# Publication Year: 2001
# Title: The Current Status of Chinese Freshwater Cultured Pearls
# Abstract: Chinese freshwater cultured pearls (FWCPs) are assuming a growing role at major gem and jewelry fairs, and in the market at large. Yet, it is difficult to obtain hard information on such topics as quantities produced, in what qualities, and the culturing techniques used because pearl culturing in China covers such a broad area, with thousands of individual farms, and a variety of culturing techniques are used. This article reports on recent visits by two of the authors (SA and LTZ) to Chinese pearl farms in Hanzhou Province to investigate the latest pearl-culturing techniques being used there, both in tissue nucleation and, much less commonly, bead (typically shell but also wax) nucleation. With improved techniques, using younger Hyriopsis Cumingi mussels, pearl culturers are producing freshwater cultured pearls in a variety of attractive colors that are larger, rounder, and with better luster. Tissue-nucleated FWCPs can be separated from natural and bead-nucleated cultured pearls with X-radiography. @chapter:53 @chapter:4 @chapter:53


# Publication Year: 2013
# Title: Buff-Top Round Diamond
# Abstract: Figure 1. A profile view of this buff-top round diamond shows its low polished dome. Photo by Jian Xin (Jae) Liao.

              The modern round brilliant diamond is getting a “new old” look with the use of Japanese laser technology. Diamond’s high refractive index and adamantine luster make it ideal for faceting to produce dramatic scintillation, brilliance, and fire. One of the oldest and simplest cuts is the cabochon, with its smooth convex dome. A popular cut among colored stones, the cabochon is rarely if ever used in diamonds due to the gem’s extreme hardness and the difficulty in polishing it into a smooth, rounded surface. The New York lab recently examined several diamonds with an interesting variation on the cabochon.

About 30 buff-top round diamonds ranging from 0.25 to 1.50 ct, originally submitted to GIA’s Japanese lab, were received for grading. The buff-top cut has a low cabochon dome with a faceted pavilion (figure 1). These diamonds were cut with four short main pavilion facets (figure 2). This rare cut posed a challenge for the grading staff, as the smooth dome and faceted pavilion combined to produce internal reflections that made it very difficult to see clearly into the stone. Although diamonds can be cut with lasers, the polishing process with the use of diamond abrasives into a smooth rounded surface is both laborious and time consuming. The unfaceted dome was likely created using the same technology that produced the first synthetic nano-polycrystalline diamond sphere in Japan in 2011. One Japanese study (T. Okuchi et al., “Micromachining and surface processing of the super-hard nano-polycrystalline diamond by three types of pulsed lasers,” Applied Physics A: Materials Science & Processing, Vol. 96, No. 4, 2009, pp. 833–842) found that pulsed lasers most efficiently produce a smooth, undamaged surface for fine finishing diamonds. A combination of three lasers was used: a near-infrared laser for the rough shaping, and ultraviolet and femtosecond lasers for fine finishing (E. Skalwold, “Nano-polycrystalline diamond sphere: A gemologist’s perspective,” Summer 2012 G&G, pp. 128–131).

	Figure 2. Viewed face-up, the buff-top diamond shows an arrangement of four main pavilion facets. Photo by Jian Xin (Jae) Liao.
This advancement in diamond finishing offers new possibilities for a variety of interesting shapes and forms that could not be achieved with previous methods of polishing and faceting alone. Diamond cabochons, completely smooth spherical beads, and sugarloaf cuts could emerge next. @chapter:36 @chapter:1 @chapter:36


# Publication Year: -
# Title: Translating Passion into Success: What “Job Success in Today’s Market” is All About
# Abstract: The opening panel, "Job Success in Today's Market," at GIA's Carlsbad Jewelry Career Fair held on Oct. 11. From left, moderator Jennifer Wilson, senior vice president and general counsel for GIA; Douglas Hucker, CEO of the American Gem Trade Association; Meghan Simmons, director of operations for Omi Privé; Cathy Calhoun, owner of Calhoun Jewelers and Mitchell Binder, president of King Baby. Video Duration: 1:18:36
“It’s not like you can go out and buy passion. You’ve got to build passion. You’ve got to learn passion,” said Douglas Hucker, CEO of the American Gem Trade Association (AGTA), a panelist at the opening of the 2019 GIA Carlsbad Jewelry Career Fair.
Career Fair, which is in its 28th year, featured 10 speakers, 25 career coaches and 42 jewelry company recruiters ‒ including Tiffany & Co. and Signet Jewelers ‒ and was attended by more than 600 students, visitors and job-seekers. The opening panel, “Job Success in Today’s Market,” featured four industry leaders who spoke about how their passion led them to where they are today.
According to Hucker, passion is acquired through education, perseverance and experience ‒ and is strengthened through networks built at industry organizations such as GIA. “You’ve got to find the things that attract you and be with them, make them a part of your lives,” he said.
For Meghan Simmons, director of operations at Omi Gems and Omi Privé, passion means communicating the provenance of gems and seeing “your own legacy [begin] to imbibe itself into those gems and jewelry.”
For Cathy Calhoun, owner of Calhoun Jewelers, a retail jewelry chain, passion means communicating the beauty and value of jewelry to your clients and to “have fun” while doing it.
To Mitchell Binder, president of the rock ’n’ roll jewelry brand, King Baby, and “go-to” jeweler for the likes of Johnny Depp, Bruce Springsteen, Slash and Aerosmith, passion means changing the world through jewelry, from the United States to Japan and China.
Each speaker shared their backstory and offered tips and advice to attendees. This overview of the panel includes time stamps that will take you to each speaker’s spot in the video.

Mitchell Binder, president of King Baby, coaches a prospective job seeker during Career Fair. Photo by Emily Lane
Douglas Hucker (Begins at 13:37)
Hucker launched a career in colored gemstones because he loved color.
With diamonds, he says, you have to explain the 4Cs, but “when you show your customers five rubies, you don’t have to tell them which one is the best one … It just jumps out at you. It attracts you.”
He also spoke about marketing to today’s generation and finding a mentor.
Meghan Simmons (Begins at 26:07)
Meghan Simmons found her path while helping out with the Elizabeth Taylor jewelry auction at Christie’s. It made her realize that, “your own legacy begins to imbibe itself into those gems and jewelry.”
That experience inspired her to ask: “What would it take to become a jewelry specialist?” The consensus was to get her Graduate Gemologist® diploma at GIA.
She connected with an employee from Omi at the 2015 GIA Career Fair while she was still a GG student.
“I introduced myself and he promised to keep me in mind. A few weeks, after I graduated, I got a call from Adam Graham. They were going to be operating two booths in Las Vegas and they needed help. I knew it would be an invaluable learning experience,” she said.
Simmons was hired by Omi right after.

A prospective job seeker meets a recruiter at GIA’s 2019 Jewelry Career Fair in Carlsbad. Photo by Emily Lane
Cathy Calhoun (Begins at 33:07)
The world of gemstones and jewelry opened up for Calhoun in a surprising way—her jeweler boyfriend had a heart attack on Thanksgiving, the start of the holiday selling season.
“He’s in the hospital and he says to me ‒ you’re going to have to go run my jewelry store,” she said.
Calhoun, not understanding why diamonds of the same carat weight had different prices, started labeling and selling same-sized diamonds all at the same price, almost giving her boyfriend another heart attack.
But “just by sheer luck,” GIA was in town that weekend to do a two-day education symposium on gemstones and Calhoun said attending it changed her life.
“I knew what I was going to do for the rest of my life,” she said, so she immediately enrolled in GIA’s Graduate Gemology program.
Calhoun shared many of the fun and interesting events she has held at her stores, including her Carat Club for self-buying women, hosting car shows and Hippy Day and setting up a bar in her store.
Mitchell Binder (Begins at 45:57)
Binder started out by hand-making jewelry for the Hell’s Angels: They were “not your classy diamond types,” he said.
His jewelry took off when Japanese buyers started bidding wars over his jewelry on eBay and two Japanese businessmen arrived at his small, 400 square-foot studio with briefcases full of cash, buying everything he had.
“It was like a drug deal,” Binder said. “I sold the jacket off my back. With the cash, I started King Baby.”
His next big break was when he was invited to pitch his jewelry at Neiman Marcus.
“You wouldn’t think that a guy like me and my designs would fit at Neiman Marcus…I had the biker rings and the skulls,” he said.
But the Neiman Marcus order quickly grew to over a million dollars and was on its way to two million before Binder stopped them and said he needed to figure out a way to hand-make all that jewelry.
Binder said his mother, who is a painter and a writer, always told him to “change the world,” and he has, by reaching the corners of the world through his jewelry. Not only does he have stores all over the U.S., but also 20 stores in China.
“I went from the black sheep of the family to the patriarch,” he said.
Future Forecast
Hucker painted a hopeful picture of where the gem and jewelry industry is headed:
“You guys have an opportunity in making this industry better, cleaner, more giving and more loving because you have access to data that 10 years ago, none of us had. Don’t think that just because you know where a gemstone came from, that you’re OK. Find out what’s happening, where that gemstone came from,” he said “You’re going to become a part of the family, and you need to take care of that family.”
Read about and watch the Creative Careers panel from the 2019 Jewelry Career Fair in Carlsbad. @chapter:45 @chapter:3 @chapter:45


# Publication Year: 2024
# Title: Gemstones and Art
# Abstract: Figure 1. Left: “Meteorites,” a mosaic by Leonardo Scarpelli. A labradorite background gives a strong sense of light shining in the night sky as the observer moves. Right: The “Starburst” mosaic by Leonardo Scarpelli. Larimar proved the perfect material to reproduce aquamarine’s transparency and color. Photos by Cristiano Brigida; courtesy of Scarpelli Mosaici.
Exploring the Tucson Fine Mineral Gallery, the author was impressed by artistic masterpieces hanging from the walls. These exhibits ranged from stone mosaics of modern subjects to watercolor paintings of minerals. The author had the chance to speak with mosaic artists Leonardo and Catia Scarpelli (Scarpelli Mosaici, Florence) and watercolor artist Ksenia Levterova (Kyiv).
The Scarpelli family creates stunning mosaics representing contemporary subjects using the technique of commesso fiorentino (from the Latin commettere, meaning “put together”), which dates back to the Italian Renaissance. In this craft, opaque stones of different colors and textures (pietra dura) are finely cut into unique shapes and seamlessly joined together. This traditional art form developed and achieved a level of perfection in the late sixteenth century in Florence, under the rule of the Medici family, who wanted to depict their era in a durable, eternal medium.
Leonardo Scarpelli, the son of a commesso fiorentino master, began his career in 1992. Challenged by the idea of moving from traditional to more modern subjects, he experimented with the commesso fiorentino technique by incorporating gem materials that had never been used before, such as labradorite. Scarpelli discovered that labradorite brought depth and life to subjects where dynamism is essential, such as a splashing water drop or meteorites falling in the night sky (figure 1, left), allowing him to create unusual motion effects unexpected from a traditional mosaic.
After Scarpelli exhibited in some gem and mineral shows, the idea of reproducing mineral specimens with the proper transparency and color nuances by means of commesso fiorentino became a compelling challenge. When commissioned to reproduce a fine aquamarine specimen from Pakistan, the Scarpellis’ extensive search for the right color landed on Larimar, the trade name for a variety of pectolite. Its light blue color and white speckles made Larimar ideal for the purpose, leading to impressive results (figure 1, right). This is one more case where the use of a gem material associated with traditional stones demonstrated all its potential in bringing into play precious effects, colors, and textures.
Ksenia Levterova is a talented Ukrainian watercolor artist. Passionate about the perfection of mineral shapes and their fascinating colors, she specializes in the reproduction of mineralogical subjects at a photorealistic level.

Figure 2. Watercolors of tourmaline with albite (left) and a diamond crystal from Kimberley, South Africa (right). Photos by Cristiano Brigida; courtesy of Ksenia Levterova.
Levterova’s artworks exhibited in Tucson this year encompassed a wide range of subjects, from the captivating beauty of fine specimens such as tourmaline to the precise reproduction of mineral crystallizations (figure 2). Watercolor makes it possible to represent the most subtle variations in color and transparency effects while displaying each crystal’s characteristics with remarkably high definition. The degree of realism and the fidelity to shapes and color nuances allow a rigorous mineralogical consistency. As a result, Levterova’s work is becoming popular in many gem and mineral shows, and she has a gallery hosted on Mindat (https://www.mindat.org/gallery-63606.html). @chapter:31 @chapter:2 @chapter:31


# Publication Year: 2019
# Title: A Near-Round Natural Pearl Discovered in the Edible Oyster Magallana bilineata
# Abstract: The inner and outer shell of M. bilineata (left and center). A near-round pearl (right) was found inside the shell. Photos by Sadar Aslam.
Pakistan, which has a coastline stretching 1,046 km (650 miles) along the Arabian Sea, the Indian Ocean, and the Gulf of Oman, is blessed with numerous marine resources, including oysters that mainly inhabit estuaries and mangrove habitats. In Sindh Province, some oyster reefs at Hab River Delta have high ecological and economic value. Nine edible oyster species belonging to the genera Crassostrea, Saccostrea, and Ostrea have been recognized from different localities there. Pearl-forming mollusks belonging to the genera Pinctada have been reported from Daran Beach.
The Ostreidae family includes edible oysters and is most commonly known as a source of seafood (K. Scarratt et al., “A note on a pearl attached to the interior of Crassostrea virginica [Gmelin, 1791] (an edible oyster, common names, American or Eastern oyster),” Journal of Gemmology, Vol. 30, No. 1-2, 2006, pp. 43–50). Of these, Magallana bilineata has the widest distribution in the Indo-Pacific region, encompassing the coasts of northern Arabia, the Bay of Bengal, the Andaman Sea, the Java Sea, South China and Vietnam, the Philippines, and Okinawa.
Magallana bilineata is a euryhaline species that inhabits backwaters, creeks, estuary banks, coastal bays, and lagoons, forming oyster beds on a large scale. A large number of specimens of this species from Hab River Delta were examined to study the taxonomic characteristics of the genus Magallana as part of a joint project between Japan and Pakistan. Ten shells of each species were opened. Only one shell of M. bilineata (150 mm shell height) contained a pearl, attached to tissues near the adductor muscle. It was near-round, with a smooth surface and a purplish and off-white color very similar to the inner shell layer of M. bilineata  (see above, left). The crystal structure of calcium carbonate was observed under high magnification. The non-nacreous, shiny pearl (see above, right) was 4.15 mm in diameter and weighed 0.02 g. The specimen is housed at the Centre of Excellence in Marine Biology, University of Karachi (part of the study collection of author SA).
Oysters living in tropical and warm regions have darker, more vivid, and more extensive coloration than those in cooler climates. Our finding is very similar to that of Scarratt et al. (2006), which found a pearl inside Crassostrea virginica that was attached to an adductor scar. In our case, the pearl was attached to the tissues near an adductor scar. This finding demonstrates the very rare phenomenon of edible oysters producing natural pearls. However, further work will be needed to determine its chemical composition using highly accurate analytical methods. @chapter:11 @chapter:4 @chapter:11


# Publication Year: 2014
# Title: Cultured Pearl Market Update – Tucson 2014
# Abstract: View Gallery

Cultured pearls shine
Fran Mastoloni (Mastoloni Pearls, New York City) updated us on the cultured pearl market during the AGTA show. He explained that for the past two years, the emphasis has been on long necklaces, double strands, and mixing different sizes, colors, and types of cultured pearls. These trends have reenergized the market, making pearls “fun to wear again.” While weddings and graduations are still occasions for classic akoya-type necklaces and studs, there are now more opportunities to sell innovative blends of color and shape. Typical of this approach is the striking necklace with 15–17 mm Tahitian baroque cultured pearls shown in figure 1 (left). Such a piece might take three years to make and could retail for tens of thousands of dollars.

With production of Tahitian cultured pearls down, Mastoloni has been using smaller off-round, pastel-colored pearls to create distinctive, competitively priced necklaces. These styles offer a “big” look for a relatively low price. The colors, including a subtle silvery gray, are all natural. Mastoloni stressed the importance of luster as a selling point.

South Sea cultured pearl production has been reliable and consistent in quality, but prices have fluctuated. While lower-quality specimens are inexpensive and readily available, high-quality pearls are expensive and difficult to obtain. Due to improvements in culturing processes—including the X-ray inspection of mollusks—baroque-shaped cultured pearls have become increasingly rare. When X-ray operators detect a non-round pearl, Mastoloni noted, they will restart the culturing process. As a result, fewer non-round shapes are available for baroque necklaces (figure 1, center).

Demand for fine cultured pearls from China has outstripped supply, with fine examples of all pearl types showing surges in price. Golden cultured pearls from the Philippines (figure 1, right) have become increasingly costly and difficult to obtain, Mastoloni noted.

View Gallery

Cultured beauty
This scarcity of cultured pearls made the necklaces exhibited by Mastoloni all the more remarkable. They included an exceptional strand of multicolor specimens from Australia, the Philippines, and Tahiti (figure 2), as well as a truly remarkable Burmese cultured pearl necklace that was the product of decades of labor (figure 3).

Mastoloni added that the cultured pearl industry has become much more competitive. Dealers require much more breadth of inventory: Simply having akoya or Chinese freshwater material is no longer enough. Customers are more educated and driven to seek out unique, striking pieces of different colors, shapes, or lengths—and want to see new variations and combinations every time they look to make a purchase. @chapter:53 @chapter:4 @chapter:53


# Publication Year: 2017
# Title: Book Review: Enduring Splendor: Jewelry of India’s Thar Desert
# Abstract: By Thomas K. Seligman and Usha R. Balakrishnan, softcover, 135 pp., illus., publ. by Fowler Museum at UCLA, Los Angeles, US$25.00.

In 2009, Thomas K. Seligman, director emeritus of the Cantor Arts Center at Stanford University, began research on the Thar of India with a focus on the soni caste of artisan jewelers. As Mr. Seligman’s research progressed, he proposed an exhibition featuring the work and stories of several individual sonis from Jaisalmer, in Rajasthan. Though many of the jewelers are highly skilled craftsmen, traditionally they do not sign their work; The study and exhibition, which would be co-curated by Mumbai-based jewelry scholar Usha Balakrishnan, would prove to be a unique opportunity to highlight these artists. This volume accompanied the exhibition.

In the book’s first chapter, “From Metal to Ornament: The Language of Jewelry,” Ms. Balakrishnan outlines a fascinating history of the region while explaining that the very nature of what jewelry represents in Indian culture has resulted in gaps in its history. For example, Hindus are traditionally cremated and their jewelry recycled within the family rather than being buried with the original owner. Also, constant migration of communities resulted in similar jewelry designs appearing in vast geographical regions. These complexities make a linear study extremely difficult. Indeed, Mr. Seligman’s study eventually became, according to folklorist Pravian Shukla, “the methodical documentation of the present in order to capture complete one moment in time.” Ms. Balakrishnan explains that there are three distinct categories of Indian jewelry: gold set with precious gems made for royalty and the very affluent, jewelry crafted primarily from silver, and finally tribal adornments made from base metals and materials such as shell and feathers. All are made by the soni, or jeweler. (The the surname Soni is common in Rajasthan to those in the jewelry-making trade.) She also discusses the deep significance of various forms of jewelry such as the hasli, a torque-type necklace that signifies a woman’s betrothal, charms that attract good luck, and pieces that fend off the “evil eye.”

The second chapter, “Four Sonis from Jaisalmer,” is a detailed examination of four of the many jewelry making families of the region. The family of Govindlal Soni, interviewed by Mr. Seligman, carries on traditional techniques and styles passed down from father to son through many generations (typically the only aspect of traditional jewelry-making undertaken by women is stringing). The family of Govindlal Soni has developed keen business acumen that has helped them to grow. Dharmendra and Om Soni are brothers who also carry on a family business established generations ago. This family specializes in making gold jewelry, with some silver jewelry made for the tourist trade. Hanuman Soni and sons specialize in traditional-style jewelry made for local people. All the jewelers in this family have trained in gold work but prefer to concentrate their efforts on fulfilling the needs of locals for traditional, heavy silver pieces. They also make pieces that are ordered and stocked by other shopkeepers. Hari Om Jewellers, established by Hari Ram Soni, and now run by his sons, developed a distinct jewelry style known for relief engraving and cut outs. This family specializes in making commissions for tourists. Several nice examples of each family’s work are depicted, showing how each has developed a distinctive style of their own.

Chapter three, “Pure Serendipity: An Odyssey into the World of Indian Jewelry” details the chance occurrence that led Ronald and Maxine Linde to collect Indian jewelry. Their first acquisition, shown in a full-page photograph on the first page of the chapter, was a spectacular necklace of gold, rubies, pearls, and diamonds. The Linde collection represents a great depth and diversity of ornaments and numerous pieces from their collection, promised gifts to UCLA, comprised most of the exhibition. The Linde’s collection is unique and special, as many collectors of Indian jewelry tend to gravitate to the Mughalera, with its grand pieces set with gold and precious gems. The Lindes have collected such items, as well as the silver jewelry of the lower castes and miniature items made for the statues of gods and goddesses. Pieces shown that the reviewer found particularly charming were a simple, silver hansadi neckpiece and a lovely gold, jade, ruby, and diamond armband dating from the late 17th to early 18th centuries.

Finally, “Selections from the Ronald and Maxine Linde Collection of Jewelry and Ritual Arts of India,” is devoted entirely to showcasing items from the collection from lavish, large, gold necklaces and earrings set with diamonds, rubies, pearls, and emeralds to humble, but still lovely, everyday silver earrings and everything in between. Photographed in high-resolution detail and shown against white backgrounds, the jewelry pops from every page and is a treat for the eye.

This reviewer found the book fascinating and very informative, as it concentrated on areas not usually visited with regards to Indian jewelry: the creation of everyday jewelry for the local communities as well as the background, histories, and motivations of the jewelers that so often remain anonymous. This is highly recommended reading for anyone interested in Indian jewelry as well as anyone interested in traditional, indigenous jewelry forms. @chapter:55 @chapter:2 @chapter:55


# 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:50 @chapter:3 @chapter:50


# 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:20 @chapter:2 @chapter:20


# 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:48 @chapter:0 @chapter:48


# 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:11 @chapter:4 @chapter:11


# 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:34 @chapter:1 @chapter:34


# 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:10 @chapter:0 @chapter:10


# 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:43 @chapter:1 @chapter:43


# 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:11 @chapter:4 @chapter:11


# 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:36 @chapter:1 @chapter:36


# 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:9 @chapter:1 @chapter:9


# 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:25 @chapter:2 @chapter:25


# 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:5 @chapter:0 @chapter:5


# 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:50 @chapter:3 @chapter:50


# 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:7 @chapter:0 @chapter:7


# 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:16 @chapter:1 @chapter:16


# 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:6 @chapter:0 @chapter:6


# 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:9 @chapter:1 @chapter:9


# 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:54 @chapter:4 @chapter:54


# 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:55 @chapter:2 @chapter:55


# 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 @chapter:0 @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:9 @chapter:1 @chapter:9


# 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:25 @chapter:2 @chapter:25


# 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:9 @chapter:1 @chapter:9


# 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:15 @chapter:0 @chapter:15


# 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:39 @chapter:1 @chapter:39


# 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:26 @chapter:0 @chapter:26


# 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:27 @chapter:0 @chapter:27


# 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:5 @chapter:0 @chapter:5