Publication Year: 2019 Title: Sourcing Stones with Columbia Gem House Abstract: Figure 1. Left: These trillion-cut blue hyalite opals from Oregon, weighing about 2.25 ct each, are reminiscent of moonstone. Right: Five Montana sapphires, ranging from 0.60 to 1.20 ct, showcase Columbia Gem House’s “GeoCut,” which follows the crystal’s natural shape. Photo by Robert Weldon/GIA.
Eric Braunwart (Columbia Gem House, Vancouver, Washington) spoke to us on how the industry has evolved since he opened his doors in 1976. Columbia Gem House has been a pioneer in the responsible sourcing of gemstones.
Braunwart traces his commitment to ethically sourced gems, those that he can track and trace and align with the company’s fair trade protocols, to a project he worked on with the World Bank in Madagascar about 20 years ago. His involvement with this project led him to set up fair trade standards for his own business—no small feat, as there were no such procedures for the gem and jewelry industry at the time. To create policies, Braunwart and his staff turned to industries such as food and agriculture. The company has remained open to public feedback; this is how Braunwart became passionate about prevention of silicosis in cutting communities. They have collaborated with different entities to create projects to benefit miners and their communities (read about one such project in J.-L. Archuleta, “The color of responsibility: Ethical issues and solutions in colored gemstones,” Summer 2016 G&G, pp. 144–160). The company continues to seek out projects in regions where they can make a difference by setting up schools, medical facilities, and other community needs.
Growing up in the American West led to Braunwart’s interest in the region’s nontraditional gem materials, such as agates, garnets, and petrified wood. Even though his business was involved in more traditional gem materials, he was drawn to the chalcedony, variscite, and turquoise that were not featured in classic jewelry. Today, Columbia Gem House sources and cuts about 150 different varieties of gemstones. American gemstones, such as the faceted blue hyalite opal from Oregon (figure 1, left), are one of their specialties. Much of their current business comes from small designers rather than large corporate interests. They have run their cutting facility in China for 35 years, with a trusted team that can quickly respond to orders.

	Sourcing stones with Columbia Gem House

While the company was in business before millennials were even born, this generation has clearly influenced the company’s sales; many of this year’s buyers in Tucson were people in their twenties representing small designer firms making modest purchases. Braunwart has been able to capitalize on social media (particularly Instagram) to make decisions on materials, colors, and cuts, allowing followers to vote on what types of material to promote. He believes that social media will continue to drive consumers toward ethical and sustainable choices in jewelry, with the full impact being felt within the next five years.

Figure 2. This 21.33 ct blue and green unheated sapphire is from Tanzania. Photo by Robert Weldon/GIA.
The 2019 AGTA show brought many new and established buyers to the Columbia Gem House booth. In fact, Braunwart said that this Tucson show, the company’s 41st, was their most successful ever. He attributes that to a growing interest in sustainably and ethically mined gemstones. Popular items included small baguettes in a variety of colors and materials, unheated Montana sapphire, Cortez pearls, and fossilized coral from Utah. The company’s “GeoCut,” a simple cut that follows the natural shape of the crystal, is used in materials such as Montana sapphire (figure 1, right). One remarkable stone from outside the United States was a 21.33 ct unheated sapphire from Tanzania showing distinct blue and green colors (figure 2). @chapter:28


Publication Year: 2017 Title: Book Review: Taffin: The Jewelry of James de Givenchy Abstract: By James Taffin de Givenchy, Tobias Meyere, and Hamilton South, hardcover, 400 pp. illus., publ. by Rizzoli, New York, 2016, $150.00.

Every time I gently eased the large volume about jewelry artisan James de Givenchy’s work with Taffin from the protective sleeve case and turned the pages, I acted as though I was removing a treasured object from a safe deposit box. I read, I stopped. I read, I stopped again. I forced myself to look a bit at a time so as not to gorge on the art represented, the craftsmanship on display for fear of spoiling myself for the next time.

As the pages turn, one can appreciate de Givenchy’s love of scale, the imaginative use of metals and their finishes, the exotic woods, and the leather used to create beautiful, singular pieces. The subtle homages to Duke Fulco di Verdura, Suzanne Belperron, and Jean Schlumberger are apparent to those familiar with their artisanship.

De Givenchy the artist comes to life through the thoughts of his friends, as written in their forewords to various sections of the book. In conjunction with the beautifully detailed photographs, one can understand why de Givenchy chose certain materials for specific pieces, and the reader takes joy in looking at the gems and the craftsmanship. A heart-shaped carved Colombian emerald, flush-mounted in a chartreuse green square ceramic base and adorned with pearls, pays homage to spring with the differing tones of green and the juxtaposition of organic elements. The inclusion of de Givenchy’s sketches of proposed pieces, along with the photo of his New York salon, elegantly bookend the jewelry depicted.

James de Givenchy delights in upending our conventional expectations. He uses unique woods and relatively common materials such as agate and leather through uncommon shapes and purpose. A broad violet wood bracelet, with its powerfully ridged grain juxtaposed with polished white chalcedony domed button shapes, makes the viewer pause in order to interact with the piece. Two pins executed in cloud-shaped faience and decorated with sweeps of diamonds results in a charming, light appearance. Some of the most intriguing works shown are those that have the gems set culet up. This causes the eye to stop and it disrupts the brain, leading to a greater appreciation of the cleverness of the method. Gemstones set in this manner cause us to approach a red spinel and ruby domed ring with a modicum of caution due to perceived prickliness. Such pieces create a visual and textural treat.

Taffin is a treasure, pure and simple. @chapter:16


Publication Year: 2018 Title: Outlook on Opals from Mexico and Australia Abstract: Figure 1. Mexican fire opal is clear enough to be faceted, and ranges from colorless to dark red. Photo by Kevin Schumacher.

Emil Weis Opals (Idar-Oberstein, Germany) opened its doors in 1905, making it the oldest opal cutting company in the world. Idar-Oberstein was the only global gem cutting center at the time, and opal buyers from all major gem markets had to send rough there for cutting. Emil Weis catered to this niche market early on and has since branched into mining; the company now owns mines in Australia and Mexico. We sat down with Jürgen Schütz, part of the founding family at Emil Weis, to discuss their activities in the opal market.

Jürgen Schütz Reflects on the Opal Market
Jürgen Schütz discusses the demand and future potential for non-phenomenal and play-of-color opal.
Currently the company is cutting 50 different types of opal from all over the world, the majority of it from Australia and Mexico. Emil Weis sells more nonphenomenal opal from these countries than it does play-of-color opal. The Mexican boulder opals they had on display were such an example. These specimens are cut to include both opal and rhyolite matrix, which some jewelry designers like to use in their pieces. According to Schütz, the nonphenomenal “fire” opal from Mexico (figure 1) is the only opal mined in quantity that is clear enough for faceting. It ranges from colorless to a dark red that is comparable with ruby. This type of material is available in large quantities and can even be calibrated.

Figure 2. Jürgen Schütz discussed the current supply and demand dynamics of Australian black opal. Photo by Kevin Schumacher.
Schütz then discussed the shortage of and demand for Australian black opals (see figure 2). In the past, Japanese demand for black opals drove prices up, but when Japan’s economy slowed in the early 1990s, prices fell and production slowed. However, recent rumors that Chinese markets are interested in black opal have doubled prices. Schütz showed us a rare black opal suite from Lightning Ridge, Australia, which took years to collect. Emil Weis has had this suite for about 10 years; today, it would be impossible to assemble this combination of black opals due to low production.

Figure 3. According to Schütz, the lack of active miners along the Queensland opal belt has led to a shortage of Australian boulder opal. Photo by Kevin Schumacher.
Production of Australian boulder opal (figure 3) is quite low. This is partially due to weather conditions, but Schütz noted that the boulder opal belt of Queensland is about 3,000 km long and 800 km wide, with only about 25 people mining it. This means that medium- to high-quality material is not produced in quantity. Schütz himself has connections with some of the older Queensland miners who have held on to parcels. Over the past two years he has been able to buy a parcel at a time from them. As a result, Emil Weis has a huge stockpile of boulder opal to cut, but does so sparingly.

Schütz noted that the supply of South Australian light opals is also severely constrained. When Ethiopian opal came on the market at one-tenth of the price, the demand for Australian opal slowed. By the time buyers regained interest in South Australian opal, the mining population had dropped from several thousand to about 20 in less than a decade. In fact, Schütz said, Australian opal mining has traditionally been such a difficult way of life that many young people are opting for more stable jobs, leaving large gaps in the mining industry. He thinks that it may take another generation or two before mining once again hits its stride Down Under. @chapter:39


Publication Year: 2021 Title: Mabe Cultivation in Mayotte Abstract: Figure 1. These assembled cultured blisters (mabe) showing a curved top (left) and flat bottom (right) were cultivated in Mayotte. The largest is 21 mm in diameter. Photos by LFG.
The Laboratoire Français de Gemmologie (LFG) received some mabe samples (figure 1) from Antoine Ganne of the Mayotte-based company Nuru Kombe for gemological characterization. According to the company, these samples were cultivated in Pteria penguin bivalves in a lagoon off the coast of Mayotte. This French territory is situated in the Indian Ocean between northwestern Madagascar and northeastern Mozambique, with one main island and several islets.
Mabe is the Japanese term designating an assembled cultured blister, traditionally from Pteria penguin but nowadays from other mollusks as well (CIBJO Pearl Commission, The Pearl Book, CIBJO, Milan, 2020, 79 pp.). Mabe is made of purpose-grown cultured blisters that have been cut from their shell. The original bead upon which they grew is removed, and the cavity is filled with various synthetic materials. It is then backed by a layer of shell, with the assemblage held together by an adhesive.
The studied samples ranged from light brown to brown (some of a “golden” color) with pronounced secondary colors such as blue, green, and red (again, see figure 1). Under the microscope, all samples presented the characteristic nacreous structures associated with overlapping layers of aragonite. The curved and flat sides looked very similar, suggesting they originated from the same mollusk species. The samples reacted purple to red under a long-wave UV lamp and remained inert under short-wave UV lamp excitation. Those with a more pronounced brown color exhibited a stronger intense luminescence. A similar luminescence reaction was observed in cultured pearls from Pteria sterna from Mexico (L. Kiefert et al., “Cultured pearls from the Gulf of California, Mexico,” Spring 2004 G&G, pp. 26–38). This response is due to a type of porphyrin (a tetrapyrrole with a cyclic structure) that also plays an important role in the samples’ coloration.

Figure 2. Photoluminescence spectrum of a brown mabe sample from Mayotte using a Raman spectrometer under 514 nm laser excitation. Three bands appearing at the orange and red parts of the electromagnetic spectrum at about 620, 650, and 680 nm are linked with uroporphyrin.
Raman analysis using a 514 nm laser revealed bands associated with aragonite along with a series of bands from 800 to 1600 cm–1 characteristic of porphyrins (S. Karampelas et al., “Raman spectroscopy of natural and cultured pearls and pearl producing mollusc shells,” Journal of Raman Spectroscopy, Vol. 51, No. 9, 2020, pp. 1813–1821). Photoluminescence spectra obtained using a Raman spectrometer and the same laser excitation presented bands in the orange and red part of the electromagnetic spectrum at about 620, 650, and 680 nm (figure 2). The relative intensity of these bands can vary. Luminescence spectra using a xenon lamp with 365 nm excitation presented similar bands with additional bands at about 435, 465, and 525 nm. The latter bands are possibly linked to the nacre of the samples, while the triplet of bands at 620, 650, and 680 nm has been attributed to a uroporphyrin (Y. Iwahashi and S. Akamatsu, “Porphyrin pigment in black-lip pearls and its application to pearl identification,” Fisheries Science, Vol. 60, No. 1, 1994, pp. 69–71).

Figure 3. The UV-Vis spectrum of a brown mabe sample from Mayotte displays bands at about 380, 400, 460, and 495 nm that are linked to porphyrin, along with a band at about 280 nm that is linked to nacre and organic matter.
The UV-Vis reflectance spectra of the samples featured a series of bands with various relative intensities at about 380, 400, 460, and 495 nm, along with a band at about 280 nm (figure 3). The latter band is linked to organic matter and the nacreous part of the samples, and the series is possibly linked to porphyrins (Kiefert et al., 2009).

Figure 4. X-ray microradiographs of two mabe from Mayotte show a lighter rim due to higher-density material (calcium carbonate), while the darker tones at the core represent a lower-density material such as resin. The top sample (21 mm in diameter) has a nacre thickness of 0.4 mm. The bottom sample (13 mm in diameter) has a nacre thickness of 1 mm. Images by S. Leblan, LFG.
All samples were inert under X-ray and EDXRF analysis, with an Mn content below the detection limit and Sr contents ranging from 3180 to 5280 ppm, indicating saltwater origin. X-ray microradiographs (figure 4) showed lighter tones at the rim, indicating a higher-density material such as calcium carbonate (usually aragonite) in the case of natural and cultured pearls, while the darker tones in the core indicated lower-density material such as organic matter and resin (S. Karampelas et al., “Real-time microradiography of pearls: A comparison between detectors,” Winter 2017 G&G, pp. 452–456). The samples, which could be called “mabe” or “assembled cultured blister” according to the current CIBJO standards, had a nacre thickness from 0.4 to 1 mm (again, see figure 4).
Mabe from Mayotte has only appeared recently in the market. The exact supply is still unknown, and other similar products are cultivated in other parts of the world, including Southeast Asia, Australia, and some Pacific island nations (P.C. Southgate and J.S. Lucas, The Pearl Oyster, 2008, Elsevier, Amsterdam). Nevertheless, this material could help develop the economy of Mayotte, where all the operations take place and jewelry pieces with a French touch are locally made. @chapter:14


Publication Year: 2013 Title: Adventures in Yakutia: On the Track of the Diamonds Abstract: This article starts with a brief history of Yakutian diamond production, from Mikhail V. Lomonosov’s theory of diamond deposits in 1761 to the discovery of the first kimberlites in 1954 to present-day operations. The bulk of the article then presents information the authors gathered during two visits to Yakutia, focusing on Mirny.

The report contains a map and a list of data on the most important mines. It is lavishly illustrated with images of Mirny—the mine, the town, the museum—and impressive diamond specimens.

Abstracted by Rolf Tatje @chapter:24


Publication Year: 1985 Title: Russian Flux-Grown Synthetic Emeralds Abstract: A relative newcomer to the international gem market is an attractive flux-grown synthetic emerald of Russian manufacture. This article provides a general discussion of the technique used to grow these stones and describes their gemological properties and chemistry. The Russian flux-grown synthetic emeralds were found to be similar to other flux-grown emeralds in refractive index and specific gravity, and therefore to be readily distinguished from natural emeralds on the basis of these two properties. @chapter:9


Publication Year: 1998 Title: Fall 1998 G&G Lab Notes Abstract: Plastic-Coated Beryl Assemblage Imitating Trapiche Emerald
Dark Green Chrysoberyl
Color Treated Diamond from Orangy Yellow to Reddish Purple
Raman Analysis of Inclusions in Diamond
Bicolored Glass
Synthetic Moissanite Submitted for Diamond Grading
Freshwater Cultured Pearls
Quartz: A Large “Crystal Ball”
Ruby with a True Double Star

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


Publication Year: 2023 Title: Shell Blister on an Isognomon isognomon Shell Abstract: Figure 1. Isognomon isognomon shell and blister. The shell measures approximately 107.76 × 72.39 mm. Photo by Gaurav Bera.
Theoretically, all mollusks are capable of producing pearls, but only a small number of them actually produce commercially traded nacreous pearls. Most come from the Pinctada and Pteria genera belonging to the Pteridae family. Species that produce the nacreous pearls regularly seen in the market, such as Pinctada maxima, Pinctada radiata, Pteria sterna, and Pteria penguin, are well known to aficionados. However, some unusual bivalve species can also produce pearls or shell blisters, and one example was recently submitted to GIA’s Mumbai laboratory for scientific examination.
The shell was from the Isognomon isognomon species, belonging to the Isognomonidae family and commonly known as the Pacific toothed oyster. It exhibited a blister feature that appeared as a folded section of nacre, located near the center, close to the posterior muscle scar and the hinge (figure 1). The shell weighed 46.88 g and measured approximately 107.76 × 72.39 mm, while the baroque-shaped silver to light gray blister measured approximately 8.80 × 4.21 mm. Not all instances of nacre growth on a shell are classified as pearls. While cyst pearls or whole pearls develop independently from the shell, blisters are nacreous concretions that appear to protrude from the shell (K. Lawanwong et al., “Natural shell blisters and blister pearls: What’s the difference?” GIA Research News, August 26, 2019). According to the pearl classification established by CIBJO, the concretion observed on the shell in question would be categorized as a shell blister.

Figure 2. Left: Dark brown rows of notch-like features observed on the hinge of the shell. Right: A whitish subsurface dendritic network of parasite channels. Photomicrographs by Prasad Mane; fields of view 16.3 mm (left) and 6.1 mm (right).
The shell itself displayed a narrow, elongated shape, featuring a straight hinge with distinct equidistant dark brown notches along its length (figure 2, left). These notches, also known as resilifers or ligament pits, resemble teeth, giving the species its common name; see I. Temkin and C. Printrakoon, “Morphology and taxonomy of Isognomon spathulatus (Reeve, 1858), a cryptic bivalve from the mangroves of Thailand,” Zootaxa, Vol. 4107, No. 2, 2016, pp. 141–174.
The interior of the shell exhibited a predominantly nacreous aragonite surface, characterized by a discernible spiral platelet structure visible under microscopic examination. This nacreous region was bordered by a non-nacreous shell margin. The central nacre displayed a light gray coloration, transitioning to a darker purplish gray toward the margin. The center of the shell had a more translucent appearance, revealing a subsurface dendritic network of parasitic channels surrounding the blister (figure 2, right).

Figure 3. Left: RTX image of the top view of the 8.80 × 4.21 mm shell blister (arrow) with a network of parasitic boreholes and channels visible around it. Right: RTX image of the side of the shell blister with more radiopaque folds marking its outline.
Real-time microradiography (RTX) revealed a network of fine channels beneath the blister and throughout the shell itself (figure 3, left). These features corresponded to the parasitic channels observed within the translucent layer on the shell’s interior. RTX imaging of the blister revealed a void (figure 3, right), potentially linked to parasitic activity that may have initiated the blister formation.
X-ray fluorescence (XRF) imaging of both the shell and the blister yielded an inert reaction. Energy-dispersive X-ray fluorescence spectrometry of the blister indicated a manganese level below the instrument’s detection limit and a strontium level of 1135 ppm. The inert XRF reaction, along with the chemical composition, proved the mollusk formed in a saltwater environment. Under long-wave UV radiation, the shell displayed a greenish yellow fluorescence reaction, while short-wave UV radiation yielded an inert response. Raman analysis using a 514 nm ion/argon laser excitation revealed peaks at 701/704 cm–1 and 1085 cm–1, indicative of aragonite. Photoluminescence spectra collected from both the shell and the blister showed three broad peaks centered at 620, 650, and 680 nm, which is observed in some naturally colored pearls.
Although the Isognomonidae family and the Pteridae family belong to the Pteroidae superfamily, pearls from oysters such as the Pacific toothed oyster (Isognomon isognomon) are rarely seen. Therefore, it was intriguing to examine this blister. Perhaps we will someday encounter a natural pearl from this mollusk species. @chapter:14


Publication Year: 2012 Title: Characterization of a Synthetic Nano-Polycrystalline Diamond Gemstone Abstract: A potential new synthetic gem material in the form of a faceted 0.88 ct brownish yellow nano-polycrystalline diamond (NPD) has undergone a full gemological examination, including detailed spectroscopic analysis, for the first time. While the material’s implications for the gem industry are still unknown, NPD’s optical characteristics along with manufacturing improvements make it a potentially important synthetic for gemologists to be aware of, even though very few samples have been faceted and future production costs and availability for gem purposes are uncertain. Features seen with magnification may provide an indication of its nano-polycrystalline nature, and the identification of this material can be confirmed by spectroscopy and other advanced testing methods. NPD is an entirely new kind of synthetic diamond, and its development illustrates the ongoing research on diamond properties for a number of important applications beyond the field of gemology. @chapter:11


Publication Year: 2023 Title: CVD “Etch” Channel Abstract: Figure 1. The etch channel in this CVD laboratory-grown diamond extends across the table facet into the crown. Photomicrograph by Elina Myagkaya; field of view 7.19 mm.
GIA’s New York laboratory recently examined a diamond that had been grown via chemical vapor deposition (CVD) and processed using a high-pressure, high-temperature (HPHT) treatment. Standard grading procedures identified it as a 4.00 ct H-color cushion modified brilliant with SI1 clarity. The diamond was identified as HPHT processed primarily due to the green fluorescence observed in the stone (see figure 3), while distinct fluorescent growth layers across the table and pavilion confirmed its CVD origin.

Figure 2. Dark residue is visible in some parts of the channel, as seen through the pavilion. The appearance of the residue is similar to that of graphitized carbon but could also be attributed to non-diamond carbon. Photomicrograph by Elina Myagkaya; field of view 1.99 mm.

Figure 3. DiamondView imaging revealed that the channel was surrounded by blue-fluorescing dislocation bundles extending across the growth layers of the CVD diamond. Image by Elina Myagkaya.
While GIA regularly receives CVD-grown diamonds submitted for laboratory-grown diamond reports, this particular example exhibited a unique characteristic. An etch channel–like structure was plainly visible across the table of the stone, a feature not observed in CVD laboratory-grown diamonds at GIA so far. The channel broke the surface of the table and extended across the stone, ending near a pavilion facet on the other side (figure 1). When viewed under high magnification, a dark residue (figure 2) was observed around parts of the channel. This residue was not present throughout the channel and appeared to be opaque. Close to the surface-reaching channel on the table facet were multiple smaller channels contained within the diamond. The surface-reaching opening of the channel was imaged with a scanning electron microscope (SEM), which revealed a jagged, slit-shaped entrance, suggesting that the shape of the channel extending throughout the diamond structure was similar in nature (figure 4). Some fragmentary material trapped just inside the entrance of the opening appeared to extend into the channel itself. This fragmentary material could have been the same type of opaque residue observed in some areas of the channel.

Figure 4. A secondary electron SEM image showed the finer structure of the channel opening, revealing a jagged, slit-like feature. Field of view 16 μm.
Fluorescence imaging with the DiamondView instrument also revealed the presence of this channel, which could be discerned by the blue-fluorescing line of dislocation bundles following the channel’s path (figure 3). These dislocation bundles appeared almost perpendicular to the green-fluorescing growth layer boundaries, suggesting the channel was created by exploiting weaker dislocation bundles that propagated through the diamond during CVD growth.
The presence of this channel in a CVD laboratory-grown diamond and the shape of the channel opening were unlike any natural etch channel opening or laser drill hole opening previously seen. It is unclear whether this channel was created during initial CVD growth or during HPHT processing. The opaque residue visible in some parts of the channel as well as the material visible at the channel surface could point to the presence of graphitized carbon, suggesting the channel was a byproduct of HPHT treatment, or it might indicate the presence of non-diamond carbon, which is a common feature found in untreated CVD laboratory-grown diamonds. In summary, the residue may arise from either the CVD growth process or post-growth treatment. Because this feature has not previously been documented at GIA, future studies may help determine the mechanism of action that could create channels in CVD-grown diamonds. @chapter:15


Publication Year: 2015 Title: Books: Van Cleef & Arpels: Treasures and Legends Abstract: By Vincent Meylan, hardcover, 344 pp., publ. by Antique Collectors Club, 2014, $95.00.

Van Cleef & Arpels: Treasures and Legends by Vincent Meylan delves into the glittering world of the venerable Parisian jewelry firm. Meylan explores the glamorous and exotic patrons who commissioned and collected these pieces, and the world in which they lived. Each chapter of Treasures and Legends is filled with both color and black-and-white photos of necklaces, rings, bracelets, brooches, and earrings. Some images show the firm’s pieces as worn by many of the prominent collectors over the past century. The original design sketches often accompany photos from the VC&A archives.

History buffs will enjoy the stories of royalty, particularly the maharajas and maharanis of Baroda (now Vadodara), India. The vast wealth of jewels that were collected in the Indian principalities is legendary, and Baroda, in Gujarat, was one of the wealthiest. The three-tier great ceremonial diamond collar necklace of Baroda, one of the crown jewels of the state, was made for Maharaja Khanderao in 1864. The necklace contained three of the world's most important diamonds: the Dresden Green, the Star of the South, and the Eugénie. At the time of its creation, it was the most valuable piece of jewelry in the world. The author traces the history of these and other magnificent jewels of Baroda, as well as the colorful and sometimes tragic stories of their owners, such as Maharani Seta Devi of Baroda. With India's independence in 1947, many maharajas had to sell their treasures to sustain their large homes. Seta Devi moved to Paris instead, where she was known for lavish parties and extravagant living. But eventually her money ran out, her beloved son was murdered, and she died in obscurity in 1989.

Other royal stories involve the coronation and crown jewels of the Shah of Iran, as well as the coronation crown of his third wife, Farah Diba. Intimate family photos and sumptuous coronation images highlight the story of the firm’s greatest commission. A first-hand account by Pierre Arpels adds to the interesting narrative of this journey to create these royal treasures. The Duke and Duchess of Windsor’s famous love affair was documented by many of the pieces of jewelry that he purchased for her at the great jewelry houses of Paris. The Duchess is seen wearing their pieces in many candid photos of them in social settings. Their wedding day photo shows the Duchess wearing her wedding gift: a large sapphire and diamond Mystery-set Jarretière bracelet from Van Cleef & Arpels.

Meylan also explores the role VC&A played in the world of Hollywood royalty. Marlene Dietrich was seen wearing her large ruby and diamond Jarretière bracelet in more than one film. At her death, Elizabeth Taylor’s estate contained more jewelry pieces from Van Cleef & Arpels than from any other jewelry house. Several of her impressive pieces are displayed in this book, and with them their stories of love and passion that defined Taylor’s life. Meylan names other luminaries, such as Barbara Hutton and Grace Kelly, as fans of the jewelry house.

The book ends with a chapter on the personalities in the family, including founders Esther Arpels and Alfred Van Cleef, their daughter Renée Puissant, and Esther’s brothers Charles, Julian, and Louis Arpels. Puissant in particular plays a fascinating role in the company’s history, becoming the artistic director of the firm in 1926. In the 1930s, under her direction, some of the firm’s most iconic pieces, including the “Mystery Setting” and the “Zipper Necklace,” are created. Van Cleef & Arpels: Treasures and Legends takes the reader on a historical journey filled with stunning pieces and interesting characters throughout the world—characters connected with a golden thread, their love of the beautiful art of Van Cleef & Arpels. @chapter:16


Publication Year: - Title: New Nigerian Source of Blue Sapphire Abstract: This parcel of 30 fine-quality rough blue sapphires is reportedly from the Mambilla area of Nigeria. They weigh between 1 and 5 ct each. Photo by Vincent Pardieu/GIA.

                      The recent arrival of high-quality blue sapphire from a new source  in Africa has caused considerable excitement in the Bangkok marketplace. These gems, reportedly from the Mambilla Plateau in Nigeria’s Taraba State, are available in large rough sizes, some as big as 100–300 ct. Like previously documented Nigerian material, these sapphires are mined from basalt-related secondary deposits. Yet the quality is significantly better than any seen to date from those sources. Initial indications suggest that this new deposit might provide a winning combination of size, high clarity, attractive color, and good crystal habit from a cutter’s perspective. Indeed, one especially fine stone is rumored to have sold for in excess of US$1 million.

As a preliminary study for a future field expedition to this location, researchers from GIA’s Thailand laboratory obtained a selection of 30 fine-quality rough sapphires from a trusted supplier in Bangkok. Representative samples were fabricated into precisely oriented wafers for the collection of high-quality optical data using FTIR and UV-Vis-NIR spectroscopy. Inclusions were identified using Raman spectroscopy, and trace-element chemical composition was analyzed using LA-ICP-MS.

A new report by the GIA laboratory in Bangkok, “Blue Sapphires from the Mambilla Plateau, Taraba State, Nigeria,” presents their initial findings. Although the inclusion suites, spectroscopic features, and LA-ICP-MS trace-element results appear similar to those of sapphires from other basalt-related deposits—including Cambodia, South Vietnam, and some Australian localities—the composition of minute “nano-inclusions” within some of the gems appears promising for origin determination purposes. @chapter:6


Publication Year: 2018 Title: Multi-Generation Cutting Family from Idar-Oberstein Abstract: Figure 1. Aquamarine has long been Arnoldi International’s signature stone. Photo by Kevin Schumacher.
Idar-Oberstein, Germany is a historic agate locality that became famous over the last century as a colored stone trading and cutting center. In recent decades, though, much of the lapidary activity has moved from Idar-Oberstein to cutting centers in Asia such as Jaipur and Bangkok. The remaining businesses in Idar are focusing on highly specialized market segments, such as precision cutting and unusual stone varieties. Alexander Arnoldi explained to us the strategy of Arnoldi International and provided an update on some new high-quality materials.

The cutting business was founded in 1919, making Alexander Arnoldi a fourth-generation gemstone dealer and cutter. They process all the goods in-house, from rough sorting to final polishing. Lapidary work is still based on the traditional techniques of Idar-Oberstein, where the wheel is turned with the dominant right hand, leaving the left hand free to hold the stone. Laps are motor-driven today, but the stone is still held with the left hand. According to Arnoldi, it takes more than five years to master cutting and learn all the facet placements and correct angles for the different styles and materials.

Arnoldi International’s Gem Cutting
Fourth-generation gem cutter Alexander Arnoldi discusses his family’s business, based in Idar-Oberstein, Germany.
The company focuses on flawless stones, a challenging segment of the gemstone industry. Prices for these goods have exploded, but supply is extremely low and competition at the source is very high. Finding extremely high-quality rough that yields large clean stones is one of the main challenges they face in the current market. Nowadays, most rough suppliers bring their goods to Bangkok and Jaipur instead of Germany. This forces companies such as Arnoldi to go source their own material on site—for instance, copper-bearing tourmaline from Mozambique.

Idar-Oberstein’s first main product more than 500 years ago was agate, polished using hard sandstones found nearby. When Germany’s population began moving abroad in the early nineteenth century, Idar’s network became more global and gained access to the Brazilian deposits, which produced many quartz varieties. The German cutters became very adept at cutting and polishing the materials sourced in Brazil. Arnoldi focused on aquamarine (figure 1), a stone that remains their strong suit in 2018. Originally they worked with goods from South America, including the fabled Santa Maria deposit in Minas Gerais, Brazil. Much of the rough is now sourced in Central and East Africa, which produces deep blue material similar to Santa Maria aquamarine.

Figure 2. More recently, Arnoldi International has begun working with tourmaline from the Democratic Republic of Congo. Photo by Kevin Schumacher.
Another stone they are focusing on is tourmaline, including Paraíba, rubellite, and bicolor stones. In December 2017, they traveled to Central Africa to source the new tourmalines from the Democratic Republic of Congo (figure 2). This material comes in different shades of green, often in the same crystal. Pink crystals are occasionally found. Supply is highly irregular, and quality varies greatly.

Arnoldi International is putting their focus on high-quality, flawless goods and excellent cutting standards. This allows them to supply high-end vendors who often ask for unique, customized cutting styles. @chapter:28


Publication Year: 1997 Title: Rubies and Fancy-Color Sapphires from Nepal Abstract: Gem-quality rubies and fancy-color sapphires have been recovered from dolomite marble lenses located high in the Himalayan mountains of east-central Nepal (Ganesh Himal). First discovered in the early 1980s, these deposits have had only limited and sporadic production because of their isolated locations, high altitudes, and harsh seasonal weather conditions. The precise locations and geology of the two best-known deposits are described. In addition, 27 polished samples and 19 rough crystals and mineral specimens were thoroughly investigated to document their gemological characteristics and crystal morphology. The most distinctive internal features are their color-zoning characteristics, various cloudlike and other patterns, as well as a wide variety of mineral inclusions, some of which have not been seen in rubies from other sources. @chapter:4


Publication Year: - Title: Emerald Care and Cleaning Guide Abstract: Emeralds set in jewelry have lasted for centuries. With the proper care, the emeralds in today’s jewelry will do the same. Courtesy Color Masters.

Hardness and toughness
Gem and mineral hardness is measured on the Mohs scale. The numbers are based on the relative ease or difficulty with which one mineral can be scratched by another. But the Mohs scale is deceptive. The steps between the minerals are not evenly spaced. For example, diamond is only one number away, but it’s many times harder than gems in the corundum family.

Emerald is 7.5 to 8 on the Mohs scale and has fair to good toughness, making it a stone that requires more care in wearing than ruby or sapphire. Even so, emeralds are beautiful stones for all types of jewelry and with proper care will last for generations.

	Emerald rates a 7.5 to 8 on the Mohs hardness scale.
Stability
Heat can damage emeralds, especially by extending existing fractures. Light and chemicals can cause the oils, resins, and polymers used to fill surface-reaching fractures to alter in appearance or deteriorate.

Cleaning
Some estimates state that 90 percent or more of emeralds are fracture-filled. Since the great majority of fashioned natural emeralds contain filled fractures, it’s risky to clean them ultrasonically or with steam. Ultrasonic vibrations can weaken already-fractured stones, and hot steam can cause oil or unhardened resin to sweat out of fractures. Using warm, soapy water coupled with gentle scrubbing is the safest way to clean emeralds. @chapter:23


Publication Year: 1986 Title: The Gemological Characteristics of Chinese Peridot Abstract: Significant deposits of gem-quality peridot have been found in the People's Republic of China. This Chinese peridot has geologic origins and gemological properties almost identical to the peridot found on the San Carlos Apache Reservation in Arizona, and cannot be distinguished
gemologically, at this time, from peridots from other known localities. @chapter:3


Publication Year: 2022 Title: 10 ct HPHT-Treated CVD Laboratory-Grown Diamond Abstract: Figure 1. This 10.04 ct G-color CVD-grown diamond proved to have been HPHT treated. Photo by Annie Haynes.
Recent years have seen several size milestones for faceted diamonds grown by chemical vapor deposition (CVD). In all the published reports that commented on treatment, these record-size CVD diamonds were indicated to be as-grown and with no indications of post-growth treatment (Winter 2016 Lab Notes, pp. 414–416; “IGI Hong Kong certifies largest CVD grown diamond to date,” 2020, https://www.igi.org/gemblog/igi-hong-kong-certifies-largest-cvd-grown-diamond-to-date/; Spring 2022 Lab Notes, pp. 54–56). For other recent milestone CVD diamonds reported within the trade, we could not confirm whether they were as-grown or treated. At the time of publication, the current benchmark is a 30.18 ct H-color diamond reportedly grown by Ethereal Green Diamond (Rapaport News, June 12, 2022).

Figure 2. The green and blue fluorescence colors in this DiamondView image of the 10.04 ct CVD-grown diamond confirm its post-growth treatment. Image by Taryn Linzmeyer.
Against this backdrop, a notable 10.04 ct CVD-grown diamond (figure 1) was recently submitted to the Carlsbad laboratory for a laboratory-grown diamond report. This emerald-cut stone with G color and VS2 clarity had several growth remnants, including a cloud of dark non-diamond carbon. As with all laboratory-grown diamonds, it underwent extensive testing including spectroscopy to verify its CVD origin. IR absorption spectroscopy identified it as type IIb with an uncompensated boron concentration of ~2 ppb. Spectral features such as the lack of a 468 nm peak in photoluminescence along with the coloration in the DiamondView fluorescence imaging (figure 2) confirmed it had undergone post-growth treatment (W. Wang et al., “CVD synthetic diamonds from Gemesis Corp.,” Summer 2012 G&G, pp. 80–97).
Many CVD-grown diamonds are subjected to high-pressure, high-temperature (HPHT) treatment after growth to remove a brownish appearance caused by extended defects (such as vacancy-related complexes). The brown color often correlates with a faster CVD growth rate, which the manufacturer uses knowing the color can be reduced by treatment afterward. It appears that when manufacturers create a CVD diamond of record-setting size, the growth is performed so slowly that subsequent HPHT treatment is not required for a colorless to near-colorless grade.
While some 80% of colorless to near-colorless CVD-grown diamonds have been subjected to post-growth treatment to reduce their brownish coloration (S. Eaton-Magaña et al., “Laboratory-grown diamond: A gemological laboratory perspective,” Journal of Gems & Gemmology, Vol. 23, No. 6, 2021, pp. 25–39), this treatment is not often applied to larger stones. Therefore, evidence of HPHT treatment in a CVD-grown diamond larger than 10 carats is noteworthy. These products will likely become more commonplace in the future. @chapter:15


Publication Year: 2007 Title: Pink-to-Red Coral: A Guide to Determining Origin of Color Abstract: Pink-to-red coral has a long history as an ornamental gem material in jewelry, carvings, and sculptures. However, due to a variety of environmental and legal factors, the supply of high-quality, natural-color coral in this color range has dramatically decreased in recent years—and the quantity of dyed coral on the market has increased. From a study of more than 1,000 natural- and treated-color samples, this article summarizes the procedures that are useful to identify the color origin of pink-to-red coral. A variety of techniques—including magnification, exposure to acetone, and Raman analysis—can determine if the color of a piece of such coral is dyed. Although there are limitations to the use of magnification and acetone, Raman analysis can establish conclusively that the color is natural. @chapter:40


Publication Year: 2023 Title: Pearls in Traditional Indian Nose Rings Abstract: Figure 1. Two traditional Indian-style pearl nose rings (nath) set with colored gemstones and pearls measuring approximately 6.63 × 6.09 mm to 8.42 mm (left) and 5.38 mm to 8.02 × 7.61 mm (right). Photo by Gaurav Bera.
The beauty of Indian jewelry lies in the artisanship involved in creating intricate, unique designs. One example is the classic Indian nose ring (known as the nath). It is typically cashew shaped, with a chain to connect it to a hairpiece or earring. The nath exemplifies traditional Maharashtrian jewelry and is usually crafted in yellow gold. Made famous during the Peshwa rule, the nath has been crafted using diamonds, pearls, rubies, and emeralds. Today, the nath is worn mainly for weddings or special occasions, while everyday nose adornments take the form of smaller, simpler studs or rings made from gold or silver. Recently, GIA’s Mumbai laboratory received two traditional nose rings for pearl identification.
Each was set with 17 drilled pearls, near-drop and button, ranging from light cream to cream in color. They were skillfully strung together with yellow metal wire and set with colored gemstones of various shapes and cutting styles. The pearls in the larger nose ring (figure 1, left) ranged from approximately 6.63 × 6.09 mm to 8.42 mm, and the item weighed a total of 13.96 g. Those in the smaller nose ring (figure 1, right) ranged from 5.38 mm to 8.02 × 7.61 mm, and this piece weighed 9.05 g overall. When viewed under 40× magnification, the pearl surfaces in both pieces showed typical nacreous overlapping aragonite platelets and a medium to high surface luster. Energy-dispersive X-ray fluorescence (EDXRF) spectrometry revealed manganese levels below the instrument’s detection level and a strontium content averaging 950 ppm. In addition, the pearls were inert to X-ray fluorescence, indicative of saltwater origin. They showed a moderate greenish yellow reaction under long-wave ultraviolet light and a weaker reaction of similar color under short-wave UV. Real-time microradiography imaging revealed internal structures similar to those observed in natural pearl studies for various Pinctada-species mollusks (K. Scarratt et al., “Natural pearls from Australian Pinctada maxima,” Winter 2012 G&G, pp. 236–261; N. Nilpetploy et al., “The gemological characteristics of Pipi pearls reportedly from Pinctada maculata,” Winter 2018 G&G, pp. 418–427). The radiopaque areas visible on the microradiographs of both items correspond to the yellow metal fittings and wire, since they are denser and prevent X-rays from passing through.

Figure 2. Real-time microradiography of the internal structures observed in the larger nose ring consisting of organic-rich acicular structures and growth arcs (left) and a “collapsed core” near the drill hole area surrounded by growth arcs (right).
Five pearls from the larger nath revealed an organic-rich internal structure with varying patchy light and dark gray contrasting areas, along with an acicular structure radiating from their centers that occupied almost half of the internal structure (figure 2, left). Two pearls showed “collapsed cores” close to the drill holes (figure 2, right); the bulk of the cores, if any, were removed as a result of drilling. The remaining ten pearls displayed fine concentric rings and growth arcs, all proving their natural origin.

Figure 3. The majority of the pearls in the smaller nose ring showed faint growth arcs and concentric ringed structures, while three of them showed organic-rich acicular cores (marked with arrows) typical of natural pearls.
Microradiography of the pearls in the smaller nath revealed similar internal structures. While the majority of those pearls showed fine concentric rings and growth arcs, three of them (marked with arrows in figure 3) also possessed organic-rich and acicular cores that occupied varying degrees of their structure. The internal structures observed in both items contained classic natural pearl structures similar to those observed in known Pinctada radiata pearls in GIA’s research database. The EDXRF results were also within the range expected for Pinctada radiata samples, with the lower levels of strontium (average of 950 ppm) and manganese (mostly below detection limits) consistent with that mollusk species and below those expected from P. maxima pearls (A. Homkrajae et al., “Internal structures of known Pinctada maxima pearls: Natural pearls from wild marine mollusks,” Spring 2021 G&G, pp. 2–21).
The combinations of natural pearls made these two pieces very attractive. It is no easy task to create traditional nose ornaments with pearls of such size. These two unique pearl jewelry items provide an excellent example of Indian heritage. @chapter:21


Publication Year: 1997 Title: Winter 1997 Gem News International Abstract: THE 26TH INTERNATIONAL GEMMOLOGICAL CONFERENCE
Diamonds
            Cathodoluminescence of Yellow Diamonds
            Diamond Inclusions in Corundum
            The Diamond Pipeline into the Third Millennium
            Mineral Inclusions in Large Yakutian Diamond Crystals
            The Morphology of Natural Gem Diamond
Colored Stones and Inorganic Material
            Identification of Amber by Laser Raman Microspectroscopy
            New Zealand ‘Kauri Gum’
            Inclusion-Related Fluorescence Zoning in Amber
            New Chrysoberyl Deposits in India
            Gem Corundum from Australia and Southeast Asia
            Bactrian Emeralds
            Emerald Origin
            Origin of Ancient Roman Emeralds
            Blue Quartz from Madagascar
            Ornamental Stones and other Gems from Bolivia
            Cultured Pearls from Indonesia
            Sapphires from Northern Madagascar
            Tunduru-Songea Gem Fields in Southern Tanzania
Synthetics and Simulants
            Imitation Pearls: So-Called “I Pearls” from Japan
            Growth-Induced Imperfections and Inhomogeneities in Single Crystals
            Surface Features and Growth Conditions of Quartz Crystals
            Reversible Twinning in an Unusual Synthetic Material
Treatments
            Heat Treatment of Garnets
            Titanium and Chromium Diffusion-Induced Star Sapphires
Announcements
            New Hall Opens at the Smithsonian Institution
            Diamonds at the American Museum of Natural History
            New Exhibits at the Cleveland Museum of Natural History
Gems & Gemology Wins ASAE Award – Again!

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


Publication Year: 2017 Title: Melee Diamond Parcel Containing Nearly One-Third CVD Synthetics Abstract: Figure 1. These 101 CVD synthetic diamonds were mixed into a parcel of 323 diamond melee, representing 31.3% of the stones. Photo by Roxane Bhot.

In February 2017, a parcel containing 323 colorless to near-colorless diamond melee was submitted to the Mumbai laboratory for screening and color sorting. The average weight of each round brilliant was 0.015 ct, with an average diameter of 1.5 mm. Of this parcel, GIA’s fully automated screening and sorting system confirmed that 219 samples were natural, with the remaining 104 samples referred for further testing. Detailed analysis determined that three of the referred stones were natural, and the remaining 101 stones (31.3%) were CVD synthetics (figure 1).

This result is especially remarkable due to the type of synthetic observed. While the undisclosed mixing of HPHT synthetic diamonds in melee has become a primary concern of the diamond trade, CVD synthetics have been very rare in this size group (Fall 2016 Lab Notes, p. 307). The synthetics were color graded using the GIA melee sorting device for research purposes. The majority of the CVD synthetics were G/H (74.3%) in color, though the D–F (20.8%) and I/J (4.9%) color ranges were also represented.

Further analysis was conducted on these synthetics using Fourier-transform infrared (FTIR) and photoluminescence (PL) spectroscopy (the latter at liquid nitrogen temperature) and DiamondView imaging. Interestingly, the group included both as-grown (10.9%) and treated synthetics (89.1%), indicating that they may have been produced by different laboratories. The treated diamonds showed evidence of annealing at high temperatures for color improvement, probably under HPHT conditions. FTIR revealed that they were all type IIa, with only two samples (1.9%) showing the CVD-specific NVH0 absorption peak at 3123 cm–1. Several impurity complexes common in CVD synthetic diamonds were detected by PL spectroscopy, including NV0/– (575 and 637 nm, 100%), the 596/597 nm center (4.0%), SiV– (736/737 nm, 100%), the 883/884 nm Ni-related center (13.9%; see J.P. Goss et al., “The lattice location of Ni in diamond: A theoretical study,” Journal of Physics: Condensed Matter, Vol. 16, No. 25, 2004, pp. 4567–4578), SiV0 (946 nm, 29.7%), and H2 (986 nm, 17.8%). The presence of SiV0/– and the 596/597 nm center were particularly indicative of CVD origin, as SiV0/– centers are routinely found in CVD synthetics yet are comparatively rare in other diamond materials. The 596/597 nm center has been observed only in CVD synthetics.

Figure 2. DiamondView images of the 101 CVD synthetic diamonds showed a wide range of patterns and colors, indicative of their different growth and treatment histories. As-grown synthetics showed orange, pink, or red fluorescence (top left), while those treated by high-temperature annealing fluoresced blue or green (top right). Slightly over a third (35.6%) of the synthetics showed layers indicative of changes in growth conditions (bottom left). Those with very high Si content were dominated by blue dislocation bundles (bottom right). DiamondView images by Priyanka Dhawale and Jemini Naik.

DiamondView imaging further emphasized the variety of CVD synthetics included in this parcel. The fluorescence of the as-grown CVD synthetics ranged from orange to red to pink, as seen in figure 2 (top left), due to emissions from NV0/– centers. The other samples showed the typical blue–green fluorescence associated with high-temperature annealed CVD synthetics (figure 2, top right). In an unusual finding, layered structures suggesting abrupt changes in growth conditions—which may include stopping and restarting growth—were seen in 35.6% of the CVD synthetic melee. These abrupt changes resulted in alterations to the impurity uptakes of the material, producing the layered structures. Layer thicknesses varied but were generally about 200–500 μm, with samples often showing two or more layers intersecting their table facets (figure 2, bottom left). Such layers are regularly seen in large CVD synthetics (Winter 2015 Lab Notes, pp. 437–439), though they have not been reported for melee-sized goods. Striations and blue dislocation bundles (the latter visible in figure 2, bottom right) were common (45.5% and 19.8%, respectively); certain high-Si synthetic diamonds were dominated by these bundles. Green or blue phosphorescence was observed for 84.2% of the CVD samples.

The substantial undisclosed mixing of CVD synthetic diamonds in this parcel, approaching one-third of the stones, emphasizes the importance of routine testing of melee to identify HPHT and CVD synthetics. GIA’s automated melee screening and sorting device was able to successfully separate the natural and CVD synthetic material, providing confidence in the stones’ origin and supporting transparency in the industry. @chapter:15


Publication Year: 2016 Title: Book Review: Stoned: Jewelry, Obsession, and How Desire Shapes the World Abstract: By Aja Raden, hardback, 368 pp., illus., publ. by Ecco/HarperCollins, New York, NY, 2015, US$27.99.

Stoned is an approachable and entertaining web of stories that sheds light on epic jewellery lore while unravelling some of the most notorious and familiar legends. Author Aja Raden takes a classic yet playful American point of view, concentrating on value and worth over the artfulness of the jewellery itself.

	Raden’s language and the organisation of the book are designed to attract a wide variety of readers, starting with the suggestive title, bejewelled cover, and high-profile praise from the likes of Madonna and David Duchovny. This general appeal extends to the clever chapter titles, unexpected terms and plays-on-words. Almost every chapter begins with a pair of quotes, one from high and another from low culture, and closes with a revelation that is unnecessary to the story, but helps to develop the author’s distinct voice.

	Raden beckons the reader, as if she’s whispering in someone’s ear at a cocktail party. She asks, “Did Marie Antoinette lose her head over a diamond necklace?” And “How did two sisters’ argument over a valuable pearl in England over almost 500 years ago help draw the map of the Middle East?” She even promises to reveal how a strand of pearls transformed Japan into a “global economic superpower”. Her aim is to strip away myths, and replace them with more complete impressions of the times and the people behind the stories.

	Part I begins with topics the reader may have heard about before: the sale of Manhattan for glass beads, the ubiquity of diamonds and how emeralds financed the Spanish Empire. Raden reveals some obscure facts and stories about these well-known fables and ties them together with an intriguing theme: the perception of value. She weaves an abundance of puns and comedic buzz with historical and scientific material, employing a quick rhythm and uncommon agility while moving around an expansive timeline. As an example, she combines the toxicology studies of Paracelsus, a quote from Groucho Marx, an account of the Spanish conquest of the Americas, and the story of the Dutch tulip bubble crash of 1637—all in just three paragraphs (on page 105). This method is likely to capture the short attention span of the millennial generation and intrigue readers who are looking for something clever to add to cocktail party conversations and long car journeys.

	In Part II, Raden delves into the meaning and symbolism of jewellery, all at a somewhat slower, more focused pace. She draws out the details of the historical moments, paints pictures of the times and the people, and in many cases, rocks the foundations of these classic myths and tales. The shortest, final section, Part III, loses steam and is not as tightly bound by a concept. The section titled “The Boss’s String” could easily have been included in Part 2, and the final story, “Timing Is Everything”, could stand alone as a journal article. A more cohesive and even playful conclusion would have made for a stronger finish, as a reader who has made it to the end is sure to be ravenous for a more revealing final thought.

	Overall, Raden is a champion of approaching fine jewellery history with an entertaining and occasionally ludicrous edge. This compilation is not meant to be an all-encompassing account of jewellery history. Rather, it is the work of an experienced and passionate author pushing open some creaky old doors to shed warm rays of light onto a selection of topics customarily considered mysterious and off-limits. All in all it makes for a fun and quick read for a wide audience. @chapter:16


Publication Year: 2014 Title: CVD Synthetic Diamond with Unusual DiamondView Image Abstract: Figure 1. This G-color, 0.32 ct CVD-grown synthetic showed DiamondView features typically associated with a natural origin. Photo by Robison McMurtry.

Over the last several years, CVD-grown synthetic diamonds have evolved rapidly in overall quality, including size and clarity. GIA’s laboratory frequently documents new, sometimes subtle developments in this material.

Recently a 0.32 ct, G-color CVD synthetic (figure 1) was submitted to the Carlsbad laboratory. DiamondView imaging (figure 2) showed a few interesting characteristics. Most of the sample displayed a deep blue fluorescence, a feature typically derived from the N3 optical center and often observed in natural diamonds. CVD-grown synthetic diamonds usually have either a greenish blue or an orange to red fluorescence, depending on whether they have been treated to generate high concentrations of NV centers. The deep blue, N3-related fluorescence is so prevalent among mined diamonds that the color itself can often verify that a diamond is not synthetic. In addition to the deep blue color of the fluorescence, its visual pattern closely resembled the dislocation networks commonly seen in natural-origin type IIa diamonds rather than the striations caused by stepwise growth in CVD synthetics (P.M. Martineau et al., “Identification of synthetic diamond grown using chemical vapor deposition [CVD],” Spring 2004 G&G, pp. 2–25).

Figure 2. In addition to blue fluorescence, the CVD synthetic’s DiamondView image displayed yellow-green fluorescence lines indicating the stop/start cycling that occurred during the growth process. Image by Sally Eaton-Magaña.
Taken together, the blue fluorescence and apparently random patterning closely resemble DiamondView images of natural-origin type IIa diamonds. This indicates that CVD manufacturers are becoming quite adept at mimicking natural growth. It is unclear whether this resemblance was a deliberate goal or a by-product of advances in CVD growth; regardless, the blue fluorescence for this CVD synthetic diamond does not appear to derive from the N3 center. Photoluminescence (PL) spectroscopy, collected with 325 nm excitation, showed only a very weak peak at 415.2 nm.

Yet this stone also contained two features that clearly indicated its synthetic origin: a large concentration of the Si-V center at 737 nm, revealed by PL spectroscopy, and the pronounced yellow-green parallel lines in the DiamondView image.

These parallel lines, with a nearly uniform spacing of approximately 0.8 mm in this sample, are created when the CVD reactor undergoes stop and start cycles during growth. These cycles create a temporary change in chemical composition, especially at the growth interface. Willems et al. (“Exploring the origin and nature of luminescent regions in CVD synthetic diamond,” Fall 2011 G&G, pp. 202–207) proposed that a change in surface roughness promotes the incorporation of impurities, which alters the fluorescence and creates new dislocations.

Four PL spectra were collected from these yellow-green lines and from the blue-fluorescing regions, using 488 nm laser excitation and normalized to the Raman peaks. The relative intensities of the peak areas from both regions were averaged to compare the optical defects that altered the fluorescence. The H3 center at 503.2 nm, the NV centers at 575 and 637 nm, and the Si-V center at 737 nm all showed higher concentrations along the yellow-green lines. These vacancy-related defects increased by a factor of approximately 1.5 for NV0 and Si-V, 3 for NV–, and 5 for H3, indicating a higher presence of vacancies at the growth interface. Several sequential growth runs were likely necessary to achieve high CVD quality, leaving behind these fluorescence lines as evidence of synthetic origin. @chapter:15


Publication Year: 2023 Title: Libyan Desert Glass Bangle Bracelet Abstract: Figure 1. A 144.67 ct Libyan Desert glass bangle measuring 66.12 × 13.10 mm. Photo by Johnny Leung.
Libyan Desert glass is a light green or yellow natural glass which is composed of almost 98% silica. It is a type of tektite formed by meteorite impact in the desert and the fast quenching of the silica-rich melt produced. It was first reported by Clayton and Spencer in 1934 (F. Fröhlich et al., “Libyan Desert Glass: New field and Fourier transform infrared data,” Meteoritics and Planetary Science, Vol. 48, No. 12, 2013, pp. 2517–2530) and is found in Egypt’s Western Desert. Common inclusions are bubbles, cristobalite, dark brown streaks, and black iron oxides (J.A. Barrat et al., “Geochemistry and origin of Libyan Desert glasses,” Geochimica et Cosmochimica Acta, Vol. 61, No. 9, 1997, pp. 1953–1959).
Recently, GIA’s Hong Kong laboratory examined a transparent light yellow bangle bracelet measuring 66.12 × 13.10 mm and weighing 144.67 ct (figure 1). It had a spot refractive index of 1.44 and revealed weak yellow fluorescence in short-wave UV. The chemical composition, determined by qualitative analysis using energy-dispersive X-ray fluorescence, was nearly pure silica with minor amounts of iron, strontium, potassium, titanium, and zirconium.

Figure 2. Various shapes of gas bubbles were dispersed individually and in clusters in the Libyan Desert glass bangle. The row of gas bubbles in this image resembles peas in a pod. Photomicrograph by Sze Ling Wong; field of view 2.40 mm.

Figure 3. White spherulites in the bangle were identified as cristobalite by Raman analysis. Photomicrograph by Sze Ling Wong; field of view 5.98 mm.
Based on the differences in molecular vibrations detected with Fourier-transform infrared (FTIR) analysis, it was determined that the molecular structure of Libyan Desert glass is significantly different from that of other pure silica glasses. It has a higher ratio of discontinuities and defects in the tetrahedral (SiO4) network (F. Fröhlich et al., 2013). Microscopic observation revealed common inclusions in glass such as numerous gas bubbles (figure 2) and flow structure. This bangle also presented abundant white spherulites identified by Raman spectroscopy as cristobalite (a polymorph of silica). These spherulites were small and individually dispersed throughout the glass (figure 3). The presence of this high-temperature low-pressure silica phase indicates a natural high-temperature formation. From all the gemological, FTIR, and Raman data collected, this bangle was identified as Libyan Desert glass.
Most Libyan Desert glass is tubular in shape, and some are approximately spherical or rod-like (R.A. Weeks et al., “Libyan Desert glass: A review,” Journal of Non-Crystalline Solids, Vol. 67, No. 1-3, 1984, pp. 593–619). Those fragments are usually 2 to 63 mm in size, so it is surprising to examine this material in the form of a bangle bracelet. @chapter:13


Publication Year: 2010 Title: The Wittelsbach-Graff and Hope Diamonds: Not Cut from the Same Rough Abstract: Two historic blue diamonds, the Hope and the Wittelsbach-Graff, appeared together for the first time at the Smithsonian Institution in 2010. Both diamonds were apparently purchased in India in the 17th century and later belonged to European royalty. In addition to the parallels in their histories, their comparable color and bright, long-lasting orange-red phosphorescence have led to speculation that these two diamonds might have come from the same piece of rough. Although the diamonds are similar spectroscopically, their dislocation patterns observed with the DiamondView differ in scale and texture, and they do not show the same internal strain features. The results indicate that the two diamonds did not originate from the same crystal, though they likely experienced similar geologic histories. @chapter:35


Publication Year: 2022 Title: Complex Fluid Inclusion in Topaz Abstract: This complex fluid inclusion in topaz is composed of minute solid crystals, an aqueous liquid, and an immiscible CO2 fluid. When cooled below 31.5°C, the CO2 is in a liquid state with a vapor bubble trapped in the CO2 liquid (left). When gently warmed, the CO2 vapor bubble shrinks (center) until it ultimately disappears (right) as the CO2 is homogenized into a single phase. Photomicrographs by Nathan Renfro; field of view 1.93 mm.
A blue topaz recently examined by the authors contained an interesting and complex fluid-filled negative crystal that revealed some remarkable behavior when cooled down. The contents of this three-phase fluid inclusion were very small solid phases, and carbon dioxide fluid trapped within an aqueous immiscible liquid, which has been previously documented (E.J. Gübelin and J.I. Koivula, Photoatlas of Inclusions in Gemstones, Volume 2, Opinio Verlag, Basel, Switzerland, 2005, p. 731). When the stone was cooled below approximately 31.5°C, the carbon dioxide fluid turned into liquid and gaseous states consisting of a multitude of tiny vapor bubbles nucleating and coalescing into a single larger bubble of gaseous CO2 within the liquid CO2 (see the video). This type of complex inclusion results in a CO2 vapor bubble trapped within a liquid CO2 bubble that is trapped within an aqueous, immiscible liquid (see above, left). If the stone is warmed above 31.5°C, the liquid and gaseous CO2 phases are homogenized into a single-phase fluid, causing the vapor bubble to shrink (see above, center) and ultimately disappear (see above, right). Similar behavior of CO2 trapped in negative crystals has been previously documented in sapphire (Spring 2016 G&G Micro-World, pp. 78–79). The extraordinary behavior of this fluid inclusion in topaz is a delight for any gemologist.

	Fluid Inclusion in Topaz @chapter:19


Publication Year: 1986 Title: Contributions to a History of Gemology: Specific Gravity—Origins and Development of the Hydrostatic Method Abstract: The development of the hydrostatic method of specific gravity determination as applied to gems is traced from Archimedes’ discovery to the present, with brief historical remarks supplied on other methods. This is the first in a series of articles on the history of gemology that will appear periodically in Gems & Gemology. @chapter:23


Publication Year: 2019 Title: Color-Change Pink Pyrope Garnet Update Abstract: This 20.00 ct oval color-change pyrope garnet was cut by Victor Tuzlukov. Photo by Kevin Schumacher, courtesy of Jewels from the Woods.

Jewels from the Woods (Blanco, Texas) displayed color-change pink pyrope garnets (see above) at the AGTA show. Their color changes from purple in daylight-equivalent light to pink in incandescent light. This was the first time there had been such a large selection of the stones at AGTA, according to independent gem cutter Desmond Chan, who was assisting Jewels from the Woods. He said the material had been very well received.

	Desmond Chan tells us about the color-change pink pyrope garnets.

The stone had been slow to come onto the market, Chan said, because not much rough was available, and the deposit—believed to be in Morogoro, Tanzania—has been depleted. The garnets are said to have been mined in 1988. Initially assumed to be rhodolite, they were put in a safe deposit box until 2014, when they were acquired by cutters Meg Berry, Todd Wacks, and Jason Doubrava. Wacks (Tucson Todd’s Gems, Tucson and Vista, California) was the first to detect the color change, and he introduced the garnets in 2015 at the Riverpark Inn (Pueblo) show (Spring 2015 GNI, pp. 88–89). GIA performed a gemological study of the material (Z. Sun et al., “Vanadium- and chromium-bearing pink pyrope garnet,” Winter 2015 G&G, pp. 348–369). One interesting finding was that two of the larger stones had the strongest color change.
Garnets have been “on fire” the last four or five years, according to Doubrava (Jason Doubrava Gems & Minerals, Poway, California). He said the public is more aware of garnets and more appreciative of their varied colors than in the past. “These just absolutely glow,” he said of the color-change pink pyrope garnets at the booth.

	Jason Doubrava shares his experience with the garnets. @chapter:6


Publication Year: 2022 Title: A Partially Hollow Natural Blister Pearl Filled with Foreign Materials Abstract: Figure 1. The 169.05 ct filled pearl, viewed from its face (left) and base (right). Note the indented feature on the base through which the filler material was inserted prior to plugging. Photos by Gaurav Bera.
Over the centuries, India has maintained its reputation as a natural pearl trading center. Since the launch of GIA’s pearl identification service in Mumbai in May 2022, the laboratory has received a variety of interesting items for identification. One that stood out owing to its size and internal structure was a unique partially hollow natural blister pearl with unidentified fillers (figure 1).

Figure 2. A: The pearl’s face showed minor surface blemishes; field of view 8.00 mm. B: The plugged area (boundary indicated by arrows) on the base with remnants of an adhesive around the oval opening; field of view 1.60 mm. C and D: Smoothed nacre layers provide evidence of heavy working and polishing on the base; field of view 3.00 mm. Photomicrographs by Nishka Vaz.
The very large baroque white pearl weighed 169.05 ct (33.81 g) and measured 43.12 × 28.83 × 19.26 mm. However, on initial examination, its “heft” (perceived weight compared to its actual weight in comparison to its size) felt heavier than it should have. While the pearl’s face-up side exhibited minor surface blemishes and good nacre condition (figure 2A), its base showed a deep oval indentation that looked a bit suspect to the unaided eye and needed further detailed examination. Under 40× magnification, the area revealed a distinct boundary with remnants of a transparent adhesive around it (figure 2B). Evidence of heavy working and polishing on and around the base was also clearly visible (figure 2, C and D).
Many loose nacreous baroque or semi-baroque pearls of this size are hollow to some degree, and most turn out to be blister pearls that were attached to the shell and removed at some point (“An unusual pearl,” GIA Research News, March 31, 2009) or were shell blisters. In order to ensure the durability of these hollow pearls, and sometimes to add weight and increase their perceived value, they are filled with various materials such as metals, resins, waxes, shell, and other pearls (Fall 2013 Lab Notes, pp. 172–173) and fashioned to improve their external appearance. Although the initial examination indicated that this pearl was likely filled with foreign materials, further analysis was required.

Figure 3. Opaque (white) areas indicate that metal pieces were placed within the pearl’s large internal cavity (left). Natural growth arcs and a small darker organic-rich area are visible at the pearl’s base (right). Images by Jayesh Surve.
Real-time microradiography revealed a large organic void/cavity filled with a radiopaque white material, probably small metal fragments or metal shavings (figure 3; see also Summer 2019 Lab Notes, pp. 251–254). Areas of greater radio-transparency suggested that some type of bonding or stabilizing material, possibly adhesive, may have been used to hold the foreign pieces in place, and there also appeared to be one other type of radiolucent material within the cavity. The pearl was examined in several directions in order to further analyze the internal structure and fillings. The outline of the void was smooth and blended with the external shape of the pearl. The outer nacre layers revealed fine growth arcs and a small organic-rich area was visible at the base, both of which aligned more with the growth features of a natural pearl. It was clear that this was originally a blister pearl or shell blister that had been cut from a shell, and that the indented area, which was the opening on the base of the pearl, was the point of attachment that was subsequently plugged. X-ray fluorescence proved that the pearl formed in a saltwater environment since most of its surface appeared inert and only a small area at the base displayed a very light greenish yellow reaction uncharacteristic of a freshwater environment.
Energy-dispersive X-ray fluorescence spectrometry on two areas (face and base) showed low or below detection levels of manganese and higher strontium levels, above 1000 ppm, both characteristic of a saltwater environment. The higher strontium levels coupled with the large size indicated that the mollusk from which the pearl originated was Pinctada maxima.
Raman analysis using a 514 nm laser excitation on two spots (face and base) of the surface produced high fluorescence due to the pearl’s light color and showed a doublet at 702 and 705 cm–1 as well as a peak at 1085 cm–1 indicative of aragonite. The photoluminescence spectra also displayed high fluorescence together with the aragonite peaks, as observed via Raman, typical of most nacreous pearls. Ultraviolet/visible/near-infrared spectra within the 220–850 nm range collected from the face and base were as expected for white to light cream-colored pearls and showed a predominantly high reflectance. The presence of a prominent 280 nm absorption feature coupled with moderate yellow reaction under long-wave UV excitation indicated that bleaching had most likely not been carried out.
After conducting a full analysis, GIA concluded that this sample most likely formed as a hollow natural blister pearl attached to its shell host. At some point, it was removed and the attachment area left an opening into the pearl. It was eventually worked and filled with foreign fillers (metal shavings/pieces and possibly some other materials) to improve its durability and make it suitable for setting; without the filling, it would not be usable in jewelry. The size, spectral characteristics, and chemistry were also consistent with a Pinctada maxima host mollusk. @chapter:14


Publication Year: 2015 Title: HPHT Synthetic Diamond Melee in High-Quality Jewelry Piece Abstract: Figure 1. A photo and a detailed illustration of the melee-set pendant show the location of all 118 samples. The single HPHT synthetic melee is highlighted in both images. Photo by Jian Xin (Jae) Liao.

Advances in the laboratory growth of diamonds have led to an increase in the number of synthetic diamonds seen at GIA. The existence of high-quality synthetic diamonds in melee sizes is of particular concern. This is due in part to the expense of examining melee relative to their value. While GIA can reliably identify synthetic melee, this requires individual analysis of each stone, preferably before mounting. In a complicated piece with hundreds of melee, this can be prohibitively expensive or time-consuming. The same is true for melee parcels. A synthetic diamond mixed into a packet may not be identified until later, deceiving dealers, jewelers, and consumers and potentially causing damage to the trade.

Recently, a pendant with 118 mounted stones was submitted to GIA’s New York laboratory for color origin analysis of each individual melee (figure 1). The pendant consisted of a central pear-shaped stone surrounded by three consecutive rows of round brilliant melee. Of the 118 stones, 58 were fancy yellow, including the center stone, and 60 were colorless. Using a Fourier-transform infrared (FTIR) microscope in reflection mode allowed detailed focusing of the infrared beam on the mounted stones, including those that were partially obscured. Analysis was carried out on a Thermo Nicolet iN10 FTIR microscope, which determined the diamond type classification of each melee stone from its mid-IR absorption spectra (C.M. Breeding and J. E. Shigley, “The ‘type’ classification system of diamonds and its importance in gemology,” Summer 2009 G&G, pp. 96–111). One melee was identified as an HPHT-grown (high-pressure, high-temperature) synthetic diamond, based on its infrared spectrum as well as its color, fluorescence pattern, and phosphorescence behavior. This 0.00431 ct melee was removed from the setting to confirm its origin as HPHT-synthetic. The rest were confirmed as natural diamonds.

Of the 118 melee, 114 were classified as type IaA or type IaAB. These were characterized by absorption from aggregated nitrogen centers, where A-centers (nitrogen pairs) and B-centers (four nitrogen atoms symmetrically surrounding a vacant lattice site) absorb infrared light at 1282 and 1174 cm–1, respectively. These spectra revealed sufficient A-center concentrations, eliminating the possibility of HPHT treatment, which would have deaggregated the centers into isolated nitrogen atoms (A.T. Collins, “The colour of diamond and how it may be changed,” Journal of Gemmology, Vol. 27, No. 6, 2001, pp. 341–359). Since A- and B-center absorptions occur solely in the infrared range, their presence does not produce color. Instead, the yellow color observed in 57 of these type IaA/IaAB stones resulted from absorption from the N3 defect at 415 nm (a complex of three nitrogen atoms surrounding a vacancy) and associated peaks at 453, 452, 465, and 478 nm. This spectrum is known as the “Cape series,” and such goods are commonly referred to as “Cape yellow.”

Two colorless stones were classified as type IaB, showing only pure B-aggregate absorption; the remaining colorless stone was type IIa, meaning it did not show IR absorption from any nitrogen-related impurities. Finally, a partially obscured yellow stone near the bottom of the piece was type Ib, showing absorption due to isolated nitrogen impurities, and characterized by features at 1130 and 1344 cm–1. Isolated nitrogen centers also produce a broad absorption feature in the UV-visible range (approximately 270 nm), resulting in a coloration often described as “Canary yellow.” Type Ib diamonds are very rare, representing only 0.1% of all natural diamonds (R. Tappert and M.C. Tappert, Diamonds in Nature, Springer, Berlin, 2011). Conversely, this diamond type is common in yellow synthetic diamonds. Due to the absence of A-centers, these four samples required further testing.

Photoluminescence spectroscopy confirmed that the type IaB and IIa stones were natural in origin. However, the type Ib stone (marked in figure 16) was further examined with DiamondView imaging, which showed that it exhibited strong yellow-green fluorescence under deep ultraviolet illumination (wavelength 230 nm) and indicated growth sector patterns typical of HPHT synthetic diamonds, as well as strong blue phosphorescence inconsistent with natural yellow type Ib diamonds (J.E. Shigley et al., “A chart for the separation of natural and synthetic diamonds,” Winter 1995 G&G, pp. 256–264; J.E. Shigley et al., “Gemological properties of near-colorless synthetic diamonds,” Spring 1997 G&G, pp. 42–53). The 0.00431 ct yellow stone was removed from its mounting for more comprehensive examination with the DiamondView (figure 2). Its cuboctahedral synthetic growth sectors were clearly seen from both the table and pavilion, confirming its HPHT synthetic origin.

Figure 2. Left and center: DiamondView fluorescence images of the 0.00431 carat type Ib diamond show clear cuboctahedral HPHT synthetic growth sectors. Right: The sample’s strong phosphorescence is atypical for a diamond of this type and color. Images by Martha Altobelli.
Although this could have been an isolated event, it underscores the need for caution when buying melee parcels or mounted pieces from unfamiliar sources. Nevertheless, it is important to note that such stones can be unequivocally identified as lab-grown. Colorless and near-colorless (D–N) unmounted diamonds larger than 0.01 ct can be tested using commercially available testing equipment such as the GIA DiamondCheck. Meanwhile, colored diamonds, smaller stones, and mounted jewelry need to be tested by a reputable gemological laboratory. Increased industry awareness, combined with diamond testing, may deter the spread of undisclosed synthetics, ultimately benefiting both sellers and buyers of polished diamond goods. @chapter:31


Publication Year: 1983 Title: Peridot from Tanzania Abstract: Peridot from a new locality, Tanzania, is described and compared with 13 other peridots from various localities in terms of color and chemical composition. The Tanzanian specimen is lower in iron content than all but the Norwegian peridots and is very similar to material from Zabargad, Egypt. A gem-quality enstatite that came from the same area in East Africa and with which Tanzanian peridot has been confused is also described. @chapter:37


Publication Year: 2013 Title: Orange Diamond with Unusual Color Origin Abstract: Figure 1. This 1.53 ct diamond was color graded as Fancy Intense pinkish orange. Spectroscopic analysis revealed it was type IIa and dominated by an approximately 550 nm band absorption, which usually introduces a pink-red color in natural diamonds rather than orange. Photo by Jian Xin (Jae) Liao.

              Orange bodycolor in diamond is usually caused by an absorption band centered at approximately 480 nm or by a high concentration of isolated nitrogen. Meanwhile, it is well known that the 550 nm absorption band often introduces pink to red colors. Physical models of these two optical centers have not been resolved yet. The New York laboratory recently examined an orange diamond whose color was attributed mainly to the 550 nm absorption band.

This 1.53 ct heart-shaped diamond (6.84 × 7.76 × 3.88 mm) was color graded as Fancy Intense pinkish orange (figure 1). Color was distributed evenly throughout the stone, which was very clean and showed no internal features under the microscope. The absorption spectrum in the infrared region revealed that it was a regular type IIa diamond, with no nitrogen-or hydrogen-related absorptions. The UV-Vis region showed a broad absorption band centered at ~550 nm and its corresponding band at ~390 nm, absorption features typical of natural type IIa pink diamonds. From the optical centers detected, we would not expect this diamond to show a dominant orange bodycolor.

The reason for this discrepancy is not fully understood. Our finding from this stone demonstrates the complexity of diamond color origin. @chapter:11


Publication Year: 2022 Title: Hyalite with Magnificent Internal Features Abstract: Figure 1. Purple fluorite cube, identified by micro-Raman spectroscopy, in a hyalite. Photomicrograph by U. Hennebois; field of view 1.2 mm.
The Laboratoire Français de Gemmologie (LFG) received for analysis a 1.83 ct hyalite, also known as opal-AN: an amorphous (A) opal containing hydrated silica molecules that are network forming (N) (E. Fritsch et al., “Green-luminescing hyalite opal from Mexico,” Journal of Gemmology, Vol. 34, No. 5, 2015, pp. 490–508). This is one of the rarest varieties of gem-quality opal. The gem fluoresced green under long-wave ultraviolet (365 nm) and, with more intensity, under short-wave UV (254 nm), due to U6+ in the form of uranyl (UO2)2+ (E. Gaillou et al., “Luminescence of gem opals: A review of intrinsic and extrinsic emission,” Australian Gemmologist, Vol. 24, No. 8, 2011, pp. 200–201). A purple fluorite (identified by a micro-Raman spectrometer; figure 1) and a series of cube-shaped cavities were visible (figure 2) in the hyalite, which appear to be all interconnected. Sometimes these cavities also contain small crystals of fluorite relics detected by Raman. Thus, these cavities may be the result of the partial dissolution of fluorite crystals. This would explain their cubic morphology, which cannot be explained by the dissolution of amorphous hyalite.

Figure 2. Interconnected cavities observed in a hyalite containing partially dissolved fluorite relics identified by Raman spectroscopy. Curved growth layers are also observed in the background. Photomicrograph by A. Delaunay; field of view 2 mm.
Between crossed polarizers, high-order interference colors were observed (figure 3), as expected for this gem. This is due to anomalous birefringence linked with the strain present between the curved growth layers of hyalite. Also, a fluid inclusion was observed in the intersection of the botryoids (again, see figure 3). This inclusion is composed mostly of gas, suggesting that this hyalite was deposited from a gaseous phase. Although some of these features have been previously observed in hyalite, it is rare to see them all in the same sample. To the best of our knowledge, this is the first reporting of pronounced cubic cavities in hyalite.

Figure 3. This fluid inclusion contains mostly a gaseous phase. It is trapped at the intersection of curved botryoidal growth zones and presents high-order interference colors obvious between crossed polarizers. Photomicrograph by U. Hennebois; field of view 1 mm. @chapter:13


Publication Year: 2002 Title: Winter 2002 G&G Book Reviews Abstract: “The Master Jewelers”
By A. Kenneth Snowman, Ed., 262 pp., illus., publ. by Thames & Hudson Inc., New York, 2002. US$29.95

“20th Century Jewelry: The Complete Source Book”
By John Peacock, 144 pp., illus., publ. by Thames & Hudson Inc., New York, 2002. US$34.95

“Louis Comfort Tiffany at Tiffany & Co.”
By John Loring, 255 pp., illus., publ. by Harry N. Abrams, New York, 2002. US$60.00

“The Love of Stones”
By Tobias Hill, 396 pp., publ. by Picador USA, New York, 2001, US$25.00

To view the full section, download the PDF above. @chapter:16


Publication Year: 2019 Title: “Rainbow Lattice” from Australia Abstract: These “rainbow lattice” specimens, a 4.14 g rough stone and a 2.18 ct kite-shaped cabochon, are from Harts Range in central Australia. Photo by Robert Weldon/GIA, courtesy of Rainbow Lattice.
One of the most striking materials encountered in the Riverpark Inn (Pueblo) Gem Show was “rainbow lattice.” This rare phenomenal gem is a variety of feldspar exhibiting aventurescence from exsolution hematite crystals and a rainbow lattice effect from oriented exsolution magnetite crystals. Supply is extremely limited, and the only source is the tiny Utnerrengatye mine in Harts Range, Northern Territory, Australia. Rainbow lattice was discovered in 1985 and acknowledged as a new gem material in 1989. One of the original discoverers, Darren Arthur, showed us all-new material he mined in 2018 and subsequently sorted and cut (see above). With its scarcity and unique appearance, rainbow lattice is a must for any serious rare gem collection. @chapter:0


Publication Year: 2022 Title: A Closer Look at Internal Etch Channels in Diamond Abstract: Figure 1. A 1.02 ct Fancy Deep brownish yellowish orange diamond with subsurface etch channels (upper right). Photo by Matthew Hardman.
The Carlsbad laboratory recently received a 1.02 ct cushion-cut Fancy Deep brownish yellowish orange diamond (figure 1). The yellowish color of this type Ib/IaA diamond is mainly attributed to single substitutional nitrogen atoms in the diamond lattice. In addition to the presence of multiple pinpoint inclusions, the diamond contained a bundle of internal etch channels extending from a single irregular-shaped opening on the girdle (figures 1 and 2).

Figure 2. A bundle of internal etch channels extending from a single opening on the girdle. Photomicrograph by Matthew Hardman; field of view 2.44 mm.

Figure 3. An irregular-shaped opening on the girdle where fluids/melts permeated through the diamond and formed the internal etch channels. Photomicrograph by Matthew Hardman; field of view 1.26 mm.
Narrow etch channels are rarely observed in gem diamonds. Etch channels can form due to dissolution of the diamond crystal by fluids/melts in the mantle, or during eruption to the surface (T. Lu et al., “Observation of etch channels in several natural diamonds,” Diamond and Related Materials, Vol. 10, No. 1, 2001, pp. 68–75;  J.W. Harris et al., “Morphology of monocrystalline diamond and its inclusions,” Reviews in Mineralogy and Geochemistry, Vol. 88, No. 1, 2022, pp. 119–166). Defects in the diamond structure such as lattice dislocations are local areas of structural weakness, which are more susceptible to etching. In this diamond, multiple narrow etch channels originate from a single surface opening (figure 3), reflecting selective diamond dissolution as fluids permeated through the stone.

Figure 4. Trigons visible in a subsurface diamond etch channel. Photomicrograph by Mei Yan Lai; field of view 1.00 mm.
An intriguing feature observed along the walls of the internal etch channels consisted of multiple triangular etch pits known as trigons (figure 4). Trigons are one of the most common features found on the surfaces of rough diamonds, with various sizes, depths, and shapes (e.g., flat- or point-bottomed, attributed to etching by oxidizing fluids/melts; Harris et al., 2022). When present on diamond surfaces, trigons are restricted to the octahedral crystal face and may occasionally form parallel rows that follow the orientation of plastic deformation lines (often called “grain lines” in the trade, caused by dislocation of carbon atoms along octahedral planes). In faceted diamonds, trigons are usually removed by polishing but are occasionally preserved on the girdle. Conversely, trigons reported within internal diamond etch channels are extremely rare (Lu et al., 2001). The occurrence of trigons within a subsurface channel indicates etching along the octahedral crystal face of this diamond. @chapter:11


Publication Year: 2023 Title: Natural Diamond with Unusual Phosphorescence Abstract: These deep-UV (<225 nm) phosphorescence images of the table (left) and pavilion (right) in a 0.90 ct D-color natural diamond with very low boron showed localized areas of the 500 nm (greenish blue) and 660 nm (red) bands. Images by Evelina Goldort.
Phosphorescence spectroscopy shows that natural type IIb diamonds can have two broad phosphorescence bands: one centered at 500 nm that appears greenish blue and one centered at 660 nm that appears red. Generally, one of these phosphorescence bands is dominant. In the Hope diamond, for example, the phosphorescence initially appears orangy red and transitions to red as the subordinate greenish blue phosphorescence fades away (S. Eaton-Magaña et al., “Using phosphorescence as a fingerprint for the Hope and other blue diamonds,” Geology, Vol. 36, No. 1, 2008, pp. 83–86). Occasionally, the faster-decaying greenish blue phosphorescence band will transition to the slower-decaying red band (Spring 2007 Lab Notes, pp. 47–48).
Recently, a 0.90 ct diamond with D color and I1 clarity was submitted to GIA’s laboratory in Ramat Gan, Israel, for a diamond dossier report. Infrared (IR) absorption spectroscopy indicated that the natural diamond was nominally type IIa. However, photoluminescence (PL) spectroscopy revealed that the diamond contained boron-related features, including the 648.2 nm peak attributed to a boron interstitial (B. Green, “Optical and magnetic resonance studies of point defects in single crystal diamond,” PhD thesis, University of Warwick, 2013), along with the observed phosphorescence. These features indicated that the diamond did contain boron, but below the detection level of IR absorption spectroscopy. The distinctive aspect was that both the red and greenish blue phosphorescence were localized and visible within the same image (see above).
The phosphorescence is attributed to donor-acceptor pair recombination. For the 500 nm band, this recombination has been identified as interactions between boron acceptors and isolated nitrogen donors (J. Zhao, “Fluorescence, phosphorescence, thermoluminescence and charge transfer in synthetic diamond,” PhD thesis, University of Warwick, 2022), while the 660 nm band is attributed to boron acceptors and unknown donors that are likely related to plastic deformation (S. Eaton-Magaña and R. Lu, “Phosphorescence in type IIb diamonds,” Diamond and Related Materials, Vol. 20, No. 7, 2011, pp. 983–989). PL maps were collected on the table and pavilion with 455, 532, and 785 nm excitation; only an undefined PL feature at 813 nm showed an apparent increase on the pavilion within the red-phosphorescing region (see above, right).
Type IIb diamonds grown by high-pressure, high-temperature (HPHT) methods almost always show the 500 nm phosphorescence and occasionally a separate orange phosphorescence band centered at 580 nm. In a few instances, HPHT-grown diamonds have shown the 500 and 580 nm bands simultaneously in different portions of the diamond (Eaton-Magaña and Lu, 2011; Spring 2023 Gem News International, pp. 155–156).
This is the first time the authors have seen spatially distinct observations of red and greenish blue phosphorescence in a natural diamond, an unusual find. @chapter:11


Publication Year: 2015 Title: Color-Change Synthetic Cubic Zirconia as Peridot Imitation Abstract: This synthetic cubic zirconia imitation of peridot, with an estimated weight of 4.50 ct, is shown in daylight (left) and incandescent light (right). Photos by Igor Iemelianov; field of view 13.20 mm.

	Peridot is a common gemstone in the jewelry industry; however, it is rarely simulated using substances other than glass (Summer 2004 Lab Notes, p. 165). The State Gemological Centre of Ukraine recently received for identification an oval-cut gemstone, with an estimated weight of 4.50 ct, set in a ring. The stone was greenish yellow in daylight, as seen in the image on the left, and orangy yellow in incandescent light (right). The client who submitted the ring specifically wished to know if the center stone was peridot. The sample was transparent and isotropic, with a refractive index of 2.150 (measured by a refractive index meter) and was inert to both short-wave and long-wave UV radiation. Microscopic examination revealed no inclusions. The measured relative reflectivity (RR 65–67), obtained using a Presidium DuoTester, clearly matched that of cubic zirconia, a result in line with the other gemological observations. This allowed us to identify the stone as cubic zirconia. Chemical analysis with energy dispersive X-ray fluorescence (EDXRF) showed Zr and Y, with minor Pr and Nd. These impurities can cause color change in this stone. Using fiber-optic light with the spectroscope, we observed a complex set of absorption lines in both the orange and green-blue regions (the same measurement can be seen at http://www.gemlab.co.uk/peridot.html). This study shows the importance of studying a variety of simulants, even those for less-expensive gems such as peridot. @chapter:9


Publication Year: 1990 Title: Fall 1990 G&G Lab Notes Abstract: Dyed Natural Beryl
Carved Chrysoberyl
Electron Irradiated Diamond
Fancy Black Diamond
Included Diamond Crystal
Opal with an Unusual Inclusion
Cultured Pearls with Colored Bead Nuclei
Freshwater Natural Pearls
Gray Baroque Cultured Pearls
Diffusion-Treated Montana Rough Sapphire
Large Colorless Sapphire
Cobalt Colored Color-Change Spinel
Synthetics and Simulants in Period Jewelry

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


Publication Year: 2022 Title: Rare Blue Apatite Inclusion in Smoky Quartz Abstract: Figure 1. A hexagonal apatite inclusion in smoky quartz. Photomicrograph by Nattapat Karava; field of view 6.3 mm.
A natural smoky quartz with an obvious mineral inclusion at the center of the stone (figure 1) was recently observed by the author. Raman analysis confirmed that this mineral was apatite. The apatite had very light blue color and a hexagonal twinned morphology. Under cross-polarized light, the inclusion showed interference colors, confirming its doubly refractive nature (figure 2).

Figure 2. A hexagonal apatite inclusion with interference colors in smoky quartz, viewed in cross-polarized illumination. Photomicrograph by Nattapat Karava; field of view 6.3 mm.
Apatite is a phosphate mineral with the chemical formula of Ca5(PO4)3(Cl/F/OH). Generally, smoky quartz and apatite can occur under the same geologic conditions, including pegmatitic hydrothermal environments. Apatite is commonly a protogenetic inclusion, but it can occasionally result from a later stage and be considered a syngenetic inclusion in quartz. The rounded shape of this apatite example suggests a protogenetic inclusion, one that would be a welcome sight for any gemologist examining stones in a microscope. @chapter:13