Publication Year: - Title: Museum, Lab Collaborate with Students on Design Project Abstract: JDT students recently completed a design project that featured tourmalines from the GIA Museum. This digital rendering shows the gold rings Tyler Abe created using 3-D scanning and CAD (computer-aided design) technology. ©GIA

	Artists are often inspired by the beauty of the materials they use. A sculptor may sense form in a block of stone; a painter might sense the image in the texture of a canvas. In the same way artists transform canvas and stone, jewelry designers manipulate gems and metals into works of art, taking inspiration from the raw material. That inspiration, however, strikes each artist or designer differently.

	GIA’s museum and laboratory staff recently collaborated with the Institute’s first Jewelry Design & Technology (JDT) class to encourage students to find inspiration in gems. The effort tapped into the museum’s wealth of history and knowledge and the analytical and research tools of the lab.

	“JDT students often have the opportunity to see beautiful gems and jewelry from GIA’s museum, but have never had the chance to create their own designs with gems from the collection,” said McKenzie Santimer, GIA museum exhibit developer. Terri Ottaway, GIA museum curator, and Santimer challenged students to design rings featuring five tourmalines from the museum.

	The tourmalines, ranging in size from eight to 11 carats, span the color spectrum. Four were originally owned by Edward J. Gübelin, a pioneer in the world of gemology who amassed one of the most extensive personal gem collections in the world, which was acquired by GIA for the museum in 2005.

	The project gave students the freedom to explore their own design style. The GIA museum staff, as clients for these designers, gave the students careful requirements. Each of the five tourmalines had to be incorporated into a size seven, yellow gold ring with up to one carat of side diamonds to enhance the designs. To encourage the students to find inspiration in the beauty of each stone, Ottaway and Santimer described the localities where each of the tourmalines were mined in Brazil (8.15 carat cushion-shaped red and 11.96 carat cushion-shaped green), Namibia (9.89 carat emerald-cut bi-colored red and blue), Nigeria (9.4 carat oval-shaped blue) and Mozambique (9.15 carat round orange).

	Hannah Becker, from Philadelphia, Pennsylvania, embraced the opportunity to design a collection that would highlight the “big and flashy” tourmalines. She relished the chance to work through her own ideas to create pieces that match her style. When she learned the green tourmaline came from Minas Gerais, a town in Brazil known for baroque-style churches, she designed a ring reminiscent of the architecture she learned about while studying art history.

	“Everyone’s projects were really different and demonstrated what we’re interested in,” she said. “It was fun to see how everybody tackled each stone.”

	Josh White, of San Francisco, California, instantly found his inspiration when he saw the tourmalines. “I knew I wanted to design something elegant,” he said. His designs featured traditional techniques such as prong and bezel settings.

	This CAD rendering, designed by Josh White, illustrates prong and bezel settings. ©GIA

	The GIA laboratory used 3-D scanning technology to create a representation of each tourmaline, called a stereo lithography file (STL file). The file was then imported into CAD (computer-aided design) systems so the students could create renderings of their designs that matched exact specifications of the stones.

	"Technology from the GIA lab, like the 3-D scanning machine, helps ensure students have the latest tools used in the jewelry industry," said Mark Maxwell, GIA's Jewelry Manufacturing Arts manager. “This is how our students benefit from the work done in our lab.”

	White learned first-hand how important this technology is when he was asked recently during a job interview if he had experience with 3-D scanning. He was able to give specific examples, including his designs from this project.

	“Cookie-cutter stones don’t exist in the real world,” he said. If you plan to work in custom jewelry, you need to know how to design using 3-D scanning, he added.

	Students also made rapid prototypes of their designs using the 3-D rendering and CAM (computer-aided manufacturing) tools. The prototypes are an exact representation of their design, from the intricate aesthetic details to dimensions that precisely match the tourmalines. Maxwell demonstrated the perfect fit by placing one of the tourmalines into the prongs of the plastic prototype designed for it.

	“Our goal is to create real-life, real-world experiences for the students,” he said. “This project is just one of many that prepares them for situations they’ll likely encounter in the jewelry industry.”

	This plastic prototype was made using CAM (computer-aided manufacturing) tools after Alyssa Brownell created a CAD rendering (inset) of her design. ©GIA

	Students presented their projects to fellow classmates, instructors and Ottaway and Santimer. The instructors gave feedback on the practical aspects of their designs; Ottaway and Santimer responded from an artistic standpoint, discussing how the rings highlighted the stones and the quality of the design.

	Santimer enjoyed working with students on the project because she said it let them explore jewelry as an art.

	“Some students designed avant-garde pieces that would be difficult to wear, but are meant for display in the museum,” Santimer said. “If it’s art, you can break the rules.”

	In the end, for Becker, it was all about the gems. “The museum is such an invaluable resource because of the beautiful and historic gems they have,” she said. “With this project the stones dictated our designs.”

	Talk about inspiration.

	Hannah Becker found inspiration for her designs from the localities where the tourmalines were mined. ©GIA @chapter:16


Publication Year: 2019 Title: Faceted Diamond Octahedron with a Remarkable Stellate Cloud Inclusion Abstract: Figure 1. This 3.70 ct brownish greenish yellow faceted octahedron contained a remarkable stellate hydrogen cloud (left) that showed strong yellowish green fluorescence under long-wave UV light (right). Photos by Diego Sanchez.
A 3.70 ct faceted Fancy brownish greenish yellow diamond (figure 1, left) was recently submitted to the Carlsbad laboratory for color origin and identification service. The diamond was remarkable in that it contained an eye-visible stellate cloud inclusion consisting of six legs that each radiated to a point on the polished octahedron. Diamonds containing star-like clouds are sometimes referred to as “asteriated” in the trade (T. Hainschwang et al., “The Rhodesian Star: An exceptional asteriated diamond,” Journal of Gemmology, Vol. 34, No. 4, 2014, pp. 306–315). While GIA occasionally encounters asteriated diamonds, this one was striking due to the well-defined nature of the star and the strong yellowish green color it exhibited under long-wave UV (figure 1, right).

Figure 2. The six-ray star pattern is composed of microscopic particles commonly referred to as “hydrogen clouds” (left) that fluoresce strong green to long-wave UV (right). Photos by Nathan Renfro; field of view 6.27 mm.
Gemological examination revealed a type Ia diamond, showing a typical cape series in the visible spectrum. Hydrogen bands in the infrared spectrum and the UV-Vis-NIR spectrum were consistent with the observed “hydrogen cloud” inclusions (figure 2). These clouds in diamonds consist of a high density of light scattering micro-inclusions consistent with those that have been reported to be graphite (B. Rondeau et al., “Three historical ‘asteriated’ hydrogen-rich diamonds: Growth history and sector-dependent impurity incorporation,” Diamond and Related Materials, Vol. 13, No. 9, 2004, pp. 1658–1673) that correlate strongly with the presence of hydrogen (W. Wang and W. Mayerson, “Symmetrical clouds in diamond—the hydrogen connection,” Journal of Gemmology, Vol. 28, No. 3, 2002, pp. 143–152). Also observed was brown radiation staining in a shallow feather, indicating that the stone had been exposed to natural alpha radiation (figure 3).

Figure 3. An irregularly shaped dark brown radiation stain on the diamond’s surface-reaching inclusion clearly shows that it was exposed to natural alpha radiation. Photomicrograph by Maryam Mastery Salimi; field of view 3.51 mm.
While the cutting style was unconventional, it served to showcase the remarkable inclusion scene contained within the diamond. This is one of the most interesting diamonds of this type examined at GIA’s Carlsbad laboratory. @chapter:11


Publication Year: 2000 Title: Spring 2000 G&G Book Reviews Abstract: “Romance of the Golcondra Diamonds”
By Omar Khalidi, 127 pp., illus., publ. by Grantha Corp., Middleton, NJ, 1999. $39.95

“Ruby, Sapphire and Emerald Buying Guide”
By Renee Newman, 164 pp., illus., publ. by International Jewelry Publications, Los Angeles, CA, 2000. US$19.95

“Rough Diamonds: A Practical Guide”
By Nizam Peters, 172 pp., illus., publ. by the American Institute of Diamond Cutting, Deerfield Beach, FL, 1997. US$89.00

“Crystal Enchantments: A Complete Guide to Stones and their Magical Properties.”
By D. J. Conway, 343 pp., publ. by the Crossing Press, Freedom, CA, 1999. US$18.95

“Diamonds and Precious Stones”
by Patrick Voillot, 127 pp., illus., publ. by Harry N. Abrams, New York, 1998, US$12.95

To view the full section, download the PDF above. @chapter:22


Publication Year: 2023 Title: Fall 2023 Auction Highlights Abstract: Figure 1. The “Infinite Blue,” an 11.28 ct Fancy Vivid blue diamond, sold for $25.3 million in Hong Kong. Courtesy of Sotheby’s.
Following the controversial three-part sale of Heidi Horten’s jewels in the spring (Summer 2023 GNI, pp. 254–256), Christie’s announced the cancellation of the fourth sale ahead of the fall auction season. The late Austrian billionaire’s estate made headlines earlier in the year because of her husband’s connection to Nazi Germany, resulting in considerable backlash against Christie’s despite their pledge to donate part of commissions to Holocaust-related charities.
In early October, Sotheby’s kicked off the season with a single-lot sale of the 11.28 ct “Infinite Blue” (figure 1) in Hong Kong. Celebrating its 50th year in Asia, the auction house offered the Fancy Vivid blue type IIb diamond from the Cullinan mine in South Africa set in a ring with a pink diamond halo and colorless diamond side stones. With GIA’s highest color grade for a blue diamond, the ring sold for $25.3 million, just below the low end of its presale estimate.

Figure 2. Selling for $44 million, the 17.61 ct Internally Flawless “Bleu Royal” became the most expensive auction jewel of 2023. Courtesy of Christie’s Images Ltd. 2023.
Another blue diamond achieved better results in early November. The pear-shaped “Bleu Royal” (figure 2), a 17.61 ct Internally Flawless Fancy Vivid blue, was offered by Christie’s in Geneva as the largest diamond of its color to ever appear at auction. Set in a ring that also featured two pear-shaped colorless diamonds of approximately 3 ct each, the piece became the most expensive auction jewel of 2023. After seven minutes of bidding, the ring featuring the GIA-graded type IIb diamond sold for $44 million, near the higher end of its presale estimate.

Figure 3. A ring featuring the “Pink Supreme,” a 15.48 ct Internally Flawless Fancy Intense pink diamond, sold in Hong Kong for almost $11 million. Courtesy of Christie’s Images Ltd. 2023.
The “Pink Supreme” (figure 3), a 15.48 ct Internally Flawless Fancy Intense pink diamond and the largest of its kind ever offered at auction, sold for $10.8 million at Christie’s Magnificent Jewels sale in Hong Kong on November 27. Set in a gold ring with pear-shaped and round colorless diamonds, the GIA-graded type IIa gem belonging to a private collector sold within its presale estimate.
In a season filled with plot twists, some highly advertised and anticipated pieces did not go under the hammer on auction day. The “Blue Lagoon,” a 93.94 ct blue Paraíba tourmaline and the top lot for Sotheby’s Magnificent Jewels in Geneva, was withdrawn before the auction went live. In the final Magnificent Jewels auction of the season in New York, Christie’s promoted the “California Sunset” diamond earrings as their top lot. Featuring a stunning pair of Fancy Vivid orange-yellow diamonds weighing approximately 12 ct each, the earrings, estimated to fetch up to $12 million, were also a no-show. @chapter:30


Publication Year: - Title: Cameos: Timeless, Miniature Carvings for Jewelry Lovers Abstract: A group of cameos shows the progression from rough shell to the final carved cameo. Gift of Kessler Mfg & Imports Inc. Photo by Kevin Schumacher/GIA

Alexander the Great commissioned his portrait – in the likeness of a god – to be engraved in stone in the third century BCE, according to jewelry expert Anna M. Miller, author of “Cameos Old and New.” This was the first time a cameo – a three-dimensional figure carved out of stone – was seen in Egypt. It is perhaps the first known selfie!

Cameo portraits of rulers and nobility or scenes of historical events have been highly valued ever since. Prior to Alexander, carvings were cut below the surface – intaglio – and used as seals of identification. The seals usually depicted animals of strength, such as lions or bears, and figures from Greek or Roman mythology.

A courtship cameo shell brooch from the Georgian era shows depth of color and detail in a landscape scene. Courtesy of MMH Collection. Photo by Robert Weldon/GIA
Cameos can be carved in low relief (barely standing out from the background) or in high relief (projecting prominently above the background). Quality factors in evaluating cameos include the type of medium used, as well as the setting, condition, detail of carving, subject matter and signature of the artist.

Shell became a popular medium in French and Italian cameos during the Renaissance. Cassis rufa, known as cornelian, is a common type of shell used for cameos and varies in color from very light to deep brown orange. Cassis madagascariensis, commonly known as emperor helmet shell or sardonyx shell, is a thick, dark brown shell. It is the largest mollusk shell and resembles banded agate when carved.

The discovery of large deposits of carnelian (an inorganic rock that is different from the shell cornelian, which is organic) and agate in the Idar-Oberstein region of Germany in the 16th and 17th century spurred a renewed interest in cameos. Onyx, sardonyx, carnelian, jasper and quartz were widely used materials during this period and are ideal for carving because of their relative hardness and color zoning.

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Cameos were popular in the Victorian era in England and Europe because Queen Victoria was fond of jewelry and favored them. Portraits of royalty and statesmen continued to be popular subjects, along with profiles of women dressed in finery, youthful maidens, religious icons and mythological gods and goddesses. Gem materials such as sapphire, garnet, jade, opal, coral and quartz gained favor for cameo carving in the Victorian era.

Queen Victoria went into mourning after Prince Albert died in 1861, but did not give up her penchant for wearing jewelry. She often chose jewelry made of jet, a fossilized form of coal. Lava cameos also rose in popularity as mourning jewelry during the Victorian era. Enterprising artisans realized that lava from the remains of Pompeii was a suitable material for carving cameos. These were sought after as a souvenir by status-conscious Victorians to show they had taken a European tour. Jet and lava are suitable for high relief carving – a quality factor in evaluating cameos – and are collectible.

The goddess Bacchante is carved in high relief from black lava and shows fine detail of leaves and clusters of grapes in her hair. Cameos dating to BCE 79 were discovered in 1748 in the ruins of ancient Pompeii. Lava cameos were popular in Victorian England as souvenirs of a European tour. Courtesy of MMH Collection. Photo by Robert Weldon/GIA
Cameos continued to be popular after Queen Victoria’s death and artisans expanded their carving materials to include turquoise, ruby, lapis lazuli, aquamarine, peridot and topaz.
In the 19th and 20th centuries, Italian carvers Tommaso Saulini, his son Luigi Saulini, along with Giovanni Noto, were known to sign their work. The British royal family commissioned Tomasso Saulini to carve portraits of Queen Victoria and Prince Albert and his work is housed at the Victoria and Albert Museum in London. The Italian Republic commissioned Noto to create official gifts, including a work for the wedding of Charles and Diana of England. Most works by these masters of cameo carving reside in museums and private collections.

The rich history and lore of cameos make them a fascinating avenue into the world of collecting for history, mythology and jewelry buffs. @chapter:21


Publication Year: - Title: Tanzanite History and Lore Abstract: This 122.70-carat tanzanite is in the collection of the Smithsonian National Museum of Natural History. - Chip Clark, courtesy Smithsonian Institution

Tanzanite is relatively new to the colored stone galaxy. As the most common story of the tanzanite mining boom goes, in 1967 a Masai tribesman stumbled upon a cluster of highly transparent, intense violet-to-blue crystals weathering out of the earth in Merelani, an area of northern Tanzania. He alerted a local fortune hunter named Manuel d'Souza, who quickly registered four mining claims.

D’Souza hoped that he’d been shown a new sapphire deposit. Instead, the deposit contained one of the newest of the world’s gems.

Although it’s a newcomer to the gemstone industry, tanzanite has quickly become one of the most popular colored gemstones. - Courtesy Richard Krementz Gemstones
Within a short time, 90 more claims appeared in the same 20-square-mile area. No one was quite sure what the beautiful crystals were, but everyone wanted to lay claim to the profits they were certain to produce. The new gem would eventually be known as tanzanite, and it would, at times, rival the Big 3 in popularity.

Tiffany & Company recognized its potential as an international seller and made a deal to become its main distributor. Tiffany named the gem after the country it came from, and promoted it with a big publicity campaign in 1968. Almost overnight, tanzanite was popular with leading jewelry designers and other gem professionals, as well as with customers who had an eye for beautiful and unusual gems.

The instant popularity of this transparent blue-to-violet gem was tied to its vivid color, high clarity, and potential for large cut stones. @chapter:18


Publication Year: - Title: Finding Inspiration Seeing Ordinary Things in an Extraordinary Way Abstract: Cuff bracelet image courtesy of Erik Stewart, GIA GG

                      Where do jewelry designers find inspiration?

Some look to influential movements of the past, like the Art Nouveau, Edwardian, and Art Deco eras. Others wander through museums and art galleries and browse through art books, journals, and magazines. And some turn to everyday objects, overlooked items, and curious places.

“Our environment is filled with beautiful things, but because we pass them all the time, we stop noticing them. Inspired jewelry designers are able to translate these overlooked everyday items into symbolic reconfigurations of wearable art,” said Katey Brunini of K. Brunini Jewels.

Here we look at five pieces of jewelry whose inspiration came (or might have come) from looking at ordinary things in extraordinary ways.

Follow the Cobblestone Road

	Bracelet courtesy of Neil Lane, Inc.: Beverly Hills, California.
Look at this circa 1933 Cartier diamond baguette bracelet and the cobblestone road. Now take a trip with us.

We imagine a jeweler in some old European city walking down a similar street to his shop. This day, he suddenly notices the beauty and workmanship of the road right beneath his feet. The tight setting, interlocking stones, and mosaic feel of the cobblestone street inspires him to make this bracelet.

Bridging Styles

Graduate Gemologist Erik Stewart shares the story behind Transit, which received 2nd place in the 2012 Saul Bell Design Awards, Gold/Platinum/Palladium category.

“I was in New York to receive an award, and was doing the touristy thing. I wanted to see the Brooklyn Bridge, while at the same time I had these jewelry concepts rolling around in my head. The Brooklyn Bridge really moved me, and its cables clarified design ideas for an original piece of jewelry.”

Stewart explains what went into making the piece: “It took two months of planning and two weeks of working day and night to create Transit. The stainless steel cables on the bracelet are meant to evoke the Brooklyn Bridge. They also give the piece a tactile feel – you can play the strings like a guitar.”

Antique Twins

Did this 19th-century pin inspire the designer of this antique mirror? Or did the mirror inspire the designer of this pin?

The makers are gone, so we’ll never know the answer, but it’s not far-fetched to think a jewelry designer used a similar mirror every day. The oval shape of the mirror, its gentle curving lines, decorative ferns and leaves, and notched wood around the glass could have been the inspiration for the nearly identical-looking pin.

The soft, feminine lines of this classic pin has made it a staple of jewelry wearers. Countless women own similar pieces, which have been passed down from one generation to the next.

These two antique pieces also show that the influence of everyday objects extended far beyond the little space they occupied.

	Brooch courtesy of Mary Mathews.
Reinventing Canyons

The title of Richard Kimball’s 36,000 Ft. Above Flaming Gorge brooch (below) tells the designer’s inspiration: a 91-mile stretch of water that slices through a canyon running from Wyoming to Utah. Seeing Flaming Gorge from the vantage point of a plane etched a vivid image in the artist’s mind.

“36,000 Ft. Above Flaming Gorge has an organic and natural feel, yet it also has very edgy, futuristic lines. It’s an unusual combination, and it shows that our imagination can reinvent what we see in extraordinary ways,” observed GIA Exhibit Developer McKenzie Santimer, GIA GG, GJ.

Kimball’s piece is part of the GIA collection and is featured In the museum’s current Birthstones exhibit.

	Gift of Richard H. Kimball.
A Blossoming Personality

	Ring courtesy of Nancy’s Collection.
Zoltan David’s AGTA Spectrum Award winning ring, Homage to Nancy, features a large, intense orange spessartine garnet (20.85 ct) – cupped by four platinum ‘petals’ studded with 320 round brilliant cut tsavorite garnets, and edged with 24K gold. The gold was set using Zoltan David’s patented metal ornamentation technique.

“The design for Homage to Nancy was inspired by a client and friend of mine who had a personality that was always blossoming. She was in a constant state of unfolding – always coming into something greater and more glorious – much like a Morning Glory,” said David.

“The orange spessartine garnet also seemed to be an appropriate choice for my friend. Just like her, the gemstone bursts with color and light,” added David.

David’s ring is currently displayed at the GIA Museum in Carlsbad. @chapter:16


Publication Year: - Title: GIA JCK 2019 Panel: Consumers Care Where Their Jewelry Comes From Abstract: Members of the GIA panel, “Embracing Sustainability Amid New Consumer Expectations” are, from left, Claire Poroddi, Kering; Dr. Saleem Ali, University of Delaware; Lisa Bridge, Ben Bridge Jewelers; Marcus ter Haar, Okavango Diamond Company; Nadja Swarovski, Swarovski; and Susan Jacques, GIA. Photo by Russell Shor/GIA

Today’s consumers want more than the 4Cs and good design from their jewelry. They also demand that its components – gemstones, diamonds and precious metals – are responsibly sourced.
That was the key message from the GIA panel “Embracing Sustainability Amid New Consumer Expectations,” held at the 2019 JCK Las Vegas show.
The panelists, representing different aspects of the industry, agreed that jewelry companies have to assume responsibility for their products all the way through the value chain.
Moderator Susan Jacques, GIA president and CEO, began the discussion with a brief video about the evolution of public perception of the industry. The video showed images of artisanal gem and gold miners coupled with negative headlines, which segued into news about industry efforts to address the issues. She commented that, despite significant efforts, including the Kimberley Process and the establishment of the Responsible Jewellery Council (RJC), this is what consumers have heard for years about the industry.
“There are so many positive stories to be told, with organizations like the Diamond Development Initiative and Responsible Jewelry Council,” she said. “Now the industry must work hard to change these perceptions.”
The five panelists - Dr. Saleem Ali, University of Delaware; Marcus ter Haar, CEO of Okavango Diamond Company, Botswana; Lisa Bridge, CEO of Ben Bridge Jewelers; Nadja Swarovski, member of the Swarovski Executive Board; and Claire Piroddi, sustainability manager for watches and jewelry at French luxury group Kering - detailed the efforts their organizations to do just that.
Ali, a professor of energy and environment, said that jewelry may be a luxury product that not everyone needs, but it does sustain a standard of living for many people who work in the gem and jewelry supply chain.
“These workers can create wealth and economic growth from the elements of the Earth,” he said, adding that conditions must be there to enable them to do so.
Ter Haar cited the benefits diamonds have brought to Botswana.
“It’s the circles of sustainability: people, planet, profit,” he said. “In Botswana, we’ve seen our capital grow from a small town to a progressive, modern city, [with] a great increase in life expectancy, free health care – all from diamonds, which account for 50% of government revenue and 30% of GNP. Every diamond purchased represents food on the table.”
Swarovski told the audience that, today, companies must think of others as well as themselves. Her company focuses on three basic principles: positive production, women’s empowerment and fair partnerships.
“Our company embraces the United Nations’ 17 sustainable development goals,” she told the audience, outlining initiatives the company was making to implement the UN goals in Swarovski’s operations and with sourcing partners worldwide. These include gender equality, clean water and sanitation, clean energy and reduced carbon footprint, responsible sourcing, equitable work standards and responsible consumption.
Piroddi said that Kering, which includes such jewelry and watch brands as Pomellato and Boucheron, has developed a sustainability road map to 2025 built on three pillars:

Care – designed to reduce the company’s environmental footprint and work toward 100% vetted sources in its supply chain
Collaborate - promote gender equality and to be an employer of choice
Create – embrace new technologies and innovation, and encouraging start-ups

She pointed out that “95% of luxury products come from nature, so we must take care of our environment.” She also said that in a company survey done for its fashion brands, “75% of people care where their products come from – they are more informed than ever.”
Lisa Bridge told the audience that “sustainability begins at home” and noted that the company supports community organizations in each town where it has stores.
“We encourage our employees to give back to their communities as well,” she said.
Further afield, Bridge staff personally visit each of its vendors so it can stand by its products “and we can be certain our jewelry is what we say it is.” @chapter:33


Publication Year: 1987 Title: The Gemological Properties of the De Beers Gem-Quality Synthetic Diamonds Abstract: Gem-quality synthetic diamond crystals weighing up to 11 ct have been grown in limited numbers at the De Beers Diamond Research Laboratory since the 1970s. These crystals have been produced strictly on an experimental basis and are not commercially available. Examination of a group of 14 brownish yellow, yellow, and greenish yellow synthetic diamonds reveals distinctive gemological properties: uneven color distribution, geometric graining patterns, metallic inclusions, and, in most cases, fluorescence to shortwave but not to long-wave UV radiation. @chapter:11


Publication Year: 2024 Title: Unique Sphalerite from Spain Abstract: A 7.70 ct yellow sphalerite from Spain exhibiting a one-of-a-kind red circular center with distinct black rings. Face-up view of the pattern (left) and face-down view showing the careful placement of the red region by the cutter (right). Photos by Robert Weldon; courtesy of Dudley Blauwet Gems.
Tucson is always full of surprises, and this year was no exception. At the AGTA show, Dudley Blauwet (Dudley Blauwet Gems, Louisville, Colorado) pulled a gem box out of his pocket to show the author a truly unique gem. This yellow sphalerite had a perfect red circle centered in the table with three sharp and distinct black rings encircling it (see above).
The stone was cut from material from Santander in Cantabria, Spain, a source known for producing the best facet-grade sphalerite in the world. The deposit yields orange and red stones that can be quite large, with some weighing hundreds of carats.
Sphalerite, a zinc sulfide (ZnS) mineral, is an important ore of zinc and rarely of gem quality. Colorless in its pure form, it goes from yellow to red to brown to a submetallic black color with the addition of iron. The presence of cobalt can cause a green color. Sphalerite has both an extremely high refractive index (2.37) and dispersion (>0.150), and when properly cut it can have significant brilliance. Despite these desirable gem qualities, sphalerite’s softness (Mohs hardness of only 3.5 to 4.0), brittleness, and perfect cleavage make it a challenge to cut and polish (R.T. Liddicoat, Handbook of Gem Identification, Gemological Institute of America, Santa Monica, California, 1989).
This one-of-a-kind stone was expertly cut in Europe by an artisan who knew how to work soft, brittle stones with cleavage and how to properly center the red “dot” in the culet. The distribution of iron in this sphalerite crystal assumes distinct regions: sharply defined black rings with high iron saturation, a red circular area of medium saturation, and a surrounding area of lower saturation.
This exceptional sphalerite is proof that the combination of Mother Nature and a skilled cutter can reveal the infinite possibilities for spectacular gems. @chapter:0


Publication Year: 2001 Title: An Update on “Paraíba” Tourmaline from Brazil Abstract: Vivid blue, green, and purple-to-violet cuprian elbaites, renowned in the gem trade as “Paraíba” tourmalines, continue to be recovered in small amounts from northeastern Brazil. Since the initial discovery of this copper-bearing tourmaline in 1982, production has been sporadic and has not kept up with the strong market demand. Mining currently takes place at the original discovery—the Mina da Batalha—and at adjacent workings near São José da Batalha in Paraíba State. At least two pegmatite localities (the Mulungu and Alto dos Quintos mines) in neighboring Rio Grande do Norte State have produced limited quantities of cuprian elbaites. All of these pegmatites occur within Late Proterozoic metamorphic rocks of the Equador Formation; the source of the copper is unknown. Six blue to blue-green elbaites from Mulungu had lower copper contents (up to 0.69 wt. % CuO) than the brightly colored Mina da Batalha material reported in the literature. @chapter:37


Publication Year: - Title: Ammolite: The Fashionable Fossil Abstract: Pieces of Ammolite resemble stained glass. Courtesy of Korite International.

If you like gemstones with provenance, then you’re going to love ammolite - iridescent fossilized ammonite shells found in Southern Alberta, Canada.

When the earth had only one continent with no forests or mammals, schools of ammonites hunted in the Tethys Ocean. Squid-like creatures with sharp, beak-like jaws buried in a ring of tentacles, ammonites ate what they could catch.

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Ammonites suffered the same fate as the dinosaurs – they became extinct about 66 million years ago. An asteroid striking the earth and the cooling climate likely caused their demise.
As countless millennia passed, two species of ammonites – Placenticeras meeki and P. intercalare – slowly turned into stunningly colored fossils called Ammolite. Their brilliant colors enchanted Native Americans who wore them to bring good luck while hunting buffalo.

Ammolite embedded in rock.
Gift of Korite International

Most Ammolite is green and red. Blue and violet Ammolite is more unusual, and typically more valuable. It is described as either fractured or sheet. Fractured Ammolite resembles stained glass; sheet Ammolite is an unbroken piece where the colors are continuous. Evocative names are used to describe its diversity of appearance: dragon skin (patterns resembling scales), cobblestone (patterns resembling a cobblestone road), moonglow (luminescent with few lines or fractures), and paint brush (looks like strokes of paint).

An Ammolite brooch by Carolyn Tyler

Sheet Ammolite is typically impregnated with a polymer to stabilize its thin surface layer. Because the layers are thin, Ammolite is almost always assembled into a doublet or triplet. Ammolite is often backed with a material like shale, black onyx, or glass to form a doublet. Sometimes a top layer of synthetic spinel or quartz is added to form a triplet.

Ammolite is often fashioned into pendants, brooches, and earrings, and sometimes sold as objet d’art. It is not a hard stone, 3.5 on the Mohs scale, which means it can scratch easily. Heat and chemicals, like acid, perfume, and hairspray, can also damage it. It’s highly recommended that you use only a damp, soft, non-abrasive cloth to clean it. @chapter:0


Publication Year: 2020 Title: Trapiche-Type Emeralds from Pakistan Abstract: Growth pattern observed in a trapiche-type emerald from Swat, Pakistan. The slice shows two colorless cores and two intermediate lighter green zones surrounded by a more intense green rim. Viewed perpendicular to the c-axis, in air (left) and immersion (right); diameter of the sample from 4.6 to 4.8 mm. Photos by Karl Schmetzer.
Numerous gem materials have been designated “trapiche” in the trade and in various publications. They generally describe a pattern consisting of a fixed non-transparent star in a transparent matrix, with the arms of the six-rayed star radiating from a central point or from a central core to the rim of the crystal. Only a limited number of mineral species show a clear trapiche pattern within crystal slices (i.e., a pattern with a clear separation of the crystal into distinct growth sectors). The boundaries of these growth sectors, running from the center to the edges between external prism or pyramidal faces, are normally sharp and contain mineral or fluid inclusions, separating different parts within the rim. These sector boundaries are also described as the arms of the fixed six-rayed star. The most prominent gem minerals showing a distinct trapiche pattern are Colombian emeralds and rubies from Myanmar.
Another group of gem materials is characterized by several areas of increased transparency and translucency that surround a central point or central core according to the symmetry of the host. The two types of areas are characterized by different concentrations of inclusions, which are trapped within specific parts of symmetry-equivalent growth sectors of the host. The arms of the fixed star are perpendicular to the external crystal faces. The most prominent gem materials of this second group are blue basaltic sapphires from different sources, but similar patterns also have been described for other gem varieties such as aquamarine from Namibia. This second group of crystals is designated “trapiche-type,” and the emeralds from Pakistan described in this entry belong to this group of gem materials.
Trapiche-type emeralds originating from the Swat mining region in Pakistan have recently been described by Y. Gao et al. (Fall 2019 Gem News International, pp. 441–442) and H. Guo et al. (“Inclusion and trace element characteristics of emeralds from Swat Valley, Pakistan,” pp. 336–355 of this issue). The samples showed an interesting growth pattern and color zoning with a colorless core, a lighter green intermediate zone, and a more intense green rim. The inclusions forming the trapiche-type pattern were restricted to the lighter green intermediate growth zone.
Recently, the author received six slices of similar material, reportedly from Swat, from the gem collector S. Hanken of Waldkraiburg, Germany; the samples had been purchased in 2020 from the U.S. gem trade. One of these samples, which were all cut perpendicular to the c-axis of the emerald crystals, showed an interesting growth pattern. The emerald slice measured from 4.6 to 4.8 mm (distances between different prism faces) with a thickness of 1.9 mm (see above). The sample revealed two colorless beryl cores of almost equal size. One of these colorless cores was surrounded by a large light green intermediate zone, which also contained the inclusions forming the trapiche-type pattern. The second core was surrounded by a lighter green intermediate zone, which was much smaller. Encompassing these two intermediate zones were intense green hexagonal growth boundaries with growth planes parallel to the external prism faces.
This intense green growth boundary surrounds both light green intermediate growth zones. Subsequent to this intense green boundary, an intense green outer rim without trapiche-type inclusions but with additional growth planes parallel to the prism faces was present.
As already described by Gao et al., the emerald was grown in three distinct steps with a colorless beryl core, a light green intermediate zone, and an intense green rim. All growth steps were separated by sharp boundaries, with a thin growth layer between the intermediate zone and the rim, which showed the most intense green coloration observed in the sample. The emerald formed with two cores, with a subsequent growth step, in which both parts were still separated from each other. Only in the last growth step, in which the intense green rim was formed, were the two parts of the final emerald crystal in contact with each other. @chapter:10


Publication Year: 2021 Title: Natural Freshwater Pearls from Europe: Russia, Scotland, and Germany Abstract: Figure 1. The eight European natural freshwater pearls reportedly produced by Margaritifera mussel species, collected from freshwater sources in Russia, Scotland, and Germany. Photo by Diego Sanchez.

The Carlsbad laboratory received eight European freshwater (FW) pearls from coauthor ES for gemological and chemical characterization (figure 1). Although the exact locations and times of discovery were not recorded, all the samples were obtained directly by ES from reputable sources in each country. The first three samples are of Russian origin and were obtained by Russian fisheries biologist Valery Ziuganov during his studies of the Varzuga River, Kola Peninsula, in the 1990s (E. Strack, “European freshwater pearls: Part 1–Russia,” Journal of Gemmology, Vol. 34, No. 7, 2015, pp. 580–593; E. Strack, “Freshwater pearls from Russia,” Margaritologia newsletter, No. 11, 2018). Two samples from Scottish rivers were provided in 2004 by Cairncross Jewellers, the only company allowed to buy pearls from the fishers in Perth, Scotland. The last three are from Lüneburg Heath in northern Germany and were supplied around 1997 by a local family that had collected and fished for pearls over the decades. European FW natural pearls have reportedly been produced for centuries from mussels belonging to the Margaritifera species, which has been referred to as the “freshwater pearl mussel” (E. Strack, Pearls, Rühle-Diebener-Verlag, Stuttgart, Germany, 2006). Today, most natural FW pearls produced in North America and cultured FW pearls from Asia form in various mussel species within the Unionidae family. Both families are member of the Unionoidea superfamily.

The samples exhibited two different surface structures: nacreous and non-nacreous. Upon examination with a loupe and microscope, samples 1–4 (see table 1) exhibited nacreous surfaces, with fine overlapping platelets visible under high magnification. Surface wrinkling was also seen in single areas on samples 1 and 3, along with fine surface fractures; the wrinkled feature in each was previously noted as a characteristic of a FW environment (Strack, 2015, 2018). The nacreous samples ranged from 0.70 to 2.68 ct and measured from 4.77 × 4.33 mm to 7.08 × 6.72 mm. According to GIA classification procedures, their shapes were semi-baroque, baroque, and circled oval, while their bodycolors varied from light pinkish brown to light purplish pink and very light pinkish brown. Sample 3 showed a dull surface lacking luster and overtone, while the other three displayed orient and pink overtones.

Figure 2. At higher magnification, the four non-nacreous pearls displayed mosaic or cellular surface patterns of different sizes and shapes. This image shows the cellular structure on the surface of sample 7 when illuminated with a fiber-optic light. Photomicrograph by Nathan Renfro; field of view 1.00 mm.
Conversely, samples 5–8 exhibited a non-nacreous surface appearance and lacked overlapping platelets characteristic of most FW pearls. They ranged from 0.94 to 2.11 ct and measured from 5.12 mm to 7.32 × 6.98 mm. The shapes were uniformly round, oval, and drop, and all the samples were brown-yellow. At higher magnification, using strong illumination such as fiber-optic lighting, all the pearls displayed mosaic or cellular surface patterns of differing sizes and shapes. The small cells, which looked like pinpoint features in lower lighting conditions, resulted in a dimpled surface texture (figure 2). A cellular pattern was also observed in a small area on the base of sample 1. The non-nacreous appearance and cellular surface structures resembled those commonly observed on pen pearls from the Pinnidae family (N. Sturman et al., “Observations on pearls reportedly from the Pinnidae family (pen pearls),” Fall 2014 G&G, pp. 202–215), as well as some non-nacreous non-bead cultured pearls from the Pinctada maxima mollusk (A. Manustrong et al., “Known non-nacreous non-bead cultured pearls and similar unknown pearls of likely cultured origin from Pinctada maxima,” GIA Research News, 2019, https://www.gia.edu/gia-news-research/known-non-nacreous-non-bead-cultured-pearls). Non-nacreous natural pearls from Pteria species mollusks have also reportedly displayed hexagonal-like cellular patterns (S. Karampelas and H. Abdulla, “Black non-nacreous natural pearls from Pteria sp.,” Journal of Gemmology, Vol. 35, No. 7, 2017, pp. 590–592).

Figure 3. Raman spectra of all eight samples obtained using an 830 nm diode laser revealed clear aragonite peaks, a doublet at 702 and 705 cm–1 (magnified in the inset), and a single intense band at 1085 cm–1. These results allowed the four non-nacreous pearls to be separated from pen pearls, which are normally composed of calcite (Sturman et al., 2014). Spectra are offset vertically for clarity.
Under long-wave ultraviolet radiation (365 nm), the nacreous samples exhibited weak bluish yellow fluorescence over most of the surface, while a yellow reaction was observed on the limited yellowish brown areas. The non-nacreous samples exhibited uniform weak to moderate chalky yellow fluorescence similar to that reported for pen pearls (Sturman et al., 2014), but different from the strong orangy red fluorescence observed in non-nacreous Pteria pearls (S. Karampelas and H. Abdulla, 2017).
A Raman spectrometer was used to examine the surface composition of all the pearls, initially using a 514 nm argon-ion laser. Owing to the high background fluorescence observed in most of the samples, an 830 nm laser provided better peak resolution. Clear aragonite peaks at 702, 705, and 1085 cm–1 were recorded in all the samples (figure 3), and the results allowed the four non-nacreous pearls to be separated from pen pearls, which are normally composed of calcite (Sturman et al., 2014). Raman spectra collected using the 514 nm laser revealed weak polyene peaks at approximately 1125 cm–1 and 1512 cm–1 in samples 1, 3, and 4, indicating their colors were natural. Polyene peaks were not observed in samples 2 and 5–8, possibly due to the samples’ high fluorescence. The 830 nm laser is not helpful in resolving polyenic peaks. Surface observations did not reveal color modification in any of the samples.
UV-Vis reflectance spectra were collected from the smoothest and most homogeneously colored area of each sample in the 250–800 nm range. An absorption feature at about 280 nm that is usually observed in nacreous pearls was clearly seen in samples 1–4 but absent in samples 5–8. Samples 1, 2, and 4 showed reflection minima in the blue to yellow range, which corresponds with their predominantly pink hue. These results correlate with those in a previous study on naturally pink FW pearls of natural origin from the Mississippi River System in the United States (Summer 2019 GNI, pp. 282–285) and with reports on natural-color FW cultured pearls from Hyriopsis species mollusks (S. Karampelas et al., “Role of polyenes in the coloration of cultured freshwater pearls,” European Journal of Mineralogy, Vol. 21, No. 1, 2009, pp. 85–97; A. Abduriyim, “Cultured pearls from Lake Kasumigaura: Production and gemological characteristics,” Summer 2018 G&G, pp. 166–183). Owing to the very light color of sample 3, the spectrum obtained was nearly flat, as would be expected for white pearls, and hence no features of any significance were observed. The spectra obtained from samples 5–8 showed a lower reflectance than the four previously reported samples due to their more saturated colors. All the spectra showed similar patterns, with an incline from 400 to 750 nm in the visible region, comparable to the reported spectra of dark-colored pen pearls (Sturman et al., 2014) and non-nacreous non-bead cultured pearls from Pinctada maxima (Manustrong et al., 2019).
Table 1 shows the internal structures of the eight samples using real-time microradiography (RTX) and X-ray computed microtomography (µ-CT). Sample 1 and all the non-nacreous samples showed clear organic-rich concentric ring structures with faint radial features radiating outward from the center across the concentric rings. The radial structures are associated with cellular surface patterns. All three sections of sample 2 showed weak growth arcs corresponding to their shapes. Sample 3 exhibited a wavy concentric growth pattern together with a dark organic-rich patch, while µ-CT analysis revealed a small dark core in the structure. Sample 4 displayed the least amount of visible structure—only a few very faint growth arcs, even when examined using µ-CT. Cracks of varying lengths and degrees of visibility were present in the samples. The structures observed confirmed their stated natural origin. However, a smaller nucleus with a lighter gray core next to the main nucleus in sample 7 did raise some concerns. If the pearl was submitted to a gemological laboratory without any known provenance, the smaller structure could be mistaken for the lighter gray carbonate “seed” features sometimes found in saltwater non-bead cultured pearls (M.S. Krzemnicki et. al., “Tokki pearls: Additional cultured pearls formed during pearl cultivation: External and internal structures,” 32nd International Gemmological Conference, 2011, https://www.ssef.ch/wp-content/uploads/2018/01/SSEF_Tokki_pearls.pdf). However, the authors are not aware that this type of feature has ever been reported in non-bead cultured pearls from a FW environment.
Chemical compositions were initially analyzed by energy-dispersive X-ray fluorescence (EDXRF) spectrometry, and some of the samples were tested twice in different positions. Most samples contained relatively low manganese (Mn) levels (0 to 240 ppm) compared to the majority of natural and cultured FW pearls in GIA’s database. The usual Mn range observed is between 150 and 2000 ppm. Samples 1, 3, and 6–8 showed Mn concentrations below 50 ppm. It was interesting to note that in sample 5, Mn was absent at one end but present (170 ppm) at the opposite end. Additionally, the samples with low Mn levels (<50 ppm) did not show visible reaction under X-ray excitation (H. Hänni et al., “X-ray luminescence, a valuable test in pearl identification,” Journal of Gemmology, Vol. 29, No. 5/6, 2005, pp. 325–329), as would be expected for such low traces of the element. Strontium (Sr) contents were relatively low (<1000 ppm) in all the samples, which is characteristic of FW origins. However, the very low concentration of Mn and lack of X-ray fluorescence reactions could create some doubts and lead to some misidentifying them as saltwater (SW) pearls.

Detailed trace element concentrations were analyzed using laser ablation–inductively coupled plasma–mass spectrometry (LA-ICP-MS) with the same parameters used in previous FW pearl studies (A. Homkrajae et al., “Provenance discrimination of freshwater pearls by LA-ICP-MS and linear discriminant analysis (LDA),” Spring 2019 G&G, pp. 47–60; Summer 2019 GNI, pp. 282–285). At least three ablation spots were tested on each sample, and the results for the 22 elements selected are shown in table 2. The five elements (sodium, magnesium, Mn, Sr, and barium) found to be useful discriminators in the differentiation of FW from SW pearls and in classifying FW pearls from different sources are bolded in the table. Mn and Sr contents obtained were consistent with the EDXRF results.

Figure 4. All the European pearl samples contained Mn levels below 500 ppm, which helped separate them from the majority of freshwater pearls previously studied. Mn and Sr levels obtained by LA-ICP-MS analysis were consistent with the EDXRF results. Yellow spots represent results from American natural pearls (USA-NAT), red spots from American cultured pearls (USA-CUL), green spots from Chinese NBC pearls (CH-NBC), and purple spots from American natural pearls from the Mississippi River System (USA-LP).
All the samples contained low Mn levels (<500 ppm), separating them from the majority of FW pearls previously studied (figure 4; see Homkrajae et al., 2019; Summer 2019 GNI, pp. 282–285). The ternary diagram of relative percentages between Ba, Mg, and Mn that was used to verify the growth environment conditions of the questionable FW pearls in previous studies (Homkrajae et al., 2019; Summer 2019 GNI, pp. 282–285) was used once again to confirm the formation environment of the six samples containing low levels of Mn (below 100 ppm). All six samples plotted alongside those of the FW pearls previously studied, confirming their FW origin. These results also help to distinguish non-nacreous samples from saltwater non-nacreous non-bead cultured pearls produced by Pinctada maxima (Manustrong et al., 2019). The values of these five discriminant elements, as well as those for lead (Pb), correspond with the chemical results reported on natural FW pearls produced by Margaritifera mollusks found in the Spey River, Scotland (S. Karampelas et al., “Chemical characteristics of freshwater and saltwater natural and cultured pearls from different bivalves,” Minerals, Vol. 9, No. 6, 2019, p. 357). The Sr-Ba concentration plot is also shown in figure 5. This result supports the observation made by Karampelas et al. (2019). Furthermore, the pearls from each European locality could be separated from each other in this plot, though it should be noted that this was based on a very limited number of known samples.

Figure 5. American and Chinese freshwater pearl samples studied previously, together with the samples from this study, were plotted in the Sr-Ba concentration plot. This result supports the observation made by Karampelas et al. (2019). Although the study was based on a limited sample pool, the pearls from each European locality could also be separated using this plot.
For centuries, the freshwater mussel species Margaritifera was abundant in the rivers and streams of Europe, and the pearls produced were part of European culture and history. The American native mussel species followed a similar path. However, environmental changes, and the impact of pollution from industry and agriculture have damaged ecosystems and directly affected the mussels’ habitat and lifespan (Strack, 2006). Freshwater pearl fishing in Europe is currently prohibited or under regulation due to the decline of mussel populations. Studying these rare European FW natural pearls provided valuable data that has enlarged GIA’s identification database, offering a useful reference for the gemological community. @chapter:14


Publication Year: 1983 Title: Art Deco: The Period, the Jewelry Abstract: Although the Art Deco period extends roughly from 1910 to well into the 1930s, it was primarily a product of the "Roaring '20s." This was a wonderfully decadent era. It was an age of Prohibition and cocktail parties, of flappers and the Charleston, of racketeers and G-men, of nouveau riche and credit spending. These were merely some of the manifestations of the social turmoil that resulted from the extreme disillusionment that followed the "war to end all wars," a violent reaction to and rejection of the strict Victorian ideals that had prevailed. Eat, drink, and be merry! The gospel according to Freud! Sexual revolution! Women were emancipated - voting, smoking, and drinking. The "modern" woman saw herself as sophisticated, worldly, even jaded, with brazenly short skirts, plunging necklines, short hair, and the "flagrant" use of rouge, lipstick, and other cosmetics. These, then, were the times that stimulated the Art Deco movement, the period and the jewelry. @chapter:16


Publication Year: 2017 Title: Interesting Growth Structure in Black Diamond Abstract: Figure 1. This 1.03 ct opaque round brilliant cut was identified as a black diamond. Photo by Yujie Li.

The color of most black diamonds is attributed to graphite micro-inclusions or metallic inclusions (S.V. Titkov et al., “An investigation into the cause of color in natural black diamonds from Siberia,” Fall 2003 G&G, pp. 200–209), and it is rare to see dense clouds of micro-inclusions producing a black appearance (see Spring 2007 Lab Notes, pp. 52–53). Since November 2016, the National Gemstone Testing Center (NGTC) in Shanghai has routinely received large quantities of polished black diamonds. One such stone, a 1.03 ct opaque round brilliant (figure 1) that we believed to have been heat treated, had a striking pattern of micro-inclusions we had never seen before.

Figure 2. The “double cross” pattern seen in the black diamond. This pattern showed that the small inclusions were restricted to certain sectors, indicating that the diamond crystallized through two separate processes. Photo by Yujie Li; field of view approximately 4 mm.
Microscopic observation revealed a “double cross” pattern arising from an abundance of pinpoint-like gray inclusions restricted to certain sectors of the diamond (figure 2). The outer black cross was oriented in the same direction as the inner pale cross. The inclusions’ crystalline forms were too small to resolve at 40× magnification. These small inclusions absorbed a large proportion of the light entering the diamond, causing the black appearance. The FTIR absorption spectrum confirmed the diamond was type IaAB and H-rich, with nitrogen-related absorption from 1000 to 1500 cm–1, a graphite-related peak at 1582 cm–1, and H-related IR peaks at 1405, 2785, 3050, 3107, 3154, 3236, 4169, and 4496 cm–1. We confirmed that the pinpoint-like inclusions were graphitized hydrogen clouds (see P. Johnson et al., “Hydrogen rich treated black diamonds,” poster presentation at Geological Society of America 2016 annual meeting).

Figure 3. The pattern as seen in the DiamondView. The well-developed cuboid growth sectors exhibited yellowish green fluorescence, while the poorly developed octahedral growth sectors were inert to the short-wave UV light. The DiamondView also revealed a mixed-habit growth structure.
When observed in the high-energy short-wave UV radiation of the DiamondView (figure 3), the bulk of this black diamond displayed moderate yellowish green fluorescence. Four small areas were basically inert to UV radiation; these also corresponded to the dark cross.
The unique double cross pattern and the DiamondView image revealed an interesting growth structure. The diamond apparently underwent two distinct phases of growth, with each phase forming a cross developing from separate mixed-habit growth with contemporaneous cuboid and octahedral sectors. The well-developed cuboid growth sectors contained regions with cloud-like light scattering that caused the black parts; very poorly developed octahedral growth sectors with a small amount of inclusions formed the light cross. The cuboid growth sectors exhibited yellowish green fluorescence, while the inclusion-poor octahedral sectors were inert to the short-wave UV light.

The interesting pattern of inclusions and distinctive growth features of black diamonds such as this one needs more attention.

Contributors’ note: This study was supported in part by the National Natural Science Foundation of China (grants 41473030 and 41272086). @chapter:11


Publication Year: 2015 Title: Large HPHT-Grown Synthetic Diamonds Examined in GIA’s Hong Kong Laboratory Abstract: These two large synthetic diamonds were produced using HPHT growth methods by the Russian firm New Diamond Technology. The 4.30 ct specimen on the left has D color and SI1 clarity. On the right is a 5.11 ct sample with K color and I1 clarity. Photo by Ming Yin Poon.

              Over the last decade, the jewelry industry has seen rapid improvement in the quality of synthetic diamond grown by the CVD (chemical vapor deposition) method. Colorless and near-colorless CVD synthetics with sizes up to 3.04 ct, with I color and SI1 clarity, have been reported. GIA’s Hong Kong laboratory recently examined two large synthetic diamonds created using the HPHT (high-pressure, high-temperature) method that demonstrated parallel progress in the two growth technologies. These samples, shown above, were produced in Russia by New Diamond Technology.

The first was a 4.30 ct cushion shape with D color and a clarity grade of SI1, based on three small clusters of metallic inclusions. The other was a 5.11 ct cut-cornered rectangular modified brilliant. It had K color and a clarity grade of I1, the result of a few metallic inclusions and two small fractures in the girdle area. Neither one showed reaction to long-wave UV radiation. When they were exposed to short-wave UV, a medium to strong green-yellow fluorescence was observed. Both showed strong yellow-green phosphorescence lasting more than 20 seconds. One noteworthy feature was the absence of pinpoint inclusions, which are common in HPHT synthetic diamonds and often distributed throughout the crystal.

Absorption spectra in the infrared region demonstrated these were type II diamonds, with no absorption band detected in the one-phonon region (approximately 1350–1000 cm–1) where nitrogen impurities occur. A very weak 2800 cm–1 band was attributed to trace substitutional boron. A higher boron concentration was recorded in the D-color synthetic diamond (7 ± 1 ppb, compared to 1.2 ± 0.2 ppb). Photoluminescence spectra collected at liquid-nitrogen temperature with varying laser excitations revealed an emission doublet at 736.6/736.9 nm from the silicon-vacancy defect, and an 882.7/884.4 nm doublet from the well-known Ni-related defect. Very weak emissions from nitrogen-vacancy centers at 575.0 and 637.0 nm were detected only in the K-color sample. Besides metallic inclusions, another important identification feature of HPHT synthetics is fluorescence. Typical fluorescence patterns showing multiple-sector growth were observed in both samples.

These two diamonds were disclosed as HPHT synthetic when submitted for examination. Tested using the GIA DiamondCheck device, both were referred for further testing. Gemological observations and spectroscopic features confirmed they were HPHT synthetics.

Examination of these improved HPHT synthetic diamonds, the largest synthetic diamonds produced by any method that GIA has examined so far, demonstrated significant progress in this growth technology. In addition to their use as gem materials, crystals of this size have many potential industrial applications. @chapter:15


Publication Year: 2009 Title: Chrysoprase and Prase Opal from Haneti, Central Tanzania Abstract: Commercial quantities of gem-quality chrysoprase and green prase opal (nickel-bearing chalcedony and common opal, respectively) have been recovered from altered serpentinite deposits near Haneti, Tanzania. Material studied for this report came from the largest mine, located on top of Iyobo Mountain, which has been actively exploited for two decades. Although somewhat similar in color and appearance, chrysoprase and prase opal can easily be distinguished from one another by differences in refractive index (~1.55 vs. ~1.45) and specific gravity (~2.60 vs. ~2.11). Chrysoprase makes up the vast majority of the output, and the mine shows good potential for continued production. @chapter:39


Publication Year: - Title: Instruments Revolutionize Gem Identification Process Abstract: Robert Shipley Jr.

                      Robert M. Shipley Jr., a bespeckled, quick-tempered young man who liked to drive fast and had a genius for innovation, joined his father at GIA in early 1933. His creative tinkering forever changed the way jewelers and gemologists around the world did business. The gem-testing equipment he designed made it possible to apply accurate gem-grading standards and made his father’s dream of gemology as an ethical, professional discipline a practical reality. While the father wasthe magnificent salesman of the gemological idea, it was the son who gave it a solid scientific backing.

Shipley Jr. quickly realized the advantage of dark-field illuminationin examining the interior of gemstones. He combined the idea with low-power stereoscopic magnification and produced the first DiamondScope, which he patented in 1938. Inspired by Edwin Land’s work at Polaroid, and with the help of French tool-and-die maker Raoul Francouer, he developed the first gem polariscope. Over the years, he also helped modify and perfect the refractometer, the Diamond Colorimeter, the Diamolite (later redesigned and named the DiamondLite), the Pearloscope, the Universal Motion Immersion Stage and the Mark III GemoLite microscope.

Shipley Jr.’s work inspired a band of gemological brothers to follow in his footsteps. Lester Benson, Kenneth Moore and Gale Johnson strove to meet the needs of the industry as the challenges of gem identification shifted and changed over the years.
Like Shipley Jr., Benson saw things from a “different” perspective. Alike in inventive imagination, these two men could not have been more dissimilar in temperament. Shipley Jr. was all “accelerator and brake,” while Benson was “calm and charming.”

	Benson’s contributions to gemology started shortly after he joined GIA in 1948, when developed the method of taking spot Refractive Index (R.I.) readings that is indispensable to gemologists today. To take advantage of this new technique, he later designed the first GIA Duplex Refractometer.

	His other contributions were equally far-ranging: he designed a pearl-testing X-ray unit, a base for gemological microscopes, and electrical conductometer, a light fixture with multiple baffles that turned florescent light into multiple spots and GIA’s Jeweler’s Camera. An expert in gem identification and photomicrography, he also redesigned the lab’s X-ray diffraction unit and adapted the spectrophotometer for gemological studies.

	When Benson died unexpectedly in 1961 at the age of 39, Liddicoat wrote that “Gemology was robbed of one of its leaders.”

	Shipley Jr. had begun his own instrument-manufacturing company after World War II, but when his interest in gemological instrumentation faded in the 1950s, he gave up the business. Benson, Moore and Johnson filled the void with iterations of the business until GIA bought it in 1966 and created GEM Instruments.

	The company grew steadily in the 1960s and ‘70s and created the ProportionScope, Mark V GemoLite microscope and overhead light, the GIA Illuminator Polariscope, the GIA Duplex Refractometer and the MiniLab. It introduced the revolutionary ColorMaster, designed to take the guesswork out of color-assessing colored gemstones, in 1980. This latest instrument set GIA firmly on the path of using special electronics in its equipment.

	At about this time and moving into the 1990s, GIA began to expand its product line to include electronic instruments that could detect diamond simulants. This equipment was created by other companies, but GIA’s research team often suggested adaptations to improve their features. GIA also began the shift in early 2000 to more advanced computer-based instrumentation designed to screen natural diamond from synthetic diamonds and simulants.

	Today, the instruments division is focused on meeting the needs of GIA research and education around the world and making sure its products meet global safety standards and regulations.

	Lester Benson

	Kenneth Moore @chapter:29


Publication Year: 2021 Title: Unique Non-Bead Cultured Freshwater Pearls from Lake Biwa, Cultured for 14 Years Abstract: Figure 1. The two Biwa pearl samples that were cultured for 14 years and acquired from Jinbo Pearls, measuring 19.75 × 10.38 × 9.84 mm (pearl A, left) and 23.48 × 12.36 × 11.08 mm (pearl B, right). Photo by Shunsuke Nagai.

Lake Biwa in Shiga Prefecture has been producing pearls since 1928, when commercial freshwater pearl culturing first started in Japan. Although production decreased in the late twentieth century due to environmental issues and the declining mussel population (S. Akamatsu et al., “The current status of Chinese freshwater cultured pearls,” Summer 2001 G&G, pp. 97–113), Biwa pearls harvested in the twenty-first century, as well as vintage ones, are popular in the Japanese market. Hyriopsis schlegelii, an indigenous freshwater mollusk found in the lake prior to the 1980s, was originally used as the host for pearl culturing before it was replaced by the hybrid Hyriopsis schlegelii × Hyriopsis cumingii freshwater mollusk.

Figure 2. Left: Macro images of pearls A and B. Photos by Nanthaporn Nilpetploy. Center and right: The internal structures as revealed by RTX and μ-CT analysis, respectively.
GIA’s Tokyo laboratory received for study 28 pearl samples with a stated Biwa provenance from Jinbo Pearls, a Shiga-based company that deals exclusively with freshwater pearls from Lake Biwa. Two of the largest samples (figure 1), weighing and measuring 16.08 ct, 19.75 × 10.38 × 9.84 mm (pearl A) and 22.85 ct, 23.48 × 12.36 × 11.08 mm (pearl B), respectively (figure 2, left), were selected for further detailed study. The intriguing fact was that they were reportedly grown over a period of 14 years—from 2002 to 2016. This is an unusually long growth period, since freshwater non-bead cultured (NBC) pearls normally take three years to form in Japanese farms. However, the farm where these samples originated was abandoned by the owner due to personal issues. Remarkably, several mussels were found alive when the farm was rechecked before being officially closed by the owner’s relatives in 2016. These two pearls were collected from two of the surviving mussels.

Figure 3. The fluorescence reactions of both pearl samples under optical X-ray fluorescence. The pearls prior to sawing (A-1, B-1) showed strong yellowish green reactions, with some weak yellowish orange areas within some imperfections around their circumference (white arrows, A-2, B-2). The sawn pearls (A-3, B-3) showed strong yellowish green reactions, with stronger reddish orange areas in some positions (A-4, B-4). Images by Kwanreun Lawanwong.
Real-time microradiography (RTX) examination revealed a faint linear feature along the length of each pearl (figure 2, center). X-ray computed microtomography (µ-CT) analysis showed these features more clearly and revealed an additional small dark void at the end of pearl A’s linear structure (figure 2, right). Their internal structures corresponded well to other non-bead cultured freshwater pearls described in previous studies (M.S. Krzemnicki et al., “X-ray computed microtomography: Distinguishing natural pearls from beaded and non-beaded cultured pearls,” Summer 2010 G&G, pp. 128–134). Additionally, optical X-ray fluorescence analysis showed a strong yellowish green reaction with weak yellowish orange areas within some imperfections around the circumference of the pearls (indicated by white arrows, figure 3, A-2 and B-2).
Each pearl was cut in half (cut surfaces were cleaned with isopropyl alcohol) and the examination results were compared with those obtained prior to sawing. Surprisingly, both showed stronger reddish orange optical X-ray fluorescence reactions within small areas along the central structure lines (RTX and μ-CT analysis) visible on each sawn face (figure 3, A-4 and B-4) than on any external surface areas when the pearls were intact. Such reactions are sometimes seen in natural and freshwater cultured pearls (Summer 2013 Lab Notes, pp. 113–114; Spring 2019 Lab Notes, pp. 94–96; S. Karampelas et al., “Chemical characteristics of freshwater and saltwater natural and cultured pearls from different bivalves,” Minerals, Vol. 9, No. 6, 2019, article no. 357, pp. 16–17).

Figure 4. Photomicrographs of the cross sections showing some dull white frosty surfaces (black arrows, A-3, B-3) that correspond to the areas showing reddish orange fluorescent reactions under optical X-ray fluorescence. Field of view 19.20 mm (A-1, B-1), 14.40 mm (A-2, B-2), and 2.88 mm (A-3, B-3). Photos by Kwanreun Lawanwong.
It was especially interesting that the reactions seemed to correlate with the dull frosty white surface areas along the central structure lines on the sawn-faces when observed under the microscope at higher magnifications (indicated by black arrows in figure 4, A-3 and B-3). This observation was consistent with previous studies on freshwater cultured pearls (Spring 2019 Lab Notes, pp. 94–96).
Raman analysis of these areas showed they consisted of two CaCO3 polymorphs: aragonite and vaterite. Aragonite features were visible at 701, 704, and 1085 cm–1, while vaterite features were noted at 740, 750, 1075, and 1090 cm–1. Aragonite and vaterite in cultured FW pearls have previously been recorded (U. Wehrmeister et al., “Vaterite in freshwater cultured pearls from China and Japan,” Journal of Gemmology, Vol. 30, No. 7/8, 2007, pp. 399–412; A.L. Soldati et al., “Structural characterization and chemical composition of aragonite and vaterite in freshwater cultured pearls,” Mineralogical Magazine, Vol. 72, No. 2, 2008, pp. 579–592; H. Ma et al., “Vaterite or aragonite observed in the prismatic layer of freshwater-cultured pearls from South China,” Progress in Natural Science, Vol. 19, No. 7, 2009, pp. 817–820). Furthermore, calcite was also detected in pearl A, where peaks at 280, 714, and 1085 cm–1 were observed. The first two peaks were isolated and did not appear in association with any other peaks (groupings or doublets), proving they were another CaCO3 polymorph. Up until recently, calcite had not been reported in freshwater cultured pearls, though it was found in a small area of pearl A in this study and was also noted in a pearl discussed in a recent study (S. Eaton-Magaña et al., “Raman and photoluminescence mapping of gem materials,” Minerals, Vol. 11, No. 2, 2021, article no. 177, pp. 24–27).
Further advanced analysis of the cross sections’ trace element concentrations was conducted using laser ablation–inductively coupled plasma–mass spectrometry (LA-ICP-MS). The reddish orange fluorescent areas were shown to contain much higher Mg (1250 ppmw for pearl A and 2260 ppmw for pearl B) and lower Na (1210 ppmw for pearl A and 1310 ppmw for pearl B) concentrations than other areas of the samples not exhibiting the reaction (Mg lower than 77 ppmw and Na higher than 1930 ppmw). This result is consistent with those detailed in the literature (Soldati et al., 2008; Eaton-Magaña et al., 2021). The results seemed to correspond with the Raman data, and the different Mg and Na ratios helped to separate aragonite and vaterite, though it is difficult to differentiate calcite from either without performing Raman analysis.
Vaterite within the structure of NBC FW pearls is thought to be related to the biomineralization process that results following the tissue/mantle insertion (Wehrmeister et al., 2007), and its presence is a strong indicator of a cultured origin. These two unique pearls are a part of 28 Biwa pearl samples collected over various time frames. Since they are worthy of being singled out for discussion, this brief report is a precursor to a more detailed review of both pearls and the other Biwa pearl samples referenced. @chapter:14


Publication Year: 2021 Title: Bicolor Rough Diamond Crystals Abstract: Figure 1. These two rough diamond crystals (1.75 ct on the left and 1.44 ct on the right) are rare examples of diamonds showing both pronounced pink and colorless sections. Field of view 10.8 mm (left) and 7.4 mm (right). Photos by Michaela Hariňová (left) and Nathan Renfro (right).

The GIA laboratory in Antwerp regularly receives pink diamond crystals for examination as part of the Diamond Origin Report. This recent service has allowed GIA researchers to study a greater number of rough diamonds in addition to their faceted counterparts. Two crystals, weighing 1.75 and 1.44 ct and both reportedly from Australia, were among those submitted. These were considered quite interesting, as they contained colorless and pink sections with distinct boundaries (figure 1).
The color in the vast majority of naturally pink diamonds is attributed to a broad absorption band at about 550 nm within the visible absorption spectrum. This band generally results from distortion of the crystal lattice from plastic deformation due to stress after crystal growth. However, much remains unknown about the actual formation and configuration of this feature. Therefore, these two crystals provide a unique chance to study natural diamond formation and the origin of pink color in greater detail.
The pink section of both analyzed samples likely experienced great stress in order to undergo the plastic deformation necessary to impart the pink color. The colorless sections were not similarly deformed so presumably they represent a different and later growth event (figure 2).

Figure 2. A close-up image of the 1.44 ct diamond crystal shows the boundary between the pink (left) and colorless (right) sections. Photo by Nathan Renfro; field of view 3.16 mm.
Visible-NIR absorption spectra collected from the pink and near-colorless sections of the diamonds show differences in the 550 nm region. Observed in the spectrum for the pink portion is the expected absorption at 550 nm, while the spectrum for the colorless portion shows a lack of absorption (figure 3, left).

Figure 3. Left: Vis-NIR absorption spectra for the 1.44 ct crystal collected from the pink and colorless sections. The 550 nm absorption band is prominently visible within the pink section. The spectra are stacked for clarity. Right: PL spectra with 532 nm excitation of the 1.44 ct crystal show a ~600–730 nm emission band collected from the areas of pink banding, which was not detected from the colorless section—this luminescence band has previously been linked with the 550 nm absorption band. The diamond Raman peaks are scaled as equal.
For the 1.44 ct crystal, we also collected infrared (IR) absorption spectra and photoluminescence (PL) spectra from both the pink and the colorless sections using 455 and 532 nm laser excitation wavelengths. The IR absorption spectra for both sections indicate type Ia diamonds with saturated concentrations of nitrogen. Due to this saturation, it was not possible to determine the total nitrogen content or the ratio of the A and B nitrogen centers, which could have helped in further distinguishing these two sections.
Within the PL spectra, the peak widths for the diamond Raman peak and the H3 peak were comparable in both the pink and colorless sections. Additionally, a PL peak at 676 nm was detected in both sections; although its configuration is unknown, it was documented previously in other rough pink diamonds (E. Gaillou et al., “Spectroscopic and microscopic characterizations of color lamellae in natural pink diamonds,” Diamond and Related Materials, Vol. 19, No. 10, 2010, pp. 1207–1220). The other notable feature detected by PL mapping was a broad (~600–730 nm) emission band (figure 3, right) that coincided with the pink banding revealed by immersion in methylene iodide (figure 4). Its detection is consistent with other pink diamonds and likely related to the 550 nm absorption band (e.g., S. Eaton-Magaña et al., “Comparison of gemological and spectroscopic features in type IIa and Ia natural pink diamonds,” Diamond and Related Materials, Vol. 105, 2020, p. 107784).

Figure 4. The 1.44 ct crystal was immersed in methylene iodide to reveal additional details. The red arrows within the inset (field of view 3.4 mm) indicate the pink banding. Photos by Troy Ardon.
As natural pink diamonds are quite rare, finding two examples of such bicolor crystals that show these distinct pink and colorless sections is an extraordinary find. @chapter:11


Publication Year: - Title: LA Museum Hosts Rare Fancy Colored Diamond Exhibit Abstract: The oval cut 30.03 ct Juliet Pink diamond set in a necklace of 98.70 carats of colorless diamonds on display at Los Angeles Museum of Natural History. Photo courtesy of L.J. West.

	The rarest fancy colored diamonds make world headlines selling for tens of millions of dollars at auction. Like celebrities, they are well known in photographs − but rarely seen in person.

	Until March 19, 2017, visitors to the Los Angeles Natural History Museum have the opportunity to view three exceptionally rare fancy colored diamonds: a 30.03 carat (ct) Fancy Intense Pink, a 2.83 ct Fancy Deep Grayish Bluish Violet and a 1.64 ct Fancy Vivid purple diamond, all loaned by L.J. West, the New York fancy colored diamond house, for an exhibit called “Diamonds: Rare Brilliance.”

	The large pink, named the Juliet Diamond, was cut from a 90 ct rough found in South Africa and set in a necklace with 98.70 carats of round brilliant, pear and marquise cut colorless diamonds of E and F color, VVS clarity.

	The violet diamond is the largest diamond of that color ever found in Australia’s Argyle Mine − 9.17 ct in rough. Named The Argyle Violet, it was the cornerstone item in the mine’s 2016 diamond tender.

	The Victorian Orchid Vivid Purple diamond is one of the very few diamonds of that color ever found.

View Gallery

	In addition to the three rare individual diamonds, L.J. West created the Rainbow Necklace from 88 fancy radiant cut colored diamonds of multiple hues. The total diamond weight is 35.93 ct.

	At the opening reception, Dr. James Shigley, distinguished research fellow at GIA, where the diamonds were graded, explained the forces of nature that create fancy colored diamonds and their rarity compared to colorless or fancy yellow diamonds.

	The exhibit is on display in the museum’s gem and mineral hall. @chapter:29


Publication Year: 1987 Title: A New Gem Material from Greenland: Iridescent Orthoamphibole Abstract: Orthoamphiboles with pronounced iridescence are found in eight localities in the vicinity of Nuuk, the capital of Greenland. The iridescence, difficult to see on rough samples, becomes clearly visible when the material is cut. This iridescent orthoamphibole is mined by a company wholly owned by Nuuk commune, and is sold under the trade name Nuummite. This orthoamphibole has a composition similar to that of iridescent orthoamphiboles described earlier from Greenland as well as from New Hampshire and Massachusetts, but is believed to be the first such orthoamphibole to be regarded as a gemstone. @chapter:0


Publication Year: - Title: Amethyst Care and Cleaning Guide Abstract: With proper care, amethyst is a beautiful and versatile gemstone for jewelry use. - Courtesy Epstein

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

Common substances like sand and dust are composed mostly of quartz, the mineral species that includes the purple variety amethyst. So, while amethyst is a great gemstone for use in jewelry, it should be treated with the proper care to prevent scratching and other damage.

Amethyst rates a 7 on the Mohs scale and has good toughness, so it is suitable for all jewelry types. This includes rings as long as the wearer understands the limits of its hardness.

A ranking of 7 on the Mohs scale means amethyst is a durable jewelry gem as long as proper precautions are followed to prevent scratching.

	A ranking of 7 on the Mohs scale means amethyst is a durable jewelry gem as long as proper precautions are followed to prevent scratching.
Stability
Abrupt temperature changes can cause amethyst to fracture. Some amethyst color can fade with prolonged exposure to intense light. Amethyst can also be damaged by hydrofluoric acid, ammonium fluoride, and alkaline solutions.

Cleaning
Amethyst can be safely cleaned with warm soapy water. Ultrasonic cleaners are usually safe except in the rare instances where a stone is dyed or treated by fracture filling. Steam cleaning is not recommended, and amethyst should not be subjected to heat. @chapter:23


Publication Year: - Title: Rose Quartz Description Abstract: The soothing soft pink shades of rose quartz appeal to gem carvers and collectors. – Valerie Power, courtesy Arunashi

                      People accept a certain amount of sand, dirt, and dust as ordinary ingredients in their lives. What they might not be aware of is that those substances are mostly quartz, one of the most common minerals on earth.

	There are many attractive and well-known quartz varieties. The oval gem—fourth from the right—is rose quartz, one of the less abundant gems in the quartz family. – Robert Weldon
Rose quartz is one of the many quartz varieties used as a gem material. It gets its name from its delicate pink color, which ranges from very light (almost white) to medium-dark. The most appealing color typically occurs in larger sizes, and small rose quartz specimens with good color tend to be rare. Rose quartz is always found in massive form, so it lacks regular, flat crystal faces. It’s typically found in pegmatites, but also occurs in hydrothermal veins.

Research has shown that rose quartz owes its delicate pink color to microscopic inclusions of aligned silicate mineral fibers. Advanced testing has shown that they’re generally similar—but not identical—to the mineral dumortierite. The fibers likely crystallized out as the host gem cooled, and they’re aligned according to the crystal directions of the rose quartz.

	Rose quartz contains mineral inclusions that give it a soft pink color. This ring was carved from a single piece of rose quartz. - Eric Welch, courtesy Jana Miyahira-Smith

	Rose quartz beads, cabochons, and rough make an enticing arrangement in a store’s display case. – Robert Weldon
This pastel gem’s inclusions give it a characteristic cloudy translucence, so it’s generally cut into beads and cabochons. Sometimes, the inclusions produce a six-rayed star if the fashioned gem is cabochon-cut and correctly oriented. Fine examples show a distinct, sharp, star floating above even pink bodycolor. The most transparent rose quartz rough might be faceted. Cutters can intensify the delicate color by applying concave facets and cutting gems in larger sizes.

	This star rose quartz is considered fine quality because of its depth of color, degree of transparency, and sharply defined star. – Robert Weldon
The delicate translucence of rose quartz inspires gem carvers to create dainty or whimsical figures. The finest-quality rose quartz rough typically comes from Brazil. Other sources include India, Madagascar, and Sri Lanka.

	This adorable piglet was carved by Gerd Dreher from rose quartz mined in Madagascar. – Robert Weldon
Besides the typical cloudy rose quartz, which is colored by inclusions, there’s a type of transparent quartz that owes its pink color to a different mechanism. Some in the trade call it “pink crystalline quartz,” “crystalline rose quartz,” or simply “pink quartz.” Compared to massive rose quartz, it’s exceptionally rare. It might occur as beautiful clusters of transparent, well-formed crystals. The finest examples are from Brazil, especially a deposit near Galiléia, located near Governador Valadares in the state of Minas Gerais. The best are often left as mineral specimens, which can command high prices at auction. In 2013, a superb example called La Madona Rosa (the Pink Madonna) sold for $662,500. This specimen measures 15.5 x 8 inches (39 x 20 cm) and features a core of smoky quartz that resembles a human form surrounded by a glittering halo of transparent pink quartz crystals.

Material from some of these deposits will fade when exposed to natural light, but its color can be restored by irradiation. Research by Russian crystal growers on synthetic pink quartz has demonstrated a color-causing mechanism, which can cause results very similar to the natural material. Growers produce pink color in transparent synthetic quartz by growing it with impurities of aluminum and phosphorous. Some of these impurities replace silicon in the quartz lattice. Subsequent irradiation produces color centers that give the crystal its pink color. @chapter:2


Publication Year: 2012 Title: Gemstones from Vietnam: An Update Abstract: This article describes the major gem materials of Vietnam, together with their new finds and recent production. The gemological properties and chemical composition of ruby, sapphire, spinel, tourmaline, garnet, and peridot from the most important Vietnamese sources are updated. Other gems such as aquamarine, green orthoclase, topaz, zircon, quartz, and pearls are briefly discussed. Commercially significant deposits of ruby, blue and fancy sapphire, and spinel are located in two northern provinces: Yen Bai (Luc Yen and Yen Binh Districts) and Nghe An (Quy Chau and Quy Hop Districts). Large volumes of blue, green, and yellow sapphire come from the Central Highlands provinces of Dak Lak and Lam Dong, as well as the southern provinces of Dong Nai and Binh Thuan. Of secondary commercial importance are the tourmaline and garnet from Yen Bai and the peridot and zircon from the Central Highlands. @chapter:3


Publication Year: - Title: Diamond Lattice Defects: GIA Researchers Explore Internal Tagging and Gray-Blue-Violet Diamond Color Abstract: GIA researchers Troy Ardon, left and Chloe Peaker, presented their diamond quantum findings at the recent Princeton-GIA Symposium. Ardon focused on an internal diamond tagging application and Peaker looked at why some diamonds have gray-to-blue-violet color.

GIA scientists presented their latest research on diamond tagging and the cause of gray-blue-violet color in diamonds at the Princeton-GIA Diamond Symposium, sponsored by GIA, on Jan. 24 at Princeton University.
The annual symposium is held to foster collaboration among quantum experimentalists, material scientists and industrial partners. Participants included quantum and materials research groups from the Argonne National Laboratory, Institut Néel Grenoble, City College of New York, Cornell University, CUNY College of Staten Island, IBM Quantum, Princeton and the University of Pennsylvania.
“This symposium is a wonderful way to bring together academic and industry scientists in the area that they are working on in a number of topics related to diamond, materials, spectroscopy and quantum technologies,” said Nathalie de Leon, associate professor of electrical engineering at Princeton and the organizer of the conference. “The discussions and the collaborations that resulted are incredibly valuable, and my students and I have really enjoyed the breadth of topics.”
Internal Diamond Tagging
Troy Ardon, who has a master’s in diamond science and technology from the University of Warwick in the UK and is a research associate at GIA in Carlsbad, presented "Laser Writing the H3 Defect into Natural Ia Diamond," which involves researching how to use laser writing to create an internal tagging system for diamonds.
In order to understand the possibilities, according to Ardon, you need to understand the structure of a diamond. A diamond is made up of carbon bonded together in a repeating structure known as a lattice. Pure diamond is pure carbon, nothing else, he said. It is very common, however, for non-carbon atoms (the most common is nitrogen) to be “substituted” into the diamond lattice. When a single nitrogen atom takes the place of a carbon atom, it is called substitutional nitrogen. A vacancy is just a missing carbon atom - an empty space in the lattice.

These lattice models show the differences between pure diamond, left, and diamonds with defects, center and right. Illustration by Troy Ardon/GIA
“You can combine these defects in a number of different ways, such as the H3 defect – a nitrogen-vacancy-nitrogen structure in the lattice,” Ardon said. “We used high powered focused laser pulses to knock carbon atoms out of the lattice, creating vacancies. The nitrogen was present in the form of A centers. We then annealed (slowly heated) the diamonds to ‘migrate’ the vacancies into the A-center to create the H3. We wanted to see if we could create H3 defects that can be measured above the background – one that ‘stands above the crowd’ so to speak.”
The results?
“We successfully wrote the H3 defect in a natural diamond with a low H3 background without producing visible damage,” he said. “We were not successful in writing a measurable H3 in a diamond with a high background, even with high energy pulses, which means we will have to expand our search for other writeable defects.”
Ardon said this kind of fundamental research from diamond quantum photonics ‒ a catch-all term for diamond optics and the usage of diamond defects as photon sources ‒ can be turned into a potential application for the gem industry: the creation of a robust internal tagging system. The goal is to create a unique serialized mark (similar to a QR code) to help prevent fraud and improve traceability.
“I greatly enjoy using new and fundamental research and applying it to an industry with which most people are familiar,” he said. “It almost provides a conduit to get information about high level research to a wide audience. It’s fun to connect new scientific ideas/methods with real world applications that anyone can understand.”
How do gray-to-blue-to violet diamonds get their color?
Chloe Peaker, Ph.D. and a postdoctoral research associate at GIA in New York, presented "Transition Metal Centers: A Potential Cause of Color in Gray-to-Blue-to-Violet Hydrogen-rich Diamonds," a snapshot of a theoretical and experimental study investigating what defect causes the color of rare gray-blue-violet diamonds.
“The cause of this diamond color has eluded the community thus far,” Peaker said. “The diamonds are rare and very valuable because the color is unique to naturals and has not been seen in laboratory- grown or treated stones.”
The color of the stone can be investigated by looking at the UV-visible absorption spectrum, she said, but from a theoretical perspective, identifying peaks and the responsible defect is inherently difficult.
Peaker said the study initially focused on the identification of the defect that causes the 3236 cm-1 absorption, a well-defined peak seen in Fourier-transform infrared spectroscopy (FTIR), an absorption spectroscopy technique that looks at absorption of light in the infrared range, as opposed to UV-visible spectroscopy that looks at absorption of light in the UV-visible range. The 3236 cm-1 peak is the second most prominent peak after the 3107 cm-1 peak, which was finally identified by combining theory with experimental stress results - after nearly 50 years of research.

In this example of a metal-nitrogen defect in diamond, the lattice is composed of one nickel atom (in red) centered in a vacancy where a carbon atom has been removed. The nickel is surrounded by four nitrogen atoms (blue) and two carbon atoms (gray). This defect is labelled as NiN4V (V refers to the vacancy) and is also referred to as NE8, a label used to identify the spectroscopic signature seen in EPR (electron paramagnetic resonance). Illustration by Chloe Peaker/GIA
“I presented promising theoretical results of metal-nitrogen-hydrogen vibrations that are found in this region of the FTIR spectrum, although an identification based on one piece of evidence is unwise,” Peaker said. “I also speculated on the formation pathway by comparing the spatial distribution of the 3236 with the 3107 peak in mixed-habit diamonds.”
Although more work needs to be done to discover what creates the gray-to-blue-violet color in these diamonds, Peaker is eager to continue her research.
“I would love to be the one that discovers what causes the color,” she said. “Knowing what causes it would be the first step to see how the defect responsible could be reproduced or modified. I would like to find out something that could have wider implications in the diamond industry. It is exciting to research the unknown!”
The opportunity for these researchers to present at Princeton-GIA Diamond Symposium gave them access to more information about quantum theory – the study of the nature and behavior of matter and energy at the atomic and subatomic level – and its possible applications in the study of gemstones.
“The conference was well attended and all the speakers seemed to have put a lot of work into their talks,” Ardon said. “There was quite a lot of discussion about new developments in quantum computing and using diamond defects as qubits, which was fascinating to learn about.”
Peaker was impressed by what she learned about quantum computing.
“Quantum computing has grown in (quantum) leaps and bounds,” she said. “It seems like a promising future in materials science as a whole.” @chapter:11


Publication Year: 2013 Title: Unusual Epigenetic Malachite Discs in Quartz Abstract: Figure 1. This 52.99 ct freeform cabochon of rock crystal quartz, reportedly from Brazil, contained several epigenetic discs of malachite. Photo by Robison McMurtry.

              When mineral-rich fluids become trapped in open cracks and evaporate, they can leave behind epigenetic mineral precipitates. These epigenetic mineral deposits are fairly common in gem materials, usually taking the form of brownish iron oxide staining in cracks. These deposits are often a nuisance, impairing the potential beauty of the finished gem, but occasionally they contribute vibrant colors with interesting geometric shapes, such as inclusions of pyrite trapped in cracks in quartz.

	Figure 2. These radial discs of epigenetic malachite were trapped within cracks of rock crystal quartz. Photomicrograph by Nathan Renfro; shadowed illumination, field of view 2.15 mm.
An unusual freeform cabochon of rock crystal quartz (figure 1), obtained from Leonardo Silva Souto (Cosmos Gems, Teófilo Otoni, Brazil) and reportedly of Brazilian origin, was examined at GIA’s Carlsbad laboratory. The 52.99 ct stone contained several interesting inclusions of malachite (figure 2). These inclusions were obviously epigenetic, as they were confined within secondary cracks in the quartz host. This planar confinement caused the inclusions to grow outward after nucleating. The flattened discs were particularly interesting due to the vibrant interference colors visible in polarized light (figure 3), as well as their uniform structure. The identification of the inclusions and the host was confirmed by Raman spectroscopy.

	Figure 3. In polarized light, these malachite discs showed vibrant interference colors. Photomicrograph by Nathan Renfro; field of view 2.15 mm.
Malachite has been previously reported as a syngenetic inclusion in chalcedony and gypsum (e.g., E.J. Gübelin and J.I. Koivula, Photoatlas of Inclusions in Gemstones, ABC Edition, Zurich, 1986), but epigenetic malachite in quartz is rather uncommon. In this stone, the resulting vivid green color is an improvement over the otherwise ordinary, colorless quartz. @chapter:13