Publication Year: 2006 Title: The Cause of Iridescence in Rainbow Andradite from Nara, Japan Abstract: “Rainbow” andradite from Nara, Japan, occurs as relatively small orangy brown crystals that show attractive iridescence in almost the entire range of the spectrum. The material is nearly pure andradite, as determined by its chemical composition and Vis-NIR and specular reflectance FTIR spectra. Microscopy revealed that two different types of lamellar structures appear to be responsible for the iridescent colors. These lamellar structures cause predominantly thin-film interference and most likely diffraction of light. The terms interference and diffraction are explained and correlated to the structure and iridescence observed in these garnets. @chapter:4


Publication Year: 2013 Title: Amber with Insect-Bearing Filling Abstract: Figure 1. The beads in this strand of prayer beads measure approximately 12 mm in diameter. Photo by Sutas Singbamroong.

              We recently tested an interesting strand of Islamic prayer beads resembling amber (figure 1). It consisted of 33 round yellow beads approximately 12 mm in diameter, two oval-shaped separators, and a fancy-shaped link. It was purchased as amber from a dealer at an annual festival in Dubai.

The round beads contained dark brown plant debris and a variety of insects: ants, flies, and spiders, all in good condition. The beads’ surfaces also featured noticeable circular zones, and when exposed to long-wave UV radiation, they displayed a weak, blue fluorescence and distinctive chalky blue circular areas (figure 2). The beads were inert to short-wave UV radiation.

	Figure 2. When exposed to long-wave UV radiation, these beads displayed weak blue fluorescence and distinct, chalky blue circular areas. Photo by Sutas Singbamroong.
These features were similar to those of copal filled with plastic (Winter 2010 GNI, pp. 326–328). We obtained spot RI readings of 1.52 on the circular zones and 1.54 elsewhere. Next, we analyzed the strand using Raman spectroscopy with a 785 nm diode laser. The separator link and the main portion of the beads showed peaks between 1434 and 1644 cm–1, consistent with amber. The circular areas’ strong bands at 623, 807, 1100, and 1599 cm–1 were consistent with epoxy resin (figure 3).

	Figure 3. Raman spectra collected from the main portion of the beads were consistent with amber, whereas the circular areas indicated an epoxy resin.
Microscopic examination with immersion in water indicated that all the round beads had been cored and filled (figure 4). The beads were identified as amber filled with colorless to light yellow plastic to imitate insect-bearing amber.

	Figure 4. Microscopic observation with immersion in water clearly indicated that these amber beads had been cored and filled with a colorless to light yellow plastic containing insects. Photomicrographs by Sutas Singbamroong; magnified approximately 10×. @chapter:37


Publication Year: 2018 Title: Turquoise from Western Arkansas Abstract: Figure 1. Recent production from a reactivated turquoise deposit in Polk County, Arkansas. The beads shown here measure up to 25 mm in diameter, while the largest cab weighs 30 ct. Photo by Robert Weldon/GIA.

At their AGTA booth, Avant Mining (Jessieville, Arkansas) displayed an unexpected material: turquoise from Polk County, Arkansas. According to owner James Zigras, this is the only gem-quality turquoise deposit in the U.S. located outside the Southwest. Calibrated goods and specimens ranging from blue-green to greenish blue were on view (figure 1). Also at the booth was a 245 lb. boulder unearthed in 1982 and polished in 2018 by Michael Beck (Copper Canyon Lapidary & Jewelry, Sedona, Arizona). The boulder, shown in figure 2, is the largest known American turquoise nugget.

Figure 2. This 245 lb. boulder of turquoise, removed from the Polk County deposit in 1982, is the largest known American turquoise nugget. Photo by Robert Weldon/GIA.
The source was first mined from 1978 to 1986 under a previous owner, but the material was likely sold as Southwestern turquoise. During these years, there was too much competition in the market for stabilized turquoise, and activity eventually ceased. In 2017, Zigras bought the previous owner’s estate, which included two tons of turquoise rough, and restaked a claim on the original mining site. He expected the source to yield planerite and was surprised to find that the material was close to ideal for the turquoise end member of the planerite-turquoise solid solution series. In January 2018, a test trench was worked for seven days. In that time, the deposit produced approximately 1,000 lbs. of turquoise and an old mine shaft was uncovered. Veins are located about 10 feet below the surface (see video below). Quartz crystals and wavellite are also found in the deposit.

Turquoise VeinsThe veins of turquoise are close to the surface of the Arkansas deposit, as seen in this short video.
Zigras indicated that the turquoise is impregnated but not dyed. Independent testing at GIA confirmed impregnation; no evidence of dye was detected on the samples. Zigras plans to submit the material for Zachery treatment, a process designed to improve the polish and color of turquoise. It will be interesting to see this source’s output in the coming years. @chapter:7


Publication Year: - Title: Fall 2012 Gem News International Abstract: Colored Stones and Organic Materials
            Beryl from Kaduna State, Nigeria
            Green and Orangy Yellow Calcite from Pakistan
            Citrine from Zambia
            Emerald from Ethiopia
            Emerald from Sumbawanga, Tanzania
            Gold in Trondhjemite Matrix Rock
            Hemimorphite from China
            Update on Some Mogok Gem Mines and Markets
            Rainbow Moonstone from Madagascar
            Yellow Muscovite from Brazil
            Blue Opal from Arizona Showing Play-Of-Color
            Yellow Opal from West Africa
            Quartz with Green Rutile Inclusions
            Quartz from Tanzania with Red Epidote-Piedmontite Inclusions
            Unusual Trapiche Sapphire
            Stichtite-Dominated Intergrowths with Serpentinite from Tasmania
            Zoisite from Pakistan
            Pink to Purple Zoisite from Merelani, Tanzania
Synthetics and Simulants
            Artistic Cutting of Russian Synthetic Moissanite
            “True” Red Synthetic Spinel Grown By a “Pulled” Technique in Russia
Miscellaneous
            Automated Colored Stone Cutting

To view the full section, download the PDF above. @chapter:3


Publication Year: - Title: Seek the World’s Most Vivid Blue Spinel with GIA Field Gemologists Abstract: Hunting for Spinels in Vietnam

	Join GIA’s field gemologists as they venture into Vietnam’s limestone mountains in search of the world’s most vivid blue spinel.

	In this new video from GIA’s field gemology department, you will accompany field gemologist Vincent Pardieu to Vietnam’s striking limestone mountains in search of sky-blue spinel.

	Although miners recover blue spinel in Sri Lanka, Tanzania, Myanmar, and Pakistan, Vietnam’s Luc Yen district is a leading source of the most vividly blue gems. The best of them have the same luminous quality as Paraíba tourmaline. “The blue spinel you have in Vietnam has really no equivalent,” explains Pardieu. “The top-quality blue spinel from Vietnam is really the top-quality blue spinel in the world, in my opinion.”

	Luc Yen district is located in Yen Bai province, in Vietnam’s scenic north. It’s a vivid patchwork of steep-sided, jungle-covered karsts separated by narrow valleys filled with paddy fields and villages. Luc Yen’s capital, Yen The (confusingly also known as Luc Yen), is about a six-hour drive, 250 km (155 miles) from Hanoi. All of the district’s blue spinel mining sites are within 20 km (12 miles) of the town.

	The GIA team starts off in Luc Yen’s bustling gemstone market. Before the 1990s discovery of Vietnamese ruby, Luc Yen was little known—a small agricultural backwater. The town grew rapidly after gems were discovered in the surrounding mountains and streams. Luc Yen’s first gem market opened in 1987, and today this once impoverished town is northern Vietnam’s busiest gem-trading center.

	At the market, gems from the area’s mountains and fields—rough spinel octahedra, faceted spinels, and cabochons—lie in rows on dealers’ little wooden tables. “Visiting the market here is quite an experience for anybody,” says gemologist Manny Diaz. Beautiful cobalt-blue spinels are present at many of the tables. “Material like this is really incredibly rare on the surface of the earth,” says Pardieu. He explains that visiting the local gem market is an excellent way to assess the availability of different materials. It also gives gemologists a way to assess current gem production in the local mining areas.

	It takes several hours to reach the blue spinel mines. The GIA team travels by motorcycle from the town to the countryside. Once there, they must make the trek up into a forbidding karst landscape to reach the mines. Luc Yen’s rugged limestone mountains formed when rainfall dissolved the limestone and created underground drainage systems, sinkholes, and caves. These features make it challenging to reach the mines, where ruby, sapphire, and spinel are recovered from primary and secondary deposits using artisanal methods. “If you want to go to see the primary mines that are producing this sky blue spinel, there is no other way,” remarks Pardieu. “You have to face the karst and go up in the mountain.”

	This means hours of steep ascent, navigating the sharp ridges and deep crevices that make up the face of the mountain. “There is a crevice about 4 to 5 meters deep, full of wood and sharp marble pinnacles,” observes Pardieu, “so you don’t want to fall in there!”

	“For the past ten minutes, we are climbing the Cung Troi cliff, which is the main spinel mining area here,” explains Pardieu. “Cung Troi is a very special place, as this is the place that produced most of the spinel crystals in matrix for the past 20 years.” Cung Troi—which means “Sky Gate”—is a source of pink-to-purple spinel, which occurs in marble along with minerals like pargasite. The spinels range in size from just a few millimeters to over five centimeters, and are of octahedral habit. Crystals in matrix are often carved into decorative shapes, which are highly valued due to the strong domestic market for items related to phong thuy—the Vietnamese version of feng shui.

	As the team nears the Cung Troi spinel mine, they clamber up steep slopes strewn with angular blocks and tailings of white marble. Standing in front of a marble cliff, gemologist Manny Diaz examines one half of a drill hole in a split rock face. “They’ll drill and they’ll pack that hole with an explosive…Once it falls, they’ll come down, out to the blast site and they’ll start picking up all the rubble,” he says. Miners attack the rubble with sledgehammers to look for spinel crystals, which stand out like glowing embers against the snowy white marble.

	When the team joins the miners in their hut for a meal, Pardieu explains Cung Troi’s geology: “It seems that you have three parallel veins…one with pink spinel, one with blue spinel, and one with ruby,” he says.

	Later, they watch as some miners struggle to move a huge marble block down a steep slope of angular, boulder-size tailings. “We just witnessed the team of miners that we spent the day with on the cliff, taking down a huge piece of marble that they collected from the top,” Pardieu observes. “Inside, we can see there is some pargasite, there is also some spinel. They’ll probably sell it to a carver and the carver will slowly take out the marble in order to reveal the spinel and the pargasite, which are hidden inside.” The heavy boulder tugs the miners downhill. They laugh, but they’re only barely in control.

	Next, the team reaches the Bai Son blue spinel mine—the main objective of the expedition. The primary deposit at Bai Son is located on a 600-meter high (1,970 foot) marble mountain. Local miners—mostly farmers—extract the spinel from the marble using hand tools and jackhammers. “Here we are on the blue spinel vein,” remarks Pardieu. “This is a most famous spot for blue spinel of the sky-blue quality.” Although blue spinel is found in the white marble at Bai Son, the crystals are usually of low transparency. Gems weathered out of the marble are also found in crevasses at Bai Son, and in places where miners follow the caves underground.

	Pardieu sums up the rationale for this and all the other field expeditions he conducts for GIA: “I travel to gem-mining areas around the world and I collect samples. So we need to have a reference sample from this area in order to be able to identify the stones that were mined in the past, that are mined today, and will be mined in the future.”

	This GIA Field Expedition (FE65) took place in 2015. Besides Pardieu, the participants were video cameramen Didier Barriere-Doleac and Didier Gruel, and expedition members Manny Diaz, Philippe Labrot, Lucie Martinez, Lauriane Pinsault, and Wim Vertriest. @chapter:3


Publication Year: 2023 Title: Inclusion Resembling a Gada in Diamond Abstract: This etch channel seen in the crown facets of a 1.00 ct diamond with SI1 clarity (left) resembled a gada (right), a mace-like weapon wielded by the Hindu god Hanuman. Photomicrograph (left) by Deepak Raj; field of view 0.80 mm. Photo (right) courtesy of the Metropolitan Museum of Art.
Recently, the authors observed an interesting etch channel (see above) in a 1.00 ct L-color type Ia round brilliant diamond with SI1 clarity. It resembled a gada, a mace-like weapon belonging to the Hindu god Hanuman. This etch channel was the only one observed in the diamond; these features are often created by dissolution processes (T. Lu et al., “Observation of etch channels in several natural diamonds,” Diamond and Related Materials, Vol. 10, No. 1, 2001, pp. 68–75).
This unusual clarity characteristic showcases the variety that is possible within the natural world. @chapter:31


Publication Year: 1982 Title: Summer 1982 Gem News International Abstract: Diamonds
            Australia: DeBeers CSO to Market Ashton Join Venture Stones
            Botswana: Depressed Market Creates Severe Economic Problem
            Ghana: Only Producing Mine Continues through U.S. Loan
            India: Government Plans to Increase Domestic Supplies
            Israel: Customs Duty Removed
            Lesotho: Mine Closure Due to Recession
            Namibia: Production Reduced
            South Africa: Coping with Depressed Market
            U.S.: West Coast Club Opens
            Zaire: Substantial Drop in Production
Emerald
            Australia: Aga Khan Mine Output Stockpiled
            Brazil: Superior Color Discovered
Pearl
            Japan: Concern About Chinese Freshwater Pearls
Topaz and Peridot Jewelry Suite Currently on Display at GIA

To view the full section, download the PDF above. @chapter:28


Publication Year: - Title: Ruby Quality Factors Abstract: Fine-color, large, and eye-clean (lacking visible inclusions) rubies like this 11.01carat (ct) stone from Myanmar (formerly known as Burma) are extremely rare and valuable. – Photo: Robert Weldon/GIA. Courtesy: Jan Goodman Co

Ruby can command the highest prices of any colored gemstone.  The per-carat prices of fine-quality rubies have been rising consistently, many times breaking auction records.

For better-quality material, slight differences in color can make significant differences in value. For top-color ruby that’s also free of eye-visible inclusions, the price rises even more.

The per-carat price of ruby can also increase dramatically as size increases, especially for better-quality stones.
The Color of Ruby

The mixture of these untreated and heat-treated rubies show a range of darker and brighter red colors. Photo: Robert Weldon/GIA. Courtesy: Tommy Wu, Shire Trading Ltd., Hong Kong
Color is the most significant factor affecting a ruby’s value. The finest ruby has a pure, vibrant red to slightly purplish red color. In most markets, pure red colors command the highest prices and ruby with overtones of orange and purple are less valued. The color must be neither too dark nor too light to be considered finest quality. If the color is too dark, it has a negative effect on the stone’s brightness. At the other extreme, if the color is too light, the stone may be considered to be a pink sapphire, even if color strength or intensity is high. That said, pink sapphires enjoy a following, at a far more competitive prices than rubies. Ultimately, the most desirable color of ruby is the one you prefer the most.
The Difference Between Pink Sapphire and Ruby
Some gem dealers debate the borderline between ruby and pink sapphire. Historically, the word ruby referred to shades of red, which technically included pink. There are also cultural differences in the interpretation of ruby versus pink sapphire. In some gem-producing nations such as Sri Lanka, pink colors were always considered ruby, while in many consuming countries it is classified as pink sapphire.

The GIA Laboratory uses a controlled set of comparison stones called masterstones to determine if corundum is ruby The laboratory grades its masterstones on the principle that red must be the dominant hue before a stone can be called a ruby. In the gem trade, though, pinpointing the dominant hue is subject to personal perception.
Burmese Pigeon Blood Ruby
Historically, the term “pigeon’s blood” described the red to slightly purplish or pinkish red color of rubies with a soft, glowing, red fluorescence.

Traditional descriptions like these are useful for evoking images and describing color among professionals. But they can be subject to misinterpretation when used to describe a ruby’s actual color.

Over time and years of experience trade terms can conjure up perceptions of certain colors and qualities that are associated with a stone’s source. However, the qualities might be typical of that source or they might represent the finest stones from that source.

A single source never yields gems that are all the same color and quality. In fact, the descriptive trade term might represent only a small, yet highly desired percentage of stones from that source.

New sources can produce material very similar to rubies from classical localities or present a slightly different appearance, but remain just as beautiful.
Ruby Clarity

Intersecting needles of the mineral rutile create a common ruby inclusion called silk. When they are intact, they prove the ruby was not heat-treated at very high temperatures. It’s still possible that lower-temperature heat treatment might have occurred. Photo: John I. Koivula, GIA.
People in the trade expect rubies to have at least some inclusions because inclusion-free rubies are practically nonexistent. Ruby value can depend on how visible the inclusions are. Obvious inclusions, or inclusions that reduce transparency or brightness, lower a ruby’s value dramatically.

If large and prominent inclusions are located under the table facet, they greatly diminish the transparency, brilliance, and value of the stone. Inclusions can also limit a ruby’s durability. Significant surface-reaching fractures can pose durability threats.

Typical ruby clarity characteristics include thin mineral inclusions called needles. When the mineral is rutile and needles are present in intersecting groups, it is called silk. Needles might be short or long and slender, and they might appear to be woven tightly together.

Ruby can also contain needles composed of other minerals, small crystals, zones of color variation, or inclusions that resemble fingerprints.

Some inclusions can actually contribute positively to a gem’s appearance. The presence of rutile silk causes light to scatter across facets that might otherwise be too dark. This adds softness to the color and spreads the color more evenly across the ruby’s crown.

Needles that intersect can also cause the star effect, called asterism, when the stone is cut with a curved upper surface, called a cabochon cut.

Long mineral inclusions that intersect can create the star effect when stones are cut as cabochons. - Photo: Robert Weldon/GIA. Courtesy: Hussain Rezayee, Rare Gems & Minerals
Ruby Cut

Rubies are commonly cut into oval and cushion shapes. – Photo: Robert Weldon/GIA. Rough: Gift of William F. Larson. Cut stone: Courtesy: Edward Boehm.
Several factors affect the cut and proportion of rubies on the market. A ruby’s crystal shape dictates its suitability for certain cuts. The most common shape is a flat tabular hexagonal shape, but ruby crystals from some sources can be elongated.

To accommodate these crystal shapes, the most common shapes of fashioned rubies are ovals and cushions, with brilliant-cut crowns of kite-shaped and triangular facets, and step-cut pavilions with concentric rows of rectangular or square facets.

Round, triangular, emerald-cut, pear, and marquise rubies are also available. But these shapes are rare in larger sizes and higher qualities.

Ruby rough is very expensive, so many cutters try to conserve as much weight as possible. They might fashion flattened ruby rough into shallow stones, even though light escapes through flattened pavilions, causing an unattractive see-through area in the stone called a window.

Pleochroism—the appearance of different colors in different crystal directions—is another factor that influences cut. In ruby it typically appears as red to purplish red in one crystal direction and orangy red in the other. Cutters can minimize the orangy red color by orienting the table facet perpendicular to the long crystal direction. Even so, it’s not always possible to orient a ruby for ideal color return because the potential loss of weight would be too great.
Ruby Size and Weight

These rubies were all mined in Myanmar (formerly known as Burma). The faceted stone weighs 11.55 carats and the rough stones weigh between 16.65 carats and 278.50 carats. Photo: Robert E. Kane/GIA.
Fine-quality rubies over one carat are very rare, but commercial-quality rubies are commonly available in a wide range of sizes. The price per carat goes up significantly for ruby as it increases in size. @chapter:25


Publication Year: 2018 Title: Opal from West Java, Indonesia Abstract: Figure 1. These cabochons, weighing 6.94 ct and 3.79 ct, were among the Indonesian opals at Rare Earth’s AGTA booth. Photo by Robison McMurtry.

At the AGTA show, Rare Earth Mining Co. (Trumbull, Connecticut) displayed an unexpected material: Indonesian opal reportedly from West Java. Two cabochons (figure 1) yielded a refractive index of 1.45 and a specific gravity of 2.13, consistent with opal. Energy-dispersive X-ray fluorescence (EDXRF) analysis revealed the presence of copper.

According to Rare Earth’s Curt Heher, the material was first seen in the spring of 2017. While the opal comes in a wide range of colors, including browns and blues, the greenish blues were of particular interest. Rare Earth displayed cabochons where this was the primary hue, with the accessory colors distributed in an aesthetically pleasing manner. @chapter:39


Publication Year: - Title: 2017 Gianmaria Buccellati Foundation Award for Excellence in Jewelry Design Showcases Jewelry Art Abstract: This close up of the pendant on Catherine Zheng’s Art Deco-inspired necklace showcases the blue sapphire, tanzanite, diamonds and enamel she used in her design.

Judges for the first annual Gianmaria Buccellati Foundation Award for Excellence in Jewelry Design were surprised when they saw the display of original hand-painted renderings from GIA's Jewelry Design Certificate program students on display in Tucson recently.

“The judges were so surprised. They walked in and said ‘Wow,’” Elizabeth Brehmer, director of GIA’s Jewelry Manufacturing Arts (JMA) program, said. “The renderings are really lifelike and executed at the right size and scale. They are colorful and lively and really jump off the page.

“There is a life to something that you render and paint,” she said. “There’s something very personal, organic and real about it.”

The Gianmaria Buccellati Foundation Award for Excellence in Jewelry Design competition was created to inspire and encourage beginning jewelry designers and celebrate the long history of hand-sketched and painted jewelry art for which Gianmaria Buccellati was known.

“Mr. Buccellati always protected his brand and ensured that the things that came out of his workshop were unique, special and always maintained a very high standard," Brehmer said. "Having a competition with the foundation’s name attached to it really speaks volumes to recognizing the work GIA student finalists provided for the judging.”

The competition was open to individuals who successfully completed the 2017 Jewelry Design Certificate program at any GIA school worldwide. The students' original works of art go through a couple of different gates of judging, according to Brehmer. First, they complete the course and showcase their work to their peers at each of the schools, then the paintings are submitted to a committee in Carlsbad to make sure they meet all of the standards and criteria taught at GIA. This year, 12 global design courses were offered and one student from each course at each school (Carlsbad, Hong Kong, India, New York, London, Taiwan and Thailand) was selected to participate.

Along with an original rendering, each entry had a material statement and an inspiration statement.
“The material and inspiration statements are a significant part of the concept and execution of the rendering – and are a critical part of the judging in the final round,” Brehmer said. “Their compelling inspiration stories contributed to their art.”

Zheng with Larry French, chief officer of North American strategies for the Gianmaria Buccellati Foundation, who will help her plan her trip to Italy. Photo by Kevin Schumacher/GIA
Brehmer said this type of competition is important for GIA students to participate in because it gives them a chance to showcase their designs to experts in jewelry design.

“The students were so excited when the announcement about the competition was made,” Brehmer said. “There’s not another competition out in the market that allows them to showcase the skills they learn as an artist and as a designer when they go through a jewelry design program at GIA, anywhere in the world.”

A panel of five industry experts from a variety of aspects of jewelry design did the final judging the morning of the “Party at the GIA Gem Mine” alumni event in Tucson: Molly Bell, executive vice president of Rio Grande Tools & Supplies; Remy Rotenier, president of Remy Design and a jewelry designer and educator; Ginger Porcella, chief curator of the Tucson Museum of Contemporary Art; Alishan Halebian, owner of Alishan, a retail and custom design-curated company; and Victoria Gomelsky, editor-in-chief of JCK magazine.

Doug Hall, a senior instructor in GIA’s JMA program, provided an overview of GIA’s Jewelry Design Certificate program to the judges before they began the process of selecting a winner, including what students learn, how they learn it, the perspective they are asked to employ, and the techniques they use.

Brehmer said the judges were impressed by the quality of the GIA students’ work and were thrilled they could pick the renderings up to examine them and then read the student’s comments on what inspired them and the materials they would use make the piece.

“The judges said they rarely get to see original renderings and several commented on the time and effort that went into this type of work. One judge noted that it really afforded an opportunity to close a sale quicker because the customer would see what something was really going to look like,” she said. “That was an interesting dialogue between the judges, because it’s a very traditional method [painting renderings] that you can apply in today’s industry.”

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The grand prize winner of the competition – Catherine Zheng – was announced during a formal presentation at the alumni event. Her platinum and tanzanite Art Deco-style necklace impressed the judges with its elegance, beautiful rendition and the fact that it could be manufactured, Brehmer said.

Zheng, a Los Angeles area real estate broker for high-end clients, was “totally shocked” when her name was announced as the grand prize winner.

“I never thought that I'd win this competition because I know there are many students in the jewelry design course who are very talented – and a lot of them either studied art in college or they already have a jewelry industry background,” she said.

Zheng said she makes a good income in real estate, but always felt like something was missing in her life.

“I was really into art while I was in high school and I earned multiple art rewards, such as the National Award for Creative Artists and a Special Congressional Recognition in ‘An Artistic Discovery.’ My dream was to become a designer, but my family, like many traditional Asians, thought it was too risky to become an artist,” she said.

So Zheng studied finance and marketing in college and become a banker and then a real estate broker after she graduated. She said her creative art ideas kept pulling at her, however, so she signed up for the Jewelry Design Certificate program course in Carlsbad. Hall, who she calls “awesome,” was her instructor.

“Doug is a perfectionist and I really learned a lot by his high standards,” she said. “The course is only nine weeks long, but we learned so much about technique and skills during this short period of time. Not only that, the second half of the course gives the students a lot of room to be creative.”

Catherine Zheng’s Art Deco-inspired necklace features blue sapphire, tanzanite, diamonds and enamel. An ornate pendant hangs from a chain with stations of embellished links in between the chain.
Zheng continued to work her real estate business while she took the course.

“The challenging part was that I had to work at night after my day job and could only sleep four to six hours every day to fit it all in,” she said. “I haven't drawn for more than 10 years, but I'm very glad that I put in my best effort while studying.”

She said all of the hard work is extremely rewarding. “It really feels great to win when you didn't expect it,” she said.

Beyond the recognition Zheng received as grand prize winner, she will go on a one week all-expense paid trip to Florence to take in Renaissance art and view part of the jewelry collection of Gianmaria Buccellati housed in the Pitti Palace. She will also travel to Milan and have the opportunity to meet Mrs. Buccellati, where she will receive a plaque acknowledging her as the winner of the competition.

“I'm super excited to go to Italy. I have been there a few times before, but this is sure to be the most exciting and memorable trip,” she said. “I am very much looking forward to meeting Mrs. Buccellati.”

Zheng said winning the Gianmaria Buccellati Foundation Award for Excellence in Jewelry Design has inspired her to continue to pursue her professional jewelry design dreams – which is exactly why it was created – and she plans to study CAD/CAM design and become a GIA Graduate Gemologist in the near future.

“I'm definitely looking into starting my career as a jewelry designer or even my own line of jewelry,” she said. “This means so much to me as a beginning designer and it really gives me a lot of encouragement and faith to continue on this career path.” @chapter:36


Publication Year: - Title: Colombian Emerald Industry: Winds of Change Abstract: Independent miners at the Rio Itoco in the Muzo Valley. This husband and wife mining team worked the tailings MTC (Mineria Texas Colombia) dumped by the river for local independent miners to go through. They are examining a significant rough emerald they found. Photo by Andy Lucas/GIA

Andy Lucas, GIA’s education manager of field gemology, researches and documents the mine to market journey of gemstones. Lucas shares the changes he observed in Colombia’s major emerald mining and cutting areas in a presentation he made at the 2017 JCK Las Vegas show.
Lucas interviewed local participants in the emerald trade to see what is causing changes in Colombia’s emerald business. He learned that there is a generational shift in approaches to mining and that the government is working to standardize the industry. The main effort is focused on combining traditional and modern mining methods to advance Colombian emeralds in the global market.
In the video, Lucas discusses the five pillars of the Colombian government’s mining plan, introduced in October 2015 during the Emerald Symposium in Bogotá. The plan is meant to formalize, regulate and provide help for geological studies and infrastructure. The goal is to create a balance for the country’s indigenous people and the publicly traded companies.

	Colombian Emerald Industry

Before joining GIA, Lucas founded and operated an international wholesale and private client retail gemstone jewelry and antiquity business. He began his GIA career as an instructor, and later developed educational products before becoming education manager of field gemology. He has published articles, created documentaries and presented lectures at countless international seminars. @chapter:24


Publication Year: 2021 Title: Thin-Film Fluid Inclusions in Aquamarine Abstract: Thin-film fluid inclusions oriented perpendicular to the c-axis of this aquamarine display interference colors when viewed using oblique fiber-optic illumination. Photomicrograph by Muzdareefah Thudsanapbunya; field of view 2.79 mm.

The author recently examined a faceted aquamarine from Brazil that showed two-phase (liquid and gas) thin-film inclusions of different sizes and shapes. When observed using oblique fiber-optic illumination, the inclusions revealed a kaleidoscopic play of interference colors (see above). The most diagnostic beryl inclusions, yet barely noticeable in brightfield illumination are ultra-thin-film fluid inclusions. The planar surface of these inclusions is oriented parallel to the basal pinacoid of their host (E.J. Gübelin and J.I. Koivula, Photoatlas of Inclusions in Gemstones, Volume 2, Opinio Publishers, Basel, Switzerland, 2005, pp. 312–314). The presence of the bright iridescent thin-film fluid inclusions resembles colorful rainbow sprinkles. @chapter:9


Publication Year: 2024 Title: Large Freshwater Cultured Pearls with Atypical Bead Nuclei Abstract: Figure 1. These two necklaces consisting of large freshwater cultured pearls displayed strong hues with orient. Photos by Sood Oil (Judy) Chia; courtesy of Yvel.
Freshwater cultured pearls are known for their wide range of attractive colors, including different combinations of white, orange, pink, and purple hues. In the past decade, round or near-round freshwater bead cultured pearls of large size, commonly called “Edison” pearls in the trade, have gained popularity (Summer 2015 Lab Notes, pp. 179–181; C. Zhou et al., “Detection of color treatment and optical brightening in Chinese freshwater ‘Edison’ pearls,” Summer 2021 G&G, pp. 124–134). Recently, two necklaces consisting of large pearls of mostly orangy pink to purplish pink colors (figure 1), ranging in size from 15.40 to 17.42 × 16.70 mm and from 18.00 to 19.96 × 19.06 mm, were submitted to GIA’s New York laboratory. The strands caught our attention for their size and intense colors, as well as the growth features found inside these pearls.

Figure 2. RTX analysis revealed the near-round atypical bead nucleus used to culture each of the pearls.
Real-time X-ray microradiography (RTX) revealed that all the pearls were bead cultured—but not with the shell bead nuclei typically used for cultured pearls. Instead, a more X-ray transparent material with a distinct outline and near-round shape was found inside them (figure 2). The material appeared porous and nonuniform and did not resemble the “mud-like” material found in “soufflé” freshwater cultured pearls previously studied (Spring 2010 Gem News International, pp. 61–63). However, the exact nature of this material could not be determined. Energy-dispersive X-ray fluorescence analysis of their trace elemental concentrations (such as manganese and strontium) confirmed that the pearls were grown in a freshwater environment. Furthermore, Raman spectroscopy using 514 nm laser excitation indicated that their colors were natural, with two strong peaks around 1125 and 1510 cm–1 associated with natural polyenic pigment.
Cultured freshwater pearls with large size, near-round shape, and intense coloration are highly sought after and more valuable than traditional freshwater cultured pearls. These large freshwater cultured pearls are especially noteworthy because of the unique bead nuclei used during the culturing process, which suggests that culturing techniques are continuously evolving, resulting in higher-quality products. @chapter:14


Publication Year: 2009 Title: “Fluorescence Cage”: Visual Identification of HPHT-Treated Type I Diamonds Abstract: HPHT-treated type I diamonds of various colors may exhibit unusually intense fluorescence at the facet edges and junctions. This effect, here named the “fluorescence cage,” is observed with a fluorescence microscope as a luminous network on the diamond’s surface. It was not observed in untreated diamonds or colorless type IIa HPHT-treated diamonds. This fluorescence pattern is believed to result from a high concentration of HPHT-induced optical centers, which remain on facet edges after repolishing. @chapter:15


Publication Year: 1993 Title: Update on Diffusion-Treated Corundum: Red and Other Colors Abstract: Blue diffusion-treated sapphires have become a subject of considerable controversy since their introduction in significant quantities a few years ago. Now it appears that diffusion-treated corundum in additional colors, including red, may also be a commercial reality in the near future. At the request of the treater, the authors examined faceted specimens in a range of colors to document their gemological properties and determine identification criteria prior to any commercial release. Diagnostic features include unusually high refractive-index readings, atypical dichroism, atypical luminescence, patchy surface coloration, color concentrations along facet junctions, and spherical voids just below the surface. @chapter:12


Publication Year: 1995 Title: Fall 1995 Gem News International Abstract: Diamonds
            Diamond with Mobile Diamond Inclusion
            Update on Russian Diamond Mining
            Spy Ship Looks for Diamonds
Colored Stones
            Cat's-Eye Apatites from Madagascar
            "Eilat Stone" from Israel and Peru
            Six-Rayed Star Emerald
            Faceted Genthelvite: A Gemological First
            "Drusy" Hausmannite
            Costa Rican Jade Museum
            Green Opal from Serbia
            "Deep" Quartz from Africa
            Egyptian Green Quartz
            Quartz with "Hematite" Inclusions
            Aromatic Resin Necklace: A form of Myrrh?
            Update on Mong Hsu Ruby
            Rubies and Sapphires from North Carolina
            Purple Scapolite from Tajikistan
            Large Spinel from Tajikistan
            Color-Change Zircons
Enhancements
            Impregnated Malachite
Synthetics and Simulants
            Unusual Color-Zoned Synthetic Amethyst
            More on Czochraski "Pulled" Synthetic Sapphires
            Tanzanite-Colored Synthetic Sapphire
            Natural and Synthetic Quartz "Constructs"
Announcements
            Dates Set for February 1996 Tucson Shows
            Education at the Tucson AGTA GemFair
            Visit Gems & Gemology in Tucson
            More GIA Tucson Show News

To view the full section, download the PDF above. @chapter:2


Publication Year: 2016 Title: Non-Nacreous Purple and White Pearls Reportedly from Spondylus Species Abstract: Figure 1. These three purple and white non-nacreous pearls weighing 7.85, 8.37, and 9.85 ct (left to right) are reportedly from Spondylus calcifer. Photo by Robert Weldon.

The Carlsbad laboratory recently examined three non-nacreous pearls, weighing 7.85 to 9.85 ct and measuring from 10.50 × 10.21 mm to 12.43 × 11.65 × 10.65 mm (figure 1). All three pearls exhibited similar uneven bodycolors and surface characteristics. They displayed purple and white colors with some yellowish brown tints and possessed a porcelaneous surface with mottled to clear fine flames. They were reportedly fished near Ligui, on the eastern coast of the Mexican state of Baja California Sur.

Similar surface structures have been reported in G&G (Fall 2014 Lab Notes, pp. 241–242; Winter 2015 Lab Notes, pp. 436–437; Summer 2016 Micro-World, pp. 202–203). A characteristic reflective blue coloration on the base of the 9.85 ct semi-baroque button (figure 2) was clearly visible when the flame structure was illuminated with a fiber-optic light. Moreover, subsurface to surface-reaching acicular inclusions found in most Spondylus pearls examined previously were also present in these samples. These inclusions, which appear in the form of tubes or needles, are often associated with the flame structure. At first the inclusions were believed to be parasite channels, which are sometimes observed in shells and pearls of various nacreous and non-nacreous mollusks. But after careful inspection they were seen to be part of the structure, radiating from within and reaching the surface in the same direction and with fairly consistent size and shape—whereas the parasite channels are irregularly shaped and in various sizes, running in random directions and usually crossing over each other.

Figure 2. The characteristic reflective blue coloration of Spondylus pearls was visible
within the flame structure of the semi-baroque button pearl when illuminated with a
fiber-optic light. Photomicrograph by Artitaya Homkrajae; field of view 5.77 mm.
The pearls’ dimpled surface texture appears to be caused by the slightly recessed openings where these inclusions reach the surface. This unique feature is also found on the interior of Spondylus shells in GIA’s Bangkok laboratory collection (figure 3). The resemblance between a pearl’s surface and the interior surface of its host are useful in identifying the mollusk species. Yet many marine gastropods and bivalves produce non-nacreous pearls, and their similar surface structure and color sometimes make mollusk identification challenging. As with the previously reported Spondylus pearls, microradiography of all three pearls revealed tight structures, and no obvious growth arcs were seen.

Figure 3. Subsurface to surface-reaching acicular inclusions were found on the interior of a Spondylus shell (left) from the GIA Bangkok reference collection and associated with the flame structure in a Spondylus pearl (right). Photomicrographs by Artitaya Homkrajae (left, field of view 1.31 mm) and Moqing Lin (right, field of view 2.37 mm).
The Spondylus genus (commonly known as “thorny” or “spiny” oyster) consists of about 76 living species distributed in tropical waters around the world. Spondylus princeps and Spondylus calcifer (also known as Spondylus limbatus) are two of the main species on the western coast of the Americas. S. princeps is found from the gulf side of Baja California down the Pacific coast of Mexico through Panama to northwest Peru. S. calcifer is found in the Sea of Cortez (Mexico) and Ecuador (K. Lamprell, Spiny Oysters: A Revision of the Living Spondylus Species of the World, Jean Lamprell, Brisbane, Australia, 2006). Most Spondylus pearls examined by GIA are reportedly from Spondylus princeps, whose bodycolor is typically white to cream or various saturations of pink, orange, and brown. This is the first time GIA has examined pearls with such a dominant purple hue reported to be from Spondylus calcifer. This species has been recorded as producing pearls in Costa Rica (E. Strack, Pearls, Ruhle-Diebener-Verlag GmbH & Co., Stuttgart, 2006, p. 59). @chapter:14


Publication Year: - Title: At the Spring Auctions: A Spending Spree for the Ultra-Wealthy Abstract: The 100.09 ct Vivid yellow from Laurence Graff brought $16.3 million at Sotheby’s Geneva sale in May 2014, the most expensive yellow diamond ever sold at auction. Photo courtesy of Sotheby’s

	The world’s ultra-wealthy open their wallets even wider for the rare and fine in the first half of 2014. A Modigliani portrait sold for a record $18.4 million at Sotheby’s Paris auction in June, and a collection of wines went for $13 million at a Sotheby’s Hong Kong auction in April.

	It’s no surprise that unheard-of auction records for diamonds and colored gems followed suit. Indeed, it’s fitting that the spring 2014 season also broke the record for a jewelry auction’s shortest stay at the top: less than 24 hours.

	Economists note that the world’s wealthy have been putting more and more of their excess funds into such items and it’s buoyed the auctions’ bottom lines. Christie’s overall sales, with art leading the way, increased 27% for the first five months of the year, according to François Curiel, president of Christie’s Asia. Christie’s jewelry sales of $360 million were up 22% from the same period last year, doubling those of five years ago.

	“The jewelry and fine art markets are expanding, attracting more buyers than ever before,” said Curiel. He added that 30% of Christie’s buyers this season were new, coming from all parts of the world.

	Here is a roundup of this past season’s gem and jewelry sales.

Single-Auction Sales
	Sotheby’s Magnificent Jewels sale on May 13 in Geneva realized $141.5 million, the highest ever at a single jewelry auction. That total surpassed the previous mark, Christie’s December 2011 Elizabeth Taylor auction, by more than $25 million. The following day, however, Christie’s regained the title with a Geneva jewelry auction that took in $154.2 million.

Individual Gems
	Not surprisingly, a number of other records fell during these sales. The records came in a variety of colors.

Yellow Diamond: At the Sotheby’s auction, a 100.09 carat (ct) GIA-graded Fancy Vivid yellow from London jeweler Laurence Graff sold for $16.3 million, the highest price ever paid for a yellow diamond. This gem was one of the final stones polished by master diamond cutter Antonio Bianco, who died in 2009.

Colorless Diamond: Moments before the Graff yellow diamond came up, an anonymous bidder paid a record per-carat price of $246,710 for a colorless diamond: a GIA-graded 25.32 ct type IIa D-color internally flawless diamond.

Blue Diamond: At Christie’s May 14 Geneva auction, the top lot was the Winston Blue, a 13.22 ct pear-shaped Fancy Vivid blue flawless diamond that brought the highest per-carat price ever paid for a stone of that color and clarity. The buyer, Harry Winston Corp., paid $23.8 million ($1.8 million per carat). GIA noted it was the largest flawless Fancy Vivid blue diamond it had ever graded.

Green Diamond: At the same Christie’s sale, a 5.5 ct. Fancy Vivid blue-green diamond, the Ocean Dream, achieved a record price of $8.63 million for a diamond of that color.

Natural Pearls: At William Doyle Galleries in New York on April 30, a bidder paid a record $3.3 million for a pair of natural pearl drop earrings thought to have once belonged to Empress Eugénie of France. They are believed to have been part of the French crown jewels sold off in 1887, seventeen years after the fall of Napoleon III. The previous high was for a pair of natural pearls owned by actress Gina Lollobrigida, which sold in May 2013 for $2.4 million.

	The 5.5 ct Ocean Dream, left, a Fancy Vivid blue-green diamond, sold for $1.4 million per carat, a record for a diamond of that color. The 13.22 ct Winston Blue, right, graded by GIA, sold for $1.8 million per carat, the highest price ever paid for a Fancy Vivid blue diamond of flawless clarity. (Photos not to scale.) Photos courtesy of Christie’s

Overall Auction Prices Remain Strong
	Beyond these records, prices were generally strong across the board for colored gems and signed jewelry pieces from the world’s top jewelry houses.

	Christie’s May 28 Hong Kong sale brought in $91 million. Some of the highlights were:

		Jadeite bangle—$5.2 million

		Burmese ruby bracelet—$4.8 million

		A 6.18 ct. Fancy Intense green diamond—$3.6 million ($594,510 per carat)

	The sale also featured a number of large D-color flawless and internally flawless diamonds ranging from $188,000 to $191,000 per carat. Christie’s ended its season with a $27.5 million sale in New York, which included a 5.5 ct. GIA-graded Fancy Vivid pink diamond that accounted for more than one-third of that total—$9.6 million.

	Not everything sold. The 31.34 ct Victory diamond, found in Africa in 1945 and formerly part of the Florence Gould estate, failed to reach its presale estimate of $5–$8 million at Sotheby’s Geneva May 13–14. Likewise, a necklace featuring the 40.05 ct type IIa D-flawless diamond called the “Eye of Golconda” did not reach its estimate of $8.5 million at Christie’s May 28 Hong Kong sale.

	With the uneven economic recovery, these well-publicized auctions have not had the coattail effect seen in the past. The 1987 Jewels of the Duchess of Windsor sale, for example, “got the world emotionally involved in jewelry,” said one jewelry dealer, with an appropriately sharp upturn in demand for gems across the board. This time, sales of more mundane-sized diamonds and jewelry have not seen a surge in prices or sales growth at retail stores around the world.

	Still, these impressive auction prices have increased popular awareness of fancy-color diamonds and added to the mystique and allure of gemstones. That could serve the entire industry well as the world economy achieves a more secure footing.

	This set of natural drop pearls, believed to have once-belonged to Empress Eugénie of France, achieved a record $3.3 million at William Doyle Galleries’ April auction in New York. Photo courtesy of William Doyle Galleries @chapter:27


Publication Year: 1993 Title: Summer 1993 Gem News International Abstract: Diamonds
            Botswana Produces Large Diamond
            DeBeers Now Marketing High-Quality, High-Pressure Synthetic Diamond Products
            DeBeers Offers CVD Industrial Synthetic Diamond Products
            "Flanders Brilliant" Cut Debuts in U.S.
            Sakha (Yakutia) Building up Diamond Reserves
            Venezuela Diamond Production Up
Colored Stones
            Blue Cancrinite from Greenland
            "Emerald Matrix" from North Carolina
            Gemstone Globe and Maps
            Lapidary Art
            Banded Iridescent Obsidian
            Gems from Orissa, India
            Cultured Freshwater Pearls from Hanoi, Vietnam
            Peridot from Zabargad Island
            Ornamental Porphyry from Canada
            Natural Resin from Colombia
            Ruby Mining near Mahenge, Tanzania
Enhancements
            Opticon Follow-Up
            Turquoise Treatment Stability
Synthetics and Simulants
            Synthetic Corundum as a Topaz Simulant
            Russian Flux-Grown Synthetic Emeralds
            Novel Opal Simulants
            More on Plastic Imitation Opal
            ''Synthetic Opal" from Russia
            More on Paraiba Tourmaline Simulants
            Color-Zoned Synthetic Blue Quartz
            Nontransparent Synthetic Quartz
            Synthetic Spinel from Eastern Germany
Announcements
            New Exhibit at the Royal Ontario Museum

To view the full section, download the PDF above. @chapter:23


Publication Year: 2019 Title: Iridescent Tabasco Geode Abstract: Figure 1. This unique Tabasco geode from Mexico’s Zacatecas State, containing greenish blue botryoidal chalcedony, measures 24 mm in the longest dimension. Photo by Diego Sanchez; courtesy of Marquez Mining.
Tabasco geodes are a small geode variety named for the area where they are mined in the Mexican state of Zacatecas, near the city of Tabasco. Typically, these geodes are lined with water-clear drusy quartz, but the author recently examined one that was filled with greenish blue botryoidal chalcedony that also showed iridescent colors (figure 1). The cause of the colors was not immediately apparent, but microscopic examination revealed clues. The outermost layer of chalcedony had not firmly adhered to the underlying botryoidal mass. This delamination allowed an air gap along the interface of the thin outermost layer of chalcedony and the botryoidal mass of greenish blue chalcedony underneath. This air gap, in addition to the transparent nature of the very thin chalcedony shell, created thin-film interference colors along the interface of the chalcedony shell and substrate (figure 2). This explanation was supported by the observation that where areas of the delicate shell were damaged, the iridescence was not present. This Tabasco geode is one of the most visually interesting geodes examined by the author.

Figure 2. The Tabasco geode hosts greenish blue chalcedony, with a thin chalcedony shell that was responsible for the iridescent thin-film interference colors. Photomicrograph by Nathan Renfro; field of view 1.83 mm. @chapter:4


Publication Year: 2018 Title: Diamond Geology Abstract: Figure 1. Left: The stone’s FTIR spectrum revealed that it is a type Ib-IaA diamond with nitrogen defects, “C” single nitrogen atoms and an “A” pair of nitrogen atoms. Right: DiamondView images show cuboctahedral growth structure containing a {100} sector with reddish orange fluorescence and a {111} sector with green fluorescence. Distinct fluorescence zoning following growth structure is caused by NV centers in {100} sectors and H3 defects in {111} sectors, which were created during the irradiation and annealing processes.
Type Ib–Dominant Mixed-Type Diamond with Cuboctahedral Growth Structure: A Rare Diamond Formation
Kyaw Soe Moe and Paul Johnson
GIA, New York
Type Ib–dominant mixed-type diamonds (Ib-IaA) can be formed by multiple growth events (Titkov et al., 2015; Smit et al., 2018). In this study, we report on a 0.41 ct Fancy Dark brown gemquality diamond that formed in a single growth event. It is a type Ib-IaA with a C defect (single-substitutional nitrogen atom) concentration up to 21 ppm. The Fourier-transform infrared (FTIR) peaks of the H1a and H1b defects (figure 1, left) suggest that this diamond was irradiated and annealed to achieve a Fancy color grade. The cuboctahedral structure can be observed in the DiamondView images (figure 1, right), which show reddish orange fluorescence in the {100} sector caused by NV centers and green fluorescence in the {111} sector caused by H3 defects. Irradiation treatment helps us to see the cuboctahedral structure. However, the presence of an amber center suggests that it did not undergo HPHT treatment.
Cuboctahedral growth structure can be usually observed in HPHT diamonds that are grown in a laboratory with a fast growth rate (i.e., less than one week per carat) under P-T conditions of 5–6 GPa and 1300–1500°C. A natural diamond that grows rapidly in a single growth event would also possess mixed cuboid and octahedral forms.
Time and temperature are critical in the aggregation of nitrogen atoms in diamond. Nitrogen atoms are initially incorporated as single atoms during diamond formation. Our sample was rich in C defects associated with A defects (a pair of nitrogen atoms). This suggests that the process of nitrogen aggregation was interrupted by the diamond’s ascent to shallower depths in the mantle at lower temperatures by rapid tectonic exhumation (Smit et al., 2018). The cuboctahedral growth structure of this diamond indicated that, prior to ascending to shallower depths of the mantle, it grew in a few days in the diamond stability field (i.e., 150–200 km in depth within the earth) in a single growth event.
REFERENCES
Smit K.V., D’Haenens-Johansson U.F.S., Howell D., Loudin L.C., Wang W. (2018) Deformation-related spectroscopic features in natural type Ib-IaA diamonds from Zimmi (West African craton). Mineralogy and Petrology, pp. 1–15, http://dx.doi.org/10.1007/s00710-018-0587-6

Titkov S.V., Shiryaev A.A., Zudina N.N., Zudin N.G., Solodova Y.P. (2015) Defects in cubic diamonds from the placers in the northeastern Siberian platform: Results of IR microspectrometry. Russian Geology and Geophysics, Vol. 56, No. 1-2, pp. 354–362, http://dx.doi.org/10.1016/j.rgg.2015.01.026
Evidence of Subducted Altered Oceanic Crust into Deep Mantle from Inclusions of Type IaB Diamonds
Tingting Gu1, John Valley2, Kouki Kitajima2, Michael Spicuzza2, John Fournelle2, Richard Stern3, Hiroaki Ohfuji4, and Wuyi Wang1
1GIA, New York
2Department of Geoscience, University of Wisconsin, Madison
3Canadian Centre for Isotopic Microanalysis (CCIM), Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton
4Geodynamics Research Center (GRC), Ehime University, Matsuyama, Japan
Nitrogen is one of the most common impurities in diamond, and its aggregation styles have been used as criteria for diamond classification. Pure type IaB diamonds (with 100% nitrogen in B aggregation) are rather rare among natural diamonds. The occurrence of the B center is generally associated with high temperature and a long residence time of the host diamond, which would potentially provide information on the earth’s deep interior. Seawater circulation is the unique process that shapes the surface of our planet and potentially has a profound effect on its interior due to slab subduction.
In about 50 type IaB diamonds with detectable micro-inclusions submitted to GIA for screening, we found that more than 70% of them contained a typical mineral assemblage from the sublithosphere. Jeffbenite (TAPP), majorite garnet, enstatite, and ferropericlase have been observed, which could be retrograde products of former bridgmanite. CaSiO3-walstromite with larnite and titanite is the dominant phase present in approximately 40% of all diamond samples. Direct evidence from oxygen isotope ratios measured by secondary ion mass spectrometry, or SIMS, (δ18OVSMOW in the range +10.7 to +12.5‰) of CaSiO3-walstromite with coexisting larnite and titanite that retrograde from CaSiO3-perovskite suggest that hydrothermally altered oceanic basalt can subduct to depths of >410 km in the transition zone. Incorporation of materials from subducted altered oceanic crust into the deep mantle produced diamond inclusions that have both lower mantle and subduction signatures. Ca(Si,Al)O3-perovskite was observed with a high concentration of rare earth elements (>5 wt.%) that could be enriched under P-T conditions in the lower mantle. Evidence from ringwoodite with a hydroxide bond, coexisting tuite and apatite, precipitates of an NH3 phase, and cohenite with trace amounts of Cl imply that the subducted brines can potentially introduce hydrous fluid to the bottom of the transition zone. In the diamonds with subducted materials, the increasing carbon isotope ratio from the core to the rim region detected by SIMS (δ13C from –5.5‰ to –4‰) suggests that an oxidized carbonate-dominated fluid was associated with recycling of the subducted hydrous material. The deep subduction played an important role in balancing redox exchange with the reduced lower mantle indicated by precipitated iron nanoparticles and coexisting hydrocarbons and carbonate phases.
Origin of Rare Fancy Yellow Diamonds from Zimmi (West Africa)
Karen V. Smit1, Ulrika F.S. D’Haenens-Johansson1, Daniel Howell2, Lorne C. Loudin1, and Wuyi Wang1
1GIA, New York
2Department of Geoscience, University of Padua, Italy, and Diamond Durability Laboratory, New York
Type Ib diamonds from Zimmi, Sierra Leone, have 500 My mantle residency times whose origin is best explained by rapid tectonic exhumation after continental collision to shallower depths in the mantle prior to kimberlite eruption (Smit et al., 2016). Here we present spectroscopic data for a new suite of Zimmi sulfide-bearing type Ib diamonds that allow us to evaluate the link between their rare Fancy yellow colors, the distribution of their spectroscopic features, and their unusual geological history. Cathodoluminesence (CL) imaging revealed irregular patterns with abundant deformation lamellae, associated with the diamonds’ tectonic exhumation (Smit et al., 2018). Vacancies formed during deformation were subsequently naturally annealed to form vacancy clusters, NV0/− centers, and H3 (NVN0). The brownish yellow to greenish yellow colors observed in Zimmi type Ib diamonds result from visible absorption by a combination of isolated nitrogen and deformation-related vacancy clusters (Smit et al., 2018). Color-forming centers and other spectroscopic features can all be attributed to the unique geological history of Zimmi type Ib diamonds and their rapid exhumation after formation.
REFERENCES
Smit K.V., Shirey S.B., Wang W. (2016) Type Ib diamond formation and preservation in the West African lithospheric mantle: Re-Os age constraints from sulphide inclusions in Zimmi diamonds. Precambrian Research, Vol. 286, pp. 152–166, http://dx.doi.org/10.1016/j.precamres.2016.09.022

Smit K.V., D’Haenens-Johansson U.F.S., Howell D., Loudin L.C., Wang W. (2018) Deformation-related spectroscopic features in natural type Ib-IaA diamonds from Zimmi (West African craton). Mineralogy and Petrology, pp. 1–15, http://dx.doi.org/10.1007/s00710-018-0587-6 @chapter:11


Publication Year: - Title: Gem-Carved Ensemble is Music to Philanthropist’s Ears Abstract: View Gallery

	“Symphony in Gemstones,” a miniature, 21-piece orchestra carved of gem materials, was donated to the GIA Museum Collection by Art Sexauer, a longtime benefactor of the museum, in 2002.

	Each instrument offers its own special characteristics, from the tourmaline violins and Persian turquoise trumpet to a lapis saxophone and a spectacular tiger-eye harp with 14K gold strings. The collection’s rhythm section is rounded out by three kettledrums made of black onyx and quartz and a grand piano that features a white quartz and black onyx keyboard

	Sexauer’s idea for the “Symphony in Gemstones” came from a visit to the Tucson Gem and Mineral shows in in the early 1980s when he came across a crude gem carving of a guitar. He was instantly inspired to create an entire gemstone orchestra carved by the expert hands of German artisans in Idar-Oberstein.

	Sexauer, who had already amassed an exceptional collection of tourmaline animal carvings, was well aware of the time and dedication assembling a miniature orchestra carved from gem materials would take. He commissioned master carver Lothar Herrmann and his partner David Hudson, who took one year to create the set, which is displayed on a three-tiered, white marble stage.

	“Symphony in Gemstones” has been on display several times at the Tucson Gem and Mineral shows, as well as in museums across the United States. Sexauer believes the collection may be the only one of its kind in the world.

	Sexauer, who’s had an appreciation for music since his childhood when he would listen to his father play the violin, says the symphony represents two of his favorite things.

	“Music is beautiful and gemstones are beautiful,” he says. “If you put the two together the combination must surely be magnificent.” @chapter:26


Publication Year: 1996 Title: A History of Diamond Sources in Africa: Part II Abstract: Following the history of diamond discoveries in southern Africa presented in Part I, this article discusses the history of diamond exploration and mining in East and West Africa. The first economic kimberlite outside South Africa was discovered in Tanzania (East Africa) in 1940, and major quantities of large, high-quality alluvial diamonds have been mined in West Africa since the mid-1930s. Early miners struggled with misconceptions about how diamonds formed and concerns as to the depth to which diamonds could occur in pipes. Mining developments and new diamond occurrences in Africa led to many of the key concepts in modern diamond geology. Although Africa's long dominance in world diamond production has diminished in recent decades, its steady output and large reserves ensure its continuing role as the most important diamond-producing region in the world, surpassing in overall impact even Australia and Russia. @chapter:20


Publication Year: - Title: Katzenbach Designs Honored with Two AGTA Awards in Two Years Abstract: Derek Katzenbach’s award-winning, 18K kaleidoscope features 71.74 carats of Maine tourmaline and 66.05 carats of Maine quartz between three separate lenses. Gifted to GIA by a private donor in memory of Nicholas Scott Golden, University of Maine Geology student. Photo by Brian Moghadam Photograhy/AGTA. Courtesy of Derek Katzenbach

There’s one question that keeps award-winning jeweler and gem cutter Derek Katzenbach motivated to “push the boundaries” of his own skills: “How did you do that?”

Katzenbach, a GIA GJG, asks it of the artists he admires, and he hopes his designs can pique a similar curiosity.

Katzenbach’s work has earned the New Jersey native two honors from the American Gem Trade Association (AGTA) in the last two years. In 2016, he won “Best Use of Color” in the Summer AGTA Spectrum Awards for a bicolor tourmaline ring created for a client, and in 2017, he took home first place honors in the Spectrum Awards’ “Objects of Art” category for his “Colors of Maine” gemstone kaleidoscope.

The recognition is exciting and humbling for Katzenbach, who owns Katzenbach Designs, a studio in the mountains of Maine that specializes in locally sourced tourmaline, precision faceting, fantasy-cut gemstones and custom-designed jewelry.

“My philosophy when designing a piece is to follow what the stone tells you,” Katzenbach says. “The best pieces come from taking risks throughout the process – it’s the only way to develop your own style and see what will work.”

Katzenbach cut this colorful, 38.04-ct Bolivian ametrine with an original design. Courtesy of Derek Katzenbach
Katzenbach, who counts artists like Dalan Hargrave, Ryan Joseph Anderson and Richard Homer among his inspirations, did not set out to become an artist or jeweler. He first moved to Maine to study marine biology, and though the subject had been a laser-focus for him since elementary school, something “didn’t click” once he began his studies.

During that time, Katzenbach visited a local gem show.

“I spent a week’s pay in about an hour, then went to the ATM and did it again,” he says. “I had zero experience buying, setting or designing stones. But I was officially addicted, and I didn’t know what had hit me.”

That summer, Katzenbach worked at a store that sold a variety of gifts, from knives to locally made jewelry. His boss showed him how to set stones in pre-notched settings, and Katzenbach began to introduce himself to others in the field who could help him navigate this newfound interest.

Derek Katzenbach, GJG, created this 12-ct, fantasy-cut stone from Colorado topaz rough. Courtesy of Derek Katzenbach
One jeweler in town connected him with local bench jeweler Addison Saunders, who became a mentor and friend. He took lessons with her for a year, learning foundational skills such as soldering and basic settings, before moving across the state. Ron Gelinas, the owner of Farmington’s Mainestone Jewelry, told Katzenbach that though he wasn’t hiring, he would show him some repair skills on Saturdays. The two struck up a friendship as Gelinas taught him how to do chain repairs and resizing.

Eventually the holidays arrived, and Gelinas offered Katzenbach his first job in the gem and jewelry industry. Katzenbach was elated, and soon began to ask Saunders and Gelinas where he could pursue further knowledge and skills. “I felt it was incredibly important to be educated properly,” he says. “They both pushed me to go to the best school in the world, GIA.”

He arrived at the Institute’s Carlsbad World Headquarters in 2005 and immersed himself in gemology and benchwork studies. Katzenbach says the instructors “went above and beyond” and he took advantage of every opportunity to learn.

“I was extremely driven,” he says. “I spent most of my spare time checking out books and instructional DVDs from the library. The amount of knowledge that sits in that building is staggering, and motivation was everywhere. Walking the halls, you see incredible displays of jewelry, minerals and faceted stones.”

This 1,452-ct, trillion-cut smoky quartz, mined at Maine’s Mount Mica, earned Katzenbach the record for the largest faceted gemstone ever cut from Maine. The gem is as big as the palm of a hand. Courtesy of Derek Katzenbach
Katzenbach passed the 20-stone exam for his GG diploma on the first try, and said that as much as he had to work, it almost felt “effortless.”

Returning to work at Mainestone after his 2006 graduation, Katzenbach was able to utilize his skills immediately as he worked on repairs, appraisals, stone cutting and custom work.

“It was the holidays – the busiest time of year for jewelers – and I was able to handle every project I was given with ease because of my GIA experience,” he says.

After a year, he began to travel around the state, selling Maine tourmaline to other jewelers. That experience, he says, opened the door to starting his own business in 2010.

“My career has been all over the place, and I try to do a bit of everything,” Katzenbach says. He wants to work on perfecting his engraving techniques, using the skills Hargrave showed him to carve larger sculptures. He also continues to create custom designs, such as the award-winning tourmaline ring.

This matched bi-color tourmaline suite, including an AGTA Spectrum award-winning ring, was designed by GIA alumnus Derek Katzenbach and recently gifted to GIA by a private donor in memory of Nicholas Scott Golden, University of Maine Geology student to the Institute by a private donor. The 14K white gold pieces, featuring tourmalines from California’s Himalaya Mine, also feature yellow diamonds, tsavorites, and rubellite. Photo by Orasa Weldon/GIA
The client who purchased that ring also commissioned a matching pendant necklace and earrings, and recently gifted the entire suite to GIA.

“Having that suite donated to GIA makes that award mean even more,” he says. “GIA was the starting point for so much knowledge and hard work. I’m so happy to see pieces of jewelry like that being preserved, shown to students, and kept in the place that gave me the knowledge to do such fine work.”

Derek Katzenbach, GJG, is an award-winning jeweler and gem cutter who studied at GIA’s world headquarters in Carlsbad in 2005 and 2006. His advice for current students? “Utilize the library,” he says. “The Richard T. Liddicoat Gemological Library and Information Center is world-class, and you will most likely never again have the opportunity to access so much knowledge about our trade, right in front of you.”  Courtesy of Derek Katzenbach
And though he’s created award-winning designs and one-of-a-kind pieces for clients, Katzenbach’s favorite piece of jewelry is his own hammered gold wedding ring, made of gold nuggets from a nearby river that he melted down. Katzenbach, who lives in Farmington with his wife, Laura, and their children, Kyran and Scarlett, knows that piece may be hard to top, but looks forward to what lies ahead.

“The best part of my job is looking for the next big project,” he says. And whatever that project is, Katzenbach says if his designs inspire curiosity, he knows he’s doing something right.

“It means I’m on the right track.” @chapter:26


Publication Year: - Title: A Study of Sapphire from Chanthaburi, Thailand and its Gemological Characteristics Abstract: Rough and facetted sapphires from Thailand. The large facetted stone in the center weighs 8.14 ct. Photo by Wim Vertriest © GIA.  Gems courtesy of Indy Khurana (Khurana Jewels, Bangkok).

Thailand has been a leader in the global corundum trade since the 1950s. Bangkok and Chanthaburi remain important treatment and trading centers even though many—though not all—of the country’s corundum deposits are nearly exhausted. Since the early 2000s, there’s been a small-scale mining revival in Thailand’s Chanthaburi province. Chanthaburi’s sapphire deposits are associated with alkali basalts, where the gems occur as xenocrysts in basalt in the Khao Ploy Waen and Bang Kacha areas. Local farmers partner with miners to work the sapphire deposits and return the land back to agricultural use when mining ceases.

A new report from the GIA Laboratory in Bangkok, A Study of Sapphire from Chanthaburi, Thailand and its Gemological Characteristics presents their findings. 59 blue/greenish-blue sapphire samples obtained from a miner in the Khao Ploy Waen area, Chanthaburi, were fashioned to optimize them for LA-ICP-MS chemical analysis, UV-Vis-NIR and FTIR spectroscopy, and inclusion studies using microscopy and Raman spectroscopy.

Thai sapphires resemble gems from other basalt-related deposits in Cambodia, Nigeria, Cameroon, Australia, Laos and Northern Madagascar. As sapphires from these sources share similar geologic origins, it’s challenging to discriminate between them. Magnification revealed angular growth structures, needles, and particles, along with mineral inclusions like plagioclase feldspar, zircon, pyrochlore, monazite, mica, and molybdenyte. UV-Vis-NIR and FTIR spectra show features typical of basalt-related sapphires. Although LA-ICP-MS analysis showed a large overlap with the trace element chemistry of sapphires from other basalt-related deposits, the authors identify some overall trends that could prove helpful. They also suggest a combination of techniques—trace-element chemistry and microscopy—can help separate Thai blue sapphire from Cambodian and Nigerian samples with similar characteristics. However, the authors note to further support geographic origin determination, the relationship between inclusions, spectra and chemistry in basalt-related sapphires needs further analysis and study. @chapter:3


Publication Year: 1993 Title: Garnets from Altay, China Abstract: Gem-quality spessartine garnet and grossular garnet have been discovered in Altay, China. Gemological and mineralogical studies show that their properties are typical for these garnet species. Spessartine and grossular are being mined commercially, but gem-quality grossular with fine color is rare. @chapter:4


Publication Year: - Title: How to Travel Brazil: Gemstones Edition Abstract: A selection of Brazilian gemstones. (From top, clockwise): rubellite tourmaline, emerald, aquamarine, imperial topaz, yellow topaz, bicolor tourmaline. Center: Paraiba tourmaline and brown diamond. Photo by Robert Weldon/GIA.

Brazil is a tropical locale well-known for exotic animals and plants, futból, sandy beaches, and jungle-clad mountains. Some of these mountains rise like monuments in the middle of cities, such as Sugarloaf Mountain in the ever-colorful and playful Rio de Janeiro. The country also contains the renowned Amazon River, not to mention superb gemstones in a kaleidoscope of saturated, luscious colors.

From the Mirador, this iconic vista of the city of Rio de Janeiro encompasses picturesque bays and inslets, surrounded by inselbergs, or mountains that jut out across the landscape. Photo by Robert Weldon/GIA
 Brazil’s rich natural gemstone resources include many varieties of tourmaline, topaz, beryl, and quartz, among others.

		If you’re a gem lover, Brazil is the dream destination, sure to top your bucket-list of must-see places in the world.

So as you plan your dream vacation, read these travel tips and information to help you get the most of your trip to Brazil.
Tourmaline

In tourmaline alone: orange, yellow, green, blue, and violet varieties hail from almost every corner of this enormous country. They are particularly found in Brazil’s state of Minas Gerais (a name which appropriately translates to “General Mines.”) It is also home to Paraíba tourmaline, a unique, electric blue-green variety, which derives its color from microscopic traces of copper. These gems are found in the northern state of Paraíba, to which they owe their name. Occasionally, the colors in tourmalines are mixed, resulting in bi-color or multicolored gemstones. There’s enough choice in tourmaline to capture everyone’s fancy.
Beryl

Miners often use water and specific gravity in a sifting exercise to separate out denser materials like gemstones. When the basket is emptied, upturned on the ground, the gems are visible on the top. Photo by Robert Weldon/GIA
Almost every member of the beryl family is represented as well: ocean-blue aquamarines and leafy green emeralds, delicate pink morganites and bright yellow heliodors make up this interesting Brazilian gem family. Cat’s-eye chrysoberyls and the extremely rare color-change alexandrites are found in Brazil as well.
Quartz

In Southern Brazil¹s state of Rio Grande do Sul the gem mines there include important deposits of amethyst and other quartzes, as well as chalcedonies. Photo by Robert Weldon/GIA
Take a trip down to Southern Brazil, known for its quartzes. Amethyst, citrine, rock crystal, and a huge variety of agate come from the State of Rio Grande do Sul. From the State of Bahia to the north comes one of Brazil’s most exotic quartzes, the dazzling, rutilated quartz. This beautiful gemstone features gleaming streaks of golden rutile running through the gem. One of Brazil’s most celebrated and unique gems is mined close to the colonial Baroque town of Ouro Preto in Minas Gerais. It is the orangey-gold variety of topaz that is often tinged with pink. In the trade, it lives up to its exalted name, “imperial topaz.”

People from all over the world collect Brazil’s finest mineral specimens, such as this amethyst and rock crystal quartz geode. Photo by Robert Weldon/GIA
Other gems you might not necessarily associate with Brazil are found here too, such as opals with strong play of color, as well as fire opals. Garnets are found in Brazil as well, and delicately-hued pink kunzite.
Diamonds
Few people are aware that Brazil was once the foremost source of diamonds, and that it remains an important source still today. In the 1700s and early 1800s, some of the world’s most celebrated diamonds were found in this enchanting land, including extremely rare red diamonds as well as green, and other fancy colors. Alluvial diamonds continue to be found in Brazil, mostly mined from riverbeds and from conglomerate host rock.
Your Brazilian Gemstone Journey: 4 Tips To Consider
Gem Places to Visit
The sprawling cities of Rio de Janeiro and São Paulo are both hosts to some of Brazil’s most venerable jewelers, such as H. Stern, Amsterdam Sauer, Natan, and Manoel Bernardes. Beyond these two metropolises, each of these jewelers also has retail outlets in Brazil’s principal cities and in many hotels and airports. They have deep roots to the gem sources of Brazil, in many cases owning mines in Brazil’s interior.

A local jeweler in Ouro Preto takes all kinds of credit cards. Photo by Robert Weldon/GIA
H. Stern is famous for taking busloads of newly arriving international passengers to its premiere headquarters in Rio de Janeiro. A tour of the facilities includes a walk through a virtual mine, a chance to see gemstones being cut and polished, and a glimpse behind the scenes to observe jewelry being made. It is a unique mine to market experience with a special Brazilian flair. Amsterdam Sauer has a museum that features Brazil’s most celebrated minerals and gemstones. The city of Belo Horizonte in Minas Gerais has one of the country’s most important gem and mineral museums, the Museu das Minas e do Metal.
If you are traveling in the interior of Minas Gerais, the Baroque Colonial city of Ouro Preto is a must-see for its picturesque architecture, spectacular churches, and rolling hills. It is near to the imperial topaz mines and a gold mine that you can visit. Diamantina is also a Baroque colonial city that was once the center of the diamond business in Brazil – hence the name. Both of these towns are UNESCO world heritage sites.
Taking Care of Yourself
If you’re traveling in Brazil, a few words of caution. Because of disparity in incomes and rising populations, visitors need to be aware of some dangers. As anywhere in the world, tourists need to be cautious of pickpockets and theft. Even though Brazil is extremely photogenic, cameras and other valuables such as cell phones and jewelry should be kept concealed as much as possible in larger cities. In fact, we recommend leaving your most valuable jewelry behind to remove the possibility of it getting lost or stolen. Rio de Janeiro has made great inroads in halting crime along its beaches, but petty theft remains ubiquitous, even in broad daylight. This threat diminishes dramatically as a traveler goes into smaller towns and villages in the interior of Brazil.

Ouro Preto is an old colonial Baroque town in Minas Gerais that was made famous for its gold deposits and also for the so-called Imperial topaz mines. Photo by Robert Weldon/GIA

What Else to See
Rio de Janeiro is famous for its beaches and also for Sugarloaf Mountain (Pão de Açúcar), a peak that rises dramatically in the middle of the city of Rio de Janiero. A trip to the summit of Corcovado is a must, from where you can see the spectacularly beautiful layout of the city with its bays and inlets and islands. If you have a chance to witness a soccer game at the famous Maracana stadium in Rio, you will experience Brazilian fervor at its zenith. São Paulo is in Brazil’s interior, devoid of Rio’s laid-back beach atmosphere. It is a sprawling metropolis filled with art galleries, malls, gardens, cathedrals, and swanky restaurants. São Paulo was the Portuguese colonists’ springboard to the discovery of Brazil’s interior in the 1600s.
What To Eat
Brazilians love meat. When you’re in any big town in Brazil, a visit to Fogo de Chão, or other churrasquerias is a must, though you should arrive with an empty stomach. For those who prefer to skip the meat at the famous Brazilian steakhouses, the salad bar will supply ample diversion. Pão de queijo, a small cheese-laden bread made with yucca flour, is found throughout the state of Minas Gerais, which is a huge agricultural region (in addition to mining). Feijoada is a bean-based meat and corn stew that is enjoyed across Brazil. A variation of stew called moqueca in which seafood is cooked in coconut milk, is found in coastal cities to the north, such as Salvador in Bahia. Yum!

Brazil and its people are among the world’s warmest and most hospitable. It is one of the greatest gemstone sources in the world where you will also be able to enjoy the deep-rooted culture, the country’s delectable food, the passion of its people, and the spectacular landscapes.

When you go home, take a gemstone with you. You’ll be returning with a small piece of Brazilian real estate, and memories to last a lifetime. Before you pack your bags for your trip, you might want to brush up on your gem photography skills with these 6 Tips for the Best Gem Photos. @chapter:3


Publication Year: 2014 Title: Eighty Years and Still Going Strong Abstract: It is truly a privilege to be at the helm of Gems & Gemology in the journal’s 80th year, following in the illustrious footsteps of Robert M. Shipley, Richard Liddicoat, and Alice Keller. We start 2014 with renewed anticipation and the strongest intention to build on the many notable innovations that shaped G&G in previous years. This year, we will continue to foster collaboration with researchers working in related fields at other institutions, while actively producing dynamic media content for the GIA website that complements and adds value to our printed journal.

This issue’s lead article focuses on the Chinese gem and jewelry industry. This paper lays the foundation for a series of articles that will explore specific aspects of China’s powerhouse industry, including diamond and colored stone cutting, jewelry manufacture, design, and jewelry retail, as well as uniquely Chinese industry sectors like jade carving. The paper is a partnership between Chinese authors Zhili Qiu, Mu Li, and Qingyuan Yu, and G&G’s own Tao Hsu and Andrew Lucas. As demand for gem and jewelry products surges in China and impacts consumption patterns elsewhere, this is a very timely topic for our journal to investigate. To reach a wider audience, we have provided a Mandarin translation.

Download: Exploring the Chinese Gem and Jewelry Industry - Mandarin translation (PDF)

Our second article is a study of near-colorless synthetic diamonds grown using high-pressure and high-temperature (HPHT) by the AOTC Group of the Netherlands. AOTC is the dominant near-colorless HPHT synthetic diamond producer targeting the gem trade. Lead author Ulrika D’Haenens-Johansson, a research scientist at GIA’s New York laboratory, investigates the gemological and spectroscopic properties of a suite of 52 colorless to light-colored synthetic diamonds. This important paper illustrates the recent strides made in growth technology and quality.

We are also delighted to present G&G’s second field report. Titled “Hunting for ‘Jedi’ Spinels in Mogok,” it details GIA field gemologist Vincent Pardieu’s decade-long quest for bright “neon” red spinel in Myanmar’s fabled “Valley of Rubies.”

In our fourth and final article, we offer a fascinating look at a baroque South Sea cultured pearl from Indonesia that is far larger than the norm for specimens of this type. Ms. Laura Otter and her co-authors use high-resolution computerized microtomography to study the cultured pearl’s interior.

In addition to our regular Lab Notes and Gem News International sections, we bring you in-depth coverage of the February 2014 Tucson gem and mineral shows. And don’t forget to take the G&G Challenge, our annual multiple-choice quiz.

We hope you enjoy the Spring 2014 edition! @chapter:29


Publication Year: 2014 Title: GIA Museum Exhibits in New York Abstract: “Fantastic Cross,” an 18K gold brooch featuring turquoise, variscite, chrysocolla, cultured pearl, and enamel, is part of the museum display at GIA’s New York laboratory and campus. Photo by Orasa Weldon/GIA, courtesy of the Anthony and Elizabeth Duquette Foundation for the Living Arts.

              GIA’s recently opened laboratory and campus at the International Gem Tower in New York’s Diamond District features a permanent museum exhibit of gems, jewelry, and mineral sculptures. Fourteen display cases highlight nearly 100 items from the GIA collection, ranging from large aquamarine crystals to a diminutive objet d’art golden cactus and a necklace featuring akoya, Tahitian, and South Sea cultured pearls (figure 1). The exhibit showcases the wonder of gems to visitors and students. @chapter:21


Publication Year: 2016 Title: Blue Dravite-Uvite Tourmaline from Koksha Valley, Afghanistan Abstract: Figure 1. This specimen of dark blue tourmaline on micaceous matrix, from the Koksha Valley of Badakhshan Province in Afghanistan, measures 28 × 25 × 17 mm. Photo by Kevin Schmacher.

	Tourmaline is popular among gem and mineral enthusiasts for its extensive variety of colors. Blue, one of the most sought-after hues, is usually encountered as elbaite, a sodium- and lithium-containing species with the chemical formula Na(Li1.5Al1.5)Al6(Si6O18)(BO3)3(OH)3(OH). While it has been reported that very limited quantities of dark blue tourmaline crystals are being mined in Afghanistan’s Koksha Valley, we have found that this material appears to be a hybrid species of dravite-uvite tourmaline (figure 1).

	Around a dozen blue crystals in pale green and brown micaceous matrix first surfaced in the gem markets of Peshawar, Pakistan, in late 2009, as confirmed by two sources (S. Khan and P. Slootweg, pers. comms., 2016). These crystals, reportedly from Badakhshan Province’s Koksha Valley, were subsequently assumed to be a member of the tourmaline group based on their ditrigonal pyramidal habit. Since that time, only very small batches of these crystals have turned up; interestingly, a few of these specimens have been associated with sapphire in the same matrix (P. Slootweg, pers. comm., 2016). In 2010, while examining sapphire rough believed to be from a deposit near the Koksha Valley, GIA’s Bangkok laboratory identified bluish green crystals present in some matrix specimens of sapphire as dravite tourmaline (Spring 2011 Lab Notes, pp. 53–54). While the Koksha Valley is most famous for extensive deposits of high-quality lapis lazuli near Sar-e-Sang, sapphire mining takes place near the village of Hazrat Saeed, 25 km north of Sar-e-Sang along the Koksha River (T.P. Moore and R.W.M. Woodside, “The Sar-e-Sang lapis mine,” Mineralogical Record, Vol. 45, No. 3, 2014, pp. 280–336). The sapphire at Hazrat Saeed is recovered from mica-rich gneiss, and it appears that these green and blue tourmalines were uncovered as a by-product of sapphire mining operations.

	Laser ablation–inductively coupled plasma–mass spectrometry (LA-ICP-MS) was used to analyze the chemical composition of the dark blue tourmaline seen in figure 1. Three spots were measured and plotted (figure 2). Two of the spots showed that the tourmaline contained dravite; the third revealed the presence of uvite (D.J. Henry et al., “Nomenclature of the tourmaline-supergroup minerals,” American Mineralogist, Vol. 96, No. 5–6, 2011, pp. 895–913). Dravite, NaMg3Al6(Si6O18)(BO3)3(OH)3OH, is a sodium- and magnesium-rich tourmaline typically encountered in brown, yellow, black, and rarely as intense green. Uvite, Ca(Mg3)MgAl5(Si6O18)(BO3)3(OH)3(F/OH), is a calcium- and magnesium-rich tourmaline that is often brown, green, or deep red. Our analysis suggests that this blue tourmaline specimen is composed of a mixture of dravite and uvite. While fibrous blue dravite has been reported in the Czech Republic (M. Novak, “Blue dravite as an indicator of fluid composition during subsolidus replacement processes in Li-poor granitic pegmatites in the Moldanubicum, Czech Republic,” Journal of the Czech Geological Society, Vol. 43, No. 1–2, 1998, pp. 24–30), this is the first large single-crystal blue dravite-uvite tourmaline the authors have encountered.

	Figure 2. Left: Three laser spots were plotted in the ternary system for the primary tourmaline groups based on the dominant occupancy of the X site. Center: Two blue laser spots that belong to the alkali primary tourmaline group were further plotted in the ternary dravite-schorl-elbaite subsystem. Right: One orange laser spot that belongs to the calcic primary tourmaline group was further plotted in the ternary liddicoatite-feruvite-uvite subsystem. These findings show a range of composition consistent with the dravite-uvite series. @chapter:5


Publication Year: - Title: GIA Researchers Reveal the Secrets to Diamond-in-a-Diamond Mystery Abstract: This 0.62 carat green “matryoshka” diamond from Siberia has an internal cavity, connected by two small channels to the outside. A small diamond crystal moves freely inside. Courtesy of Alrosa. Photo by Jianxin (Jae) Liao/GIA

A diamond is a rare and beautiful gift from the earth. But a diamond within a diamond? That is an extra special gift.
Researchers in the GIA laboratory in New York recently had the opportunity to examine one of the most interesting and unique diamond crystals ever found. The crystal, dubbed “matryoshka” after the iconic Russian nesting dolls, was discovered by the Russian mining company Alrosa in Siberia in 2019. While it has several unusual characteristics, including its color, etching and internal cavity, it is the crystal that is trapped, but moves freely, inside the larger diamond that attracted a lot of interest.
“We have never seen anything like this,” said Tom Moses, GIA executive vice president and chief laboratory and research officer. “This is a truly unusual diamond, not only for the fact that there is a small diamond crystal inside and entirely detached from the host crystal, but also for the mystery of how this diamond-in-a-diamond formed.”

This video shows how the internal diamond crystal moves freely in the host diamond. Video by Towfiq Ahmed/GIA
The GIA research team – Dr. Wuyi Wang, GIA vice president of research and development; Staff Gemologist Emiko Yazawa, Senior Analytics Technicians Stephanie Persaud and Elina Myagkaya, Senior Research Scientist Dr. Ulrika D’Haenens-Johansson and Moses – examined the 0.62 carat rough crystal using advanced instrumentation.
Based on their observations and expertise in diamond formation, they determined that over time – millions or billions of years – about 0.11 carats of diamond material dissolved away through two small etched channels that extended from the surface of the diamond to the internal cavity. The diamond material that remained formed into a small diamond crystal of 0.03 carats that is entirely detached from the host crystal.
Detailed analysis confirmed that the small internal diamond has nearly the identical trace element chemistry as its host and that when the host formed in the earth’s mantle, it was a solid diamond without the cavity.

This animation shows the host crystal, internal cavity and the internal crystal. Produced by Emiko Yazawa/GIA
The team was also intrigued by the natural clear green body color of the internal crystal and the “Christmas-tree” like etchings that decorated its surface. They determined that these were small, dark green radiation stains that were present in shallow fractures along its edges, which revealed that this diamond was naturally irradiated. Fluid with radioactive elements is responsible for the green body color and formation of radiation stains, and would have been the last step in decorating this crystal.
“Examining this nesting-doll diamond was a remarkable opportunity,” Moses said. “We know that most diamonds form in a melt/fluid environment, and that they often are partially resorbed and reformed from interactions with multiple types of melt/fluid materials. The opportunity to examine this special diamond-within-a-diamond added to our understanding of how diamonds form.”
A more detailed article is planned for the Lab Notes section of the Spring 2020 edition of Gems & Gemology. @chapter:35


Publication Year: 1997 Title: Summer 1997 G&G Lab Notes Abstract: Etched Chalcedony
Diamond with “Additional” Color
Rough Diamond with Contrasting Colors
Treated-Color Yellow Diamonds with Green Graining
An Unusual Assembled Imitation Emerald
Star Feldspar
Jadeite Jade Beads of an Unusual Color
Jadeite Cavity Impregnated with a Colored Filler
Dyed Impregnated Jadeite Bangle without a “Dye Band” Spectrum
Assembled Imitation Ruby
Sapphire with Evidence of Heat Treatment
Serendibite, a Rare Gemstone
Zircon with “Play-of-Color”

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


Publication Year: 2017 Title: Cat’s-Eye Kornerupine Abstract: Figure 1. This 1.44 ct yellowish green kornerupine displayed strong chatoyancy. Photo by Sood Oil (Judy) Chia.

A dark, translucent, yellowish green oval cabochon (figure 1) was recently submitted to the New York lab for identification. The 1.44 ct stone displayed an intense chatoyancy. With a spot refractive index reading of 1.67 and a hydrostatic specific gravity of 3.32, the stone was identified as kornerupine, a rare borosilicate mineral found in boron-rich volcanic and sedimentary rocks that have undergone metamorphism (http://rruff.info). Raman spectroscopy confirmed the identification.

Cat’s-eye kornerupine is an extremely rare gemstone. Its chatoyancy is caused by rutile and graphite inclusions (H.N. Lazzarelli, Gemstones Identification: Blue Chart, 2010, www.gembluechart.com). However, we were unable to identify the needles in this stone using Raman spectroscopy. Fiber-optic illuminated magnification exposed dense clusters of these needles, some displaying iridescence (figure 2). This was GIA’s first encounter with this material in more than a decade.

Figure 2. A dense collection of needle inclusions was the cause of the chatoyancy.
Photo by Daniel Girma; field of view 2.08 mm. @chapter:13


Publication Year: - Title: Extraordinary Gemstone Sculptures Make Debut at GIA Abstract: View Gallery

The display of Perry Brent Davis’s carvings of agate and gem quartz at GIA’s Carlsbad campus looks like a colorful seascape of otherworldly designs. Many float above sensuously curved bronze arms; others are grounded on sleek blocks of black granite. Each is carved and highly polished to showcase its internal features and patterns.

	“I choose stones that exemplify the power of nature,” Davis says. He finds “some of the most beautiful, naturally colored minerals the earth produces” and turns them into works of art.

	“This incredible medium forms my raw material – often there are natural crystal pockets and features that accentuate the simple form of my contemporary pieces,” Davis says. Several of the designs, for instance, reveal drusy-lined interior pockets that sparkle against the high polish of the exterior surface.

	Davis, a graduate gemologist with three decades of experience in the gem and lapidary fields, moved to China from the U.S. in 2006 to pursue his interest in large gemstone carvings. He opened a studio and hired a team of traditional carvers. He and his team incorporate modern and ancient Chinese carving techniques into each piece.

	The results are larger-than-normal gemstone sculptures that emphasize the rich colors, ornamental patterns and internal features in agate, rock crystal and jasper. Most of the design process takes place on the stone itself, Perry says, and is refined as the carving evolves. It can take 200 to 1,400 hours to complete a piece, but many fall in the 200-500 hour range.

	“To get such amazing carvings in such large sizes is a feat,” says Terri Ottaway, curator of collections for the GIA Museum. “But then to carve and polish them so beautifully to bring out the intricate patterns is quite an accomplishment and rarely seen.”

	Davis gets his rough pieces from mines in the U.S., Mexico, Brazil and Austrailia. He says that going to the mines is "like going to Las Vegas" unless he knows an owner is going to be there with rough. He says he has better luck at gem and mineral shows where there are large quantities at good prices.

	Davis selects gemstones that are technically complex and require a vast array of diamond tools and other equipment to carve. Working on them requires a high level of technical ability and articulate workmanship, according to Nathan Renfro, a gemologist in GIA’s Carlsbad laboratory who is also a gem carver.

	“From the captivating design to the quality of his workmanship,” Renfro says, “each piece Davis creates makes it clear he is a world-class artist and gem carver.” @chapter:26