While there, he visited the Hong Kong office and Shenzhen factory where Cruzeiro’s rubellite is fashioned and distributed to the market.

	The Miranda Group
Our representative’s documentation of the journey of rubellite tourmaline from Brazil to China began at the Hong Kong office of Miranda Group Co. Ltd. There, he interviewed Miranda Costa, a co-founder of the company. They spoke in detail about his experience in the market and the connection between Brazil’s rubellite tourmaline and the Chinese market. Mr. Costa had been a partner in Miranda Gem Hong Kong between 2005 and 2009. When that company closed in 2009, Mr. Costa co-founded Miranda Group Co. Ltd.

Miranda Costa of Miranda Group Co. Ltd. examines parcels of rubellite that were cut at the company’s factory in Shenzhen. Photo by Andrew Lucas/GIA, courtesy Miranda Group Co. Ltd.
The Miranda Group started working with rubellite in 2010 and entered into a joint venture with KGK, a global diamond, colored stone, and jewelry wholesaler, to acquire and market rubellite in China. At that time, the Miranda Group was buying rubellite from Africa. In 2011, they started working with the Cruzeiro mine and its owners, the Neves family.

	The Business Model
Today, the Cruzeiro mine, the Miranda Group, and KGK work together to bring Brazil’s rubellite tourmaline to the market in China. The Cruzeiro mine provides the rough rubellite to the Miranda Group, which cuts the material. The rough crystals are sliced or sawn in the Miranda Group office in Hong Kong, and then faceted and polished at the factory in Shenzhen, China. The stones then go to KGK’s factory and offices in Panyu, China.

KGK markets and sells the cut stones and also mounts cut stones into jewelry for sale, primarily in China. The Cruzeiro mine also cuts its own facet-grade green and blue tourmaline in Brazil and produces bicolor and multicolor tourmaline, which the Miranda Group has been cutting and stockpiling.

Rubellite rough is sawn at Miranda Group Co. Ltd. facilities in Hong Kong before being sent to the factory in Shenzhen for preforming and faceting. Photo by Andrew Lucas/GIA, courtesy Miranda Group Co. Ltd.
The Miranda Group can cut about 25,000 to 30,000 carats a month at their factory in Shenzhen. They then provide the cut stones to KGK. The Miranda Group also works with bicolor tourmaline, aquamarine, morganite, emerald, and Mozambique ruby. They cut these materials and work with KGK to sell primarily to the Chinese market. They also deal in Mozambique copper-bearing tourmaline and Brazilian Paraíba tourmaline which, in cooperation with KGK, they will supply to the market in 2015.

The factory in Shenzhen was cutting tourmaline as well as morganite during the visit. Photo by Andrew Lucas/GIA, courtesy Miranda Group Co. Ltd.

After cutting a parcel of rubellite, the factory turned to cutting morganite, which has been growing in popularity in China. This rough morganite crystal is being sawn as part of the process. Photo by Andrew Lucas/GIA, courtesy Miranda Group Co. Ltd.

	Interview with Miranda Costa

	Fashioned Rubellite Production
The Miranda Group needs to receive 100 kilos of rough rubellite a month to meet its production goal of 25,000 to 30,000 carats. They promote more-included material for beads and carvings. The company’s goals for facet-grade material are to produce clean stones that meet the requirements of the high-end Chinese market.

Maintaining quality cutting procedures, resulting in clean stones, is of optimum concern in the factory. Photo by Andrew Lucas/GIA, courtesy Miranda Group Co. Ltd.
In the United States, the Miranda Group plans to market gems of three carats or smaller, to meet what they feel is the right price point for that market. In China, there is a ready market for sizes over three carats, including very large sizes of 100 carats or more.

Miranda Costa estimates that the demand from the Chinese market has caused the price of rubellite tourmaline to double over the last three years. Even though there is current resistance to the high prices, the company still finds it difficult to meet the demand for fine-quality faceted stones, so he thinks there is still room for price increases.

At the Miranda Group Co. Ltd. office in Hong Kong, parcels of fine-color, clean rubellites in large sizes were being sorted for delivery to KGK. Photo by Andrew Lucas/GIA, courtesy Miranda Group Co. Ltd.
For high-end consumers, the rubellite needs to be well proportioned, bright, and clean, and have fine color. Because these qualities are essential, the Miranda Group only gets about 12 percent weight retention from the rough.

The faceting equipment was optimized for precision and speed. Some machines use a two-wheel set-up that cuts the facets and then polishes them without a need for stopping and changing wheels. Photo by Andrew Lucas/GIA, courtesy Miranda Group Co. Ltd.
Since many of the crystals from the Cruzeiro mine are bicolor or multicolored, the Miranda Group also cuts that material. Many of the tourmaline crystals from Cruzeiro are zoned with black, green, and rubellite colors. The Miranda Group has been cutting and accumulating green-and-rubellite material over the last two years, so they have about 80,000 to 100,000 carats in stock now. They plan on marketing it in the US and China in the near future.

The Miranda Group obtains green-and-rubellite bicolor tourmaline rough for cutting. Photo by Andrew Lucas/GIA, courtesy Miranda Group Co. Ltd.

The Miranda Group is stockpiling inventory to launch a marketing campaign with KGK for bicolor tourmaline. Photo by Andrew Lucas/GIA, courtesy Miranda Group Co. Ltd.
Comparing Brazilian rubellite tourmaline rough to the material Miranda Costa used to get from Nigeria, he finds the Cruzeiro material to be cleaner, with better crystallization and more even color.  Mr. Costa sees much less Nigerian material on the market today, and the prices are much higher than when the company was buying large quantities in 2010.

Brazilian rough can yield fine-color, clean, bright, and good-sized stones. However, to meet those standards, the weight loss is high, saving only an average of 12 percent of the rough weight. Photo by Andrew Lucas/GIA, courtesy Miranda Group Co. Ltd.

	Completing the Journey
Visiting a mining operation and witnessing the challenges involved in bringing colored gemstones out of the earth gives you a sense of perspective on how rare and valuable they really are. It’s exhilarating to observe the production at a prolific mine like the Cruzeiro, where impressive crystals come right out of the ground in large quantities. It’s also satisfying to complete the journey by seeing the rough crystals turned into beautiful faceted stones. Finally, seeing the ferocious and increasing appetite of a consuming country for the material puts the relationship between supply and demand perfectly in perspective. @chapter:18


Publication Year: 2020 Title: Black Star Sapphire with Dual Treatments Abstract: Figure 1. The 75 ct black star sapphire that was brought in for testing. Photo by Wimon Manorotkul.

Black star sapphires primarily come from Kenya, Australia, and Thailand. Unlike other star sapphires and rubies, the asterism in these stones generally results from the exsolution of ilmenite (FeTiO3) and/or hematite (α-Fe2O3) instead of rutile (TiO2). Rutile and ilmenite/hematite exsolve in different directions: rutile along the second-order hexagonal prism {112̅0} and ilmenite along the first-order hexagonal prism {101̅0}. If both are present in the same stone, a 12-ray star results. The ilmenite/hematite crystals are far more “platy,” and thus their layers tend to form planes of weakness. Breakage along those planes is termed parting. Parting differs from cleavage in that it results from structural planes of weakness due to imperfect growth rather than inherent weakness. There are often two different parting planes in the stones. One corresponds to the exsolution of ilmenite/hematite in the plane of the basal pinacoid {0001}. The other corresponds to planes of exsolved boehmite/diaspore along the rhombohedron {101̅1}.
In Thailand, one often sees cavities on the back of black star sapphires filled in with brown dopping varnish. It is only the basal parting that comes into play with black star sapphires, because the exsolved hematite that causes the lack of adhesion is only in the basal plane. It is because of this parting that the stones get filled with dopping varnish, to conceal large holes in the base. Note that the type of dopping varnish is of a color that matches the stone.

Figure 2. Left: Two large pits on the base of the star sapphire contain brown dopping varnish (the white areas are adhesive from tape). Field of view 30 mm. Right: Under long-wave ultraviolet light (365 nm), the dopping shellac fluoresced bright orange. Field of view 27 mm. Photomicrographs by Richard W. Hughes.
In May 2020, a client submitted a large 75 ct black star sapphire for testing (figure 1). The base of the stone contained two large pits filled with brown dopping shellac (figure 12, left). Interestingly enough, the shellac fluoresced bright orange under long-wave ultraviolet light (365 nm) (figure 2, right). Following the client’s approval, we removed the shellac with alcohol and noticed a curved area exhibiting an unusual flow-like structure that looked suspiciously like glass. Unfortunately, attempting to get a Raman spectrum on the area was unsuccessful.

Figure 3. A close-up view of the shellac in the lower pit revealed trapped gas bubbles and black debris. Photomicrograph by Richard W. Hughes; field of view 5 mm.
Careful microscopic examination showed what looked like gas bubbles trapped between the glassy material and the sapphire below (figure 3). Scratching the surface of the cavity with a number 7 hardness point confirmed that the area could not be corundum. Immersing the gem in methylene iodide showed the glassy area to cover roughly two-thirds of the base of the cabochon (figure 4). Energy-dispersive x-ray fluorescence (EDXRF) testing on the area suspected to be glass revealed a lead (Pb) component of over 3%.

Figure 4. Immersion in methylene diiodomethane (n = 1.741) reveals the extent of the glass filling on the base of the cabochon (the dark area that spreads across a large portion of the base). Photomicrograph by Richard W. Hughes; field of view 30 mm.
A variety of tests were brought to bear on this specimen, from the simple (hardness) to the high-tech (EDXRF). The results of these tests revealed a gem that had been treated by filling with two different substances: glass and dopping varnish. @chapter:12


Publication Year: 1996 Title: Spring 1996 G&G Book Reviews Abstract: “Synthetic Diamond: Emerging CVD Science and Technology”
By K. E. Spear and J. P. Dismukes (Eds.), 663 pp., illus., publ. by John Wiley & Sons, New York City, 1994. US$89.95

“The Peking Diamonds”
By Peter Read, 208 pp., publ. by Gembooks, Dorset, United Kingdom, 1995. US$17.00

“Colorado Rockhounding, A Guide to Minerals, Gemstones, and Fossils”
by Stephen M. Voynick, 372 pp., illus., publ. by Mountain Press Publishing Co., Missoula, MT, 1994, US$14.00 (paper)

“Mineral Books”
a special issue of Mineralogical Record, Vol. 26, No. 4, July-August 1995, 256 pp., illus., publ. by Mineralogical Record, Tucson, AZ, 1995, US$24.00* (hardcover with supplementary text, US$49.00

To view the full section, download the PDF above. @chapter:20