# Publication Year: -
# Title: Exhibition Review: Maker & Muse, Women of the 20th Century Art Jewelry
# Abstract: Figure 1. This aquamarine necklace (c. 1890) by Mrs. Philip (Charlotte) Newman, is seen here in its original box. Newman's work inspired artists and designers of the Arts and Crafts Movement. From the collection of Tereza M. M. Driehaus. Photograph by John A. Faier, 2014, © The Richard H. Driehaus Museum.

Maker & Muse, Women of the 20th Century Art Jewelry, which opened at Chicago’s Driehaus Museum on February 14, 2015, features over 250 pieces of jewelry made during the Arts and Crafts and Art Nouveau movements from British, French, German, Austrian, and American artisans.

The exhibit, which runs through January 3, 2016, is housed in the opulent Driehaus Museum, a fairly new space housed in Gilded Age mansion, located in the heart of McCormickville and a block away from Chicago’s Magnificent Mile. Built in 1879, the Driehaus Museum was originally the home of the Nickerson family, whose patriarch, Samuel, was a distiller for the Union Army and at one-time president of The First National Bank of Chicago. Richard H. Driehaus, who founded the museum in 2003, spent five years restoring it, opening it to the public in 2011. These ever-changing galleries are filled with furnishings, chandeliers, and decorative art from the 19th century to early 20th century Driehaus Collection.

The exhibit is housed on the second floor hallway and in bedrooms that were once inhabited by the Nickersons. At the top of the landing is a case of four pieces of distinctive jewelry, including an aquamarine necklace (figure 1), by Charlotte Newman (1840–1927), who broke through the glass ceiling of women jewelers. After the death of her mentor, John Brogden, Newman continued producing pieces in her own workshop. At the 1889 Paris Exposition, just as the Arts and Crafts movement was beginning she was the only woman listed as a collaborator on the jewelry exhibited.

The first room of the exhibit is titled “With A Hammer in Her Hand: British Arts and Crafts Jewelry.” As the Arts and Crafts Movement (1890–1910) took hold, simpler designs became the fashion for clothing, and the jewelry was made to compliment this change. Brooches, necklaces, clasps, and buttons were became common accoutrements, while earrings and bracelets fell out of favor. The movement away from industrialization allowed time for handmade items with natural materials, colored gems, and enamel which was affordable for many economic classes. Famous British jewelry designers included in this room are Charles Ashbee, Liberty & Company and its designers, Archibald Knox and the Guild of Handicraft, Child & Child, Sybil Dunlop, and Dorrie Nossiter. Husband and wife teams such as the Gaskins and Dawsons also gained acclaim. Notable pieces in this room include the silver blue enameled winged tiara set with a central citrine made in 1990 by Child and Child and a pair of life-like horn lily pad hair combs with moonstone drew drops made in 1906 by Ella Naper (figure 2).

Figure 2. English designer Ella Naper completed these lily-pad hair combs circa 1906. From the collection of Richard H. Driehaus. Photograph by John A. Faier, 2014, © The Richard H. Driehaus Museum.
Tiffany & Company and Marcus & Company, who were in fierce competition, are shown in the next room, themed “American Art Jewelry.” After his father’s death in 1902, Louis Comfort Tiffany became Tiffany & Co.’s first official design director. He established Tiffany Studios on the sixth floor of the 5th Avenue building at Madison and 45th Streets in New York, which was supervised by artists Julia Munson from 1902 until 1914 and Meta K. Overbeck from 1914 until 1934. Louis Tiffany himself left the studio in 1918.

As a leader of the Art Nouveau movement, Louis Comfort Tiffany is best known for his stained glass windows and lamps, several of which are exhibited here. Since he was inspired by nature, color, and design, his move into jewelry, particularly his smaller enameled works, was a natural progression, resulting in beautiful pieces encrusted with opals, garnets, moonstones, and jade. The most notable piece by Louis Comfort Tiffany is in the central case, the 1918 platinum, blue zircon, diamond, chrysoberyl, amethyst, and demantoid garnet necklace. Marcus and Company rivaled this piece with it 1900 gold, natural pearl, demantoid garnet and enameled necklace. In Germany, the Arts and Crafts movement was known as Jugendstil. In Vienna it was founded by Josef Hoffman of the Wiener Werkstätte as a cooperation of designers, artists and architects best known for their work on the Fledermaus Caberet (1907-1913). This movement is encompassed in “Jewelry as Art, Germany and Austria in the Early 20th Century.” Jewelry and objects in this gallery include boxes, dishes, and vases mostly made by Josef Hoffman and Karl Rothmuller. One striking piece on display is a silver, opal, and mirrored glass pendant created by Josef Hoffman in 1904 (figure 3).

Figure 3. Austrian artisan Josef Hoffmann, of the Wiener Werkstätte, completed this silver, opal, and mirrored glass pendant in 1904. From a private collection. Courtesy of the Richard H. Driehaus Museum.
The awe-inspiring pieces in “Metamorphosis, The Female Figure in Art Nouveau” are all about the muse: curves, folds, winged sylphs, femme fatale, Medusa. This room is filled with nature-inspired objects. Beautifully crafted art pieces were made for wealthy clients by men such as Rene Lalique, Alphonse Mucha, Louis Aucoc Fils, Georges Fouquet, and Maison Vever. Rene Lalique’s stunning gold, enamel, glass, diamond and baroque pearl chrysanthemum pendant/brooch is found in this room (figure 4).

Figure 4. Rene Lalique’s chrysanthemum pendant/brooch, completed c. 1900. From the collection of Richard H. Driehaus. © 2014 Artists Rights Society (ARS), New York / ADAGP, Paris. Photograph by John A. Faier, 2014, © The Richard H. Driehaus Museum.
The final room, “Beautiful, Useful, and Enduring, Chicago Arts and Crafts Jewelry”, is filled with Chicago-based jewelers such as LeBolt & Company, Elinor Klapp, Madeline Wynn, Florence Koehler, Frances Glessner, and the now-defunct Kalo Shop. The Christia Reade crown for the Queen of the Lombard (Illinois) Lilac Festival, still used every year, and made from donated silver spoons, is also on display.

This exhibit is a must see for anyone interested in the Arts and Crafts and Art Nouveau periods. It is a rarity that all of these exquisite pieces are open to public viewing in the same place and time.

The admission fee to the museum is $20.00 which includes the special exhibit. Audio and guided tours are also available for an additional $5.00 each. The museum, located at 40 East Erie, is open every day, except Monday, from 10am to 5pm. @chapter:20 @chapter:2 @chapter:20


# Publication Year: 2023
# Title: Nickel-Diffused Spinel, Vietnamese Augite, Brown Mammoth Ivory, and More…
# Abstract: Welcome to the Summer 2023 issue of Gems & Gemology! Loaded with noteworthy content, the articles in this volume cover timely topics, such as a new treatment process identified in natural spinel, a recent source of augite in Vietnam, and research identifying the origin of the surface color of brown mammoth ivory.
“…an undisclosed diffusion treatment process for spinel that is being used to convert lightly colored gems to hues ranging from green to blue.”
In our lead article, Dr. Michael Jollands and fellow GIA researchers report on an undisclosed diffusion treatment process for spinel that is being used to convert lightly colored gems to hues ranging from green to blue. Testing a set of spinel samples represented as “cobalt diffused” revealed that the stones were actually diffused with nickel. With this treatment now present in the gem market, the authors suggest identification criteria for spinel samples within the green to blue color range.
Next, a team led by Le Ngoc Nang investigates a variety of gem-quality augite from Dong Nai, Vietnam. The magnesium-rich augite, characterized by its intense dark orangy brown or dark green color under transmitted light, has potential use in jewelry and as a carving material.
Another carving material, mammoth ivory, is typically found with a brown surface color. Our third article, from Zhaoying Huang and coauthors, examines the origin of this color. They determine that iron oxides and sulfides and manganese oxides and hydroxides crystallized on the mammoth ivory’s surface while underground, causing it to turn brown.
Our regular columns offer a host of interesting finds from all over the globe, including an aquamarine displaying asterism, a CVD-grown diamond over 34 carats, and an exceptionally large South Sea cultured pearl in the Lab Notes section. Explore the inner wonders of gemstones in Micro-World, with a feather inclusion resembling a mountain range in natural diamond, metallic platelets in Brazilian Paraíba tourmaline, an intriguing metal sulfide crystal in garnet, and more. Colored Stones Unearthed returns in this issue, covering gemstones that formed through metamorphic processes. Highlights from the Gem News International section include the characteristics of treated rubies from Greenland as they become more common in the market, the 2023 Sinkankas Symposium, and the latest auction season. Also in this issue, we put fire obsidian In the Spotlight. Tom Dodge’s impressive lapidary work reveals the vivid spectrum of iridescent colors in this rare volcanic glass found only in the Glass Buttes region of Oregon.
Lastly, we invite you to join the G&G Facebook group (facebook.com/groups/giagemsgemology). Since its launch in February 2020, our growing community has surpassed 35,000 members. Thank you for your continued support and interest in Gems & Gemology! @chapter:6 @chapter:0 @chapter:6


# Publication Year: 2023
# Title: Quarterly Crystal: Hiddenite from Idaho
# Abstract: Figure 1. Weighing 20.57 ct and measuring 37.10 mm in length, this doubly terminated, heavily etched spodumene crystal contains chromium as its coloring agent or chromophore. Photo by Adriana Robinson.
Not every day do we encounter a known but rare gem mineral from a previously unknown locality for the species. But that is exactly what happened when we examined the doubly terminated, heavily etched green crystal shown in figure 1. This slightly yellowish green crystal, weighing 20.57 ct and measuring 37.10 × 10.00 × 8.50 mm, is from Sawtooth National Forest in Elmore County, Idaho. It came to us from the mineral collection of Jack Lowell of Tempe, Arizona.

Figure 2. Found on the surface of the heavily etched crystal, these sail-shaped etch features captured with differential interference contrast photomicrography provide definitive proof of the mineral spodumene. Photomicrograph by Nathan Renfro; field of view 1.44 mm.
Mined by Geary Murdoch in the 1990s, the crystal was sold to Lowell as an etched aquamarine. Lowell suspected that it was a spodumene crystal due to the very distinctive and diagnostic etching on its surfaces (figure 2). The authors examined the crystal with Raman analysis to confirm its identity as spodumene. Energy-dispersive X-ray fluorescence identified its chromophore as chromium, indicating the specimen was the rare green variety known as hiddenite.

Figure 3. This 2.30 ct doubly terminated hiddenite crystal comes from the Adams mine in North Carolina, the first known locality for the gem. Photo by Annie Haynes.
Idaho is only the second known hiddenite source. The first to yield gem crystals (figure 3) was the Adams hiddenite and emerald mine in Alexander County, North Carolina. @chapter:1 @chapter:0 @chapter:1


# Publication Year: 2017
# Title: Cat’s-Eye Alexandrite with Unique Inclusion Pattern
# Abstract: Figure 1. This alexandrite cabochon appears brownish green in fluorescent light (left) and brownish purple in incandescent light (right). The cabochon shows chatoyancy under both forms of illumination due to light reflection from the shallow plane of dense fine parallel needles. Photos by Shunsuke Nagai.

Chatoyancy is an optical effect caused by light reflecting off dense concentrations of parallel needles or hollow tubes in cabochon-cut gem materials. To maximize chatoyancy, the base of the cabochon should be cut parallel to the inclusions to produce an even effect across the dome. In some cases, the parallel inclusions are not distributed throughout the stone and are only in zones or narrow bands. In such cases the cutter must orient the needles with care to produce a cat’s-eye.A chatoyant cabochon, weighing 21.22 ct and measuring 17.75 × 17.50 × 6.77 mm, was recently submitted to GIA’s Tokyo laboratory for identification service. This stone displayed a change of color (figure 1) from brownish green in fluorescent light to brownish purple in incandescent light. Standard gemological testing resulted in a spot refractive index (RI) reading of 1.75, a specific gravity (SG) of 3.74, and strong trichroism. In addition to these properties, heterogeneous needle-like inclusions and infrared and Raman spectroscopy revealed that the stone was natural chrysoberyl.

What is notable about this stone is that all the needle-like inclusions that cause the chatoyancy are confined to a narrow layer at the very bottom of the cabochon (figure 2). The rest of the stone is nearly free of inclusions. The cutter obviously knew to orient what must have been a narrow layer of needles at the bottom of the cabochon so that the dome would form a complete cat’s-eye. Some synthetic or imitation stones have an engraved foil backing or an engraved base to produce a cat’s-eye or star in much the same way. Raman spectroscopic analysis indicated that the needle-like inclusions were rutile (figure 3). While the boundary between the included and inclusion-free areas looks sharp, the stone is not assembled.

Figure 2. A side view of the cabochon, immersed in water, showing the localized inclusions near the base. Photo by Makoto Miura; field of view 1.6 cm.

Figure 3. Iridescent minute parallel needles and particles in the alexandrite cabochon. Photo by Makoto Miura; field of view 2.0 mm. @chapter:26 @chapter:0 @chapter:26


# Publication Year: 2018
# Title: Ponderosa Sunstone Update
# Abstract: Figure 1. A new test pit on Desert Sun's Ponderosa claim has produced much larger rough, with a high proportion of large dichroic stones. The largest recovered so far was approximately 1,800 ct. Photo by Kevin Schumacher.

John Woodmark, president of Desert Sun Mining & Gems (Depoe Bay, Oregon), provided an update on the Ponderosa mine. According to Woodmark, the mine is Oregon’s most prolific sunstone source, producing about 95% of all material currently on the market. He explained that the mine’s operations have changed to compensate for the characteristically short May-to-October mining season at the Ponderosa, which is at an elevation of 6,000 feet. In September 2015, Woodmark contracted with a sand and gravel company to bring a much larger excavator on site along with a high-capacity screen. This allowed the operators to stockpile a large enough volume of concentrate to sustain production through the entire following season.

News from the Ponderosa Mine
John Woodmark provides a status report of activities at Oregon’s Ponderosa mine.
In years past, even though the miners had access to the site as soon as the snow cleared in mid-May, they had to wait for the ground to dry out before they could mine. Now they can process the prior year’s stockpiled concentrate through a wet trammel—which removes some of the volcanic crust on the rough feldspar—and pickers can start work immediately. The new process ensures more production: During the five-month 2017 season, Ponderosa produced 4,400 kg of rough labradorite feldspar.

In September 2017, the combination of the bigger excavator and the high-capacity screen produced approximately 5,000 cubic yards of concentrate in just under a month. Woodmark estimated that the concentrate contains 5 kg of Oregon sunstone per cubic yard, and the new process has dramatically increased production of Ponderosa sunstone.

Figure 2. Oregon sunstone retains its rich orangy red hues even in smaller sizes. Photo by Kevin Schumacher.
Another development has been extensive test digging to determine gem potential over Desert Sun’s existing 60-acre claim. Woodmark explained that these test digs located a promising area of approximately one quarter of an acre, which has been developed into an open pit about 50 feet deep. Woodmark’s miners are finding larger stones as they go deeper, including one that weighed approximately 1,800 ct (figure 1). In addition, many of these larger gems are red/green dichroic stones, along with approximately 18 kg of extremely rare fine red and orangy red material (figure 2).

Woodmark has streamlined the company’s operations in other ways. He now contracts with a cutting house in India that grades the rough gems into categories. This frees Woodmark’s team from having to grade and allows them to focus on mining and production. It also allows the cutting company to respond more quickly to customers’ requests for a particular color or grade of finished gems. According to Woodmark, this development helps manufacturers use sunstone more effectively. He mentioned that sales have increased year-on-year since the andesine controversy earlier in the decade as trust in the natural-color Oregon gem has increased. He noted that 2017 was the company’s most successful year to date.

Woodmark noted that sustained production has been a major factor in this renewed confidence. He also told us that recent interest in North American gemstones, especially among TV merchandisers, has driven sales. He says that when clients see the quality of an untreated red Oregon sunstone and compare the pricing for a one-carat stone to that of an equivalent-color ruby or spinel, they realize the $150-per-carat price tag is an absolute bargain.

Woodmark added that consumer concern about the integrity of the gem supply chain has fostered interest in domestic gems. People are looking for gems that can be followed “from the dirt to the finger."

Figure 3. Desert Sun hires Native American teenagers from the local community to separate sunstone from ore. Photo by Duncan Pay.
Desert Sun Mining & Gems hires local Native American teenagers to help pick the sunstones from the processed ore (figure 3), which helps the local community. Woodmark explained that each picker can typically produce between 10 and 11 kg per day, but some might pick as much as 17 kg. He mentioned that the company had recently raised the pickers’ hourly wage by 20%, citing the community unemployment rate of 87%. He told us, “They’re always available…and they’re good kids.”

Woodmark told us the operation had recently hosted a PhD geoscience student from Washington State University who was studying the volcanism of the area. The student determined that the flow that hosts the sunstone at Ponderosa is approximately 18 million years old, and that the mine sits atop a vent, which is why those searching for similar deposits nearby have yet to find anything. As Woodmark said, “It just came up, and we’re right on it.” He added that the deposit “looks inexhaustible. From the bores that we’ve done, we have over a trillion carats.” @chapter:17 @chapter:0 @chapter:17


# Publication Year: -
# Title: Developing Tanzania's Gem and Jewelry Industry
# Abstract: Susie KennedyICA Director and Jewelry Designer

	Interview with Susie Kennedy, ICA Director and Jewelry Designer
A native of Kenya, Susie Kennedy teamed up with her husband in the 1990s to establish their place in the gem industry. With Mrs. Kennedy specializing in tanzanite and her husband in tsavorite garnet, they started out dealing in rough, then moved to gem cutting. Their business expanded into jewelry manufacturing when clients started demanding more than just unset gemstones. They opened their first jewelry store, The Kennedy’s International, in Nairobi, Kenya, in 1997.

The pair eventually opened another jewelry store and a gallery. Their enterprises became popular stopping places for organized tours from all over the world.

Mrs. Kennedy happily relates a highlight of her career so far: creating a beautiful pair of tanzanite earrings for Hillary Clinton, then the U. S. Secretary of State. Mrs. Kennedy and her team created the earrings under a tight deadline—just in time for Secretary Clinton’s meeting with Tanzania’s President Jakaya Kikwete. Mrs. Kennedy says she was proud and happy to see her earrings take a prominent place in press coverage of the day’s events.

In a discussion of the growth of the mining industry in Tanzania, she cites the arrival of foreign investment in gold and gem mining as well as gem sorting and cutting. She also says that both Kenya and Tanzania are reviewing their mining legislation to maximize the benefits to the local population. She expresses concern as well as optimism about the developing benefits to her people and the environment.

While it’s in short supply at the moment, she predicts tsavorite supplies will rise as investment increases and local laws make tsavorite mining more beneficial to miners and landowners. And although tanzanite supply is generally low, she is able to keep up her supply by taking advantage of her good, long-term relationships with local sources and by buying gems when demand is low.

Mrs. Kennedy’s advice to students was simple: “This business is based on trust:” If people know you to be trustworthy and that you keep your word, they will pass on your good name to others. “Let the customer be the king:” Find a source that you can trust rather than a chain of middlemen, which will raise your costs (and prices) while cutting down your profit. She winds up by saying, “Buy good, you sell good. That’s my philosophy.” @chapter:47 @chapter:3 @chapter:47


# Publication Year: 2022
# Title: One-of-a-Kind Designs from Zoltan David
# Abstract: Figure 1. Zoltan David working at the bench in his studio, located in his store in Austin, Texas. Photo by Patti David.
2022 marks the 42nd year in the industry for iconic jewelry designer Zoltan David (figure 1). At the AGTA show, the authors had an opportunity to converse with David about his passion, career, and inspired jewelry creations.
Curiosity and the drive to create led David to his career in metalsmithing. For David, creativity can be furthered by an in-depth understanding of the materials and skillful maneuvers. While modern technology allows for efficient jewelry sketching and design, the lack of knowledge about metals—base or precious—limits the execution of a great design or even the creativity of the design itself. David’s jewelry pieces reflect this philosophy. Each of his creations is a three-dimensional “architecture,” which must be viewed from multiple directions to fully appreciate its beauty.

	Zoltan David Interview

The “Time” pendant (figure 2) is David’s most recent award-winning design. In 2020, this piece won second place in the Business/Day Wear category of the AGTA Spectrum Awards. This pendant features a 19.54 ct fantasy-cut citrine as the center stone, surrounded by eight suspended metal elements forming two circles. The metal elements are made of iridescent blue and purple steel with 24K textured yellow gold inlays, a signature patented technique invented by David. In addition, all these metal elements are suspended and well connected with each other. David wanted to create a sense of rotation with this design: All elements rotate around the center of the universe, trying to find the perfect balance.

Figure 2. Exotic metals such as the iridescent blue and purple steel in the “Time” pendant are Zoltan David’s signature. 24K gold inlay is also a Zoltan David distinction. This piece features a 19.54 ct citrine. Photo by Robert Weldon; courtesy of Zoltan David.

	Zoltan David “Time” Pendant

More than four decades of knowledge building and practice have made David’s jewelry pieces the perfect combination of metal art and architectural construction. The “Mirror Mirror” pendant (figure 3) represents the continuous exploration and technique refinement by the master designer. To fully understand this piece, one needs to carry out a jewelry “anatomy.” Starting from the center of the pendant, an elongated oval pink opal is encased by a cut piece of mother-of-pearl, which was carved and inlaid with beaded pure platinum. The mother-of-pearl is surrounded by polished surgical steel and inlaid with 24K engraved and shaped rose gold. All of these elements are nestled in a framework of green gold leaves. From the side view, diamonds mounted in the surgical steel layer are exposed through the space between the green gold leaves (figure 3, right).

Figure 3. Zoltan David’s “Mirror Mirror” pendant combines multiple innovative techniques and materials. The piece features platinum inlays in the mother-of-pearl surrounding the pink opal center stone, highly polished surgical steel as the base frame (left), a leaf wreath made of green gold wrapping around the outer edge of the whole piece, and diamonds mounted in the steel base (right). Photos by Robert Weldon; courtesy of Zoltan David.

	Zoltan David “Mirror Mirror” Pendant

Although renowned for his metalsmithing, David is also drawn to spectacular colored stones. The “Ruby Flight” ring (figure 4), a piece from the Duchess collection, features a 2.45 ct Burmese ruby. The ruby is held by 18K gold prongs between two platinum wings inlaid with 24K gold. The engraved and shaped gold inlays form patterns on both sides of the wings. The interior walls of the wings are set with melee diamonds in between the gold inlays, while the exterior walls are set with melee rubies along the inlaid lines. More than 300 melee rubies also decorate the edges of the wings. The shank of the ring is also one of a kind, made up of three components: a melee diamond stud band sandwiched by the bottom of the two wings.

Figure 4. The “Ruby Flight” ring is representative of Zoltan David’s stone selection and construction of a complex jewelry piece. Photo by Robert Weldon; courtesy of Zoltan David.

	Zoltan David “Ruby Flight” Ring

From the start, David has been an eager learner and has never stopped his exploration of the metalsmith profession. He is involved in all aspects of his business: designing, crafting, and trading each one of his creations. As David said, he would like to keep traveling along this journey by continuously surpassing himself. @chapter:20 @chapter:2 @chapter:20


# Publication Year: 2021
# Title: Constantin Wild (Constantin Wild GmbH & Co. KG)
# Abstract: Figure 1. A lively 24.07 ct yellowish green cushion-cut tourmaline from new fields in the Democratic Republic of the Congo. Photo © Constantin Wild.

Constantin Wild and his team started 2020 with a strong Tucson show and orders to fulfill from 2019. Upon returning to Germany, the severity of the COVID situation became apparent, and on March 14 they were forced to temporarily shut down the business. Mr. Wild was fortunate to keep his staff, though they did have to cut back work initially to only one day a week. Since August, they have been able to work at 80% of full-time. The second half of 2020 saw business levels basically return to normal, and overall the year was pretty good. Tucson was the company’s only trade show in 2020, and they do not expect to attend any shows in 2021. The biggest disadvantage of not going to trade shows has been missing out on new opportunities.
To keep in touch with clients and partners, Zoom and WhatsApp became essential for video calls. Mr. Wild has also been inviting clients to their facility in Idar-Oberstein for relaxed face-to-face visits. The business has been sharpening its brand image and plans to relaunch its website and blog as well as provide regular Facebook and Instagram feeds.
Without being able to travel, the team has taken the time to sort and recut stock in their inventory. They have also been cutting rough from their vaults, as the new rough supply has been restricted during the pandemic.
When asked about pandemic sales, Mr. Wild noted that gemstones suitable for high jewelry have been in demand, in addition to a new trend for high-value gems as standalone pieces. During the past year, sales have been particularly good for Paraíba tourmaline, green tourmaline (figure 1), aquamarine, and Imperial topaz (figure 2).

Figure 2. This 4.06 ct red pear-shaped Imperial topaz is from Ouro Preto, Brazil. Photo © Constantin Wild.
Mr. Wild also noticed strong demand for gray spinel, whether atonal or modified by blue or purple. He has done well selling color suites of stones, such as his “Rhapsody in Blue,” which features a diverse array of blues provided by tanzanite and both greenish blue and intense blue aquamarine from Brazil and Mozambique (figure 3).

Figure 3. The “Rhapsody in Blue” suite (145.2 carats total) is composed of 17 gems: nine greenish blue cushion-cut aquamarines from Brazil, four oval-cut tanzanites, and four intense blue oval-cut Mozambique aquamarines. Photo © Constantin Wild.
During this time, Mr. Wild has been able to work on a book commemorating the firm’s 175th anniversary next year. Titled Gems, Colours, and Wild Stories… 175 Years of Constantin Wild, the book will explore the history of the company and provide many entertaining stories and high-quality images to capture the unique emotions associated with colored gems.
Mr. Wild looks forward to returning to Tucson in 2022 and predicts that demand will focus on vibrant colors to celebrate the end of the pandemic. @chapter:38 @chapter:3 @chapter:38


# Publication Year: 2018
# Title: Michael Dyber’s Innovative Gem Carving
# Abstract: Figure 1. For 30 years, Michael Dyber has designed and fashioned gems, such as this aquamarine, in ways that please the eye and amaze the connoisseur. Photo by Albert Salvato.

Michael Dyber (Rumney, New Hampshire) discussed how 30 years as a gem artist have influenced his techniques and informed the creation of his optically stunning carvings (figure 1). He believes his method is a gift, one from the heart, and knows that his approach would not suit everyone’s style.

Dyber prefers to pay premium prices for flawless material, as flaws that cannot be removed during preforming affect the polished piece’s entire appearance. He finds sourcing rough to be a challenge and buys select pieces rather than lots of material. He also makes his own tools in his studio. When starting a piece, he chooses the rough by intuition and begins preforming the stone on a large grinding wheel by removing sharp edges and letting the lines and sides join together naturally. After preforming, he sits at the wheel with his handmade diamond tools and looks for inspiration in the piece, which he might find in the shape or an inclusion.

Michael Dyber Discusses His ProcessGem carver Michael Dyber provides insight into his process for cutting, carving, and polishing his unique pieces.
“So instead of trying to force a design into the stone,” Dyber explains, “what I end up doing is sitting and looking at it and deciding, ‘Let’s start here,’ and not having to think about where it’s going to go. By doing this, and having this open-minded, I’m not confined.” Dyber works with the stone in three dimensions—from the front, back, and sides—without any dopping or affixing to a surface. He holds the stone throughout, even during the four-hour process of drilling each one-millimeter hole into a piece (figure 2); this allows for a more continuous workflow. He noted that the pre-polish is the most important step of all. Carving can be finished quickly, but the pre-polish requires a great deal of patience or else the scratches will remain in the piece for good. Over the past three decades, he has managed to reduce pre-polishing from six steps to three. While the work is time consuming, Dyber finds his work emotionally satisfying, because he gets to see the potential of the rough transform into the finished piece.

Figure 2. Each hole Dyber drills into a gem, as in this Brazilian green beryl, can take up to four hours to complete. Photo by Albert Salvato.
In the future, Dyber wants to keep refining his techniques so that his pieces stay simple without losing their dynamic. “That’s the excitement of the work, what drives me on. Just changing something I’ve done for years and seeing how it turns out. Sometimes it’s that simple.” @chapter:28 @chapter:2 @chapter:28


# Publication Year: -
# Title: Signs Still Point to ‘Decent’ U.S. Season
# Abstract: A 61.35 carat emerald ring sold for $4.65 million – four times the pre-sale estimate – at a Sotheby’s auction Dec. 11, 2013 in New York. Photo courtesy of Sotheby’s

	Jewelry sales for the 2013 holiday season continue to point to decent, if not spectacular, growth in the U.S. market, which accounts for about 35% of world volume.  While most diamond and gemstone sales happen in the week before Christmas, the results so far indicate that most of the growth will be driven by higher-end and on-line merchants.

	High-end stores had a strong start to the season, according to a survey by The Centurion Newsletter, with 87% of jewelers reporting sales increases over last year. About a third reported increases between 6% to 10% and a fourth showed increases above 10%. Results tapered off a bit during the second week of the season, but still pointed to a strong showing, especially for diamonds, which accounted for about half of the sales volume.

	The e-commerce research firm comScore reports that on-line sales of all merchandise have been running at 9% above last year. Some surveys note that diamond and jewelry sales are running at higher growth rates.

	U.S. sales of diamonds may be dampened slightly by the continued curtailment of memo business. Banks financing the diamond pipeline have been cracking down on expensive memo deals – where diamond suppliers put goods in retailers’ showcases with little or no money upfront, and collect on sales after January. Banks have also been requiring diamond suppliers to sell goods on shorter payment terms. On the other side, many retailers, citing the huge upfront investment needed, say they cannot afford to keep large diamond inventories.

	Dealers report that demand in China should pick up for the Chinese New Year on Jan. 31, when many workers receive a bonus. Retailers there continue to stock diamonds cautiously, but anticipate strong demand at the end of January—mainly in gold items.

	De Beers’ December sight was about $565 million, much larger than expected. In contrast to the previous sights, clients left few goods on the table – mainly small stones that were not profitable to cut in today’s market, particularly after the value of the rupee plunged in relation to the U.S. dollar, the currency in which De Beers conducts its diamond sales.

	One report noted that few De Beers’ sightholders have been able to make a profit since last June and, as the rupee continues to struggle in the currency exchange markets, they continue to pressure for additional price reductions.

	It is likely, however, that despite the current “break-even” prices of De Beers rough, clients will resist deferring or refusing their sight allocations, because 2014 is the review year for the new client sight contracts that begin in January 2015.

	One area of the market where there seems to be no end to growth is auctions: Christie’s and Sotheby’s combined sales for the year have exceeded $1.2 billion ‒ by far a record.

	Both Sotheby’s and Christie’s had extremely strong end-of-season sales in New York. Sotheby’s total of $60.5 million for its Dec. 11 sale was a record for that venue.  A 61.35 carat Colombian emerald ring soared four times over its pre-sale estimate of $1-$1.5 million, achieving a hammer price of $4.65 million.

	Christie’s Dec. 10 New York sale totaled $65.8 million, with the top lot, a GIA-graded 52.28 ct D –IF, type IIa diamond selling for $10.9 million, or $208,817 per carat. @chapter:32 @chapter:3 @chapter:32


# Publication Year: 2017
# Title: Sapphire Chart Article: Suggested Reading on Sapphires and Their Inclusions
# Abstract: Abraham J.S.D. (1982) Heat treating corundum: The Bangkok operation. G&G, Vol. 18, No. 2, pp. 79–82, http://dx.doi.org/10.5741/GEMS.18.2.79

Andersen O. (1967) A prospector's guide to the Anakie sapphire fields. G&G, Vol. 12, No. 6, pp. 173–178, 192.

Atkinson D., Kothavala R.Z. (1983) Kashmir sapphire. G&G, Vol. 19, No. 2, pp. 64–76, http://dx.doi.org/10.5741/GEMS.19.2.64

Buravleva S.Y., Smirnov S.Z., Pakhomova V.A., Fedoseev D.G. (2016) Sapphires from the Sutara placer in the Russian Far East. G&G, Vol. 52, No. 3, pp. 252–264, http://dx.doi.org/10.5741/GEMS.52.3.252

Coldham T. (1985) Sapphires from Australia. G&G, Vol. 21, No. 3, pp. 130–146, http://dx.doi.org/10.5741/GEMS.21.3.130

Crocker R.C. (1956) The Yogo sapphire mine. G&G, Vol. 8, No. 11, pp. 323–330.

Crowningshield G.R. (1983) Padparadscha: What's in a name? G&G, Vol. 19, No. 1, pp. 30 –36, http://dx.doi.org/10.5741/GEMS.19.1.30

Dharamaratne P.G.R., Premasiri H.M.R., Dillimuni D. (2012) Sapphires from Thammannawa, Kataragama area, Sri Lanka. G&G, Vol. 48, No. 2, pp. 98–107, http://dx.doi.org/10.5741/GEMS.48.2.98

Elen S., Fritsch E. (1999) The separation of natural from synthetic colorless sapphire. G&G, Vol. 35, No. 1, pp. 30–41, http://dx.doi.org/10.5741/GEMS.35.1.30

Emmett J.L., Douthit T.R. (1993) Heat treating the sapphires of Rock Creek, Montana. G&G, Vol. 29, No. 4, pp. 250–272, http://dx.doi.org/10.5741/GEMS.29.4.250

Emmett J., Scarratt K., McClure S.F., Moses T., Douthit T.R., Hughes R., Novak S., Shigley J.E., Wang W., Bordelon O., Kane R.E. (2003) Beryllium diffusion of ruby and sapphire. G&G, Vol. 39, No. 2, pp. 84–135, http://dx.doi.org/10.5741/GEMS.39.2.84

Emmett J.L., Stone-Sundberg J., Guan Y.B., Sun Z.Y. (2017) The role of silicon in the color of gem corundum. G&G, Vol. 53, No. 1, pp. 42–47, http://dx.doi.org/10.5741/GEMS.53.1.42

Epstein D.S., Brennan W., Mendes J.C. (1994) The Indaia sapphire deposits of Minas Gerais, Brazil. G&G, Vol. 30, No. 1, pp. 24–32, http://dx.doi.org/10.5741/GEMS.30.1.24

Farges F., Panczer G., Benbalagh N., Riondet G. (2015) The Grand Sapphire of Louis XIV and the Ruspoli sapphire: Historical and gemological discoveries. G&G, Vol. 51, No. 4, pp. 392–409, http://dx.doi.org/10.5741/GEMS.51.4.392

Gübelin E.J. (1942) Local peculiarities of sapphires; Part 1, 2 and 3. G&G, Vol. 4, No. 3, pp. 34–39, No. 4, pp. 50–54 and No. 5, pp. 66–69.

——— (1944) Gemstone inclusions – Sapphire. G&G, Vol. 4, No. 10, pp. 142 –149.

Guo J.F., Wang F.Q., Yakoumelos G. (1992) Sapphires from Changle in Shandong Province, China. G&G, Vol. 28, No. 4, pp. 255–260, http://dx.doi.org/10.5741/GEMS.28.4.255

Holmes R.J. (1947) The new Linde Stars: Man–made star rubies and star sapphires. G&G, Vol. 5, No. 11, pp. 452–456 and 478–479.

Johnson M.L., Mercer M.E., Fritsch E., Maddison P., Shigley J.E. (1995) Ti–sapphire: Czochralski–pulled synthetic pink sapphire from Union Carbide. G&G, Vol. 31, No. 3, pp. 188–195, http://dx.doi.org/10.5741/GEMS.31.3.188

Kane R.E. (1982) The gemological properties of Chatham flux–grown synthetic orange sapphire and synthetic blue sapphire. G&G, Vol. 18, No. 3, pp. 140–153, http://dx.doi.org/10.5741/GEMS.18.3.140

——— (1985) A preliminary report on the new Lechleitner synthetic ruby and synthetic blue sapphire. G&G, Vol. 21, No. 1, pp. 35–39, http://dx.doi.org/10.5741/GEMS.21.1.35

Kane R.E., Kammerling R.C. (1992) Status of ruby and sapphire mining in the Mogok Stone Tract. G&G, Vol. 28, No. 3, pp. 152–174, http://dx.doi.org/10.5741/GEMS.28.3.152

Kane R.E., Kammerling R.C., Koivula J.I., Shigley J.E., Fritsch E. (1990) The identification of blue diffusion–treated sapphires. G&G, Vol. 26, No. 2, pp. 115–133, http://dx.doi.org/10.5741/GEMS.26.2.115

Kane R.E., McClure S.F., Kammerling R.C., Khoa N.D., Mora C., Repetto S., Khai N.D., Koivula J.I. (1991) Rubies and fancy sapphires from Vietnam. G&G, Vol. 27, No. 3, pp. 136–155, http://dx.doi.org/10.5741/GEMS.27.3.136

Kan–Nyunt H.P., Karampelas S., Link K., Thu K., Kiefert L., Hardy P. (2013) Blue sapphires from the Baw Mar Mine in Mogok. G&G, Vol. 49, No. 4, pp. 223–232, http://dx.doi.org/10.5741/GEMS.49.4.223

Keller A.S., Keller P.C. (1986) The sapphires of Mingxi, Fujian Province, China. G&G, Vol. 22, No. 1, pp. 41–45, http://dx.doi.org/10.5741/GEMS.22.1.41

Keller P.C. (1982) The Chanthaburi–Trat gem field, Thailand. G&G, Vol. 18, No. 4, pp. 186–196, http://dx.doi.org/10.5741/GEMS.18.4.186

Keller P.C., Koivula J.I., Jara G. (1985) Sapphire from the Mercaderes–Río Mayo area, Cauca, Colombia. G&G, Vol. 21, No. 1, pp. 20–25, http://dx.doi.org/10.5741/GEMS.21.1.20

Kissin A.J. (1994) Ruby and sapphire from the Southern Ural Mountains, Russia. G&G, Vol. 30, No. 4, pp. 243–252, http://dx.doi.org/10.5741/GEMS.30.4.243

Koivula J.I. (1986) Carbon dioxide fluid inclusions as proof of natural–colored corundum. G&G, Vol. 22, No. 3, pp. 152–155, http://dx.doi.org/10.5741/GEMS.22.3.152

Krzemnicki M.S., Hänni H.A., Walters R.A. (2004) A new method for detecting Be diffusion–treated sapphires: Laser–induced breakdown spectroscopy (LIBS). G&G, Vol. 40, No. 4, pp. 314–322, http://dx.doi.org/10.5741/GEMS.40.4.314

Levinson A.A., Cook F.A. (1994) Gem corundum in alkali basalt: Origin and occurrence. G&G, Vol. 30, No. 4, pp. 253–262, http://dx.doi.org/10.5741/GEMS.30.4.253

Mychaluk K.A. (1995) The Yogo sapphire deposit. G&G, Vol. 31, No. 1, pp. 28–41, http://dx.doi.org/10.5741/GEMS.31.1.28

Nassau K. (1981) Heat treating ruby and sapphire: Technical aspects. G&G, Vol. 17, No. 3, pp. 121–131, http://dx.doi.org/10.5741/GEMS.17.3.121

Nassau K., Valente G.K. (1987) The seven types of yellow sapphire and their stability to light. G&G, Vol. 23, No. 4, pp. 222–231, http://dx.doi.org/10.5741/GEMS.23.4.222

Pham V.L., Pardieu V., Giuliani G. (2013) Update on gemstone mining in Luc Yen, Vietnam. G&G, Vol. 49, No. 4, pp. 233–245, http://dx.doi.org/10.5741/GEMS.49.4.233

Schmetzer K., Medenbach O. (1988) Examination of three–phase inclusions in colorless, yellow, and blue sapphires from Sri Lanka. G&G, Vol. 24, No. 2, pp. 107–111, http://dx.doi.org/10.5741/GEMS.24.2.107

Schmetzer K., Peretti A. (1999) Some diagnostic features of Russian hydrothermal synthetic rubies and sapphires. G&G, Vol. 35, No. 1, pp. 17–28, http://dx.doi.org/10.5741/GEMS.35.1.17

Schmetzer K., Steinbach M.P., Gilg H.A., Blake A.R. (2015) Dual–color double stars in ruby, sapphire and quartz: Cause and historical account. G&G, Vol. 51, No. 2, pp. 112–143, http://dx.doi.org/10.5741/GEMS.51.2.112

Schwarz D., Kanis J., Schmetzer K. (2000) Sapphires from Antsiranana Province, northern Madagascar. G&G, Vol. 36, No. 3, pp. 216–233, http://dx.doi.org/10.5741/GEMS.36.3.216

Schwarz D., Pardieu V., Saul J.M., Schmetzer K., Laurs B.M., Giuliani G., Klemm L., Malsy A.K., Erel E., Hauzenberger C., Du Toit G., Fallick A.E., Ohnenstetter D. (2008) Rubies and sapphires from Winza, central Tanzania. G&G, Vol. 44, No. 4, pp. 322–347, http://dx.doi.org/10.5741/GEMS.44.4.322

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Sorokina E.S., Litvinenko A.K., Hofmeister W., Hager T., Jacob D.E., Nasriddinov Z.Z. (2015) Rubies and sapphires from Snezhnoe, Tajikistan. G&G, Vol. 51, No. 2, pp. 160–175, http://dx.doi.org/10.5741/GEMS. http://dx.doi.org/10.5741/GEMS.51.2.160

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Zwaan J.C., Buter E., Mertz–Kraus R., Kane R.E. (2015) Alluvial sapphires from Montana: Inclusions, geochemistry and indications of a metasomatic origin. G&G, Vol. 51, No. 4, pp. 370–391, http://dx.doi.org/10.5741/GEMS.51.4.370 @chapter:16 @chapter:0 @chapter:16


# Publication Year: 2021
# Title: Expanded Diamond Surface Due to Radiation Staining
# Abstract: Figure 1. Dark green radiation stains on a natural diamond surface. This is a partially faceted diamond with some of its natural surface bounded by laser markings, seen as dark lines in the image. Photomicrograph by Nathan Renfro; field of view 2.24 mm.

The author examined a 0.56 ct Fancy grayish bluish green diamond with prominent green radiation stains. Studies have shown that radiation can cause staining that expands the surface of a diamond (L. Nasdala et al., “Radio-colouration of diamond: A spectroscopic study,” Contributions to Mineralogy and Petrology, Vol. 165, 2013, pp. 843–861; S.C. Eaton-Magaña and K.S. Moe, “Temperature effects on radiation stains in natural diamonds,” Diamond and Related Materials, Vol. 64, 2016, pp. 130–142). This can create a noticeable bump that is visible in the microscope. The effect in this diamond is so pronounced that the radiation stains appear encased in a protective plastic bubble. This expansion effect is believed to be caused by the radiation damage creating an expansion in the diamond lattice (Nasdala et al., 2013).

Figure 2. The radiation stains on a natural surface in reflected light, which highlights the smooth texture of the stained and expanded areas. Photomicrograph by Nathan Renfro; field of view 2.24 mm.
When viewed with transmitted light (figure 1), the raised lattice can be seen extending beyond the dimensions of the stain itself. The green-colored stains are very dark. Using reflected light (figure 2), the difference between surface textures is apparent. The surface that has been damaged and expanded by the radiation staining has a much smoother texture than the unaltered diamond surface. It is unknown why this diamond lattice was so distorted compared to typical radiation stains; they showed no unusual spectroscopic features that might provide a clue as to their formation. @chapter:29 @chapter:1 @chapter:29


# Publication Year: 2018
# Title: 15 Carat HPHT Synthetic Diamond
# Abstract: Figure 1. This 15.32 ct cushion modified brilliant, with grades equivalent to H color and I1 clarity, is the largest HPHT synthetic diamond graded by GIA. Photo by Robison McMurtry.

The Carlsbad laboratory recently examined an HPHT synthetic diamond that is now the largest faceted lab-grown diamond examined by GIA. The specimen was a cushion modified brilliant weighing 15.32 ct, with grades equivalent to I1 clarity and H color (figure 1). The largest previously reported fully faceted synthetic diamonds were a 10.02 ct emerald-cut HPHT-grown (equivalent to E-color; Summer 2016 Lab Notes, pp. 195–196) and a 10.08 ct emerald-cut HPHT-grown diamond (equivalent to Fancy Deep blue; Winter 2016 Lab Notes, p. 416). The 15.32 ct synthetic contained large metallic flux inclusions (figure 2) as well as numerous fractures. Examination under crossed polarizers revealed no strain patterns, except for small strain fields around the metallic flux inclusions.

Figure 2. The metallic flux inclusions present in the synthetic diamond. Several rod-shaped structures can be seen, as well as an inclusion with a trapezoidal shape. Photomicrograph by Jonathan Muyal; field of view 4.79 mm.

Figure 3. Left: This DiamondView fluorescence image of the HPHT-grown diamond’s pavilion shows a combination of apparent layered growth, along with the more common cross-pattern morphology seen in HPHT synthetics. The area of the pavilion shown here also indicates the region of PL mapping. The red arrow indicates the regions that showed a high concentration of nickel, silicon, and NV center defects compared to the remainder of the mapped region. Above this more heavily doped layer is the metal rod inclusion also seen in figure 2. Right: The patterning in the corresponding phosphorescence image closely resembles the fluorescence image. A thin layer of material showing orange (~580 nm) phosphorescence is indicated by the white arrow.
The infrared absorption spectrum showed no detectable boron or nitrogen, indicating that the sample was type IIa. DiamondView imaging did reveal blue phosphorescence, which is characteristic of boron impurities (figure 3, right), but any boron present was below the detection level of the FTIR spectrometer. Photoluminescence (PL) spectroscopy taken with the 514 nm laser revealed the presence of the negative silicon vacancy defect at 737 nm; the neutral nitrogen-vacancy center was also seen at 575 nm. The nickel-related doublet at 882/884 nm was seen in the 830 nm PL spectrum. Energy-dispersive X-ray fluorescence (EDXRF) revealed the presence of iron and cobalt which, together with the nickel feature in the PL, gives insight into the flux mixture used to grow this specimen.
Due to their growth method, HPHT synthetics generally show very distinct growth patterns when examined in the DiamondView. While they can show dramatic differences in fluorescence color, these are generally seen within angular zones that radiate from the center and extend through the volume of the specimen. In contrast, CVD synthetic diamonds are grown as layers. The start/stop events of the CVD reactor result in distinct changes in diamond chemistry that are visible in DiamondView fluorescence images; the changes in fluorescence color are usually parallel due to the layered growth. Therefore, it was quite interesting to see DiamondView fluorescence patterns in which the pavilion section toward the culet far more closely resembles the layers seen in CVD growth than the cross-pattern color zoning often seen in HPHT synthetics (figure 3, left). The fluorescence zoning commonly found in HPHT-grown material can be seen towards the girdle section of this sample. PL mapping at liquid nitrogen temperatures was used to verify the DiamondView observations and detect the distribution of defects through the synthetic diamond (for more on the PL mapping collection technique see L.C. Loudin, “Photoluminescence mapping of optical defects in HPHT synthetic diamond,” Summer 2017 G&G, pp. 180–189). We mapped the PL spectra of the region shown in figure 31 using 532, 633, and 785 nm laser excitations. One of the layers (red arrow in figure 3) in particular showed greatly elevated concentrations of nickel (as the 883/884 nm doublet; average concentration in this area was 5× greater than the average intensity of the doublet in other portions of the mapped pavilion), silicon (as the SiV– defect at 737 nm; 10× greater), and NV centers (NV0 at 575 nm [2× greater] and NV– at 637 nm [2.5× greater]). This particular layer also showed orange phosphorescence in the DiamondView, assumed to be centered at approximately 580 nm (U.F.S. D’Haenens-Johansson et al., “Large colorless HPHT synthetic diamonds from New Diamond Technology,” Fall 2015 G&G, pp. 260–279), in addition to the more common blue phosphorescence.
The specific growth process that creates the apparent layers in this HPHT synthetic is unknown, but it may be a necessary condition to grow synthetic material in such large sizes. The manufacturer may use successively larger seeds in separate growth runs or alter the pressure or temperature conditions within a single growth experiment. It should be noted that this growth feature, while layered in appearance, is quite different from CVD growth layers, which have sharp boundaries and are often differently colored. The chemistry collected on the layered portion was consistent with HPHT growth and not CVD growth; the chemistry was also consistent between the layered portion and the cross-patterned portion of growth. Therefore, a CVD seed was not used to grow this specimen. Similar layers were observed in the DiamondView images of the 10.08 ct blue HPHT synthetic (unpublished data). However, the size of this most current specimen demonstrates that the growth technologies and processes are continuing to improve and continuing to impress. @chapter:9 @chapter:1 @chapter:9


# Publication Year: 2021
# Title: Chromite in Emerald
# Abstract: A Brazilian emerald with green color zoning and strong graining surrounding clusters of chromite. Photomicrograph by Nicole Ahline; field of view 1.58 mm.

The beryl species is known for its different colored varieties, such as pink morganite and blue aquamarine, which are directly influenced by the chemical composition of the stone. The emerald variety is colored green by the trace elements chromium and/or vanadium. Beryl, a beryllium aluminum cyclosilicate, has a crystal structure that readily integrates foreign elements. When an elevated amount of chromium is present in the growth environment, a beryl crystal has a chance of becoming an emerald. One inclusion that has been well documented in emeralds is the mineral chromite, an iron chromium oxide. Specifically, this mineral is a source of chromium for some Brazilian emeralds.
The author recently examined a matching jewelry set consisting of a bracelet and ring that were decorated with emeralds from Brazil. Each stone exhibited a unique concentration of color when viewed through diffused lighting. Compared to the angular or linear color zoning generally seen in emeralds, each of these stones displayed an irregular, circular green zone with strong graining. The color zoning correlated with crystallites of chromite (see above). During the emerald’s crystallization, chromite from the growth environment was incorporated into the stone as an inclusion. A chemical alteration along the interface of the chromite and the beryl occurred due to the presence of chromium from the crystallites. The altered chemistry of the beryl led to the green bodycolor adjacent to the chromite crystals. The strong graining is the result of the difference in refractive index in the green-colored area from the elevated chromium in contrast to the host beryl.
While chromite is regularly seen in emeralds from Brazil, it is not common to see such a strong correlation of color with the mineral inclusion. @chapter:10 @chapter:0 @chapter:10


# Publication Year: 1999
# Title: Winter 1999 G&G Lab Notes
# Abstract: Beryl with Unusual Eye
Diamond Exhibiting Much Fire
Identifying Treated-Color Rough Diamond with the Spectroscope
Yellow to Yellow-Green Diamonds Treated by HPHT
Freshwater Natural Pearls
Notable Strand of Large Black Cultured Pearls
Sapphire with a Valuable Inclusion
Sapphire with High Refractive Indices

To view the full section, download the PDF above. @chapter:18 @chapter:1 @chapter:18


# Publication Year: 2023
# Title: Exceptionally Large Synthetic Rutile
# Abstract: Figure 1. Three large synthetic rutile brilliants weighing 11.13, 110.18, and 11.91 ct. Photo by Robert Weldon; courtesy of Arya Akhavan.
The Carlsbad laboratory received three light yellow modified round brilliants weighing 11.13, 11.91, and 110.18 ct (figure 1) for identification reports. Standard gemological testing revealed the stones to be synthetic rutile based on over-the-limit refractive index readings and extreme fire and doubling, an identification that was supported by Raman spectroscopy.
Of particular note was the astonishing size of these stones. The 110.18 ct synthetic rutile is the largest encountered in the GIA laboratory. Even the smaller 11.13 ct and 11.91 ct stones are much larger than normal for this material, which is usually seen in sizes up to several carats. The owner of the stones indicated that the manufacturer had to modify their furnace to accommodate growth of the 110.18 ct crystal. Also notable were the novel facet pattern and precision cutting usually only seen in the high-end collector market.

Figure 2. UV-Vis-NIR absorption spectra comparing the 110.18 ct and 11.13 ct synthetic rutile studied, here demonstrating the effect of aluminum doping in the smaller stone to produce a nearly colorless appearance.
Interestingly, the two smaller stones had a much lighter yellow color than the 110.18 ct stone, which was notable even considering the shorter light path length through the smaller stones. Chemical analysis using laser ablation–inductively coupled plasma–mass spectrometry showed a higher concentration of aluminum in these two samples (~80 ppm Al compared to ~3 ppm). The difference in color was also demonstrated in the ultraviolet/visible/near-infrared absorption spectra (figure 2). This finding aligns with the practice of growing rutile doped with small amounts of aluminum to bring the appearance of the material closer to nearly colorless (C.H. Moore, “Rutile boule and method of making the same,” U.S. Patent 2,715,070, issued August 9, 1955). Additionally, the owner indicated that the two smaller rutile crystals were grown by National Lead Co. between 1961 and 1964, while the larger stone is from a modern producer. @chapter:24 @chapter:0 @chapter:24


# Publication Year: 2017
# Title: Atypical Bead-Cultured Pearls with Unusual Nacre Growth
# Abstract: Figure 1. The 10 loose pearls submitted for identification. Samples 1, 4, and 5 are conventional bead-cultured pearls, while the rest were cultured with atypical nuclei. Photo by Sood Oil (Judy) Chia, courtesy of Aloha Pearls.

Atypical bead-cultured pearls are, by definition, cultured with unconventional beads as opposed to the typical round, predominantly freshwater shell beads. Examples of such atypical bead nuclei are irregularly shaped pieces of shell, ceramic, plastic, wax, coral beads, or even cultured or natural pearls.

Recently, GIA’s New York laboratory received 10 loose undrilled pearls for identification. These samples exhibited a brownish bodycolor and measured from 7.17 × 6.92 × 6.42 mm to 12.25 × 9.72 × 9.28 mm (figure 1). Many were unusually lightweight for their size. Microradiographic examination of seven of the pearls revealed atypical bead nuclei (figure 2). The X-ray transparencies of the bead nuclei allowed us to observe faint demarcations and drill holes with varying degrees of clarity in the nuclei.

Figure 2. Microradiographs of seven pearls revealed atypical beads that were transparent to X-rays. The beads showed faint demarcations and drill holes of varying clarity. Unusual nacre growth that partially filled the drill hole of the bead of one pearl is seen in image C.
These atypical bead nuclei permitted some unusual nacre growth to develop within the drill holes, as shown in figure 2C, where the nacre secretion flows into the drill hole. This interesting observation concerning nacre viscosity was also described in recent work on atypical bead culturing experiments (K. Scarratt et al., “Atypical ‘beading’ in the production of cultured pearls from Australian Pinctada maxima,” GIA Research & News, Feb. 13, 2017).

To better visualize the unusual nacre growth within the drill hole of the bead in one of the pearls, we used computed X-ray microtomography (μ-CT) and subsequently reconstructed the pearl using computer software (figure 3). The reconstructed image displayed a surface indentation aligned with the bead’s drill hole (shown in orange in figure 3, left). Additional nacre growth (shown in green, figure 3, right) filled about half of the drill hole. The yellowish outer region in figure 3 (left) represents the outer nacre of the pearl.

Figure 3. Left: A computed 3-D reconstruction of one of the atypical bead-cultured pearls. The orange area represents the transparent bead revealed by X-rays, with a drill hole partially filled by nacre growth shown by the whitish area (indicated by the arrow). A surface indentation toward the top also corresponds to the orientation of the bead’s drill hole. Right: Reconstruction of the internal bead only. The central pink area is the drill hole inside the bead nucleus. The green area represents the nacre growth that formed inside the drill hole. Photos by Emiko Yawaza.
Although this is not the first time GIA has received pearls cultured using X-ray transparent bead nuclei (Fall 2011 Lab Notes, pp. 229–230), the unusual nacre growth pattern within some of the drill holes in this sample group is worthy of note. Three-dimensional rendering using computer software and μ-CT data sets also proved very useful in visualizing the internal structure, further demonstrating the technique’s worth as a powerful tool in pearl identification. @chapter:11 @chapter:4 @chapter:11


# Publication Year: 2018
# Title: Fortieth Anniversary of the Belmont Mine
# Abstract: Figure 1. This 13 ct emerald represents some of the finest production material from Belmont’s underground tunnel. Photo by Kevin Schumacher.

This year marks the 40th anniversary of the Belmont emerald mine. Director Marcelo Ribeiro updated us on mining and cutting activities in Brazil and shared his thoughts on today’s dynamically changing market.

As in 2017, mining activities are still focused on underground mining below the original Belmont open-pit site and the newly developed Canaan mine about 2 km away. In the near term, underground mining will continue to dominate emerald production. Ribeiro shared some new geological study findings related to multiple deposits in the Belmont area. Detailed geological analysis proved that over the past 40 years, only about one-fifth of the deposit within the Belmont property has been mined. Some exciting mineralogical study results from a mining site nearby hint at even deeper extension of the emerald-bearing rocks. Belmont has better wall rock stability than some other famous emerald sources around the globe. This makes underground mining an ideal option in the foreseeable future.

Updates from the Belmont Mine
Marcelo Ribeiro, director of Brazil’s Belmont mine, talks about new developments at the site.
Currently, all rough emerald with a value of more than $20 per carat is faceted by Belmont’s own cutters, while everything else is transported to Jaipur, India, for processing. The cutting facility at the Belmont mine now handles 1,500 to 2,000 carats of emerald per month. Ribeiro visited the factories in Jaipur in late 2017 and is very satisfied with the quality of goods produced from the rough he exports to India. In terms of adding value to the medium- to low-quality rough stones, cutters in Jaipur have more experience and expertise. According to Ribeiro, the company’s sales jumped about 15% each of the past three years. A 13 ct top-quality emerald recovered in 2017 from the underground mine at the original site (figure 1) and a 15.01 ct stone from the Canaan mine (figure 2) were brought in by Ribeiro. The stone from Canaan showed a very special color reminiscent of the electric bluish green color of some copper-bearing tourmalines. This stone also displayed quite strong green and blue pleochroism. Ribeiro informed us that this is a very rare color and only a very limited amount of rough can potentially produce stones of this color.

Figure 2. This 15.01 ct emerald from the Canaan mine had an unusual color, and many customers at the show thought it was a Paraíba tourmaline. Photo by Kevin Schumacher.
Belmont has exhibited in Tucson for the past 17 years, and Ribeiro pointed out that the way of doing business has changed dramatically in recent years. The booth at the GJX show once generated about 80% of the company’s sales. Now, 80% of the sales happen online. Ribeiro used to stay at the booth to sell stones, but nowadays he needs to spend most of his time walking around the show to talk to different people. When asked about the role of middlemen in the current and future marketplace, Ribeiro shared his opinion. When he first got into the trade, he envisioned that one day middlemen would be removed from the picture and he would market his stones directly to end consumers. With the industry experiencing dramatic changes these days, he has started to feel that middlemen will remain but must change their mindset to adapt to new ways of doing business.

The State of the Emerald Industry
Marcelo Ribeiro talks about how the emerald business has changed over the years he has exhibited at Tucson.
The logistics network within the United States allows very fast, safe, and economically viable transportation of gemstones between dealers and jewelers. Overseas suppliers like Belmont do not have access to the same services, which makes it necessary to have an intermediary located in the States who can handle shipping, receiving, and securing stones between the supplier and the buyers. This person also works as a sales representative to connect the supplier and the buyers. Ribeiro pointed out that unlike the traditional middleman, this person does not do business by trying to hide the supplier from the buyers and vice versa. In fact, this representative should ideally make the supply chain even more transparent by letting the two ends easily see and connect with each other to build more solid trust, connections, and inventory in between.

For the past 40 years, the Belmont mine has practiced community building and empowered people through gemstone mining. Ribeiro feels that this is already embedded in the DNA of the company and will continue to guide their good work. He hopes that gemstone purchasing will remind younger buyers of the benefits these stones bring to the local people and their next generation. @chapter:17 @chapter:0 @chapter:17


# Publication Year: -
# Title: Turquoise Description
# Abstract: This 18-karat gold collar, designed by Pierre Touraine, is set with a turquoise cabochon of fine texture and color. - Gift of Touraine Family Trust

                      Turquoise is found in only a few places on earth: dry and barren regions where acidic, copper-rich groundwater seeps downward and reacts with minerals that contain phosphorus and aluminum. The result of this sedimentary process is a porous, semitranslucent to opaque compound of hydrated copper and aluminum phosphate.
Turquoise is a prime example of an opaque colored stone that can be marketed both as a gem for jewelry and as an ornamental material.

	The Abdurreza turquoise mine lies in a dry, remote area of Iran.
Turquoise might lack the sparkle and clarity of transparent colored gemstones like ruby, emerald, and sapphire, but its multi-layered history and soul-satisfying color make it a desirable gem. Its color can range from dull greens to grass greens to a bright, medium-toned, sky blue. People value turquoise highly for its combination of ancient heritage and unforgettable color.

The traditional source for the top color, sometimes described as robin’s-egg blue or sky blue, is the Nishapur district of Iran, the country formerly known as Persia. So, quite often, you’ll hear people in the trade call turquoise of this beautiful color “Persian blue,” whether or not it was actually mined in Iran.

Top-quality turquoise has inspired designers to create elegant jewelry. It’s most often cut into cabochons, but it might also be cut into beads or flat pieces for inlays.

Although much turquoise jewelry is sleek and modern, many US consumers are familiar with the traditional jewelry of Native American peoples such as the Pueblo, Hopi, Zuni, and Navajo. People interested in Native American arts and crafts frequently collect this stylized silver jewelry.

	Elaborate silver and turquoise squash blossom necklaces like this are prized by collectors
	of Native American jewelry. - Courtesy Jaime Steelman
Turquoise is relatively soft, so it’s ideal for carving. Artists in Europe, Asia, the Middle East, and the Americas choose turquoise as a medium for carved jewelry and art objects. It’s often fashioned into talismans with Native American significance, such as bird and animal carvings, called fetishes.

	Native American jewelry often features carved turquoise birds and animals, called fetishes.
	- Courtesy Jaime Steelman
Turquoise owes its texture to its structure and composition. It’s an aggregate of microscopic crystals that form a solid mass. If the crystals are packed closely together, the material is less porous, so it has a finer texture. Fine-textured turquoise has an attractive, waxy luster when it’s polished. Turquoise with a less-dense crystal structure has higher porosity and coarser texture, resulting in a dull luster when it’s polished.

	Turquoise is soft enough to be carved. This turquoise from China was crafted into an
	ornate vase. – Courtesy Geological Museum, Beijing, China
Porosity and texture don’t just affect appearance: They also affect durability. Turquoise is fairly soft—it ranks 5 to 6 on the Mohs scale. Turquoise with a coarse texture might have poor toughness, too. Samples with finer texture have fair to good toughness.

	This Van Cleef & Arpels ballerina brooch and matching clip earrings are designed with gold, diamonds, turquoise, and ruby. - © GIA & Tino Hammid, courtesy private collector
In turquoise, low porosity and fine texture are more valuable than high porosity and coarse texture. Coarse, porous stones are usually treated to make them smoother, shinier, and more marketable.

	The smooth, waxy luster of these turquoise earrings results from closely grouped crystals that lessen porosity. - Courtesy GLEAM
Turquoise deposits usually form in iron-rich limonite or sandstone. Limonite creates dark brown markings in turquoise, while sandstone creates tan markings. These markings are remnants of the host rock within the turquoise, and can resemble splotches or veins. They’re called matrix.

	Turquoise is generally embedded in its host rock, like this specimen from Iran.
Manufacturers try to fashion turquoise so that no matrix is visible, but sometimes it’s unavoidable. Small amounts of turquoise might be scattered through the host rock in such a way that the rough material can’t yield any cut specimens large enough to fashion into gems without including some matrix.

	The matrix in spiderweb turquoise is attractively arranged in a network of thin lines.
The presence of matrix can lower the value of turquoise, but that doesn’t mean turquoise with matrix is worthless or unmarketable. Some buyers actually prefer the presence of matrix in fashioned turquoise if its effect is attractive and balanced.

This is especially true if it’s a type of turquoise known in the trade as spiderweb turquoise. It contains matrix in thin, delicate, web-like patterns across the face of the gemstone. The patterns provide a dark contrast to the gem’s bright blue.

In the market for top-quality turquoise, stones with no matrix at all command the highest prices. Gems with attractive spiderweb matrix rank second in value. @chapter:31 @chapter:2 @chapter:31


# Publication Year: 2022
# Title: Acicular Troughs Coincident with Green Stains on Rough Diamond Surface
# Abstract: Figure 1. A ~0.12 ct green-skinned diamond from Guyana. Photo by Roy Bassoo.
The author acquired an alluvial rough diamond from Guyana showing unique surficial features that do not appear to have been documented elsewhere. The specimen was a twinned crystal consisting of two intergrown octahedral crystals, ~0.12 ct in weight, with numerous flat-bottomed hexagonal etch features and trigons and a nearly pervasive green skin (figure 1). Most interesting were fine, linear, and randomly oriented features on the diamond surface that were spatially associated with the green stains (figure 2). Radiation stains are known to cause localized expansion in diamond (L. Nasdala et al., “Radio-coloration of diamond: A spectroscopic study,” Contributions to Mineralogy and Petrology, Vol. 165, 2013, pp. 843–861; S.C. Eaton-Magaña and K.S. Moe, “Temperature effects on radiation stains in natural diamonds,” Diamond and Related Materials, Vol. 64, 2016, pp. 130–142). These features also cross-cut trigons, implying that they post-date the diamond’s growth in the earth’s mantle and its surface dissolution within the kimberlite magma (figure 3). These features may be the result of localized dissolution caused by proximal acicular, radioactive, and as yet unknown minerals, leaving behind a cast impression. Green color in diamond can be produced by natural irradiation of the crystal lattice by exposure to radiation from proximal and adjacent radioactive grains (e.g., zircon, monzonite, uraninite, and K-feldspar) or salts dissolved in percolating fluids surrounding the diamond (C.M. Breeding et al., “Natural-color green diamonds: A beautiful conundrum,” Spring 2018 G&G, pp. 2–27). Gamma, alpha, or beta radiation emanating from these sources are thought to cause collections of defects and impurities within the diamond. Gamma and beta radiation have low energies and long penetration depths producing green bodycolors. Due to its high energy, alpha radiation has the shortest penetration depth and only within the first 25 μm of the diamond surface, creating green skins, stains, and spots.

Figure 2. Left: A magnified view of green radiation stains on an unpolished diamond surface in transmitted light. Right: An image of the same surface in reflected light with the radiation staining (outlined in red) and preserved acicular troughs. Photomicrographs by Roy Bassoo; field of view 0.5 mm.

Figure 3. A further magnified view of the green radiation stains on an unpolished diamond surface in transmitted light (left) and an image of the same surface in reflected light with the radiation staining outlined in red and preserved acicular troughs which cross-cut a flat-bottomed trigon (right). Photomicrographs by Roy Bassoo; field of view 0.25 mm.
Although unusual, radiation-related surface features have been previously documented (e.g., Spring 2021 G&G Micro-World, pp. 66–67). The ones seen in this diamond from Guyana appear to be unique, however. It is quite likely that these features are pervasive in placer diamonds but have not been studied in detail. @chapter:52 @chapter:1 @chapter:52


# Publication Year: 2023
# Title: Triplite Inclusions in Quartz from Yaogangxian, China
# Abstract: Figure 1. A 30.80 ct faceted quartz containing pinkish orange inclusions. Photo by Hongtao Shen; courtesy of Jinrui Dong.
Quartz is host to a wide variety of inclusions. Recently, the authors examined a 30.80 ct transparent faceted quartz with several pinkish orange crystal inclusions, from the town of Yaogangxian in Hunan Province, China (figure 1). This quartz was cut from a rough stone collected by a local miner. In this quartz, the pinkish orange inclusions were unique and attractive.

Figure 2. Magnification of pinkish orange triplite in a transparent quartz from Yaogangxian in Hunan Province, China. Photomicrograph by Hongtao Shen; field of view 11.15 mm.
After grinding, one of these inclusions was exposed to the surface (figure 2). Raman spectroscopy and energy-dispersive X-ray fluorescence were used to identify the inclusion as triplite.
Triplite, (Mn2+,Fe2+)2PO4(F,OH), is a rare phosphate mineral that can be found as either a gem material or an inclusion. Most triplites are produced in pegmatite, as with quartz. Triplite inclusions have been reported in topaz (Summer 2016 G&G Micro-World, p. 205) and beryl (Spring 2020 G&G Micro-World, p. 145). To the best of our knowledge, this is the first discovery of triplite as an inclusion in quartz. @chapter:15 @chapter:0 @chapter:15


# Publication Year: -
# Title: Aquamarine Quality Factors
# Abstract: This 3.74-ct. princess-cut aquamarine’s prized medium-blue color is highlighted by the 22 diamonds that surround it. The ring is an original, copyrighted design by Zoltan David. - Robert Weldon, courtesy of Nancy's Collection

                      In the commercial market, aquamarine competes with treated blue topaz for attention, but fine aquamarine sells for far more than equivalent-quality treated blue topaz.

Color
Aquamarine’s color range is very narrow: It can be blue, very slightly greenish blue, greenish blue, very strongly greenish blue, or green-blue. The gem’s most valuable color is a dark blue to slightly greenish blue with moderately strong intensity. In general, the purer and more intense the blue color, the more valuable the stone. Most aquamarine is a light greenish blue.

	This superb 32.10-carat heart-shaped Brazilian aquamarine shows the gem's finest color, a moderately strong, medium-dark, very slightly greenish blue. - Courtesy M.Chung Gemstones and Fine Jewelry Co.
Although some buyers prefer the more greenish natural color, most of the aquamarine in the market was heat-treated to give it more of a pure blue.

Fashioned aquamarines often have to be fairly large—generally over 5 carats—to show intense, dark color. Although small gems are rarely saturated enough to be attractive, stones from some mines in Africa—Nigeria, Madagascar, and Mozambique, for example—are known for intense color in sizes under 5 carats. For this reason, smaller, top-color stones might sell for more per carat than larger stones of the same color.

Clarity
Most faceted aquamarines are eye-clean. Some crystals might contain liquid inclusions, but clarity characteristics are few or absent in most finished gems. Stones with eye-visible inclusions are usually fashioned into cabochons, beads, or carvings.

	Carvings are popular for translucent to opaque aquamarine. - Courtesy Neoart Peru

	Faceted aquamarine usually has no eye-visible inclusions. - Courtesy Dudley Blauwet
In some beryl crystals, there are enough parallel inclusions—usually long hollow or liquid-filled tubes—to allow cutters to fashion the rough to show a cat’s-eye.

	This very greenish aquamarine cabochon has enough parallel inclusions to display a cat’s-eye.
Cut
Aquamarines can be cut into almost any shape, but cutters often fashion them as emerald cuts or as round or oval brilliants. The rough is fairly plentiful, so well-cut stones are fairly common. The gemstone’s hardness and transparency make it popular with designers, artists, and carvers. Gem sculptors use aquamarine for fantasy cuts and ornamental objects.

	Aquamarine can be cut in a variety of standard shapes.

	Emerald cuts are among the common aquamarine cutting styles. - Courtesy ICA
The gem is pleochroic, which means it shows different colors in different crystal directions—in the case of aquamarine, they’re near-colorless and strong blue. Fortunately, the blue pleochroic color corresponds with the cutting orientation that retains the most weight, with the table facet aligned parallel to the length of the crystal.

	Aquamarine is a great medium for artistic designer cuts like this 10.37-carat beauty. - Lydia Dyer, gem courtesy John Dyer & Co.

	Aquamarine that’s too included for faceting is often carved and set into designer jewelry. - © GIA and Tino Hammid
Carat Weight
Aquamarine crystals come in sizes from very small to very large—some even up to 100 lbs. (45 kg). While large stones are readily available, it’s difficult to use them in jewelry, so there’s less demand for them, except as center stones. As a result, per-carat prices tend to decrease for sizes above 25 carats.

Many very large aquamarine crystals have been discovered. The largest Brazilian aquamarine on record was found in 1910, in Minas Gerais, Brazil. It weighed 244 lbs. (110 kg) and measured 19 in. (48 cm) long and 15 in. (38 cm) in diameter. @chapter:16 @chapter:0 @chapter:16


# Publication Year: 2016
# Title: Book Review: Gems & Crystals: From One of the World’s Great Collections
# Abstract: By George E. Harlow and Anna S. Sofianides, with photography by Erica and Harold Van Pelt, hardcover, 232 pp., illus., rev. edition publ. by the American Museum of Natural History with Sterling Publishing, New York, 2015, US$27.95.

	This volume is a pleasing combination of coffee-table book, reference book, and guide to a museum collection. It is the 25th anniversary revised edition of the authors’ Gems and Crystals: From the American Museum of Natural History (1990). There is a certain sense of continuity conveyed by having the same authors still working in the field adding to the collection and knowledge base.

	The introduction details the notable acquisitions, sponsors, and curators over the years. It all started with the collection assembled by George Frederick Kunz in 1889, financed by John Pierpont Morgan. The department was expanded in the 1970s and renamed the Department of Mineral Science, and in 1995 it became the Department of Earth and Planetary Sciences, which includes minerals, gems, and meteorites. Of the 110,000 minerals and 4,500 gems total, 1,800 are on display in the Morgan Hall of Gems and 2,600 in the Guggenheim Hall of Minerals. A much larger percentage of the gems are on display because they tend to be more visually interesting. The stored collections, however, are a tremendous resource for scientific data gathering.

	Part One, “The World of Gems,” gives a very brief history of gems, highlighting the fact that the use of stones for personal adornment can be traced to 25,000 BCE. Through archeological findings and historical texts, it has been determined that there was early interest in the scientific properties of gemstones and not just their beauty or use as amulets. It goes on to describe very basic crystallography concepts and physical properties such as pleochroism and fluorescence, using well-known gems as examples. The writing is clear and not overly technical. Formation and quality factors are briefly addressed. The sections on synthetics, simulants, and enhancements are also brief and do not cover the myriad topics within.

	Part Two, “Gallery of Gems & Crystals,” represents the bulk of the book and delves into the details of specific gemstones. It starts with the most commercially significant and well-known: diamond, corundum, and beryl. The format includes a small information box of properties and sections on history and lore, sources, value factors, and specific examples in the AMNH collection. The accompanying photos show the range of colors and phenomena, rough and jewelry examples, historical illustrations, and specimens from the museum.

	The section on diamonds includes updates since the 1990 edition for new mining areas, the advent of the Kimberley Process, and synthetic diamonds production by the CVD method. But it neglects to indicate that high-pressure methods are still widely used and have been optimized. Since synthetic diamonds are a hot topic for consumers, it would have been helpful to mention the colors and sizes now attainable. Irradiation is mentioned, but not multistage treatments with irradiation plus HPHT treatment.

	In the corundum section, when discussing the benefits of heat treatment, the authors quip, “We could heat the Star of India [the museum’s most famous gem, a 563.35 ct gem-quality star star sapphire] and create a fabulous blue cabochon—perish the thought!” Seasoned gemologists will pick up on the inconsistencies related to padparadscha sapphire—described as “orange” on p. 37 but referred to five pages later as pink-orange and orangy pink (though the famous 100 ct Sri Lankan example shown does look too orangy). And even though there are numerous treatment processes for corundum, only heat treatment is mentioned.

	Paraíba tourmaline is given short shrift, only noted as a highly valued blue-green color variety but not highlighted as a recent find, with unique coloration and limited sources. Most disappointingly, it is not illustrated. Perhaps there have been no donations of this fabulously expensive gemstone? There is an interesting comment on the pyroelectric effect that causes the tourmalines in the AMNH collection to attract dust under the heat of the display lights, something that observant museum-goers would notice.

	Although the sections are brief, there are interesting tidbits to spark the reader’s interest and understanding: for instance, the observation that treated zircon was commercially available and accepted as early as the 1920s, or that turquoise is the most widely imitated and treated of all gems.

	The chapter on jade does skillfully distinguishes nephrite, jadeite, and omphacite, highlighting the huge boulder on display at the museum.

	In the section on organic gems, pearls, coral, amber, and jet are covered. The pearl section is a bit brief, considering what is widely available to consumers. Only saltwater pearls are mentioned as cultured, overlooking the enormous significance of freshwater cultured pearls made by bead, tissue nucleation, and other rapidly evolving techniques. Other pearl types that would be of great interest to amateurs, such as conch or clam pearls, are not mentioned.

	In the last section, on rare and unusual and ornamental materials, the authors acknowledge their own biases in ranking the gems in descending order of quality. Zoisite has been given just one paragraph and an illustration of a rough crystal. Tanzanite has become so mainstream that it need not be relegated to the “rare and unusual” section.

	The book ends with a glossary and an annotated reading list. I heartily agree with the list of 25 books, journals, and websites, as it resembles my own core collection.

	A good balance is struck between illustrations of rough, exemplary crystal specimens, faceted specimens, and historical illustrations and jewelry. The biggest disappointment in this book is the quality of the photos. The Van Pelts are legends, but the quality of film photography from 1990 cannot compete with quality of digital photography today. That, coupled with the difference in technology of color reproduction and printing, leaves some photos lacking depth or brilliance. They are simply not up to contemporary expectations.

	This book goes well beyond its purpose as an introduction to the museum’s collections and a basic primer on the geology of gemstones as well as the jewelry arts. It is eminently readable and draws the reader into the fascinating world of gemology. It would be useful in a professional environment where one could use the information in the “Historic Notes” and “Legends and Lore” sections to add color to a presentation. The “Evaluation” section serves as basic guidance and a starting point for budding collectors. Some information in “Occurrences” is not up to date, which is understandable given that colored stone mining sites tend to be small and can shift within months. Nevertheless, this book stands on its own as a reference book or—if one is fortunate enough to visit the AMNH in New York—a wonderfully readable guide to the museum’s collection. @chapter:17 @chapter:0 @chapter:17


# Publication Year: 2017
# Title: First Observation of H4 Defect in CVD Synthetic Diamond
# Abstract: Figure 1. This 0.26 ct pink synthetic diamond contains the first H4 defect GIA has observed in a CVD synthetic diamond. Photo by Robison McMurtry.

	Diamond consists of a relatively simple lattice of carbon atoms wherein only a few impurities can substitute into the structure. Despite the apparent simplicity, the diversity of defects that can exist in the diamond lattice is astounding. Nitrogen is the most abundant impurity in diamond; one of the defects commonly seen in natural diamonds, the H4 defect, consists of four nitrogen atoms and two vacancies. It is strongly associated with B-aggregated nitrogen impurities, which consist of four nitrogen atoms surrounding a single vacancy. H4 is created through a fairly straightforward formation mechanism where a single vacancy is trapped adjacent to a B-aggregate of nitrogen. H4 is often seen in irradiated and annealed diamonds with suitable amounts of B-form nitrogen, and is a mature aggregate of nitrogen that is very difficult to achieve in synthetic diamond growth or even post-growth treatment.

	We were very surprised to observe an H4 peak at 496 nm in a pink synthetic diamond grown by chemical vapor deposition (CVD) that was recently submitted to GIA’s Carlsbad laboratory for a synthetic colored diamond grading report. This 0.26 ct round brilliant (figure 1) was type Ib (single substitutional nitrogen impurities) with a very low total nitrogen content and no detectable A or B form nitrogen. FTIR spectroscopy also showed a peak at 3107 cm–1, indicating the presence of a defect consisting of three nitrogen atoms surrounding a vacancy along with a hydrogen atom.

	In addition to the observation of the H4 defect (figure 2, left), the synthetic nature of the sample was revealed by the 737 nm SiV– defect in the photoluminescence (PL) spectrum (figure 2, right). The presence of (subtle) growth layers in the DiamondView fluorescence images provided further confirmation. This diamond was grown using gas that was doped with nitrogen, allowing its incorporation into the diamond lattice as single substitutional nitrogen. The pink color was produced by NV– centers created during post-growth irradiation and annealing treatment. Nitrogen aggregation from single substitutional nitrogen to the more complex B-form nitrogen requires very high temperatures and pressures: 2500°C and 9.5 GPa for several hours (I. Dobrinets et al., HPHT-Treated Diamonds: Diamonds Forever, Springer Science & Business Media, 2013, p. 41) and generally requires a high starting concentration of nitrogen. This CVD synthetic diamond had low total nitrogen content and was grown under vacuum and likely irradiated and annealed at atmospheric pressure, making the occurrence of H4 even more puzzling. It is possible that the H4 was created during the irradiation and annealing process, but among the many samples GIA has examined, this was the first observation of this defect in a CVD synthetic diamond.

	Figure 2. Photoluminescence spectra of the pink CVD synthetic diamond showed the occurrence of an H4 defect (left) as well as a SiV– defect (right). @chapter:9 @chapter:1 @chapter:9


# Publication Year: 2016
# Title: Blue Sapphire Reportedly from Badakhshan, Afghanistan
# Abstract: Figure 1. These blue and purplish sapphires are reportedly from a new deposit near Khash in Badakhshan Province, Afghanistan. The largest stone weighs 19.6 ct and measures 19.2 × 13.9 mm. Photo by Lhapsin Nillapat.

Recently, Habib Khan (Royal Gems Stone, Bangkok) donated a parcel of more than 40 rough sapphires to the GIA laboratory in Bangkok. Mr. Khan reported that they were mined from a new deposit in Badakhshan Province of northeastern Afghanistan. A few days later, Kamran Wahidy from the city of Fayzabad informed author VP of a new sapphire deposit near Khash in Badakhshan. This site produces material similar to the stones presented by Mr. Khan. Previous discoveries of corundum around Khash have been reported (Fall 2007 GNI, pp. 263−265; Winter 2010 GNI, pp. 319−320).  The samples (see figure 1) were blue, purplish, or near-colorless. The rough sapphires ranged from 0.9 to 19.6 ct and were transparent to translucent. Standard gemological testing revealed an RI of 1.760−1.768 and an SG of 3.71−3.98. The wide range in SG can be explained by the large pieces of lighter matrix attached to some of the corundum samples. The stones displayed weak orange to inert fluorescence under long-wave UV and were inert under short-wave UV.  All samples were originally covered with a thick, dark greenish black skin that was removed to reveal the blue sapphire inside. Most samples still had some of this skin attached. The skin contained dark green spinel, phlogopite, chlorite, feldspar, amphibole, and tourmaline, which were identified by Raman spectroscopy.  Flat negative crystal fingerprints were commonly seen; some contained CO2 bubbles and diaspore fibers that became visible at 60× magnification. The samples displayed ladder- or dust-like inclusions similar to those seen in sapphires from Kashmir (figure 2; see H.A. Hänni, “A contribution to distinguishing characteristics of sapphire from Kashmir,” Journal of Gemmology, Vol. 22, No. 2, 1990, pp. 67−75).

Figure 2. Inclusion scenes in the Badakhshan sapphire. Left: Ladder-like inclusions under darkfield illumination; field of view 2.7 mm. Right: Negative crystals with CO2 bubbles; field of view 1.8 mm. Bottom: Crystal inclusions of amphibole (green circles) and mica (white circles); field of view 2.4 mm. Photomicrographs by Charuwan Khowpong (left) and Victoria Raynaud (right and bottom).
Crystal inclusions were identified (using Raman spectroscopy and the RRUFF reference database) as apatite, amphibole, mica, diaspore, chlorite, tourmaline, feldspar, and spinel. We also observed unidentified clusters of tiny black crystals and crystals that might have been epidote or allanite. FTIR spectroscopy revealed the presence of boehmite, kaolinite, and a peak at 3161 cm−1. LA-ICP-MS showed an iron content between 154 and 402 ppma, while gallium ranged from 7 to 11 ppma.  If confirmed, the discovery of a new blue sapphire deposit near Khash could be interesting for the gem trade in Afghanistan. However, this new material represents a true challenge for gemologists working on origin determination, as its inclusion scene is, in some aspects, very similar to those in sapphires from Kashmir. @chapter:3 @chapter:0 @chapter:3