Publication Year: 2020 Title: Dendritic Inclusions in Nephrite from Dahua, China Abstract: Figure 1. The nephrite samples with dendritic inclusions from Dahua County. Photos by Zuowei Yin.
Since the 2010s, with the discovery of nephrite ore deposits in Luodian County, Guizhou Province, a significant amount of nephrite has been mined in the town of Yantan in Dahua Yao Autonomous County, located in the northwest of the Guangxi Zhuang Autonomous Region (Z. Yin et al., “Nephrite jade from Guangxi Province, China,” Fall 2014 G&G, pp. 228–235). Previously we reported on the nature of the chlorite inclusions found in this nephrite, and here we identify the chlorite as penninite.
The discovery of Dahua nephrite has eased the increasingly tight nephrite supply situation in China. Owing to its large reserves, the deposit has vast potential for future development. This material is of high quality and comes in a diverse array of colors including white, gray, light green, dark green, light yellow, and black. All bodycolors have been found to contain distinctive dendritic inclusions (figure 1). Dahua nephrite is popular with consumers, thus bringing huge economic benefit to the locality.
Dahua nephrite is mainly distributed around the river near the Yantan hydropower station. The ore body occurs in the limestone formed at the Qixian stage of the Paleozoic Permian system. The magmatic rocks in the area are basic intrusive rocks, divided into diabase and gabbro. The ore bed containing the nephrite is composed of dark gray stratified limestone of low to medium thickness, interspersed with fine calcite veins (B. Wang et al., “Gemmological and mineralogical characteristics of nephrite from Guangxi,” Journal of Gems and Gemmology, Vol. 14, No. 3, 2012, pp. 6–11). The samples were tested by standard gemological methods, polarizing microscopy, environmental scanning electron microscopy (ESEM), X-ray diffraction (XRD), Raman spectroscopy, laser ablation–inductively coupled plasma–mass spectrometry (LA-ICP-MS), and energy-dispersive spectroscopy (EDS). We conducted the tests at the National Key Lab of the China University of Geosciences in Wuhan.
The refractive index of Dahua nephrites ranged from 1.60 to 1.63. The average hydrostatic specific gravity was 2.99, and the Mohs hardness was about 6.5. These properties were very similar to those of the samples previously tested, which had a spot RI of 1.61–1.62 and a hydrostatic SG of 2.88–2.90 (Yin et al., 2014).
The Raman spectra (peaks at 225, 370, 676, 1029, and 3677 cm–1), infrared spectra, and X-ray powder diffraction (characteristic lines at 3.1189, 8.3968, 3.2702, and 2.7007 Å) were consistent with tremolite, showing that the main composition mineral of Dahua nephrite is tremolite with good crystallinity. Chemical composition analysis showed that the Mg2+/(Mg2+ + Fe2+) value of nephrite samples from Dahua was 0.973, identifying the main mineral as tremolite.
The REE distribution pattern of Dahua nephrite had an average value of ∑ REE and LREE/HREE of 5.32 and 2.60, respectively, indicating that Dahua nephrite is slightly enriched in light rare earth elements. The δCe of the samples ranged from 0.21 to 0.91, with an average value of 0.47, indicating a negative Ce anomaly. This suggests that Dahua nephrite was formed in a sedimentary metamorphic environment, with high oxygen fugacity and a single source of nephrite ore-forming fluid. The average δEu value of the samples was 0.71 in the range of 0.12–2.01, indicating a negative Eu anomaly. The negative Eu anomaly in this area may be due to the separation and crystallization during the ore-forming process of nephrite.
Most nephrite in Dahua has dendritic inclusions whose colors are mainly brownish yellow, brownish green, and black distributed in the form of branches, clumps, and the like. These “variegated” inclusions were actually determined to be penninite (belongs to the chlorite group) using modern techniques including routine gemstone testing, X-ray powder diffraction, scanning electron microscope, and EDS. According to the composition determined by EDS testing, we calculated the atomicity of Si with O20 as a reference. The results were as follows: The number of Si atoms was 6.4, and Fe2+/Fe + Mg was 0.16, indicating that the chlorite inclusion was a type of penninite (red cross in figure 2, from the chlorite classification scheme in Y. Hu et al., “Related studies on characteristic altered mineral chlorite,” West-China Exploration Engineering, No. 11, 2019, pp. 132–134).

Figure 2. EDS compositional analysis showed that the chlorite inclusion in Dahua nephrite was penninite. From the chlorite classification system in Hu et al. (2019).
The variegated chlorite inclusions in Dahua nephrite are very useful identifying characteristics. With the exception of Luodian nephrite, which contains similar inclusions, such distinctive dendritic inclusions have yet to be discovered in white nephrite deposits; therefore, it is potentially a significant tracer for origin. The Dahua nephrite contains penninite, a type of chlorite (i.e., hydrothermally metamorphosed tremolite) (Yin et al., 2014). As an inclusion unique to Dahua nephrite, penninite serves as an important reference for origin tracing. @chapter:5


Publication Year: - Title: Romancing the Source: Pakistan Abstract: Pakistan

	Pakistan’s portion of the Silk Road traverses some of the highest mountains in the world, where mining benefits locals and helps them rebuild their lives.

	This series of articles and videos follows a team of GIA Field Gemologists on their travels from the mountains of Afghanistan to the jungles of Sri Lanka in search of the sources of colored gemstones and the people who pursue them. This thrilling journey will take you to remote gemstone-mining areas, where you’ll witness the extreme effort required to wrestle nature’s treasures from the earth.

	The romance of a colored gemstone arises from its beauty, the exotic qualities of its source’s location, the adventure leading to its discovery, and the stories of the people who seek it. These factors have united to create the allure of gemstones through the ages, and continue to do so even in modern times.

The northern region of Pakistan is home to some of the world’s highest mountains. In a ruby-producing area near the beautiful Hunza Valley, this miner’s wife attends a program created to educate her children and teach her to cut gemstones. Photo by Andrew Lucas.

	Pakistan yields a wealth of gemstones for jewelry and for mineral collectors. Incredible crystal specimens from the areas around Skardu, ruby from the Hunza Valley, and emerald from the Swat Valley are a few of the area’s treasures.

	Reaching the Gilget/Hunza valley area can involve a 17-hour drive from Islamabad, as flights are often cancelled due to weather conditions in the mountains. The drive is on the Karakoram Highway that passes through the area where three of the world’s greatest mountain ranges meet: the Karakoram, Hindu Kush, and Himalaya ranges. The dramatic forces created by the collision of these mountain ranges led to geological events that formed gemstones and shaped the area’s rugged terrain. This highway is part of the old Silk Road, and traveling on it today is still an exhilarating experience.

	The Swat Valley has been called the Switzerland of Central Asia. It’s surrounded by beautiful mountains covered with snow in the winter. After a violent conflict between Pakistani military forces and Taliban militants that led to the overthrow of Taliban control, emerald mining resumed in the valley as a means to rebuild the area and people’s lives. @chapter:18


Publication Year: - Title: Winter 2012 G&G Lab Notes Abstract: Artificially Irradiated Brown Diamond
Diamond with Diopside-Pyrope Contact Inclusion Pair
Treated Yellow Diamond with Unusual Spectroscopic Features
Unusual Omphacite and Pyrope-Almandine Garnet Inclusion in Diamond
Polymer-Beryl Assemblage
Bicolored Spinel
Silicon-Vacancy Defect in HPHT-Grown Type IIb Synthetic Diamond

To view the full section, download the PDF above. @chapter:11


Publication Year: 2019 Title: Book Review: Geology: A Very Short Introduction Abstract: By Jan Zalasiewicz, paperback, 168 pp., illus., publ. by Oxford Academic Press, Oxford, England, 2018, US$11.95.

Geology–it’s a fairly large subject to take on in a pocket-sized book. The entire 4.54-billion-year history of the earth—the ceaseless shifting of tectonic plates, the rise of multicellular organisms, the shaping of the planet that would one day be called home by us homo sapiens—all captured in a mere 168 pages. As a geologist, I approached Geology: A Very Short Introduction cautiously, hoping the topic could be faithfully represented in a book whose size doesn’t embody the enormous complexity of the subject. I was pleasantly surprised as the author wove his way through not only the history of the earth, but also the history of the study of the history of the earth, deftly moving from one geological development to the next, finding the common theme in all these stories to bring it together into a coherent narrative. The book is an approachable introduction to the earth and humankind’s endeavors to better understand its rocky abode through scientific examination. Yet the content is engaging and thorough enough that professional geologists might find themselves transported back to the airy university lecture halls of their youth where their passion for geology was once uncovered.
After a brief introductory chapter, Zalasiewicz delves into the historical underpinnings of modern geology in chapters 2 and 3. This engrossing history is neatly summarized. From the study of fossils to the development of the first geological maps, readers are given a view into the minds of the first serious thinkers who pursued the study of the earth and formed the foundation of geology as we know it. Zalasiewicz tends to favor the study of fossils and stratigraphy in his coverage, although this might be fair given the early importance of those fields in forming our understanding of earth processes.
The rest of the book focuses on more specific topics within the field of geology, from the deep earth (chapter 4) to the surface (chapter 5), from man’s search for natural resources (chapter 7) to the environmental repercussions that sometimes result (chapter 8). Zalasiewicz keeps readers’ interest by emphasizing human connection in the advancement of the study of Earth. The pages abound with stories of the scientific luminaries who uncovered many of the earth’s mysteries. Understanding the motivations and passions of these geological pioneers helps make their great scientific achievements more approachable and puts the historic progression of geological thought into perspective.
The book is a quick but interesting read, and its small size makes it a convenient travel partner. Zalasiewicz’s writing is familiar and engaging, never too technical but also never shying away from taking on important yet uncomfortable topics such as humankind’s sometimes negative impacts on the environment. The book is graced by 40 illustrations, maps, and photographs. These are generally of very high quality and complement the text even though they are printed in black and white. While Zalasiewicz’s coverage in this (very) introductory text is only skin-deep, he provides excellent suggestions for further reading for the reader who needs to dig in deeper. Ultimately, Geology: A Very Short Introduction should serve as a superb read for a wide spectrum of readers, from the most erudite professional geologists to those with almost no prior interest in geology. @chapter:20


Publication Year: 1999 Title: Russian Synthetic Ametrine Abstract: Gem-quality synthetic ametrine has been produced commercially in Russia since 1994, by hydrothermal growth from alkaline solutions. Faceted synthetic ametrine has many similarities to its natural counterpart from Bolivia. For the most part, however, the synthetic ametrine obtained for this study could be identified by a combination of characteristics, including growth features such as twinning and color zoning. EDXRF chemical analyses revealed higher concentrations of K, Mn, Fe, and Zn than in natural ametrine. IR spectra of the synthetic citrine portions showed more intense absorption in the 3700–2500 cm−1 range compared to natural ametrine; the synthetic amethyst zones showed a weak diagnostic peak at 3543 cm−1. @chapter:10


Publication Year: 2018 Title: Tucson 2018 Overview Abstract: Figure 1. Although traffic at the AGTA show was lighter than in some previous years, demand was brisk and most traders were satisfied with their 2018 business. Photo by Kevin Schumacher.

Every February the gem and mineral world descends on Tucson, transforming the downtown convention center and a great many of the city’s hotels into a fascinating collage of traders bearing goods from all over the planet (figures 1 and 2).

Figure 2. Customers in Tucson sought out unique goods, a trend that carried over from last year's shows. Photos by Kevin Schumacher.
Many of the exhibitors we spoke with described 2018 as the strongest year since 2008. Although traffic wasn’t especially heavy at the AGTA and GJX shows, most dealers there enjoyed brisk sales and healthy demand for high-quality goods. Some of the same trends from last year were evident. Customers still sought out one-of-a-kind pearls and colored gemstone pieces, and the secondary market in the U.S. for exceptional pieces remained highly significant. There was a continuing focus on untreated material and ethically sourced gemstones, a subject articulated for us by Jean Claude Michelou of the International Colored Gemstone Association and officials from the Responsible Jewellery Council. Market realities such as very strong price competition for newly mined gem rough were mentioned as a major challenge by many dealers and cutters.

In addition to strong demand for high-end gems, many dealers at AGTA and GJX reported a surge in more moderately priced goods. Meanwhile, dealers at other locations told us the commercial end of the market remained soft.

Pantone’s color of the year for 2018, a shade of purple called Ultra Violet, was well represented at the shows. A couple of dealers had exceptional examples of purple sillimanite. Many dealers posted strong sales of pastel-colored spinel—in pink and lavender hues—in suites and sets as customers found the scarcity and high prices of red spinel prohibitive. In a similar vein, Margit Thorndal of Madagascar Imports reported strong demand for purple-lavender spinel and purple sapphire from Madagascar, as well as teal hues of unheated Montana sapphire.

We noted that electric blues, teals, hot pinks, hot yellow greens, and pastel-colored gems were quite popular. Bill Larson of Pala International pointed to this trend and showed us a number of spectacular examples from his inventory. Fine blue zircon from Cambodia was prominent, as was attractive sphene from Zimbabwe and Madagascar.

Figure 3. Dave Bindra of B&B Gems showed us a selection of standout gems from the secondary market, including this 61.92 ct Imperial topaz. Photo by Kevin Schumacher.
Dave Bindra of B&B Fine Gems said his company was very active in scouring the secondary markets for old jewelry items and gemstones that have been out of circulation for decades. This year’s standouts were two incredible red beryls from Utah (a 3 ct emerald cut and a 4 ct round brilliant), a 61.92 ct Imperial topaz (figure 3), and a fine selection of Kashmir sapphires, which were very sought after this year. Fran Mastoloni of Mastoloni Pearls updated us on current trends in the cultured pearl market and showed examples of unique pieces.

Dealers specializing in domestic gems reported strong demand. John Woodmark of Desert Sun Mining & Gems told us the market for Oregon sunstone was the strongest he had seen since the andesine controversy challenged suppliers of the natural Oregon gem a decade ago. As a result, the company has scaled up its mining activities and built new relationships with gem cutters to improve supply to its clients.

As always, the Tucson shows were a rich source for the latest on global colored stone supply. Conversations with Luis Gabriel Angarita and Edwin Molina revealed insights on the mining and branding of Colombian emerald. Marcelo Ribeiro shared details on mining and cutting at the Belmont emerald mine in Brazil. Alexey Burlakov offered his perspective on Russian demantoid production, while Stephan Reif did the same for demantoid from the Green Dragon mine in Namibia. Miriam Kamau shared information on her Kenyan tsavorite mining operation and offered her own inspirational success story. From Jürgen Schütz of Emil Weis Opals we learned about the cutting of opal, both play-of-color and nonphenomenal, from sources around the world. Alexander Arnoldi explained Arnoldi International’s strategy in sourcing and cutting high-quality aquamarine and tourmaline. We also saw examples of gem production from unexpected sources: Indonesian opal and turquoise from the state of Arkansas.

View Gallery

Tucson is also a destination for many leading gem artists and jewelry designers. Award-winning carver Michael Dyber explained the inspiration behind some fantastic one-of-a-kind pieces bearing his signature optical disks. At the intersection of science and art, Rex Guo discussed his approach to recutting gems to optimize light performance and beauty. And designers Paula Crevoshay and Erica Courtney showed us striking and innovative new pieces with unexpected and fascinating gem combinations. @chapter:33


Publication Year: - Title: De Beers Holds Line of Prices for Feb. What About April? Abstract: Rough diamond crystals. Courtesy of De Beers.

	Buoyed by encouraging retail signs in the U.S. and Asia, De Beers allocated another large sight in February ‒ an estimated $730 million ‒ but left prices at January levels.

	Premiums on De Beers’ sight boxes rose on the wave of optimism and increased prices at tender sales in January, but De Beers’ executives held the line of prices. They are probably waiting for the results of March’s Hong Kong show to gauge the true state of the market. Diamond dealers hope that rising demand will lift polished prices, which have been stagnant for most of last year. The next sight is the first week of April.

	De Beers is also making the most of these early-year sights because the application process for the next sight term is beginning soon, and one of the criteria for selection will apparently be clients’ purchase history. Some clients deferred a significant percentage of their purchases in the first half of last year, while some potential clients were strong buyers at De Beers’ rough auctions, which comprise about 10% of its sales.

ZALE CORP. SALE: The announcement of the acquisition of Zale Corp by its chief competitor, Signet Group (Kay Jewelers and Jared, The Galleria of Jewelry), caught most in the industry by surprise; not because Zale would be sold ‒ retail analysts were predicting this for several years ‒ but that another major jewelry chain would snap it up.

	Signet has fared well in recent years, holding its own through the worst economy this generation has known, in an increasingly competitive retail arena. Zale, however, has struggled to reposition itself in an environment that has changed drastically in the past decade. The company made some progress in retooling itself during the past two years, which probably made it a more attractive acquisition, especially for a price of $1.4 billion (all figures in U.S. dollars).

	Zale earned $10 million on sales of $1.9 billion in fiscal 2013, but showed losses of $26.9 million on sales of $1.86 billion in 2012 and $112 million on sales of $1.74 billion in 2011.

	The question now is what will happen with a retail chain that is nearly 3,600 stores strong, especially since many of those stores operate in the same shopping malls as the company that bought it. Shifting an operation of Zale’s size to Signet’s vastly different business model will take years, even if it seems likely that a number of the Zale and Gordon’s stores will close.

	Integrating the two companies on such a large scale will have its challenges. Signet never lost sight of the fact that it is a jewelry seller and has combined a strong sales associate training program with a very highly targeted merchandising plan. Additionally, its advertising always stressed the romantic side of the product.  Zale’s incorporated a department store approach with little variation in its product mix between regions or store brands and its advertising tended to be more price-oriented.

DIAMONDS: The  29.62 carat blue diamond mined recently by Petra Diamond Ltd., brought a top bid of $25.5 million ($862,780 per carat), an astounding price for a rough diamond, from Cora International of New York.

	In recent years, top fancy colored diamonds have been fetching record prices at the world’s leading auction houses. Last November, a New York diamond dealer paid $85 million for a GIA-graded 59.6 carat Fancy Vivid pink diamond sold by Sotheby’s at its Geneva auction. This stone nearly doubled the previous record for the highest price ever paid for any gem at auction, the 24.78 carat Fancy Vivid pink diamond that sold for $46 million in 2010. (Update: According to media reports, Sotheby’s cancelled the sale of the Pink Star several months after the auction when the the winning bidder was unable to complete the transaction.) The highest price per-carat ever paid for a blue diamond was $1.8 million for the 5.30 carat Bulgari Blue diamond which GIA graded Fancy Deep blue. It was sold by Bonham’s in London in November of last year.

	The large blue diamond was found in the Cullinan Mine which, since its opening in 1903, has yielded an unparalleled treasure trove of legendary diamonds, starting with the 3,106 carat Cullinan, which was polished into the 530 carat pear-shaped diamond that is the centerpiece of Britain’s crown jewels and eight other significant stones. The mine also yielded the 240.8 carat Taylor-Burton diamond, the 353.9 carat Premier Rose, the 755.5 carat Golden Jubilee and the 599.1 carat Centenary diamond, among others. Last year, a 25.5 carat blue diamond that sold for $17 million, or $663,000 per carat, was found there.

COLORED STONES: The Myanmar military has reportedly moved in to secure the jade mining area around Hpakant, in the southern part of the nation, after a miner discovered a 37-ton jade boulder in mid-February. According to local press reports, the jade rock measured 13 feet high. Local authorities reportedly halted all informal mining in the region until the boulder could be relocated to a secure facility. @chapter:30


Publication Year: 2012 Title: Color Origin of Lavender Jadeite: An Alternative Approach Abstract: The market value of jadeite has risen dramatically in recent decades, often rivaling that of fine ruby and sapphire. Understanding the color origin of jadeite and reliably determining treatments have become increasingly important in the trade. This study uses single-crystalline analogs in conjunction with polycrystalline jadeite to examine the color origin of lavender jadeite through quantitative spectroscopy and modern trace-element analytical techniques. Several previously proposed chromophores are assessed for their possible contribution to jadeite coloration. Quantitative analysis confirms that green and lavender colorations are caused by chromium and manganese, respectively. The relative significance of these two chromophores is compared to determine their impact on observable coloration. The findings on color origin are applied to the identification of treated material on the current market. @chapter:37


Publication Year: 2008 Title: Identification of Melee-Size Synthetic Yellow Diamonds in Jewelry Abstract: Melee-size yellow synthetic diamonds have recently been seen in the gem market, mostly as loose stones but sometimes set in jewelry. The material identified to date is synthesized by the high-pressure, high-temperature (HPHT) process. Randomly occurring pinpoint or flux-metal inclusions are diagnostic identification clues. However, some synthetic diamonds require advanced laboratory methods. This report describes the effectiveness of a technique new to gemology, infrared microspectroscopy, in combination with cathodoluminescence imaging for the rapid and accurate separation of melee-size natural and synthetic diamonds based on their characteristic mid-infrared absorption spectra and growth structures, respectively. With these techniques, the GAAJ-Zenhokyo Laboratory in Tokyo determined that approximately 10% of loose—and dozens of mounted—yellow melee diamonds submitted over a four-month period were synthetic. @chapter:31


Publication Year: - Title: M.D. Hohenstine’s Gem Displays: The Process of Creating Popular Window Art with Loose Gemstones Abstract: M.D. Hohenstine frequently paid homage to the local theater and dance scene in his gemstone displays. This 1974 design honors the VaudVillities, a still-active Columbus group that bills itself as “the longest-running music and dance spectacular in the nation.” Photo by M.D. Hohenstine/Courtesy of Judith Allen Hall

Editor’s Note: Jeweler M.D. Hohenstine’s spectacular window displays  were a beloved tradition in downtown Columbus, Ohio from the 1920s until his death in 1976. The displays, consisting of hundreds of loose, natural gemstones arranged into a variety of shapes, patterns and figures, were changed every other week. Hohenstine photographed each of the 2,000-plus displays and turned them into slides that he used to educate fellow jewelers and gemologists. He gifted dozens of the slides to former employee and longtime family friend Judith Allen Hall when she began teaching. Hall donated the slides to GIA’s Richard T. Liddicoat Gemological Library and Information Center in 2016.

Here, she remembers the remarkable process Hohenstine followed to create fresh window art for his store for decades.

Mr. Hohenstine made a dozen opaque glass plates with matte surfaces and gilded wood frames. Each was about 10-12 inches in diameter. Some were round, others square; some were white, others were pale green. A couple of them had a small hole drilled in the plate. Under the plate was some sort of a small motor, and on top of the plate was a post that held the 10-ct. diamond upright so that it rotated and glittered.

He would begin by drawing the design on the plate with a soft pencil, and then open the desk drawer full of loose gemstones. With tweezers and an optivisor, he would painstakingly start putting the gems in place. The tables of brilliant cuts would be turned in certain directions to give the illusion of depth. All of the gems were simply laid on the plate – there was nothing to secure them.

It took six or more hours to complete the design, depending on its complexity. Customers could look in the curved window in front of the diamond room window to watch him work.

Hohenstine’s displays – including this bird’s nest scene with 202 diamonds, 238 garnets, 286 hessonites, 92 rubies, 11 pearls and one onyx – were a marvel of craftsmanship and logistics. None of the hundreds of gems on each design was secured to the display boards. Photo by M.D. Hohenstine/Courtesy of Judith Allen Hall
He was very inventive and created a way to photograph every design. A camera was mounted facing downward in a cabinet behind his desk in the diamond room, and it was exactly the right height to put the completed gem design in focus. All you had to do was slide the glass plate on the shelf, push the camera button, and it was done. Each slide contained the number of the design and the number and type of gems included in the design.

Once the design was completed and photographed, it was ready for Tuesday night window trim after the store closed. The left front window was about 90 to 100 feet from the diamond room, which seemed like a mile if you were carrying the plate – which was ever-so-slightly tilted, with the unsecured gems in place.

The left window had one-inch thick, bulletproof glass and a huge I-beam under it, so that street and foot traffic would not jar the design. The back glass lifted up when unlocked to give access to the window. The old design was very, very carefully removed and put on the showcase behind the window. Care was taken so that if there was any calamity getting the new one in place, the old one could be put back in the window.

When the new design was in place, Mr. Hohenstine would put on his optivisor and pick up tweezers and move any gem that might have been displaced. Then the frame was put in place, along with a little typed sign that would read something like: “This is the 1543rd design and contains 200 rubies and 56 emeralds.”

The old design was then carefully carried back to the diamond room, and the next day he would take it apart and put all the little gems back in their respective envelopes. @chapter:26


Publication Year: 2024 Title: Phenomenal Emeralds from Chitral, Pakistan Abstract: Cat’s-eye emerald (11.31 ct) and star emerald (4.99 ct) from Chitral, Pakistan. Photo by Lhapsin Nillapat; courtesy of Mohammed Ayub (Pretty Little Gem Co, Ltd, Bangkok).
In November 2023, GIA researchers had the chance to study a parcel of emeralds reportedly from Chitral in Pakistan. All of the stones matched previously documented characteristics of emeralds from Chitral (C.S. Hanser et al., “Comparison of emeralds from the Chitral District, Pakistan, with other Pakistani and Afghan emeralds,” Journal of Gemmology, Vol. 38, No. 6, 2023, pp. 582–599).
Among the stones were two cabochons that showed unusual phenomena: chatoyancy and asterism (see above). Both had a refractive index of 1.57 (spot reading) and a yellowish green to green color, which identified them as emerald.
Cat’s-eye emeralds are found in a number of locations, most notably Brazil and Colombia. The effect is caused by large concentrations of fine parallel tubes. Proper orientation of these linear features during cutting can result in a sharp, centered cat’s-eye when the tubes reflect light.
Star emeralds are even rarer, with most originating from Brazil and Madagascar. The effect is usually caused by very small thin films that reflect light. The proper orientation of the cabochon dome with respect to tiny platelets can result in a six-rayed star that moves across the curved surface of the stone. In this emerald, some of the platelets that create the lower left arm are highlighted by iridescent reflective colors.
To our knowledge, these are the first phenomenal emeralds from Chitral, and they offer prime examples of lesser-known phenomenal emeralds. @chapter:9


Publication Year: 2018 Title: Very Small Akoya Cultured Pearls Abstract: Figure 1. The graduated strand of small akoya bead-cultured pearls with nine tiny shell bead nuclei and loose akoya NBC pearls next to a Pinctada fucata (martensii) akoya shell. Photo by Nuttapol Kitdee.

Akoya cultured pearls are produced by the Pinctada genus, specifically Pinctada fucata (martensii). The mollusk and closely related species are found in the seas off Japan, China, South Korea, and Australia, as well as in the Mediterranean and Arabian Gulf and in the waters of other countries between the Tropic of Cancer and the Tropic of Capricorn such as Vietnam and India.

Akoya pearl farming was first established in the Mie Prefecture in Japan by Kokichi Mikimoto more than a century ago and still exists there to this day. Other suitable locations in Japan such as the waters off the islands of Shikoku and Kyushu, as well as pearl farms in other parts of the world such as Bai Tu Long and Ha Long Bays in the north of Vietnam and in the waters along the southern coast of China from Leizhou peninsula to the border of Vietnam also produce cultured akoya pearls. The round nuclei are commonly fashioned from freshwater shell imported from the USA (T. Hsu et al., “Freshwater pearling in Tennessee,” 2016). The technicians who insert the nuclei usually surgically maneuver one or two bead nuclei, ranging from 1.5 to 1.7 mm, into position within the gonad using a piece of mantle tissue from a donor mollusk to produce the bead-cultured pearls. Akoya mollusks are typically left in the water for 10 to 14 months. The best harvesting time is in the winter season, when cooler temperatures ensure the mollusks produce nacre slowly and more tightly, yielding the highest luster possible in akoya pearls before any processing is applied. Akoya bead-cultured pearls are typically round and range from 2 to 11 mm in diameter, with the most common sizes between 6 and 8 mm.

During the formation of bead-cultured pearls, the accidental formation of some non-bead cultured pearls (NBC), sometimes referred to as “keshi” pearls, may also take place. Those produced by the akoya mollusk are generally very small (the word “keshi” translates in Japanese to “poppy seed”).

GIA’s Bangkok laboratory examined a short strand of what were supposedly the smallest commercially produced akoya bead-cultured pearls available today, together with a selection of randomly picked NBC pearls from the same origin (figure 1), all loaned by Orient Pearl Company. The pearls and the shell reportedly came from Vietnam, and the author was informed that the shell used to culture the pearls was Pinctada fucata (martensii). The graduated strand, consisting of 42 very small bead-cultured pearls, weighed 4.68 ct total, and the pearls ranged from 1.90 to 3.17 mm. Also examined were nine tiny shell bead nuclei between 1.59 and 1.74 mm and weighing 0.30 carats total, as well as 67 loose akoya NBC pearls, ranging from 0.80 mm in diameter to 2.82 × 1.91 × 1.75 mm and weighing 2.31 carats total. The akoya bead-cultured pearls in the strand were round and near-round with a predominantly cream color. The NBC pearls were mostly baroque and predominantly white, with some cream and light gray samples.

Figure 2. RTX analysis revealed the round shell bead nuclei used in the production of the bead-cultured pearls in the strand. A typical-size (7.70 mm) akoya bead-cultured pearl is shown in the center for comparison. Image by Promlikit Kessrapong.
Although observation down the drill holes with a loupe indicated bead-cultured pearls, real-time X-ray microradiography (RTX) proved this beyond any doubt. A clear bead nucleus was visible in each pearl (figure 2). Characteristic small voids and/or organic features seen in many bead-cultured pearls were present in some cases between the shell bead nucleus and nacre overgrowth. Banded structure within the beads and/or differences in radio-opacity between the shell bead nuclei and nacre were other characteristic features of bead-cultured pearls noted when the pearls were examined at higher magnification. Measurements of five randomly selected pearls revealed nacre thicknesses from 0.20 to 0.41 mm, within the usual commercially accepted range (0.15–0.50 mm) expected for akoya bead-cultured pearls. The majority of the larger pearls showed very good nacre thickness, and none of them were below the minimum standard that might lead to durability concerns.

RTX analysis of the loose NBC pearls revealed typical void-like structures expected for akoya NBC pearls in most of the samples (H.A. Hänni, “A short review of the use of ‘keshi’ as a term to describe pearls.” Journal of Gemmology, 2006, Vol. 30, pp. 51–58; N. Sturman, “The microradiographic structures of non-bead cultured pearls,” 2009). Those with less-defined structures needed further RTX analysis in additional directions to find sufficient evidence of their claimed origin (figure 3).

Figure 3. RTX analysis of tiny loose akoya NBC pearls revealed void-like structures in most of them. Image by Promlikit Kessrapong.

Figure 4. RTX analysis of some of the smallest pearls, claimed to be NBC, revealed structures more consistent with natural pearls. Image by Kwanreun Lawanwong.
After additional RTX analysis in other directions, some of the more questionable structures showed features that were clear enough to consider as NBC. Most of the smallest pearls from the group revealed structures that were not consistent with those commonly seen in NBC pearls. Their “meaty” structures, central rounded dark organic features, and/or boundary or fold lines (seen in multi-nuclei/part pearls such as twins or aggregates) are in fact more typical of natural saltwater pearls (figure 4). Advanced analysis such as X-ray computed microtomography (µ-CT) may be required in these difficult cases, but owing to their very small sizes, obtaining clearer imagery is impractical. In this case, the lab gemologists did not find enough evidence to identify these pearls as non-bead cultured. Since most pearls are submitted without any information and laboratory gemologists have to go by what they see, such pearls would likely be considered natural, even if they are not such by definition. This clearly shows the challenges faced by gemologists carrying out pearl identification on some client-submitted items. @chapter:14


Publication Year: 2021 Title: Somewhere in the Rainbow Finds a Home at the Alfie Norville Gem and Mineral Museum Abstract: Figure 1. This 203 × 254 mm azurite mineral specimen from Bisbee, Arizona, is emblematic of the strong mineral representation of the Southwest at the Alfie Norville Gem and Mineral Museum. Photo by Jeff Scovil; courtesy of the Alfie Norville Gem and Mineral Museum.

A decade ago, a private gemstone collection was established to celebrate their beauty and stimulate curiosity and gemological education. Today, the Somewhere in the Rainbow collection has found a prominent new home.

Somewhere in the Rainbow joins the University of Arizona’s renowned mineral collection consisting of 20,000 global specimens, which is also noted for its strength in minerals from the southwestern United States and Mexico. Together with the Somewhere in the Rainbow collection (a large part of it exhibited under a five-year agreement), 6,000 of the finest mineral specimens will be on exhibit (figure 1) at the new Alfie Norville Gem and Mineral Museum, located at the historic Pima County Courthouse in downtown Tucson (figure 2). The museum is on the verge of reopening in 2021, says manager Eric Fritz. Its location in Tucson is apt, given that the city is a global destination for gemstones, minerals, and the visitors who trade in them.

Figure 2. The Alfie Norville Gem and Mineral Museum will be housed at Tucson’s recently refurbished Pima County Courthouse. The building renovation cost over US$30 million. Courtesy of the Alfie Norville Gem and Mineral Museum.

The museum is named after the wife of noted Tucson real estate developer Allan Norville. In the 1990s, the couple founded the Gem and Jewelry Exchange (GJX), which remains a major force among the many shows that come to Tucson every year. To date, more than 40 gem and mineral shows exhibit across the town every January and February. The Norvilles are major patrons of the new museum.

At 1,600 pieces and counting, the Somewhere in the Rainbow collection consists mainly of finished gem material complementing the mineral displays (see below). Its strength lies in gem carvings, loose gemstones, and jewelry. This collection has traveled across the United States in recent years, visiting AGS Guild stores and other high-end retailers. Its mission is “to bring hands-on education and enjoyment of fine colored gems to museums, galleries, gemologists, and facilities dedicated to preserving the rarity, history, and beauty of the gems and articles of jewelry.”

Shelly Sergent, the Somewhere in the Rainbow collection’s manager, is credited with building it at the behest of unnamed patrons. She says that it offers the public, students, scientists, and educators a distinct snapshot of the gemstone supply chain. “Mother Nature gives us rocks. Cutters and carvers give us gemstones, and jewelry designers give us heirlooms,” Sergent explains.

View Gallery

The collection provides enthusiasts with a better understanding of the beauty and rarity—as well as the unique collaboration between nature and artists. “I realize truly that our mission is not only about education—it’s about community,” says Ms. Sergent. “In that regard, we have brought together more than 127 different people that have worked with us in some capacity on this collection, whether that be miners, stone chasers, lapidary artists, designers, jewelers, and the heads of different laboratories.”

Ahead of the Alfie Norville Gem and Mineral Museum’s 2021 reopening, GIA had the opportunity to visit with Sergent to examine, handle, and photograph some of the collection’s significant pieces. The accompanying photo gallery offers just some of the highlights. @chapter:24


Publication Year: - Title: A Visit to the Natural History Museum of Los Angeles County Abstract: The Gems of California pedestal in the F.C. Hixon Gem Vault serves as the centerpiece of the museum’s gem and mineral gallery. Photo by Duncan Pay/GIA, courtesy Gem & Mineral Department, Natural History Museum of Los Angeles County.

                      In 2014, a team from GIA visited the Natural History Museum of Los Angeles County (NHMLAC) to document its gem and mineral collection. It’s thought to be the second-largest such collection in the United States, behind the Smithsonian Institution in Washington, DC.

This report documents the museum’s remarkable reference collection as well as its active research programs. You’ll explore its Mineral Hall and get an insider’s view of its collections area, including the normally off-limits “goodie room” with its standout specimens. The museum’s expert curators will also explain their research into new minerals and the causes of diamond color.

Our group was guided by the Mineral Sciences staff: associate curator Eloïse Gaillou, collections manager Alyssa Morgan, and curator emeritus Anthony Kampf. All have advanced degrees in their fields. Eloïse has a master’s degree in geology and a Ph.D. in materials science. Alyssa has bachelor’s and master’s degrees in geological sciences. And Anthony’s Ph.D. is in mineralogy and crystallography.

The NHMLAC’s Mineral Sciences staff consists of associate curator Eloïse Gaillou, curator emeritus Anthony Kampf, and collections manager Alyssa Morgan. Photo by Duncan Pay/GIA, courtesy Gem & Mineral Department, Natural History Museum of Los Angeles County.

	Museum Origin and History
The site now occupied by the Natural History Museum was once known as Agricultural Park. Established in the 1870s, it is described by the museum’s website as “a lawless area with horse racing, gambling, and prostitution.” That all changed when the site was renamed Exposition Park in 1910 and construction of the museum began. The Los Angeles Museum of History, Science, and Art opened its doors on November 5, 1913. Its first mineral collection consisted of just five boxes of specimens—a donation from Los Angeles capitalist General Charles Forman.

The collection grew steadily through a series of small donations. Then, in 1920, a major donation came from the Los Angeles Chamber of Mines and Oil. The collection was rich in fine specimens of copper-bearing minerals from Bisbee, Arizona.

In 1946, the museum established Mineralogy and Geology as a separate department. In 1952, the Mineral Hall was installed in the museum’s original rotunda. A series of donations over the next decade from Los Angeles jeweler William E. Phillips initiated the gem collection.

Many important donations followed, and in 1959, the museum began a campaign to build its mineral and gem collections through both donations and purchases. The source of many of the purchases was Martin Ehrmann, an important dealer in museum-quality minerals. He also sold many specimens to museum supporters, who later donated them.

View Gallery

	The museum’s collection features crystal specimens from all over the world, with an emphasis on gems of California.
In 1971, the museum began construction on a new north wing to house its Hall of Gems and Minerals, which opened in 1978. The hall was enhanced by an important series of donations from San Antonio plutocrat Frederick C. Hixon, who donated his gem collection between 1971 and 1977, and from Jean Bandy, who donated a collection rich in Bolivian mineral specimens between 1977 and 1980. In 1985, the Ben Chromy mineral collection arrived, along with more than $100,000 for museum activities.

1985 marked the opening of additional gallery space known as the Deutsch Gallery: Gemstones and Their Origins. It was funded by Alex Deutsch, a pioneer in the aerospace industry, and by the Weingart Foundation. The gallery exhibits focused on explaining how gemstones form and where they are found.

Retired lawyer John Jago Trelawney donated his gem collection to the museum in 1988 and bequeathed around $450,000 to support research projects upon his death in 2001. In 2005, the exceptional Weber-Perloff collection was donated to the museum. Consisting of about 50,000 small specimens, called micromounts, it was one of the largest collections of its kind in the world. In 2010, NHMLAC received the extraordinary collection of Hyman and Beverly Savinar, which is especially rich in gem-quality crystals. In 2011, the museum received the collection of Mel and Lois Hindin, which consisted of many remarkable minerals and gems.

Today, the museum is a living, vibrant institution, filled with the chatter of schoolchildren as they press their noses against the display cases. But there’s much more to the museum than its public face. The off-display areas house one of the most significant mineral and gem collections in the United States.

View Gallery

	Among its treasures, the museum boasts a dazzling collection of fashioned gems.

	An Overview
The museum’s gem and mineral collection consists of approximately 150,000 specimens representing about half of the world’s known mineral species. Of that number, there are about 143,000 minerals, 3,000 rocks (mineral aggregates), 3,000 gems, and 50 meteorites.

The specimens come from purchases, donations, and exchanges with other institutions. The museum has specimens from around the world, including the largest and most extensive collection of California gems and minerals.

There are more than 2,000 specimens on display in the 6,000-square-foot Gem and Mineral Hall. Yet this number is dwarfed by the total of specimens available behind the scenes for research or future display. One of the major storage areas is the Collections Room.

	The Collections Room
The vast majority of the museum’s mineral specimens are housed in the Collections Room. Most of them are not worthy of display, but they are invaluable to geologists and other scientists as research subjects.

As collections manager for the museum, Alyssa Morgan works among rows of mineral-filled cabinets, stacked almost floor to ceiling. Her job is to maintain the collection and the database and catalog.

Users of the collection—mostly geologists and material scientists in research institutions—can request specimens related to their studies of minerals from a certain area, or of rare or unusual minerals. Samples are broken off from larger specimens and mailed to the requesting parties.

View Gallery

	The collections are carefully organized and catalogued to make searches easier.
The museum’s staff works to obtain rare or unusual items to make the collections complete. When a specimen comes in, it gets a catalog number. The number is glued to the mineral and recorded on the box it’s stored in for tracking purposes. The mineral is weighed and sometimes measured, and its information—source, how it was obtained, and other important details—is entered into the database.

Specimens in the Collections Room are organized into several sub-collections. The general reference minerals are arranged systematically by chemical class (elements, sulfides, oxides, etc.). California specimens are arranged by locality. Small micromounts and thumbnails are arranged alphabetically by species.

	Maintaining the Collection

	In this series of videos, Alyssa Morgan and Eloïse Gaillou discuss the mechanics of establishing and maintaining the main collection.

	Micromounts and Thumbnails
Micromounts and thumbnails are popular with an important segment of the mineral collecting world, and they are often excellent candidates for scientific research. Through large donations, especially the exceptional Weber-Perloff collection, the museum has amassed more than 100,000 micromounts—the largest such collection in the world. It includes many gold specimens, mostly from California, and more than 2,000 diamond crystals.

The thumbnail collection is also quite large, consisting of about 10,000 specimens that came mostly from a single donor, Jessie Hardman, in the year 2000. Because Mrs. Hardman was determined to have a piece of everything, the collection includes many rare minerals representing a variety of rarely represented localities.

Small plastic boxes provide some protection from the environment, humidity, and other factors. Although the specimens are small, they’re valuable because of their diversity. They also require little storage space and, because of their uniform sizes, are easily organized.

	Organizing by Size

	Minerals in the collection are organized in part by their size.
The micromounts and thumbnails come from sources around the world and are arranged alphabetically by location. The staff is working to catalog the entire micromount and thumbnail collections.

	The “Goodie Room”
The museum’s “goodie room” is the staging area for specimens in fine, unbroken condition. Of the approximately 4,500 mineral specimens and gemstones in this room, some are not quite worthy of display and some are simply duplicates of items already on display. Some have good enough color and transparency to be suitable for faceting. For the most part, these specimens are not available to researchers for sampling.

View Gallery

	Some of the museum’s finest specimens not on display are stored in the goodie room.
Most of the goodie room’s collection comes from donors. One example is the extraordinary Savinar collection, which is full of fine-quality crystals from all over the world, along with many faceted gems.

	The Goodie Room

	Specimens in the museum’s goodie room are all fine quality. Most come from donors.

	Standout Specimens

	Anthony Kampf and Eloïse Gaillou introduce some of their favorite specimens and describe the characteristics that make them so special. Anthony then describes the museum’s acquisition process, which sometimes results in beautiful surprises.

	Researchers and Their Research
The core of any major natural history museum is the research that takes place behind the scenes. Current projects at NHMLAC include Anthony Kampf’s research into new minerals and Eloïse Gaillou’s studies on colored diamonds.

Curator emeritus Dr. Anthony (Tony) Kampf joined the museum in January 1977, and helped create the world-renowned Hall of Gems and Minerals. Tony played an important role in soliciting acquisitions and arranging the galleries. He has overseen the growth of the museum’s mineral and gem collection from about 20,000 to more than 150,000 specimens.

Dr. Kampf’s bulletin board is full of diagrams that show crystal structures of minerals he’s worked on. Photo by Duncan Pay/GIA, courtesy Gem & Mineral Department, Natural History Museum of Los Angeles County.
Now retired, he still comes in every day to engage in research that focuses on discovering and characterizing new minerals. He uses sophisticated instrumentation to identify minerals and study their internal structure.

	Research Projects

	In these videos, Drs. Kampf and Gaillou discuss their research projects on behalf of the museum.
Associate curator Dr. Eloïse Gaillou came to the museum in 2012 after holding a combined postdoctoral research fellowship with the Smithsonian and Carnegie Institutions. Eloïse’s work at NHMLAC focuses on diamonds, especially colored ones in the pink and purple ranges. Her goal is to determine the elusive cause of the pink color. Another of her research interests is the geology of diamond formation.

View Gallery

	This slideshow takes you on a tour of the Gem and Mineral Hall, where the public can view a portion of the museum’s massive collection.
For more information about the museum and its mineral exhibits, visit the NHMLAC Mineral Sciences website at http://www.nhm.org/site/research-collections/mineral-sciences. @chapter:24


Publication Year: 2019 Title: Pyrope-Almandine Garnet in Sapphire Host Abstract: A protogenetic crystal of pyrope-almandine garnet with reflective needles in a greenish blue sapphire. Photomicrograph by Nattida Ng-Pooresatien; field of view 2.70 mm.

In gemology, garnet occurs in a wide variety of colors, including red, orange, yellow, and green. Garnet is also found as inclusions in diamond, quartz, topaz, aquamarine, and zircon (E.J. Gübelin and J.I. Koivula, Photoatlas of Inclusions in Gemstones, Vol. 1, ABC Edition, Zurich, 1986, pp. 158–160).
GIA’s Bangkok laboratory recently received a 3.97 ct transparent greenish blue sapphire for a colored stone identification report. Standard gemological testing and advanced analysis revealed properties consistent with natural sapphire. Interestingly, microscopic examination with a combination of darkfield and oblique fiber-optic illumination revealed a well-formed brownish orange crystal cluster with reflective needles (see above). The crystal was singly refractive, and Raman spectrometry matched it with pyrope-almandine garnet. Sapphires with garnet inclusions are rarely seen in laboratory examination, although they are occasionally found in samples from Tanzania and the state of Montana (E.J. Gübelin and J.I. Koivula, Photoatlas of Inclusions in Gemstones, Vol. 3, Opinio Publishers, Basel, Switzerland, 2008, pp. 228–242). @chapter:10


Publication Year: - Title: Romancing the Source: Cruzeiro Mine, Brazil Abstract: Brazil

	Tons of tourmalines are mined in Brazil, with much of the production destined for China.

	This series of articles and videos follows a team of GIA Field Gemologists on their travels from the mountains of Afghanistan to the jungles of Sri Lanka in search of the sources of colored gemstones and the people who pursue them. This thrilling journey will take you to remote gemstone-mining areas, where you’ll witness the extreme effort required to wrestle nature’s treasures from the earth.

	The romance of a colored gemstone arises from its beauty, the exotic qualities of its source’s location, the adventure leading to its discovery, and the stories of the people who seek it. These factors have united to create the allure of gemstones through the ages, and continue to do so even in modern times.

Beatrice Neves examines two tourmaline crystals taken from the family mine’s tunnel walls. The Neves family pulled together after great loss, and through their strength, developed the Cruzeiro mine into a source reliable enough to meet China’s insatiable demand for tourmaline. Photo by Andrew Lucas/GIA.

	Brazil is blessed with a wide variety of gemstones, and the country is a major source of tourmaline. One of the country’s most productive states is Minas Gerais, which means “general mines.” This is where the Cruzeiro tourmaline mine is found. All colors of tourmaline are mined here, including the coveted reddish rubellite variety. The mine produces eight tons of tourmaline a year. Twenty percent of that is rubellite. Still, this massive amount finds an equally massive market in China.

	The Cruzeiro mine is also a story of tragedy, perseverance, and triumph. When two brothers were killed in a plane crash, the widow and son of one of the brothers and a son of the second brother took over the mine and developed it into an overwhelming success in the global market supply chain. @chapter:25


Publication Year: - Title: Will Auction Records Continue to Shatter in 2014? Abstract: The Orange, a 14.82 ct Fancy Vivid orange diamond, fetched a record $2.4 million per carat. It was the centerpiece of Christie’s Nov. 12 sale in Geneva, which brought the highest auction total ever—$125.4 million. Photo by Christie’s Images Ltd. 2013, courtesy of Denis Hayoun Diode SA Geneva.

Update: According to media reports, Sotheby’s cancelled the sale of the Pink Star several months after the auction when the winning bidder was unable to complete the transaction.

The world’s two leading auction houses are gearing up for another extraordinary year.

In 2013, Christie’s and Sotheby’s posted record jewelry sales of $678 million and $600 million, respectively, through auctions of mega diamonds, rare colored gems and classic period jewels. Economists predict the demand for ultra-luxury items that drove these auction numbers should be even stronger in 2014.

Three landmark diamonds in 2013 contributed to the record-breaking sales:

		The highest price ever paid for a gemstone: Sotheby’s estimated a price tag of $61 million for the Pink Star diamond offered at its Nov. 13 Geneva sale, but the GIA-graded 59.6 ct Fancy Vivid pink sold for $83.02 million, nearly doubling the 2010 record price of $46 million, also for a pink diamond. The buyer, New York diamond dealer Isaac Wolf, promptly renamed the stone the Pink Dream.

		The highest per-carat price ever paid: the Orange, a GIA-graded 14.82 ct Fancy Vivid orange diamond, was sold by Christie’s to an anonymous buyer for $35.54 million, or $2.4 million per carat.

		The record total for a single jewelry auction: Sotheby’s Nov. 13 auction in Geneva, which featured the Pink Dream, had a dozen lots sell for more than $1 million each, and seven that went for more than $6 million each—for a total of $199.5 million.

	Sotheby’s November sale in Geneva saw the highest price ever paid for a gemstone at auction: $83.02 million for the Pink Star, a 59.6 ct Fancy Vivid pink diamond. Courtesy of Sotheby’s.
The record setting began in May at Christie’s Geneva, when Harry Winston paid $26.7 million for a 101.73 ct D-Flawless diamond it named the “Winston Legacy.” Another highlight from that sale was the 19.88 ct Star of Kashmir sapphire, which sold for $3.48 million, a record $175,202 per carat.

	This 101.73 ct D-Flawless pear shape, the Winston Legacy, sold for $26.7 million at Christie’s May 2013 sale in Geneva. Photo by Christie’s Images Ltd. 2013.
Sotheby’s Oct. 7 Hong Kong sale saw the highest price ever paid at auction for a colorless diamond: a GIA-graded 118.28 ct oval D-Flawless, cut from a 299 ct piece of rough, sold for $30.6 million to an Asian buyer. Despite the record amount, the final price was on the lower end of the pre-sale estimate.

The surge really gained momentum a month later, when  Christie’s Nov. 12 Geneva sale broke the record for the highest jewelry sale total—$125.4 million—with the Orange as its centerpiece. The sale also had a record 22 lots top $1 million, including a Cartier emerald and diamond necklace that generated $9.9 million; a seven-strand natural pearl necklace that topped $9 million; and a brooch by designer Anna Hu, featuring a 58.29 ct Burmese sapphire, that sold for $4.5 million. Hu’s brooch set a record price for a contemporary designer at auction.

Sotheby’s Geneva auction the next night was, according to David Bennett, Sotheby’s chairman for jewelry in Europe and the Middle East, “charged with energy … everything seemed to be selling for more than their estimates. The night could not have conceivably gone better.”

Four records were broken:

		The highest price ever paid—both total price and per carat—for sapphire jewels: $8.45 million ($175,821 per carat, breaking the record set in Geneva in May) for the Richelieu Sapphires, a pair of Kashmir sapphires, weighing 20.88 and 26.66 ct.

		A record price for a Burmese sapphire: a 114.73 ct gem that sold for $7.14 million, or $62,214 per carat.

		The most expensive piece of jewelry ever sold at auction by Sotheby’s: a Van Cleef & Arpels brooch, featuring a GIA-graded 96.62 ct Fancy Vivid Yellow briolette-cut diamond, that went for $10.55 million.

François Curiel, chairman of Christie’s Asia, explained that the growing wealth in that region is one reason for the sharp rise in prices for rare stones and jewels.

“In 1994, we sold two lots above $5 million, with a 19.66 ct pink as the top lot for $7.3 million ($375,000 per carat). This was the year we inaugurated our Hong Kong auctions, which brought 11% of our $190 million annual total,” Curiel said. “In 2013, we sold 14 lots above $5 million, with the 34.65 ct Fancy Intense pink Princie diamond fetching $39.5 million ($1.1 million per carat). Hong Kong last year contributed 29% of our $675 million annual total. We have just started selling in Shanghai.”

	Asian wealth was a major force behind the surging prices for rare gems and jewels in 2013. At Christie’s Hong Kong, the 34.65 ct Fancy Intense pink Princie diamond brought $1.1 million per carat. Photo by Christie’s Images Ltd. 2013.
Will 2014 see more records fall? Economist say the boom isn’t over, and that the ultra-wealthy are still seeking outlets for their excess cash.

Curiel believes there will be more rare gems on the market, because the rarest items tend to be offered for the first time—or come up for sale again—when people know they may get top prices.

“There is an extreme shortage of rare diamonds, jewels, colored stones and pearls; the same items are fetching many times more than their first time on the auction block,” Curiel said. “These new prices are bringing more rarities to the market than ever before—and promise another exciting year for the jewelry industry worldwide.” @chapter:30


Publication Year: 2020 Title: New Blue Sapphire from Rakwana, Sri Lanka Abstract: A 49.99 ct rough sapphire crystal (5.8 cm in length) and a 33.16 ct cut stone with exceptional color from the 2019 Rakwana find. Photo by Robert Weldon/GIA.
The town of Rakwana, in southern Sri Lanka, has been known for decades as a premier source of royal blue sapphires. Often, a simple mention that a gemstone is from Rakwana will immediately explain the price and quality. In August 2019 a small pocket yielding numerous large sapphire crystals was discovered in the nearby Sinharaja Forest area of the Ratnapura District, Sabaragamuwa Province. What was unique about this find was the quality and size of the lustrous crystals. The 49.99 ct rough crystal in the figure above, measuring 5.8 cm in length and 1.6 cm at its widest point, was one of about 60 found in August 2019. It was also the largest complete crystal found. The beautiful 33.16 ct gem beside it was cut from a 207 ct piece of rough, the end of a large portion of a crystal. This crystal and cut gem rival the famous ones from Kataragama found four years ago. @chapter:3


Publication Year: 1988 Title: Fall 1988 G&G Book Reviews Abstract: “Gems and Jewelry Appraising”
By Anna M. Miller, 198 pp., illus., publ. by Van Nostrand Reinhold, New York, 1988. US$29.95

“Dictionary of Gemmology,” 2nd Edition
By Peter G. Read, 266 pp., illus., publ. by Butterworths, London, 1988. US$49.95

“Modern Jeweler's Gem Profile, the First 60”
By David Federman and Tino Hammid, 129 pp., illus., publ. by Vance Publishing Corp., Lincolnshire, Illinois, 1988. US$39.95

“The History of Beads”
By Lois Sherr Dubin, 364 pp., illus., publ. by Harry N. Abrams, New York, 1987. US$60.00

To view the full section, download the PDF above. @chapter:26


Publication Year: 2023 Title: The history of gemstones in Chanthaburi_21 Abstract: If we rewind, there is evidence, walking and kicking stones up in various colors. This clearly shows the origins of having raw materials. Later, there were traders in the town who could take those stones and trade with them. @chapter:25


Publication Year: 2022 Title: The Grass Is Always Greener… Abstract: Figure 1. Blade-like green radiation stains. Also indicated is the boundary of the close-up view of the green stains in figure 2. Photomicrograph by Michaela Stephan; field of view 2.9 mm.
The Carlsbad laboratory recently examined a 0.97 ct Fancy grayish green diamond submitted for colored diamond grading service. Microscopic examination revealed a colorless diamond with green radiation stains scattered across the pavilion (figure 1).
These radiation stains were particularly unusual due to their linear appearance and resembled blades of grass in their morphology and color. These stains were prevalent along intentionally preserved rough natural diamond surfaces on the pavilion. Faceted surfaces along the pavilion were polished with particular effort to retain some of the green radiation stains. The resultant internal reflection of green light to the table created a uniform green bodycolor in this rare and beautiful diamond.

Figure 2. Radiation stains on the rough diamond’s surface also penetrate to a polished side (left). Viewed with reflected light, the surface shows acicular indentations coincident with green stains (right). Photomicrographs by Michaela Stephan and Roy Bassoo.
Surface photomicrographs revealed long, linear, and acicular indentations concentrated near the center of the radiation stains (figure 2). Indentations crosscut flat-bottomed trigons, suggesting they post-dated diamond dissolution in the earth’s mantle (e.g., R. Tappert and M. Tappert, Diamonds in Nature: A Guide to Rough Diamonds, Springer, Heidelberg, 2011). The green stains along the polished surface indicate that the radiation stains penetrated some depth into the diamond. These features have been observed previously at GIA (e.g., Spring 2021 G&G Micro-World, pp. 66–67; Spring 2022 G&G Micro-World, pp. 64–65) and may result from acicular to tabular radioactive minerals precipitating directly on the diamond surface in a paleoplacer to recent alluvial environment (e.g., R. Lauf, Mineralogy of Uranium and Thorium, Schiffer Publishing, Ltd., Atglen, Pennsylvania, 2016). Radiation damage created vacancies in the diamond lattice, which absorb red light and reflect green light, resulting in the green color of the radiation stains. Uncharged or neutral vacancies produce a photoluminescence response near the 741 nm zero phonon line called the GR1 defect (e.g., J.E. Shigley and C.M. Breeding, “Optical defects in diamond: A quick reference chart,” Summer 2013 G&G, pp. 107–111). The GR1 defect area from photoluminescence spectra can be measured and mapped to indicate the spatial distribution of this defect coincident with the radiation stains (figure 3).

Figure 3. Left: Map of the integrated area beneath the GR1 defect peak of the radiation stains on the diamond surface, derived from photoluminescence spectroscopy. Right: Reflected light image of the surface showing radiation stains (outlined in red) coincident with acicular indentations. The measurements were taken with a 532 nm laser at 1 mW power, 25 μm confocal spot size, 5 μm step size, and 100 Hz.
It is unusual to see green radiation stains of this shape that correspond with indentations on a diamond surface. These features could be a commonly overlooked characteristic of green diamonds. @chapter:35


Publication Year: 2014 Title: Fancy Black NPD Synthetic Diamond Abstract: Figure 1. This 0.9 ct marquise proved to be a synthetic nano-polycrystalline diamond (NPD), the first one detected by a gemological laboratory. Photo by Jian Xin (Jae) Liao/GIA.

              As reported previously in Gems & Gemology, nano-polycrystalline diamond (NPD) growth technology is one of the most significant new developments in diamond synthesis (see E.A. Skalwold, “Nano-polycrystalline diamond sphere: A gemologist’s perspective,” Summer 2012 G&G, pp. 128–131). The material is completely transparent and comparable to natural diamond, while tougher than natural diamond or previous synthetic diamonds. NPD could pose a challenge to the natural diamond industry once these goods, particularly higher-quality transparent samples, enter the consumer market.

Recently, the New York laboratory tested a small, black marquise-cut stone for identification and color origin. At first glance, the 0.9 ct translucent specimen (figure 1) resembled a typical black diamond submitted to the lab for identification and color origin. One must be careful to separate such stones from synthetic moissanite. This marquise, however, revealed unusual properties strikingly similar to those of the NPD synthetic diamonds reported on by Skalwold, as well as other previously tested samples. These previously studied specimens were transparent with a yellow to brown range of color.

	Figure 2. Photomicrograph images of the heavily included synthetic diamond showed an abundance of graphite inclusions and a murky yellowish matrix. Fields of view (clockwise from top left): 1.5, 3.1, 1.5, and 4.1 mm. Photomicrographs by Paul Johnson.
Unlike natural diamond, the stone in question was heavily included with graphite crystals. The matrix hosting the inclusions had a murky yellowish color (figure 2). Using diffuse reflectance, we obtained a mid-infrared absorbance spectrum strikingly similar to that of the NPD synthetic diamonds reported in the aforementioned article. We observed the diagnostic diamond absorption peaks at approximately 2000 cm–1 and absorption in the one-phonon region, possibly due to nitrogen impurity. Peaks at approximately 3727 and 3611 cm–1 were also observed, as in the previously tested NPD samples (figure 3). Raman spectroscopy is a common and useful technique in identifying a gem diamond. Due to the nano-sizes of the crystals that compose the aggregated sample, a Raman shift is usually not detectable in NPD using visible-light laser excitations. The same feature was observed in this specimen.

	Figure 3. The mid-infrared spectrum of the synthetic NPD displayed peaks at approximately 3727 and 3611 cm–1.

	Figure 4. DiamondView images of the synthetic NPD exhibited a distinct fluorescence pattern. Images by Paul Johnson.
Further analysis using the DiamondView instrument revealed a fluorescence pattern and structure that was, again, very similar to earlier NPD samples (figure 4). Raman analysis showed a broad band at approximately 1350 cm–1 and a weak band at about 1580 cm–1; these are assigned as D- and G-bands, respectively (S. Odake et al., “Pulsed laser processing of nano-polycrystalline diamond: A comparative study with single crystal diamond,” Diamond and Related Materials, 2009, Vol. 18, pp. 877–880). Odake reported the two bands in NPD samples grown from high-purity graphite at a temperature of 2600K and a pressure of 15 GPa; both are caused by nanocrystalline graphite or amorphous carbon. Unlike Odake’s samples, which showed G- and D-bands of equal intensity, ours showed a strong D-band with a weak G-band. We measured Raman spectra at many different locations but did not observe the diamond Raman band at 1332 cm–1, an absence Odake also reported.

Testing and observations revealed the diamond to be an NPD synthetic diamond, the first detected by a gemological laboratory. @chapter:15


Publication Year: 2023 Title: Rare Double Pseudomorph Ikaite-Calcite-Opal Abstract: Figure 1. The Heart of Australia, a 3,510 ct double pseudomorph ikaite-calcite-opal gem specimen, is considered one of the finest ever unearthed. Courtesy of Graeme Dowton.
At the Pueblo Gem & Mineral Show, Graeme Dowton of Red Earth Opal (White Cliffs, Australia) exhibited rare double pseudomorph ikaite-calcite-opal gem specimens mined from the Naatji Nest mine at White Cliffs in New South Wales, Australia. Ikaite was initially substituted with calcite and then opalized, therefore making these double pseudomorph opals. Also called “pineapple opal” in the market due to the form of their clusters, they are found exclusively in White Cliffs and typically occur within weathering-bleached siltstones and claystones. According to Dowton, no other type of gem-quality opal was found in the same layer where the pineapple opals were mined. During mining, it was noticed that two opals had formed within a few feet of each other but with distinctly different coloration: One displayed a rich spectrum of play-of-color, while the other showed almost no coloration. The 3,510 ct Heart of Australia (figure 1) shows rich play-of-color and is considered one of the finest specimens of this type ever unearthed. In some of Dowton’s samples, the precursor calcite was not fully substituted by silica gel, and white calcite crystals can be observed (figure 2).

Figure 2. The intergrowth of opal and its precursor calcite in pineapple opal. This specimen is 12 × 10 × 8 cm and weighs 690 g. Photo by Si Athena Chen; courtesy of Graeme Dowton.
Ikaite, CaCO3•6H2O, is a rare and metastable hydrated carbonate in sedimentary rocks that has only been identified in environments ranging from –2° to 7°C in nature (M.L. Vickers et al., “The ikaite to calcite transformation: Implications for paleoclimate studies,” Geochimica et Cosmochimica Acta, Vol. 334, 2022, pp. 201–216). The occurrence of ikaite suggests a period of very cold to near-freezing paleoclimate conditions in White Cliffs. At ambient temperatures (10°–30°C), ikaite transforms to more stable carbonate polymorphs such as calcite, aragonite, and/or vaterite. The ikaite and its following pseudomorphs act as paleothermometers (D. Shearman and A. Smith, “Ikaite, the parent mineral of jarrowite-type pseudomorphs,” Proceedings of the Geologists Association, Vol. 96, No. 4, 1985, pp. 305–314). When the host sedimentary rocks were weathered, they released silica into groundwater. This silica-bearing groundwater contacted with calcite, which gradually dissolved and reprecipitated to opal over time (B. Pewkliang et al., “The formation of precious opal: Clues from the opalization of bone,” Canadian Mineralogist, Vol. 46, No. 1, 2008, pp. 139–149). However, the detailed formation mechanism of ikaite-calcite-opal in White Cliffs requires future investigation. @chapter:5


Publication Year: 2018 Title: Twelve-Rayed Star Sapphire from Thailand Abstract: A 12-rayed black star sapphire, weighing 3.6 ct, with one set of golden rays and another set of silver rays producing two different-colored stars. Photo by Simon Bruce-Lockhart.
The Thai city of Chanthaburi is a well-known international trading hub for colored gemstones but was once an important corundum mining center. In recent decades, mining activity in the area has decreased, but there are still several smaller-scale operations active. The 3.6 ct 12-rayed black star sapphire shown above was mined in 2017 in Bang Kha Cha (or Bang Kaja), a mining locality near Chanthaburi.
Thailand’s gemstone deposits typically produce blue, green, and yellow sapphires (and combinations of these colors). The deposits in eastern Thailand also produce a peculiar sapphire variety: black star sapphire. This variety is found in other basalt-related deposits like Australia, but they rarely match the size, quality, and abundance that the Thai stones are famous for.
The black color is due to a very high concentration of Fe-rich particles, identified as hematite and ilmenite. This high density of particles completely masks the bodycolor of the stone. When strongly illuminated from the back, glimpses of the bluish green bodycolor in this gem can be seen. If the platy, Fe-rich particles are oriented in the correct way, they result in a six-rayed star pattern. This star is often yellowish golden in color.
Another common inclusion in corundum is rutile needles. When they are abundant and correctly oriented in the crystal, this might also result in a six-rayed pattern, often with a whitish silvery color. In some cases, both of these patterns overlap, creating a 12-rayed star with one set of golden-yellow rays and one set of silver-white rays. The stone in this entry is an excellent example of this phenomenon, displaying well-centered, sharp asterism with two different-colored stars. @chapter:6


Publication Year: 2003 Title: Fall 2003 G&G Book Reviews Abstract: “The Eras of the Diamond”
By Jules Roger Sauer, publ. by Amsterdam Sauer, Rio de Janeiro, Brazil, 2003, price available on request. E-mail: julessauer@amsterdamsauer.com

“Jadeite Jade, A Stone & A Culture”
By Chiu Mei Ou Yang, 184 pp., illus., publ. by the Hong Kong Institute of Gemmology, 2003. US$45.00

“Pegmatology: Pegmatite Mineralogy, Petrology and Petrogenesis”
By William “Skip” Simmons, Karen L. Webber, Alexander U. Falster, and James W. Niamoff, 176 pp., illus., publ. by Rubellite Press, New Orleans, LA, 2003. US$47.50

“At the Bench: An Illustrated Guide to Working with Gold & Silver”
By Gregg Todd and Greg Gilman, 116 pp., illus., publ. by MJSA/AJM Press, Providence, RI, 2002, US$28.50

“Auction Market Resource”
June 2003, Vol. 10, No. 1. Publ. by Gail Brett Levine, P.O. Box 7683, Rego Park, NY 11374-7683. Tel: 718-897-7305. Available by subscription: $195.00 in the U.S., $250.00 elsewhere

To view the full section, download the PDF above. @chapter:18


Publication Year: 2016 Title: Largest Blue HPHT Synthetic Diamond Abstract: Figure 1. A 5.03 ct Fancy Deep blue HPHT synthetic diamond was examined by GIA (left). Faint but sharp color zoning was observed (middle, field of view 4.77 mm) along with small metallic inclusions and a cavity at the girdle (right, field of view 2.19 mm). Photos by Sood Oil (Judy) Chia (left) and Kyaw Soe Moe (center and right).
Recently, large colorless and near-colorless HPHT-grown diamonds by the Russian company NDT have been investigated, with sizes up to 5.11 ct (U. D’Haenens-Johansson et al., 2015, “Large colorless HPHT-grown synthetic gem diamonds from New Diamond Technology, Russia,” Fall 2015 G&G, pp. 260–279; Spring 2015 G&G Lab Notes, pp. 65–66). The largest faceted colorless HPHT-grown synthetic diamond reported to date is a 10.02 ct E-color, VS1-clarity specimen, reported by IGI Hong Kong in 2015. In January 2016, GIA’s New York laboratory examined a 5.03 ct fancy-color HPHT-grown type IIb synthetic diamond (figure 1, left) produced by NDT, the largest faceted blue laboratory-grown diamond studied so far.
This emerald-cut synthetic diamond was color graded as Fancy Deep blue. This is a very attractive color with no other color component, a prized rarity among natural type IIb diamonds (the Blue Moon, for instance, was graded as Fancy Vivid blue). When viewed under a microscope, faint but sharp color zoning could be seen (figure 1, center), indicative of the uneven impurity incorporation of HPHT synthetic diamonds. No strain was observed under crossed polarizers, indicating a very low dislocation density, which is also characteristic of HPHT-grown diamonds. It had VS1 clarity, with only very small metallic inclusions and a cavity observed at the girdle (figure 1, right). Fluorescence and phosphorescence images collected using a DiamondView instrument revealed the sample’s cuboctahedral growth pattern (figure 2, left), another feature of HPHT synthetics. The long-lasting chalky blue phosphorescence was further analyzed using spectroscopy, and the emission was found to originate from two broad bands centered at approximately 500 and 575 nm (figure 2, right). These bands have previously been reported in NDT’s type IIa and IIb HPHT synthetic diamonds (D’Haenens-Johansson et al., 2015).

Figure 2. DiamondView images of fluorescence (top left), and phosphorescence (bottom
left) revealed a cuboctahedral growth pattern, which is typical for HPHT-grown synthetic
diamond. Phosphorescence spectra (right) show two peaks at approximately 500 and
575 nm, contributing a chalky blue color.
Absorption spectroscopy for the mid-infrared region confirmed the sample was type IIb, with strong boron-related features at 1290, 2458, and 2800 cm–1. The average bulk boron concentration was 0.82 to 1.12 ppm, calculated according to the equation NA-ND = (1.00 ± 0.15) × H1290 ppm cm–3 , where NA is acceptor concentration, ND is donor concentration, and H1290 is peak height at 1290 cm–1 (A.T. Collins, “Determination of the boron concentration in diamond using optical spectroscopy,” Proceedings of the 61st Diamond Conference, Warwick, UK, 2010). Otherwise, this large synthetic diamond exhibited an extremely low concentration of optical defects. Photoluminescence spectroscopy was conducted at liquid nitrogen temperatures using a range of laser excitations covering the UV-visible-IR range. The PL spectra only revealed emission from a single defect species, a Ni-related emission multiplet with peaks at 483.6/483.8/484.1/484.4 nm (484 nm center) detected using 324.8 nm laser excitation (A.T. Collins, “The characterisation of point defects in diamond by luminescence spectroscopy,” Diamond and Related Materials, Vol. 1, 1992, pp. 457–469). As with previous type IIb synthetic diamonds, its visible-NIR spectrum showed a transmission window in the blue region and an absorption in the red, caused by the presence of boron, resulting in the observed blue bodycolor.

This 5.03 ct sample is the largest HPHT-grown blue synthetic diamond examined at a GIA laboratory. As the size and quality of synthetic diamonds improve, careful identification is essential. Representative HPHT synthetic diamond characteristics seen in this specimen, such as the lack of tatami strain patterns (which are typically observed in natural type IIb diamonds), faint but sharp color zoning, and small metallic inclusions from the metal-catalyst flux, can be detected using a gemological microscope, emphasizing its continued importance in gem identification. Examination of this large IIb synthetic diamond, combined with those previously reported from NDT, illustrates the rapid progress in HPHT growth technologies. This is a development that will eventually impact the jewelry industry. @chapter:15


Publication Year: 1998 Title: Fall 1998 Gems News International Abstract: Diamonds
            Diamonds at the International Mineralogical Association Meeting
            Update on the Ekati Project, Northwest Territories, Canada
Colored Stones
            Amethyst from Arizona
            Andradite Garnet from Yemen
            Danburite from San Diego County, California: A Potential Gem Mineral
            Application of Large-scale Mining Techniques to Colombian Emeralds
            Gem-Quality Grossular Garnet from Mali
            Pyrope-Spessartine Garnet from Madagascar
            Color-Change Pyrope-Spessartine Garnet, Also From Madagascar
            Hackmanite from Myanmar
            “Striped” Labradorite Feldspar
            Colorado Lapis Lazuli
            Pearls Highlighted at the 2nd International Jewellery Show in Kobe, Japan
            Vietnamese “Trapiche” Rubies
            “Sliders”: Rutile Inclusions in Quartz
            Sapphire from the Ural Mountains, Russia
            Sapphirine: Gems & Gemology Reader to the Rescue
Treatments
            Radioactive Rubies
Synthetics and Simulants
            Gallium Phosphide, Resembling Fancy Dark Orange Diamond
            Unusual Jade Look-Alike
            “Wild Life” Assembled Gemstone Cabochons
Announcements
            Rossmanite, a New Variety of Tourmaline

To view the full section, download the PDF above. @chapter:1


Publication Year: - Title: GIA Opens Laboratories in Israel and Japan Abstract: GIA opened two new diamond grading laboratories in 2012: one in Ramat Gan, Israel and one in Tokyo, Japan. These facilities, the eighth and ninth GIA global laboratories, are the latest steps in the Institute’s efforts to expand its ability to fulfill its mission to ensure the public trust in gems. By bringing industry-leading diamond grading services directly to important gem markets, GIA is making its services more easily accessible to laboratory clients.

“Offering GIA’s diamond grading standards and research-backed lab services to these important markets serves the public interest by supporting the Israeli and Japanese gem and jewelry industries,” said Tom Moses, GIA senior vice president for laboratory and research. “Our global network of laboratories enables GIA to remain at the forefront of gemological developments and provide the best possible service to our laboratory clients.”

Both facilities offer Diamond Dossier® and Diamond Grading Report services for colorless diamonds up to 2.99 cts. Additional services may be added in the future.

A reservation system for direct submission to the Israel facility, located in the diamond center of Tel Aviv, enables clients to schedule drop-off and pick-up appointments, eliminating the need to wait on-site to submit stones for grading services. They are also able to monitor the progress of their services online. If reservations are not available, clients can submit stones through GIA LabDirect consolidators who provide take-in services. Consolidators also take in diamonds larger than 2.99 carats, fancy color diamonds, colored gemstones and pearls.

The Tokyo lab also takes in colored stones and pearls for any other GIA services. At this time, those gems will be sent to another GIA global laboratory and returned to Tokyo for pick-up. GIA plans to expand the menu of services offered by its Tokyo facility in the coming months.

GIA began its global expansion in 2008, adding diamond grading services to its Bangkok laboratory and opening new laboratory facilities in Johannesburg, South Africa; Gaborone, Botswana; and Mumbai, India. In 2010, a lab opened in Hong Kong and a ninth facility is slated to open in Japan later this year.

All gemstones submitted to GIA anywhere in the world may be sent to any GIA laboratory, ensuring the equal, unbiased and neutral examination based on the rigorous and consistent standards that characterize all of GIA’s gem identification and grading services. @chapter:29


Publication Year: 2019 Title: Euhedral Phantom Sapphire in Sapphire Abstract: Figure 1. A partially tapered bipyramid sapphire inclusion within a sapphire. Photomicrograph by Britni LeCroy; field of view 2.90 mm.

A phantom sapphire crystal within a host sapphire crystal was recently examined at GIA’s Carlsbad laboratory. The inclusion showed euhedral morphology as one half of a partially tapered bipyramid. The visible boundaries of the included crystal were composed of unaltered fingerprints with geometric patterns and fine linear rows. The crystal’s surface also showed moderate-order birefringence colors; these represented the shared interface between the host’s crystal lattice and the inclusion’s crystal lattice (figure 1). External local fingerprints also terminated around the crystal’s end point. Negative crystals within the inclusion showed tabular hexagonal habit (figure 2, left). When the host sapphire was exposed to temperatures below the freezing point of water, a CO2 bubble was seen within the largest negative crystal (figure 2, right). A sapphire with this inclusion combination is rarely seen.

Figure 2. Left: Negative crystals with tabular hexagonal habit within a euhedral sapphire inclusion. Right: A CO2 bubble appears within the largest negative crystal (see arrow) after the stone was exposed to temperatures below the freezing point of water. Photomicrographs by Britni LeCroy; field of view 1.76 mm. @chapter:12


Publication Year: 2018 Title: Pink Diamonds, Russia’s Amber Room, and More… Abstract: The beauty and desirability of pink diamonds is exemplified by the Winston Pink Legacy, a stunning 18.96 ct Fancy Vivid pink diamond that realized US$50 million at auction in November 2018. Such sought-after diamonds are the subject of the third installment of our colored diamonds series. GIA researchers Sally Eaton-Magaña, Troy Ardon, Karen Smit, Christopher Breeding, and James Shigley summarize the current science on natural-color pink to red diamonds and detail the cause of their color. The authors provide an unprecedented gemological and spectroscopic characterization by presenting absorption and luminescence spectra drawn from a representative sample of 1,000 diamonds from GIA’s database.

“An unprecedented characterization of naturally colored pink to red diamonds…”

Our second paper, by GIA’s Russell Shor, surveys the history of the legendary Amber Room. Originally commissioned for Prussia’s King Frederick I in the early 1700s and presented to Czar Peter I of Russia in 1716, the amber panels disappeared from St. Petersburg during the Second World War. In 1979, the Soviet Union initiated a painstaking reconstruction of this cultural treasure. Besides its rich history, the author provides firsthand accounts from those who participated in its recreation.
Next, Che Shen, a graduate student at the Gemmological Institute of China University of Geosciences in Wuhan, and Ren Lu investigate the color origin of gem-grade diaspore using LA-ICP-MS spectrometry.
A reaction rim or “corona” results from alteration of a crystal’s exterior after its formation due to changes in geological conditions. In our fourth paper, researchers led by Nguyen Ngoc Khoi, from the Hanoi University of Science, provide a study on corundum with spinel corona from northern Vietnam. The authors explain the genesis of the corona by examining its reaction textures, chemical composition, and mineral inclusions and applying thermodynamic phase equilibria calculations.
Our fifth paper offers a gemological characterization of pipi pearls from the bivalve mollusk Pinctada maculata. Authors Nanthaporn Nilpetploy, Kwanreun Lawanwong, and Promlikit Kessrapong detail the internal structures and further investigate these small, sometimes strongly colored natural pearls using microradiography and UV-Vis, Raman, and photoluminescence spectroscopy.
Our final article is a brief summary of diamond inclusions by GIA’s Nathan Renfro, John Koivula, Jonathan Muyal, Shane McClure, Kevin Schumacher, and James Shigley. A foldout wall chart with photomicrographs showcasing remarkable inclusions in natural, synthetic, and treated diamonds accompanies this article.
Besides our six articles and the chart, there’s plenty to enjoy in our regular features: Lab Notes offers analysis of three freshwater blister pearls attached to their host shells, De Beers’ Lightbox CVD-grown diamonds, and an exceptionally rare Montana ruby. Our new Diamonds from the Deep section provides an examination of how diamonds form in the deep earth. Micro-World serves up an array of internal features observed in gem materials, while Gem News International reports on sapphire treated with high pressure and high temperature, coated rough and faceted synthetic moissanite, and gemological conferences around the world.
Finally, don’t forget to check our listing of the 2018 G&G Challenge winners, and please do remember to cast your vote for the Most Valuable Article of 2018. @chapter:35


Publication Year: 2005 Title: Winter 2005 G&G Book Reviews Abstract: “Crystals: Growth, Morphology and Perfection”
By Ichiro Sunagawa, 295 pp., illus., publ. by Cambridge University Press, Cambridge, United Kingdom, 2005. US$95.00)

“The Gem Merchant: How to Be One, How to Deal with One, 2nd Edition”
By David Stanley Epstein, 158 pp., illus., publ. by Gem Market Publications, Piermont, NY, 2003, US$20.00

“Arts and Crafts to Art Deco: The Jewellery and Silver of H. G. Murphy”
By Paul Atterbury and John Benjamin, 183 pp., illus., publ. by Antique Collectors’ Club, Suffolk, United Kingdom, 2005. US$69.50

“Daniel Swarovski: A World of Beauty”
Text by Vivienne Becker, produced under the direction of Markus Langes-Swarovski, 139 pp., illus., publ. by Thames & Hudson, New York, 2005. US$75.00

To view the full section, download the PDF above. @chapter:21


Publication Year: - Title: Spring 2010 G&G Lab Notes Abstract: Coated and Fracture-Filled Orangy Red Diamond
Diamond with Rare Green Fluorescence
Identification of Irradiated Black Diamonds
Large HPHT-Treated Type IIb Blue Diamond
Pink Diamonds Colored by Multiple Treatment Processes
Type IIa Greenish Yellow Diamond Colored by IR-Inactive Nitrogen
Red CVD Synthetic Diamond with Multiple Treatments
Exceptionally Transparent Treated Jadeite
Large Pair of Natural Freshwater Pearls
Blockage-Induced Growth Tubes in Tourmaline
Treated Green Turquoise

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


Publication Year: - Title: Atypical “Beading” in the Production of Cultured Pearls from Australian Pinctada maxima Abstract: Eleven of the atypical “bead” cultured pearls and one “keshi” produced from the authors’ experiments. Photo by Lhapsin Nillapat.

In 2011, the authors began to see cases of low-quality natural pearls being used as unconventional “beads” for cultured nacre growth. These natural pearls had been inserted into the gonads of Pinctada maxima along with a piece of donor mantle tissue, or in some cases into the cultured pearl sacs created by initial or subsequent operations, to facilitate the growth of cultured nacre on to their surfaces.

To better understand this deceptive “beading” process, the authors conducted a total of 91 experiments on Australian Pinctada maxima. In 75 of the experiments, atypical “beads” (including natural abalone, scallop, Pteria sterna, Pinna, drilled coral, and faceted sapphire) were inserted. The other 16 tests consisted of irritating, folding, or inserting tissue into the mantle.

The results of their investigations appear in a study titled “Experiments in Using Atypical ‘Beads’ and Mantle Interference in the Production of Cultured Pearls with Australian Pinctada maxima.”

The study presents real-time X-ray (RTX) and X-ray computed tomography (µ-CT) images of the resulting cultured pearl products. Of the 91 experimental operations, 23 proved successful in cultured nacre growth over the unconventional “beads” and forming “bead” cultured pearls. In most cases, the process could be readily identified with either RTX or µ-CT analysis. @chapter:14


Publication Year: 2017 Title: Multi-Color-Zoned Quartz from Brazil Abstract: Cabochons of strongly zoned Brazilian quartz, measuring up to 4 cm long. The five described zones are numbered. Photo by Jaroslav Hyršl.

Quartz very often crystallizes in zones during formation, when chemical or physical conditions change. An interesting example of strong zoning caused by variable iron content came recently from Bahia State in Brazil. No rough specimens were seen by the author, but several dozen flat cabochons up to about 4 cm long (see above) were available for study.

The quartz crystallized in five stages, each with a different type of iron. If there is any Fe in the original solution, it acts as a chromophore and produces citrine or amethyst; a higher Fe content will cause separate iron minerals to form. The oldest generation (1) is represented by parallel crystals of yellow citrine with small amethyst sectors, which can be described as ametrine. Their surface was covered by a thin quartz layer (2) with tiny goethite needles. The next generation (3) was a red layer, consistently about 3 mm thick, with fine agate-like zoning. The color was probably caused by very finely dispersed hematite, an identification based on typical color and microgranular texture. The next zone (4) was rich in pyrite, which formed fibers perpendicular to the older red layer, but pyrite can also form in this layer as tiny cubic crystals. After crystallization of the pyrite, the last pale purple amethyst layer (5) was filled with bundles of brown goethite needles up to about 3 mm, which also grew perpendicular to the original surface.

The inclusions in these attractive specimens can explain their complicated formation, with iron found in quartz structure (amethyst and citrine), in sulfide (pyrite), or in oxide (goethite and hematite). @chapter:13


Publication Year: 2021 Title: Internal Structures of Natural Pearls from Pinctada maxima, Identification of Resin-Filled Turquoise, Spinel Inclusions Chart, and More…… Abstract: Spring ushers in a feeling of renewal, and as we start to slowly recover from the global pandemic, it is a welcome sentiment. Join us as we investigate the inner structures of natural Pinctada maxima pearls, the technical evolution of turquoise treatments using resin filling, and a mathematical approach to predicting color in uniaxial gemstones. Even though the Tucson gem shows were canceled this February, we are able to offer more than 20 pages of captivating interviews covering how many in the trade have been weathering the situation along the entire supply chain.

“A mathematical method using visible spectroscopy to accurately predict color, the most important quality for a colored gemstone…”

Natural Pinctada maxima pearls take center stage in the lead article as Artitaya Homkrajae and fellow GIA researchers conduct a detailed analysis of 774 natural pearls collected from wild marine mollusks. These pearls were classified into six broad internal structural types based on X-ray techniques such as real-time microradiography (RTX) and X-ray computed microtomography (μ-CT). The results of this work support the efforts to aid in the dependable identification of natural versus cultured pearls by gemological laboratories.

In the second article, Ling Liu and a team from the Gemmological Institute, China University of Geosciences in Wuhan use ultraviolet fluorescence, spectrofluorometry, and Fourier-transform infrared (FTIR) spectrometry to characterize resin-filled turquoise. Their research addresses an urgent need to detect the prevalence and constantly evolving treatment techniques applied to turquoise sourced from China’s Hubei Province.

Next, Che Shen and coauthors provide a mathematical method using visible spectroscopy to accurately predict color, the most important quality for a colored gemstone, and guidance on cutting backed by science. This comprehensive study predicts the color of a uniaxial gem when viewed in any direction by reconstructing unpolarized spectra provided the polarized spectra and relative viewing angle to the c-axis are known.

In our last article, Nathan Renfro and coauthors present a beautiful array of inclusions in natural, treated, and synthetic spinel, as well as inclusions of spinel in other gemstones. Their colorful spinel inclusions chart is enclosed with every printed copy of this issue. Laminated versions of it, along with the five inclusion charts, are also available at store.gia.edu.

As always, interesting gemological findings abound in our regular sections. Discover natural diamonds displaying asterism and bicolor rough diamond crystals featuring distinct colorless and pink areas in Lab Notes, while Micro-World delights with a glimpse into the inner landscapes of gems: a kaleidoscopic play of interference colors seen in thin-film fluid inclusions in aquamarine and a cloud inclusion shaped like a diamond profile mimicking its diamond host. The Gem News International section features a virtual report on the pandemic’s impact and how the trade adapted their business practices to continue to flourish, as well as the headline-grabbing Cookie Monster geode and a glance back in time at hand-drilled holes in diamond briolettes. This issue also contains the annual G&G Challenge, where you can test your gemological knowledge of our 2020 issues. Finally, be sure to see our announcement of the Dr. Edward J. Gübelin Most Valuable Article Award winners.

We hope you enjoy the Spring 2021 edition of Gems & Gemology!

Duncan Pay | Editor-in-Chief | dpay@gia.edu @chapter:40