# Publication Year: -
# Title: Katzenbach Designs Honored with Two AGTA Awards in Two Years
# Abstract: Derek Katzenbach’s award-winning, 18K kaleidoscope features 71.74 carats of Maine tourmaline and 66.05 carats of Maine quartz between three separate lenses. Gifted to GIA by a private donor in memory of Nicholas Scott Golden, University of Maine Geology student. Photo by Brian Moghadam Photograhy/AGTA. Courtesy of Derek Katzenbach

There’s one question that keeps award-winning jeweler and gem cutter Derek Katzenbach motivated to “push the boundaries” of his own skills: “How did you do that?”

Katzenbach, a GIA GJG, asks it of the artists he admires, and he hopes his designs can pique a similar curiosity.

Katzenbach’s work has earned the New Jersey native two honors from the American Gem Trade Association (AGTA) in the last two years. In 2016, he won “Best Use of Color” in the Summer AGTA Spectrum Awards for a bicolor tourmaline ring created for a client, and in 2017, he took home first place honors in the Spectrum Awards’ “Objects of Art” category for his “Colors of Maine” gemstone kaleidoscope.

The recognition is exciting and humbling for Katzenbach, who owns Katzenbach Designs, a studio in the mountains of Maine that specializes in locally sourced tourmaline, precision faceting, fantasy-cut gemstones and custom-designed jewelry.

“My philosophy when designing a piece is to follow what the stone tells you,” Katzenbach says. “The best pieces come from taking risks throughout the process – it’s the only way to develop your own style and see what will work.”

Katzenbach cut this colorful, 38.04-ct Bolivian ametrine with an original design. Courtesy of Derek Katzenbach
Katzenbach, who counts artists like Dalan Hargrave, Ryan Joseph Anderson and Richard Homer among his inspirations, did not set out to become an artist or jeweler. He first moved to Maine to study marine biology, and though the subject had been a laser-focus for him since elementary school, something “didn’t click” once he began his studies.

During that time, Katzenbach visited a local gem show.

“I spent a week’s pay in about an hour, then went to the ATM and did it again,” he says. “I had zero experience buying, setting or designing stones. But I was officially addicted, and I didn’t know what had hit me.”

That summer, Katzenbach worked at a store that sold a variety of gifts, from knives to locally made jewelry. His boss showed him how to set stones in pre-notched settings, and Katzenbach began to introduce himself to others in the field who could help him navigate this newfound interest.

Derek Katzenbach, GJG, created this 12-ct, fantasy-cut stone from Colorado topaz rough. Courtesy of Derek Katzenbach
One jeweler in town connected him with local bench jeweler Addison Saunders, who became a mentor and friend. He took lessons with her for a year, learning foundational skills such as soldering and basic settings, before moving across the state. Ron Gelinas, the owner of Farmington’s Mainestone Jewelry, told Katzenbach that though he wasn’t hiring, he would show him some repair skills on Saturdays. The two struck up a friendship as Gelinas taught him how to do chain repairs and resizing.

Eventually the holidays arrived, and Gelinas offered Katzenbach his first job in the gem and jewelry industry. Katzenbach was elated, and soon began to ask Saunders and Gelinas where he could pursue further knowledge and skills. “I felt it was incredibly important to be educated properly,” he says. “They both pushed me to go to the best school in the world, GIA.”

He arrived at the Institute’s Carlsbad World Headquarters in 2005 and immersed himself in gemology and benchwork studies. Katzenbach says the instructors “went above and beyond” and he took advantage of every opportunity to learn.

“I was extremely driven,” he says. “I spent most of my spare time checking out books and instructional DVDs from the library. The amount of knowledge that sits in that building is staggering, and motivation was everywhere. Walking the halls, you see incredible displays of jewelry, minerals and faceted stones.”

This 1,452-ct, trillion-cut smoky quartz, mined at Maine’s Mount Mica, earned Katzenbach the record for the largest faceted gemstone ever cut from Maine. The gem is as big as the palm of a hand. Courtesy of Derek Katzenbach
Katzenbach passed the 20-stone exam for his GG diploma on the first try, and said that as much as he had to work, it almost felt “effortless.”

Returning to work at Mainestone after his 2006 graduation, Katzenbach was able to utilize his skills immediately as he worked on repairs, appraisals, stone cutting and custom work.

“It was the holidays – the busiest time of year for jewelers – and I was able to handle every project I was given with ease because of my GIA experience,” he says.

After a year, he began to travel around the state, selling Maine tourmaline to other jewelers. That experience, he says, opened the door to starting his own business in 2010.

“My career has been all over the place, and I try to do a bit of everything,” Katzenbach says. He wants to work on perfecting his engraving techniques, using the skills Hargrave showed him to carve larger sculptures. He also continues to create custom designs, such as the award-winning tourmaline ring.

This matched bi-color tourmaline suite, including an AGTA Spectrum award-winning ring, was designed by GIA alumnus Derek Katzenbach and recently gifted to GIA by a private donor in memory of Nicholas Scott Golden, University of Maine Geology student to the Institute by a private donor. The 14K white gold pieces, featuring tourmalines from California’s Himalaya Mine, also feature yellow diamonds, tsavorites, and rubellite. Photo by Orasa Weldon/GIA
The client who purchased that ring also commissioned a matching pendant necklace and earrings, and recently gifted the entire suite to GIA.

“Having that suite donated to GIA makes that award mean even more,” he says. “GIA was the starting point for so much knowledge and hard work. I’m so happy to see pieces of jewelry like that being preserved, shown to students, and kept in the place that gave me the knowledge to do such fine work.”

Derek Katzenbach, GJG, is an award-winning jeweler and gem cutter who studied at GIA’s world headquarters in Carlsbad in 2005 and 2006. His advice for current students? “Utilize the library,” he says. “The Richard T. Liddicoat Gemological Library and Information Center is world-class, and you will most likely never again have the opportunity to access so much knowledge about our trade, right in front of you.”  Courtesy of Derek Katzenbach
And though he’s created award-winning designs and one-of-a-kind pieces for clients, Katzenbach’s favorite piece of jewelry is his own hammered gold wedding ring, made of gold nuggets from a nearby river that he melted down. Katzenbach, who lives in Farmington with his wife, Laura, and their children, Kyran and Scarlett, knows that piece may be hard to top, but looks forward to what lies ahead.

“The best part of my job is looking for the next big project,” he says. And whatever that project is, Katzenbach says if his designs inspire curiosity, he knows he’s doing something right.

“It means I’m on the right track.” @chapter:28 @chapter:2 @chapter:28


# Publication Year: -
# Title: A Study of Sapphire from Chanthaburi, Thailand and its Gemological Characteristics
# Abstract: Rough and facetted sapphires from Thailand. The large facetted stone in the center weighs 8.14 ct. Photo by Wim Vertriest © GIA.  Gems courtesy of Indy Khurana (Khurana Jewels, Bangkok).

Thailand has been a leader in the global corundum trade since the 1950s. Bangkok and Chanthaburi remain important treatment and trading centers even though many—though not all—of the country’s corundum deposits are nearly exhausted. Since the early 2000s, there’s been a small-scale mining revival in Thailand’s Chanthaburi province. Chanthaburi’s sapphire deposits are associated with alkali basalts, where the gems occur as xenocrysts in basalt in the Khao Ploy Waen and Bang Kacha areas. Local farmers partner with miners to work the sapphire deposits and return the land back to agricultural use when mining ceases.

A new report from the GIA Laboratory in Bangkok, A Study of Sapphire from Chanthaburi, Thailand and its Gemological Characteristics presents their findings. 59 blue/greenish-blue sapphire samples obtained from a miner in the Khao Ploy Waen area, Chanthaburi, were fashioned to optimize them for LA-ICP-MS chemical analysis, UV-Vis-NIR and FTIR spectroscopy, and inclusion studies using microscopy and Raman spectroscopy.

Thai sapphires resemble gems from other basalt-related deposits in Cambodia, Nigeria, Cameroon, Australia, Laos and Northern Madagascar. As sapphires from these sources share similar geologic origins, it’s challenging to discriminate between them. Magnification revealed angular growth structures, needles, and particles, along with mineral inclusions like plagioclase feldspar, zircon, pyrochlore, monazite, mica, and molybdenyte. UV-Vis-NIR and FTIR spectra show features typical of basalt-related sapphires. Although LA-ICP-MS analysis showed a large overlap with the trace element chemistry of sapphires from other basalt-related deposits, the authors identify some overall trends that could prove helpful. They also suggest a combination of techniques—trace-element chemistry and microscopy—can help separate Thai blue sapphire from Cambodian and Nigerian samples with similar characteristics. However, the authors note to further support geographic origin determination, the relationship between inclusions, spectra and chemistry in basalt-related sapphires needs further analysis and study. @chapter:14 @chapter:0 @chapter:14


# Publication Year: 1993
# Title: Garnets from Altay, China
# Abstract: Gem-quality spessartine garnet and grossular garnet have been discovered in Altay, China. Gemological and mineralogical studies show that their properties are typical for these garnet species. Spessartine and grossular are being mined commercially, but gem-quality grossular with fine color is rare. @chapter:7 @chapter:0 @chapter:7


# Publication Year: -
# Title: How to Travel Brazil: Gemstones Edition
# Abstract: A selection of Brazilian gemstones. (From top, clockwise): rubellite tourmaline, emerald, aquamarine, imperial topaz, yellow topaz, bicolor tourmaline. Center: Paraiba tourmaline and brown diamond. Photo by Robert Weldon/GIA.

Brazil is a tropical locale well-known for exotic animals and plants, futból, sandy beaches, and jungle-clad mountains. Some of these mountains rise like monuments in the middle of cities, such as Sugarloaf Mountain in the ever-colorful and playful Rio de Janeiro. The country also contains the renowned Amazon River, not to mention superb gemstones in a kaleidoscope of saturated, luscious colors.

From the Mirador, this iconic vista of the city of Rio de Janeiro encompasses picturesque bays and inslets, surrounded by inselbergs, or mountains that jut out across the landscape. Photo by Robert Weldon/GIA
 Brazil’s rich natural gemstone resources include many varieties of tourmaline, topaz, beryl, and quartz, among others.

		If you’re a gem lover, Brazil is the dream destination, sure to top your bucket-list of must-see places in the world.

So as you plan your dream vacation, read these travel tips and information to help you get the most of your trip to Brazil.
Tourmaline

In tourmaline alone: orange, yellow, green, blue, and violet varieties hail from almost every corner of this enormous country. They are particularly found in Brazil’s state of Minas Gerais (a name which appropriately translates to “General Mines.”) It is also home to Paraíba tourmaline, a unique, electric blue-green variety, which derives its color from microscopic traces of copper. These gems are found in the northern state of Paraíba, to which they owe their name. Occasionally, the colors in tourmalines are mixed, resulting in bi-color or multicolored gemstones. There’s enough choice in tourmaline to capture everyone’s fancy.
Beryl

Miners often use water and specific gravity in a sifting exercise to separate out denser materials like gemstones. When the basket is emptied, upturned on the ground, the gems are visible on the top. Photo by Robert Weldon/GIA
Almost every member of the beryl family is represented as well: ocean-blue aquamarines and leafy green emeralds, delicate pink morganites and bright yellow heliodors make up this interesting Brazilian gem family. Cat’s-eye chrysoberyls and the extremely rare color-change alexandrites are found in Brazil as well.
Quartz

In Southern Brazil¹s state of Rio Grande do Sul the gem mines there include important deposits of amethyst and other quartzes, as well as chalcedonies. Photo by Robert Weldon/GIA
Take a trip down to Southern Brazil, known for its quartzes. Amethyst, citrine, rock crystal, and a huge variety of agate come from the State of Rio Grande do Sul. From the State of Bahia to the north comes one of Brazil’s most exotic quartzes, the dazzling, rutilated quartz. This beautiful gemstone features gleaming streaks of golden rutile running through the gem. One of Brazil’s most celebrated and unique gems is mined close to the colonial Baroque town of Ouro Preto in Minas Gerais. It is the orangey-gold variety of topaz that is often tinged with pink. In the trade, it lives up to its exalted name, “imperial topaz.”

People from all over the world collect Brazil’s finest mineral specimens, such as this amethyst and rock crystal quartz geode. Photo by Robert Weldon/GIA
Other gems you might not necessarily associate with Brazil are found here too, such as opals with strong play of color, as well as fire opals. Garnets are found in Brazil as well, and delicately-hued pink kunzite.
Diamonds
Few people are aware that Brazil was once the foremost source of diamonds, and that it remains an important source still today. In the 1700s and early 1800s, some of the world’s most celebrated diamonds were found in this enchanting land, including extremely rare red diamonds as well as green, and other fancy colors. Alluvial diamonds continue to be found in Brazil, mostly mined from riverbeds and from conglomerate host rock.
Your Brazilian Gemstone Journey: 4 Tips To Consider
Gem Places to Visit
The sprawling cities of Rio de Janeiro and São Paulo are both hosts to some of Brazil’s most venerable jewelers, such as H. Stern, Amsterdam Sauer, Natan, and Manoel Bernardes. Beyond these two metropolises, each of these jewelers also has retail outlets in Brazil’s principal cities and in many hotels and airports. They have deep roots to the gem sources of Brazil, in many cases owning mines in Brazil’s interior.

A local jeweler in Ouro Preto takes all kinds of credit cards. Photo by Robert Weldon/GIA
H. Stern is famous for taking busloads of newly arriving international passengers to its premiere headquarters in Rio de Janeiro. A tour of the facilities includes a walk through a virtual mine, a chance to see gemstones being cut and polished, and a glimpse behind the scenes to observe jewelry being made. It is a unique mine to market experience with a special Brazilian flair. Amsterdam Sauer has a museum that features Brazil’s most celebrated minerals and gemstones. The city of Belo Horizonte in Minas Gerais has one of the country’s most important gem and mineral museums, the Museu das Minas e do Metal.
If you are traveling in the interior of Minas Gerais, the Baroque Colonial city of Ouro Preto is a must-see for its picturesque architecture, spectacular churches, and rolling hills. It is near to the imperial topaz mines and a gold mine that you can visit. Diamantina is also a Baroque colonial city that was once the center of the diamond business in Brazil – hence the name. Both of these towns are UNESCO world heritage sites.
Taking Care of Yourself
If you’re traveling in Brazil, a few words of caution. Because of disparity in incomes and rising populations, visitors need to be aware of some dangers. As anywhere in the world, tourists need to be cautious of pickpockets and theft. Even though Brazil is extremely photogenic, cameras and other valuables such as cell phones and jewelry should be kept concealed as much as possible in larger cities. In fact, we recommend leaving your most valuable jewelry behind to remove the possibility of it getting lost or stolen. Rio de Janeiro has made great inroads in halting crime along its beaches, but petty theft remains ubiquitous, even in broad daylight. This threat diminishes dramatically as a traveler goes into smaller towns and villages in the interior of Brazil.

Ouro Preto is an old colonial Baroque town in Minas Gerais that was made famous for its gold deposits and also for the so-called Imperial topaz mines. Photo by Robert Weldon/GIA

What Else to See
Rio de Janeiro is famous for its beaches and also for Sugarloaf Mountain (Pão de Açúcar), a peak that rises dramatically in the middle of the city of Rio de Janiero. A trip to the summit of Corcovado is a must, from where you can see the spectacularly beautiful layout of the city with its bays and inlets and islands. If you have a chance to witness a soccer game at the famous Maracana stadium in Rio, you will experience Brazilian fervor at its zenith. São Paulo is in Brazil’s interior, devoid of Rio’s laid-back beach atmosphere. It is a sprawling metropolis filled with art galleries, malls, gardens, cathedrals, and swanky restaurants. São Paulo was the Portuguese colonists’ springboard to the discovery of Brazil’s interior in the 1600s.
What To Eat
Brazilians love meat. When you’re in any big town in Brazil, a visit to Fogo de Chão, or other churrasquerias is a must, though you should arrive with an empty stomach. For those who prefer to skip the meat at the famous Brazilian steakhouses, the salad bar will supply ample diversion. Pão de queijo, a small cheese-laden bread made with yucca flour, is found throughout the state of Minas Gerais, which is a huge agricultural region (in addition to mining). Feijoada is a bean-based meat and corn stew that is enjoyed across Brazil. A variation of stew called moqueca in which seafood is cooked in coconut milk, is found in coastal cities to the north, such as Salvador in Bahia. Yum!

Brazil and its people are among the world’s warmest and most hospitable. It is one of the greatest gemstone sources in the world where you will also be able to enjoy the deep-rooted culture, the country’s delectable food, the passion of its people, and the spectacular landscapes.

When you go home, take a gemstone with you. You’ll be returning with a small piece of Brazilian real estate, and memories to last a lifetime. Before you pack your bags for your trip, you might want to brush up on your gem photography skills with these 6 Tips for the Best Gem Photos. @chapter:6 @chapter:0 @chapter:6


# Publication Year: 2014
# Title: Eighty Years and Still Going Strong
# Abstract: It is truly a privilege to be at the helm of Gems & Gemology in the journal’s 80th year, following in the illustrious footsteps of Robert M. Shipley, Richard Liddicoat, and Alice Keller. We start 2014 with renewed anticipation and the strongest intention to build on the many notable innovations that shaped G&G in previous years. This year, we will continue to foster collaboration with researchers working in related fields at other institutions, while actively producing dynamic media content for the GIA website that complements and adds value to our printed journal.

This issue’s lead article focuses on the Chinese gem and jewelry industry. This paper lays the foundation for a series of articles that will explore specific aspects of China’s powerhouse industry, including diamond and colored stone cutting, jewelry manufacture, design, and jewelry retail, as well as uniquely Chinese industry sectors like jade carving. The paper is a partnership between Chinese authors Zhili Qiu, Mu Li, and Qingyuan Yu, and G&G’s own Tao Hsu and Andrew Lucas. As demand for gem and jewelry products surges in China and impacts consumption patterns elsewhere, this is a very timely topic for our journal to investigate. To reach a wider audience, we have provided a Mandarin translation.

Download: Exploring the Chinese Gem and Jewelry Industry - Mandarin translation (PDF)

Our second article is a study of near-colorless synthetic diamonds grown using high-pressure and high-temperature (HPHT) by the AOTC Group of the Netherlands. AOTC is the dominant near-colorless HPHT synthetic diamond producer targeting the gem trade. Lead author Ulrika D’Haenens-Johansson, a research scientist at GIA’s New York laboratory, investigates the gemological and spectroscopic properties of a suite of 52 colorless to light-colored synthetic diamonds. This important paper illustrates the recent strides made in growth technology and quality.

We are also delighted to present G&G’s second field report. Titled “Hunting for ‘Jedi’ Spinels in Mogok,” it details GIA field gemologist Vincent Pardieu’s decade-long quest for bright “neon” red spinel in Myanmar’s fabled “Valley of Rubies.”

In our fourth and final article, we offer a fascinating look at a baroque South Sea cultured pearl from Indonesia that is far larger than the norm for specimens of this type. Ms. Laura Otter and her co-authors use high-resolution computerized microtomography to study the cultured pearl’s interior.

In addition to our regular Lab Notes and Gem News International sections, we bring you in-depth coverage of the February 2014 Tucson gem and mineral shows. And don’t forget to take the G&G Challenge, our annual multiple-choice quiz.

We hope you enjoy the Spring 2014 edition! @chapter:44 @chapter:1 @chapter:44


# Publication Year: 2014
# Title: GIA Museum Exhibits in New York
# Abstract: “Fantastic Cross,” an 18K gold brooch featuring turquoise, variscite, chrysocolla, cultured pearl, and enamel, is part of the museum display at GIA’s New York laboratory and campus. Photo by Orasa Weldon/GIA, courtesy of the Anthony and Elizabeth Duquette Foundation for the Living Arts.

              GIA’s recently opened laboratory and campus at the International Gem Tower in New York’s Diamond District features a permanent museum exhibit of gems, jewelry, and mineral sculptures. Fourteen display cases highlight nearly 100 items from the GIA collection, ranging from large aquamarine crystals to a diminutive objet d’art golden cactus and a necklace featuring akoya, Tahitian, and South Sea cultured pearls (figure 1). The exhibit showcases the wonder of gems to visitors and students. @chapter:28 @chapter:2 @chapter:28


# Publication Year: 2016
# Title: Blue Dravite-Uvite Tourmaline from Koksha Valley, Afghanistan
# Abstract: Figure 1. This specimen of dark blue tourmaline on micaceous matrix, from the Koksha Valley of Badakhshan Province in Afghanistan, measures 28 × 25 × 17 mm. Photo by Kevin Schmacher.

	Tourmaline is popular among gem and mineral enthusiasts for its extensive variety of colors. Blue, one of the most sought-after hues, is usually encountered as elbaite, a sodium- and lithium-containing species with the chemical formula Na(Li1.5Al1.5)Al6(Si6O18)(BO3)3(OH)3(OH). While it has been reported that very limited quantities of dark blue tourmaline crystals are being mined in Afghanistan’s Koksha Valley, we have found that this material appears to be a hybrid species of dravite-uvite tourmaline (figure 1).

	Around a dozen blue crystals in pale green and brown micaceous matrix first surfaced in the gem markets of Peshawar, Pakistan, in late 2009, as confirmed by two sources (S. Khan and P. Slootweg, pers. comms., 2016). These crystals, reportedly from Badakhshan Province’s Koksha Valley, were subsequently assumed to be a member of the tourmaline group based on their ditrigonal pyramidal habit. Since that time, only very small batches of these crystals have turned up; interestingly, a few of these specimens have been associated with sapphire in the same matrix (P. Slootweg, pers. comm., 2016). In 2010, while examining sapphire rough believed to be from a deposit near the Koksha Valley, GIA’s Bangkok laboratory identified bluish green crystals present in some matrix specimens of sapphire as dravite tourmaline (Spring 2011 Lab Notes, pp. 53–54). While the Koksha Valley is most famous for extensive deposits of high-quality lapis lazuli near Sar-e-Sang, sapphire mining takes place near the village of Hazrat Saeed, 25 km north of Sar-e-Sang along the Koksha River (T.P. Moore and R.W.M. Woodside, “The Sar-e-Sang lapis mine,” Mineralogical Record, Vol. 45, No. 3, 2014, pp. 280–336). The sapphire at Hazrat Saeed is recovered from mica-rich gneiss, and it appears that these green and blue tourmalines were uncovered as a by-product of sapphire mining operations.

	Laser ablation–inductively coupled plasma–mass spectrometry (LA-ICP-MS) was used to analyze the chemical composition of the dark blue tourmaline seen in figure 1. Three spots were measured and plotted (figure 2). Two of the spots showed that the tourmaline contained dravite; the third revealed the presence of uvite (D.J. Henry et al., “Nomenclature of the tourmaline-supergroup minerals,” American Mineralogist, Vol. 96, No. 5–6, 2011, pp. 895–913). Dravite, NaMg3Al6(Si6O18)(BO3)3(OH)3OH, is a sodium- and magnesium-rich tourmaline typically encountered in brown, yellow, black, and rarely as intense green. Uvite, Ca(Mg3)MgAl5(Si6O18)(BO3)3(OH)3(F/OH), is a calcium- and magnesium-rich tourmaline that is often brown, green, or deep red. Our analysis suggests that this blue tourmaline specimen is composed of a mixture of dravite and uvite. While fibrous blue dravite has been reported in the Czech Republic (M. Novak, “Blue dravite as an indicator of fluid composition during subsolidus replacement processes in Li-poor granitic pegmatites in the Moldanubicum, Czech Republic,” Journal of the Czech Geological Society, Vol. 43, No. 1–2, 1998, pp. 24–30), this is the first large single-crystal blue dravite-uvite tourmaline the authors have encountered.

	Figure 2. Left: Three laser spots were plotted in the ternary system for the primary tourmaline groups based on the dominant occupancy of the X site. Center: Two blue laser spots that belong to the alkali primary tourmaline group were further plotted in the ternary dravite-schorl-elbaite subsystem. Right: One orange laser spot that belongs to the calcic primary tourmaline group was further plotted in the ternary liddicoatite-feruvite-uvite subsystem. These findings show a range of composition consistent with the dravite-uvite series. @chapter:7 @chapter:0 @chapter:7


# Publication Year: -
# Title: GIA Researchers Reveal the Secrets to Diamond-in-a-Diamond Mystery
# Abstract: This 0.62 carat green “matryoshka” diamond from Siberia has an internal cavity, connected by two small channels to the outside. A small diamond crystal moves freely inside. Courtesy of Alrosa. Photo by Jianxin (Jae) Liao/GIA

A diamond is a rare and beautiful gift from the earth. But a diamond within a diamond? That is an extra special gift.
Researchers in the GIA laboratory in New York recently had the opportunity to examine one of the most interesting and unique diamond crystals ever found. The crystal, dubbed “matryoshka” after the iconic Russian nesting dolls, was discovered by the Russian mining company Alrosa in Siberia in 2019. While it has several unusual characteristics, including its color, etching and internal cavity, it is the crystal that is trapped, but moves freely, inside the larger diamond that attracted a lot of interest.
“We have never seen anything like this,” said Tom Moses, GIA executive vice president and chief laboratory and research officer. “This is a truly unusual diamond, not only for the fact that there is a small diamond crystal inside and entirely detached from the host crystal, but also for the mystery of how this diamond-in-a-diamond formed.”

This video shows how the internal diamond crystal moves freely in the host diamond. Video by Towfiq Ahmed/GIA
The GIA research team – Dr. Wuyi Wang, GIA vice president of research and development; Staff Gemologist Emiko Yazawa, Senior Analytics Technicians Stephanie Persaud and Elina Myagkaya, Senior Research Scientist Dr. Ulrika D’Haenens-Johansson and Moses – examined the 0.62 carat rough crystal using advanced instrumentation.
Based on their observations and expertise in diamond formation, they determined that over time – millions or billions of years – about 0.11 carats of diamond material dissolved away through two small etched channels that extended from the surface of the diamond to the internal cavity. The diamond material that remained formed into a small diamond crystal of 0.03 carats that is entirely detached from the host crystal.
Detailed analysis confirmed that the small internal diamond has nearly the identical trace element chemistry as its host and that when the host formed in the earth’s mantle, it was a solid diamond without the cavity.

This animation shows the host crystal, internal cavity and the internal crystal. Produced by Emiko Yazawa/GIA
The team was also intrigued by the natural clear green body color of the internal crystal and the “Christmas-tree” like etchings that decorated its surface. They determined that these were small, dark green radiation stains that were present in shallow fractures along its edges, which revealed that this diamond was naturally irradiated. Fluid with radioactive elements is responsible for the green body color and formation of radiation stains, and would have been the last step in decorating this crystal.
“Examining this nesting-doll diamond was a remarkable opportunity,” Moses said. “We know that most diamonds form in a melt/fluid environment, and that they often are partially resorbed and reformed from interactions with multiple types of melt/fluid materials. The opportunity to examine this special diamond-within-a-diamond added to our understanding of how diamonds form.”
A more detailed article is planned for the Lab Notes section of the Spring 2020 edition of Gems & Gemology. @chapter:39 @chapter:1 @chapter:39


# Publication Year: 1997
# Title: Summer 1997 G&G Lab Notes
# Abstract: Etched Chalcedony
Diamond with “Additional” Color
Rough Diamond with Contrasting Colors
Treated-Color Yellow Diamonds with Green Graining
An Unusual Assembled Imitation Emerald
Star Feldspar
Jadeite Jade Beads of an Unusual Color
Jadeite Cavity Impregnated with a Colored Filler
Dyed Impregnated Jadeite Bangle without a “Dye Band” Spectrum
Assembled Imitation Ruby
Sapphire with Evidence of Heat Treatment
Serendibite, a Rare Gemstone
Zircon with “Play-of-Color”

To view the full section, download the PDF above. @chapter:52 @chapter:1 @chapter:52


# Publication Year: 2017
# Title: Cat’s-Eye Kornerupine
# Abstract: Figure 1. This 1.44 ct yellowish green kornerupine displayed strong chatoyancy. Photo by Sood Oil (Judy) Chia.

A dark, translucent, yellowish green oval cabochon (figure 1) was recently submitted to the New York lab for identification. The 1.44 ct stone displayed an intense chatoyancy. With a spot refractive index reading of 1.67 and a hydrostatic specific gravity of 3.32, the stone was identified as kornerupine, a rare borosilicate mineral found in boron-rich volcanic and sedimentary rocks that have undergone metamorphism (http://rruff.info). Raman spectroscopy confirmed the identification.

Cat’s-eye kornerupine is an extremely rare gemstone. Its chatoyancy is caused by rutile and graphite inclusions (H.N. Lazzarelli, Gemstones Identification: Blue Chart, 2010, www.gembluechart.com). However, we were unable to identify the needles in this stone using Raman spectroscopy. Fiber-optic illuminated magnification exposed dense clusters of these needles, some displaying iridescence (figure 2). This was GIA’s first encounter with this material in more than a decade.

Figure 2. A dense collection of needle inclusions was the cause of the chatoyancy.
Photo by Daniel Girma; field of view 2.08 mm. @chapter:15 @chapter:0 @chapter:15


# Publication Year: -
# Title: Extraordinary Gemstone Sculptures Make Debut at GIA
# Abstract: View Gallery

The display of Perry Brent Davis’s carvings of agate and gem quartz at GIA’s Carlsbad campus looks like a colorful seascape of otherworldly designs. Many float above sensuously curved bronze arms; others are grounded on sleek blocks of black granite. Each is carved and highly polished to showcase its internal features and patterns.

	“I choose stones that exemplify the power of nature,” Davis says. He finds “some of the most beautiful, naturally colored minerals the earth produces” and turns them into works of art.

	“This incredible medium forms my raw material – often there are natural crystal pockets and features that accentuate the simple form of my contemporary pieces,” Davis says. Several of the designs, for instance, reveal drusy-lined interior pockets that sparkle against the high polish of the exterior surface.

	Davis, a graduate gemologist with three decades of experience in the gem and lapidary fields, moved to China from the U.S. in 2006 to pursue his interest in large gemstone carvings. He opened a studio and hired a team of traditional carvers. He and his team incorporate modern and ancient Chinese carving techniques into each piece.

	The results are larger-than-normal gemstone sculptures that emphasize the rich colors, ornamental patterns and internal features in agate, rock crystal and jasper. Most of the design process takes place on the stone itself, Perry says, and is refined as the carving evolves. It can take 200 to 1,400 hours to complete a piece, but many fall in the 200-500 hour range.

	“To get such amazing carvings in such large sizes is a feat,” says Terri Ottaway, curator of collections for the GIA Museum. “But then to carve and polish them so beautifully to bring out the intricate patterns is quite an accomplishment and rarely seen.”

	Davis gets his rough pieces from mines in the U.S., Mexico, Brazil and Austrailia. He says that going to the mines is "like going to Las Vegas" unless he knows an owner is going to be there with rough. He says he has better luck at gem and mineral shows where there are large quantities at good prices.

	Davis selects gemstones that are technically complex and require a vast array of diamond tools and other equipment to carve. Working on them requires a high level of technical ability and articulate workmanship, according to Nathan Renfro, a gemologist in GIA’s Carlsbad laboratory who is also a gem carver.

	“From the captivating design to the quality of his workmanship,” Renfro says, “each piece Davis creates makes it clear he is a world-class artist and gem carver.” @chapter:28 @chapter:2 @chapter:28


# Publication Year: 2014
# Title: Distinguishing Between Natural and Synthetic Green Chrysoberyl
# Abstract: K. Schmetzer, M.S. Krzemnicki, T. Hainschwang, and H.-J. Bernhardt. “Natural and synthetic vanadium-bearing chrysoberyl,” Journal of Gemmology, Vol. 33, No. 7–8, 2013, pp. 223–238. These photos show natural chrysoberyl from Tanzania (left) and synthetic green chrysoberyl crystals manufactured by the Kyocera Corporation of Japan. Photos courtesy of Karl Schmetzer.

              Bright mint-green chrysoberyl emerged from Tunduru, Tanzania, in the mid-1990s. This material, which owes its color to V3+ substituting for Al3+ in the chrysoberyl lattice, does not exhibit the green-red color change of the alexandrite variety of chrysoberyl (colored by Cr3+). Prior to the introduction of these goods into the marketplace, manufacturers in both Japan and Russia demonstrated that vanadium-containing chrysoberyl could be grown using the Czochralski technique. Only after the popularity of natural mint-green chrysoberyl did the production of gem-quality synthetic material begin, however. That was when Kyocera of Japan (and to a much lesser extent the Russian company Tairus) developed V-bearing synthetic alexandrite to mimic the crystals coming from Tanzania.

Natural mint-green chrysoberyl, much of it extremely clean, is also found in Ilakaka, Madagascar; Sri Lanka; and Mogok, Myanmar. Prior to this study, there had been very little investigation into either natural or synthetic V-bearing chrysoberyl. The authors compare the optical characteristics and trace element composition of the Kyocera synthetic material with natural specimens from all four regions to help distinguish between the various sources. Additionally, they evaluate the impact of V3+, Cr3+, and Fe3+ on color and absorption characteristics.

The Kyocera synthetic chrysoberyl, most similar in appearance to the Tunduru material, almost exclusively contained the chromophore V3+ (approximately 0.1 wt.% V2O3), with little to no Ti4+, Cr3+, or Fe3+ present. Natural green chrysoberyl had much more variable amounts of these cations, with Tunduru specimens containing 0.04–0.30 wt.% V2O3, 0.004–0.040 wt.% Cr2O3, 0.001–0.110 wt.% TiO2, and 0.08- 0.32 wt.% Fe2O3. The Ilakaka material, some of which appeared more yellow than the Tunduru chrysoberyl, had similar levels of V2O3, was nearly Cr2O3 free, and had lower levels of TiO2. In some cases, the samples showed significantly more Fe2O3, with levels as high as 0.55 wt.%. Sri Lankan material, which was more yellowish green than the other studied samples, had substantially more Fe2O3 (0.47 – 0.90 wt.%), with generally less V2O3 and similar Cr2O3 contents as compared to Tunduru material. The Mogok chrysoberyl, which was an intense bluish green, had essentially no iron but high levels of both V2O3 and Cr2O3, at 0.38 and 0.24 wt.%, respectively. The Mogok material also demonstrates the strongest pleochroism, with observed colors ranging from grayish violet to yellowish green to intense blue-green. Additionally, gallium was detected in all of the natural chrysoberyl and none of the synthetics. Tin is also found in much of the natural green chrysoberyl but not in the synthetic form.

Spectroscopically, the positions of the absorption maxima and the intensity ratios for the V3+ absorption bands were found to be consistent between synthetic and natural material containing little to no Cr3+. Features attributable to Cr3+ and Fe3+ were detectable in the corresponding natural spectra. Finally, the authors show that with the proximity of the Cr3+ and V3+ bands in chrysoberyl, separate bands for the two cations are not visible. Instead, a shift of the ν1 band to shorter wavelengths was observed with increasing Cr3+ content. Visually, much of the material was inclusion free, but all natural samples contained growth patterns not observed in the Kyocera synthetics. @chapter:10 @chapter:0 @chapter:10


# Publication Year: 2018
# Title: Crowningshieldite: A New Mineral
# Abstract: Figure 1. Left: A diamond sample from the Letšeng mine in Lesotho that contains the newly recognized mineral crowningshieldite, in the area circled in red. Right: Electron microscopy reveals individual grains of crowningshieldite in a fine-grained mixture with other minerals. Photos by Evan M. Smith (left) and Fabrizio Nestola (right).
GIA, in collaboration with researchers at the University of Padova, recently discovered crowningshieldite (figure 1), a new mineral named in honor of G. Robert Crowningshield (1919–2006), a pioneering researcher at GIA for more than 50 years. His many landmark contributions included the detection of irradiated diamonds, the initial report on General Electric’s facet-quality synthetic diamonds, and the description of “padparadscha” sapphire’s orangy pink to pinkish orange color. Crowningshieldite is a nickel sulfide mineral with a hexagonal crystal structure and can be regarded as the high-temperature polymorph of the mineral millerite. Discovered as an altered inclusion in two diamonds from the Letšeng mine in Lesotho, it was accepted as a mineral on September 18, 2018, by the International Mineralogical Association. @chapter:35 @chapter:1 @chapter:35


# Publication Year: 2021
# Title: Honey Brown and Light Yellow Hydrogrossular: An Uncommon Jade Imitation
# Abstract: Figure 1. This light yellow carving (36 × 21 mm) and honey brown cabochon (15 × 12 mm) were identified as hydrogrossular. Photo by C. Kamemakanon; courtesy of Pachara Chonlakit.

Hydrogrossular or hydrogarnet is a translucent to opaque, water‐bearing calcium aluminum silicate garnet that commonly shows microcrystalline texture. It has a range of colors: brown, colorless, green, gray, pink, and yellow. The most popular is the shade of green known in the trade as “Transvaal jade” or “African jade.” Recently, the GIT-Gem Testing Laboratory (GIT-GTL) received two samples of hydrogrossular garnet for identification: the light yellow carved pendant (~70 ct, 36 × 21 mm) and the honey brown oval cabochon (8 ct, 15 × 12 mm) shown in figure 1. These are not typical colors used for jade imitations.

Figure 2. The microscopic observation of the honey brown hydrogrossular sample (left) revealed a fine-grained aggregate structure and color patches (white arrow), as compared with the coarse-grained aggregate structure of the brown jadeite sample (right). Oblique fiber-optic light. Photomicrographs by S. Promwongnan; field of view ~14 mm.
Standard gemological testing of the honey brown cabochon showed a specific gravity of ~3.66 and a refractive index of ~1.71, while those of the light yellow piece were undeterminable due to the nature of the mounting and carving. Nonetheless, both stones exhibited weak red fluorescence to long-wave UV and were inert to short-wave UV radiation, and displayed massive fine-grained aggregate structures with a translucent glassy appearance (figure 2, left), which was quite different from the coarse-grained aggregate structure of jadeite (figure 2, right).

Figure 3. Raman spectra of the honey brown and light yellow samples (blue and red lines, respectively) as compared to the reference spectrum of grossularite from the RRUFF database (green).
The identity was also confirmed by advanced testing. The Raman spectra of both samples showed dominant peaks at 374, 415, 548, 825, and 879 cm–1 and other smaller peaks at 246, 278, 508, 627, and 1005 cm–1 (figure 3) that matched perfectly with the spectrum of grossularite in the RRUFF reference database (R040065). Semi-quantitative chemical analyses of both stones revealed enriched contents of silica, calcium, and aluminum, which are closely consistent with grossularite, a calcium-aluminum garnet.

Figure 4. The infrared spectrum in reflection mode of the honey brown sample (blue line) exhibits characteristic reflectance peaks of hydrogrossular garnet at 616, 843, 866, and 954 cm–1, as compared with the spectrum of the hydrogrossular reference sample (purple line). The spectrum of the light yellow sample was not measured due to the nature of the carving.
The infrared spectrum of the honey brown cabochon sample, measured in reflection mode between 580–1400 cm–1, showed characteristic reflectance peaks at 616, 843, 866, and 954 cm–1 that are similar to the spectra of the hydrogrossular reference sample (figure 4) as well as green hydrogrossular (see Fall 2015 GNI, pp. 342–343). Note that the reflectance spectrum should be almost identical to the transmission spectrum of the sample, and the same features should be observed in both cases.

Figure 5. Infrared spectra by transmission mode of the honey brown and light yellow samples (blue and red lines, respectively) show very strong broad (water-related) absorption bands between ~3000–4000 cm–1 as compared with the spectra of a hydrogrossular reference sample (purple line) and grossular (tsavorite and hessonite) samples (green and black lines, respectively). The vertical dashed lines at 3598 and 3662 cm–1 mark water-related absorption bands of hydrogrossular (>5 wt.% H2O) based on Rossman and Aines (1991).
The infrared spectra of both samples, measured in transmission mode between 1000 and 5000 cm–1 and displayed in % transmittance, showed very strong broad absorption bands between ~3000–4000 cm–1 that are somewhat similar to the spectrum of our hydrogrossular reference sample (figure 5), and coincide with water-related absorption bands of hydrogrossular (>5 wt.% H2O) centered at 3598 and 3662 cm–1 (see G.R. Rossman and R.D. Aines, “The hydrous components in garnets: Grossular-hydrogrossular,” American Mineralogist, Vol. 76, No. 7-8, 1991, pp. 1153–1164). In comparison, our grossular (tsavorite and hessonite) samples reveal much narrower absorption bands between 3500–3700 cm–1 (figure 5). Thus, the presence of very strong broad (water-related) absorption bands has confirmed that both stones submitted for investigation were indeed hydrogrossular.
In summary, the gemological properties, Raman spectra, and chemical compositions of the light yellow and honey brown samples are consistent with those of grossular garnet. However, the infrared spectra showing characteristic transmission peaks of hydrogrossular at 616, 843, 866, and 954 cm–1 and very strong occurrence of structural water (i.e., significant OH replacing Si in tetrahedral sites) have confirmed that these two stones are indeed hydrogrossular rather than grossular garnet. It is worth noting that one of the materials commonly used to imitate jade is fine-grained aggregate hydrogrossular garnet, not single-crystal garnet. @chapter:46 @chapter:0 @chapter:46


# Publication Year: 2015
# Title: Synthetic Moissanite Melee in a Colored Diamond Bracelet
# Abstract: Figure 1. This fancy-color melee diamond bracelet contained two synthetic moissanites. Photo by Sood Oil (Judy) Chia.

A colored diamond bracelet submitted to the New York laboratory for identification (figure 1) contained 162 round brilliants ranging from 0.05 to 0.20 ct, with a color range from near-colorless to fancy yellow and brownish yellow. Melee-size diamonds below 0.20 ct are usually not screened for synthetics and imitations, and melee set into fine jewelry are very seldom tested due to limitations from the mounting. But because of recent concerns over fine diamond jewelry set with melee-size synthetics and imitations (see H. Kitawaki et al., “Identification of melee-size synthetic yellow diamonds in jewelry,” Fall 2008 G&G, pp. 202–213; Winter 2014 Lab Notes, pp. 293–294), we decided to conduct a full analysis on the mounted round brilliants in this bracelet.

Testing was first performed on the 60 near-colorless round brilliants with the DTC DiamondSure. Several samples were referred and sent for further testing using Raman spectroscopy. Of these, two round brilliants were suspected as imitation. Close examination under the optical microscope revealed obvious doubling on the facet junctions, a key identification feature for synthetic moissanites (K. Nassau et al., “Synthetic moissanite: A new diamond substitute,” Winter 1997 G&G, pp. 260–275). Further testing with Raman spectroscopy confirmed this identification with three peaks at 768, 789, and 966 cm–1 (figure 2).

Figure 2. Raman spectroscopy confirmed the identification of two colorless round brilliants as synthetic moissanite with peaks at 768, 789, and 966 cm–1.
FTIR spectroscopy performed on the other referred near-colorless and colored melee identified them as natural. One melee was found to be type IaB, while the others were type IaA.

This analysis showed that melee-sized diamond imitations are being mixed with natural diamond parcels and set into fine jewelry without proper disclosure. Therefore, proper identification by a gemological laboratory is an essential tool to maintaining the integrity of the industry. @chapter:43 @chapter:1 @chapter:43


# Publication Year: 1995
# Title: A Chart for the Separation of Natural and Synthetic Diamonds
# Abstract: A chart is provided that describes those gemological properties that are key to the separation of gem-quality yellow, blue, and near-colorless (to colorless) natural diamonds from synthetic diamonds. This format was designed to give jewelers and gemologists a ready reference to identify synthetic diamonds as they enter the jewelry trade. Magnification and luminescence are the most important testing techniques currently available to jewelers and gemologists. The most distinctive features of synthetic diamonds include color zoning, graining, metallic inclusions (often making the stone magnetic), and uneven ultraviolet fluorescence. @chapter:39 @chapter:1 @chapter:39


# Publication Year: -
# Title: New 3-D Software Expands GIA’s Pearl Identification Capabilities
# Abstract: 3-D modeling software helps researchers visualize the internal structure of this pearl. Image by Emiko Yazawa/GIA.

	Pearls are one of nature’s most beautiful and intriguing gems. They glow with life and warmth, connecting us to the life of a gem like no other. Whether natural or cultured, pearls possess a mystique and allure all their own.

	For much of its history, GIA has been collecting and studying pearls from around the world. Its scientists have used a variety of tools and techniques to help identify the different types of pearls, most notably X-ray images. But in the past few years, real-time X-ray microradiography (RTX) and computed X-ray microtomography (μ-CT) have provided the most advanced means of revealing internal structure and drawing useful conclusions on pearls the Institute examines. These images help GIA technicians and scientists determine whether a pearl is natural, bead-cultured, non-bead cultured, and so on. The addition of X-ray fluorescence and chemical analysis using energy-dispersive X-ray fluorescence (EDXRF) helps separate those of freshwater origin from their saltwater counterparts.

	Some pearls remain an identification challenge for even the most well-equipped laboratories. Researchers sometimes find surprises hidden inside—a piece of shell or other object that is difficult to identify. Until recently, they were only able to see a two-dimensional view of the pearl’s internal structure, which limited their ability to resolve the gem’s entire structure.

These μ-CT images were processed by GIA researchers and gemologists using 3-D software to further analyze the pearls’ internal structure. Photo by Jian Xin (Jae) Liao/GIA.

	That’s where the latest technology can step in to help.

	GIA recently acquired software that expands its ability to probe the internal features of pearls. This powerful research tool makes it possible to virtually explore, manipulate, extract and reconstruct specific areas of a pearl for analysis. It also gives researchers the ability to enhance the existing μ-CT data collected to see the details more clearly.

	Three examples demonstrate the potential of this software. The first shows one half of a well-defined shell that caused the natural pearl’s formation. The second example is of a pearl examined in the GIA laboratory in Bangkok and described in a recent Gems & Gemology Lab Note. It clearly shows the form of the central radiating structure, as well as the extraction capabilities of the software. The third shows a challenging structure that the software helps define more clearly.

	EXAMPLE 1

	The images below are conventional 2-D μ-CT slices of a pearl with a strange internal structure. Researchers suspected it was a piece of shell, but the exact shape or structure of the shell was hard to visualize.

The modeling software extracted the internal structure of this pearl from hundreds of μ-CT slices and reconstructed its three-dimensional shape.

Specific internal structures in the pearl were selected to reconstruct its 3-D shape, as shown from a screenshot of the software. The top left image is the 3-D model, while the others are 2-D slice images.

The 3-D image of the shell within the pearl provides much more information than the original 2-D X-ray images. Images by Chunhui Zhou.

	See the video of the internal shell.

	3-D Model of Shell in Pearl

	This video shows 3-D imaging of a shell within a pearl.

	EXAMPLE 2

	This pearl contains a structure thought to be a tiny organism called a foraminifera.

These examples are known as star sands, marine protozoa that belong to the same order as foraminifera and once lived on the ocean floor. While not usually associated with pearl formation, foraminifera were recorded in pearls as early as 1980 (A.E. Farn, “Notes from the Laboratory,” The Journal of Gemmology, Vol. 17, No. 4, 1980, pp. 225–228). Image by Emiko Yazawa/GIA.

The 3-D software makes it possible to extract and reconstruct the internal features to further support our opinion. The bumpy, uneven surface strongly resembles the structure of a foraminifera. Image by Emiko Yazawa.

	See the video of the internal foraminifera.

	Foraminifera Structure in Pearl

	This video shows 3-D imaging of a foraminifera structure within a pearl.

EXAMPLE 3

	The software also has the potential to analyze other unusual structures within a pearl. The following example is a freshwater pearl with a large internal void, along with an associated white growth feature that is connected to the main solid portion. The 3-D model of the pearl after segmentation provides much more information on the overall shape and size of the void components. By observing the shape of the entire void, a clearer understanding of the pearl’s identity emerges. This gives researchers an opportunity to analyze the internal structure of both natural and cultured pearls in a way that wasn’t possible before.

Left: A 2-D μ-CT slice of a reportedly natural freshwater pearl shows unusual void and growth structures. Right: The 3-D model generated using the μ-CT slices shows the outer transparent area as the white growth structure, while the red area represents the black void component and the green area is the boundary between the white growth and the void structures. Image by Emiko Yazawa.

	GIA researchers continue to explore these fascinating internal structures as part of the Institute’s long-term research into the “Queen of Gems.” The new 3-D software is the latest tool at their disposal. Delving into these mysteries will further our understanding and support the research-based identification and evaluation of pearls. As GIA researchers master the capabilities of this powerful software tool, they can apply their experience to these more challenging pearls. @chapter:11 @chapter:4 @chapter:11


# Publication Year: 2019
# Title: Quarterly Crystal: Orpiment in Barite
# Abstract: Figure 1. Numerous bright yellow crystals dominate the interior of this 74.31 ct barite cluster from Nevada. Photo by Nathan Renfro.

The 74.31 ct crystal cluster of transparent to translucent colorless barite columns shown in figure 1 measures 37.89 × 20.83 × 15.27 mm. It plays host to numerous small yellow crystals and radial sprays, which together give the cluster a light yellow color. The barite specimen is from the Regent mine in the Rawhide District of Mineral County, Nevada. The Regent mine was known to produce barite crystals with yellow orpiment inclusions in the mid-1990s. The pure yellow bodycolor of these numerous inclusions suggested they might be orpiment. Laser Raman microspectrometry was able to confirm our suspicions. Focused energy-dispersive X-ray fluorescence (EDXRF) analysis was used in an attempt to examine the chemical makeup of the inclusions, since orpiment contains arsenic as a main constituent. The EDXRF analysis showed the presence of arsenic. Based on chemistry, we determined that the yellow inclusions shown in figure 2 are indeed the arsenic sulfide mineral orpiment.

Figure 2. A combination of Raman and EDXRF analysis identified the inclusions as orpiment, a yellow arsenic sulfide. Photomicrograph by Nathan Renfro; field of view 3.83 mm. @chapter:15 @chapter:0 @chapter:15


# Publication Year: 2017
# Title: New Ruby Miner in Mozambique
# Abstract: Figure 1. The washing process used by Mustang Resources is different from most jigs used for colored stone mining. Photo courtesy of Mustang Resources.

Mustang Resources LLC, a publicly listed Australian company, is developing a ruby mining operation in northern Mozambique. With the success of the colored stone mining giant Gemfields, Mozambique has secured its position in today’s global ruby market. Mustang’s concession is located about 8 km northwest of Gemfields’ Montepuez ruby mine. Both properties are located on the ruby mineralization belt in the Montepuez Complex, where ideal physical and chemical conditions favored the formation of gem-quality ruby. In between the two concessions there are some designated ruby-bearing areas where individual small-scale miners can legally work.

While the geology of the Mustang operation is generally similar to that of the Gemfields concession, the bulk sampling strategy and washing process are slightly different (figure 1). Currently, the miners focus on exploring and sampling the secondary deposits. They open pits of 20 × 5 meters or 20 × 7 meters and immediately refill the first pit before opening the adjacent ones; this way, no large pit is left open on the surface of the mining area. Mustang has been using scrubbers instead of log washers to break the clay bodies in the ore. A new customized scrubber system will soon be in place to optimize this process. Unlike the jig system applied by many colored gemstone mining operations around the world, the team uses a giant rotary pan to concentrate the heavy minerals, including ruby, through the centrifugal forces generated during rotation.

Since the team from Mustang started to develop the project in early 2016, the exploration, bulk sampling and ruby recovery have made significant progress. Christiaan Jordaan, the managing director of Mustang’s Montepuez ruby project, informed the authors that the washing plant had been successfully relocated and tuned to operate efficiently and that grading into parcels had begun (figure 2). The team has test marketed these rubies in the United States, where some large, significant stones will be cut by well-known cutters. Mustang will also test the ruby market in Asia and other parts of the world. Jordaan reassured the authors that Mustang will focus on improving quality of life in the mining community and promoting their ruby as an ethically mined product. Since the beginning of this ruby mining project, the company has hired and trained 70 local employees to work together with foreign experts.

Figure 2. Taking a cue from Gemfields, Mustang Resources grades rough rubies into
specific quality and size parcels. Photo by Andrew Lucas and Tao Hsu, courtesy of
Mustang Resources. @chapter:30 @chapter:0 @chapter:30


# Publication Year: 2023
# Title: Artisanal Diamond Mining: Addressing the Knowledge Gap
# Abstract: Figure 1. Artisanal mining in Liberia. Courtesy of Diamonds for Peace.
In the developed world, the word diamond immediately evokes the allure and sparkle of a polished brilliant. What does the word mean, however, for an artisanal diamond miner living in poverty?
Artisanal diamond mining accounts for 20% of global production and significantly impacts millions of lives in the developing world, particularly in Africa. “Artisanal” simply implies that the tools and equipment used by the miners are rudimentary. This type of mining is conducted predominantly by individuals, small groups, or families, who frequently migrate in search of the next deposit. The work is subsistence labor, and the miners typically sell to anyone willing to buy (often without the luxury of a legal transaction). Despite its numerous challenges, which also include smuggling and human rights abuses, artisanal mining is their principal form of income. But beyond the fact that diamonds can be exchanged for subsistence money, what do these miners know about them?
In many countries where artisanal mining is prevalent, miners often have an innate and comprehensive understanding of the material. For example, Sri Lankan gem miners can expertly locate and sort through the illam (gem gravel) and differentiate between the fine-quality and lesser-quality material. They have been doing this for thousands of years. But diamond mining is different, particularly in Africa, where the first known primary deposit was discovered less than 200 years ago. In the twentieth century, the system of grading based on the Four Cs (color, cut, clarity, and carat weight) established a framework for price setting in the diamond trade. This pricing system for polished material underlies the value of rough material and determines its selling price. Therefore, understanding the Four C s is vital to the effective trade of diamond rough.

Figure 2. Miners sorting through gem gravel. Courtesy of Diamonds for Peace.
However, the majority of artisanal miners in Africa do not yet have a strong working knowledge of rough diamond, placing them at a significant disadvantage when negotiating the price of rough with buyers. In 2022, the NGO Diamonds for Peace conducted basic training on rough diamond grading for Liberian miners (figures 1 and 2), a project funded by the World Bank and operating in collaboration with Empowerment Works Incorporated.
Liberia’s first major diamond deposit was discovered in 1957 along the Lofa River, close to the border of Sierra Leone to the north, which has much higher diamond production. Currently, figures stand at around 50,000 carats per annum. Production peaked at 600,000 carats annually in the 1970s (although most of that figure could be attributed to smuggled material coming in from bordering countries). Two civil wars, starting with a military coup in 1980, resulted in export sanctions imposed by the United Nations. Since 2007, when the country joined the Kimberley Process, diamond has been reestablished as an important mineral resource, particularly with the recent discovery of diamond-bearing kimberlites. These deposits have not been commercially exploited. Instead, the mining remains artisanal and the material is found primarily in alluvial placers along the Lofa River.
In pre-training interviews given to establish each miner’s level of knowledge, numerous misconceptions became evident. For instance, they valued a diamond based on carat weight alone, regardless of quality, color, and potential yield. They had also been told that colored diamonds have no value. Such diamond “myths” have disseminated over the past fifty years, and buyers are often quick to exploit the miners’ lack of knowledge.

Figure 3. A parcel of rough diamonds, collected over a month by a Liberian artisanal miner. The diamond indicated by the arrow weighs 0.80 ct. Photo by Beth West.
For artisanal diamond mining to benefit the future of Liberian communities, the diamonds need to be traded for a price that reflects their real-time value according to their potential polished price (figure 3). The diamonds must be fed into the supply chain correctly, and the economic gain needs to find its way back into these rural communities. This boomerang-back of benefit is no easy feat in West Africa.
Yet small steps toward progress can be made by adjusting the information asymmetry. These artisanal miners need to understand the material they are working with. At the very least, it will give them a little more cash in their pocket and a slightly more comfortable standard of living. Regardless of the big picture, a simple win on that level is easily achievable.
Knowledge—and the sharing of it—is the key to building a stronger and more equitable supply chain. It is one thing for the supply chain to be traceable, but quite another for it to be equitable and ethical. To level the playing field, each player must be equally empowered. One thing that allows for such empowerment is knowledge. It is a simple right.
Diamonds for Peace, in collaboration with the author, is currently working on a next-stage “train to teach” program for the miners. @chapter:49 @chapter:3 @chapter:49


# Publication Year: 1993
# Title: Winter 1993 Gem News International
# Abstract: Colored Stones
            Update on Colombian Emerald Mining
            Vietnamese Garnets
            Myanmar Mid-Year Emporium
            Update on Monghsu Ruby
            Ruby in Kyanite from India
            Rare Gemstones from Quebec
            Attractive Ornamental Marble
            Thai-Myanmar Jewelry Manufacturing Joint Venture
Enhancements
            Irradiated Phenomenal Quartz
Synthetics and Simulants
            Amber Simulant from India
            Artificial Glass with High R.I. and S.G.
            More on Vietnamese Deceptions
The 24th International Gemmological Conference
Diamonds
            Canada
            India
            Green-to-Blue Diamonds
            History of Diamond Cutting
Colored Stones and Organic Material
            Amphiboles
            Beryl
            Charoite
            Corundum
            Garnet
            Meteorites with Gems
            Natural Glass
            Opal
            Porcelaneous "Pearls"
            Quartz
Gemstone Enhancement
Synthetics
            Early Synthetics
            Russian Synthetics
            Douros Flux-Grown Synthetic Ruby
Instrumentation
Miscellaneous
            Early Collections
            Colored Stone Cutting

To view the full section, download the PDF above. @chapter:16 @chapter:0 @chapter:16


# Publication Year: 2000
# Title: Technological Development in the 1990s: Their Impact on Gemology
# Abstract: In the last decade, technology has improved how we synthesize, process, identify, and otherwise study gem materials. Significant trends include: the widespread availability of computerized communication; the application of synthesis techniques to gem treatments; the increased prominence of treated synthetics; the greater need for expensive instrumentation to solve gem problems in general, and the broader availability of small dedicated instruments to solve specific problems; and the adaptation of techniques from other sciences. Potentially applicable technology must be evaluated critically to assess its usefulness and appropriateness to solve a particular gemological problem. @chapter:27 @chapter:1 @chapter:27


# Publication Year: 2018
# Title: Update on Russian Demantoid Production
# Abstract: Figure 1. Russian demantoids are well known for their pure colors and remarkable inclusions. Photo by Kevin Schumacher.

Russian demantoids (figure 1) are renowned in the gem community for their pure, vivid colors and spectacular inclusions. Alexey Burlakov, founder of Tsarina Jewels, shared some insights on the current production of Russian demantoids and emeralds. Tsarina Jewels is based out of Bangkok and was co-founded with his father, Dr. Evgeny Burlakov, curator of the Ural Geological Museum in Yekaterinburg.

According to Burlakov, there are currently two mines in the Urals producing demantoid in commercial quantities: Korkodin and Poldnevaya. They are about 7 km apart, located in the same geological massif that also hosts numerous gold and platinum mineralizations. Although the two mines are very close to each other, the material is very different. The Korkodin mine is characterized by a darker color, often with a brownish tint that can be removed by heat treatment. Poldnevaya produces material of lighter, more “open” colors without the secondary brown. Because they are naturally a pure green, these demantoids do not require heating to optimize the color.

A third known deposit is Nizhny, located in the Tagil region about 200 km north of the other two mines. This was the original deposit where Russian demantoid was discovered, but it is currently inactive. The material from this mine typically has a lighter color with a slightly bluish tint, setting it apart from the other two.

Russian Demantoid Production
Alexey Burlakov of Tsarina Jewels gives insight into production of demantoid from two Russian deposits.
Russian demantoid comes in a wide range of colors, covering all shades of green. Much of the material has a brown color that can become dominant. The finest color is considered a pure, vibrant green with no secondary hues. It is estimated that around 80% of the Poldnevaya mine production has a secondary yellow color, while 15% is apple green and around 5% top vibrant green.

A typical feature of Russian demantoids is the horsetail inclusion, a radiating pattern of asbestos fibers. Fully developed horsetails are still rare. This inclusion has been found in demantoids from other localities as well, but none of these deposits match the importance of Russia’s.

The main markets for Russian demantoid are the United States, China, and France. The French market demands smaller melee-sized stones, while Chinese and U.S. customers opt for stones over 1 ct. Prices of Russian demantoid have increased, especially for larger sizes. This is due to the limited production. It is estimated that the Poldnevaya mine produces between 300 and 1,000 carats of gem-quality material per month. This means that only a few stones over 3 ct are produced on a yearly basis.

Other important gemstones from the Ural Mountains are emeralds and alexandrites. The Urals produced large volumes of emerald in the beginning of the 20th century. During the Soviet era, the mines were reopened for beryllium mining. In recent years, emerald mining has started again. New production and specimens have already reached the market. The Russian emeralds are generally lighter green but clean compared to other deposits. Alexandrite is not being mined, but a Russian government corporation is actively developing and expanding the alexandrite/emerald mines in the Urals. @chapter:0 @chapter:0 @chapter:0


# Publication Year: 2013
# Title: Diamond with Unusual Laser Manufacturing Remnant
# Abstract: It is common to see laser manufacturing remnants on diamonds, especially stones in blocked form where the cut is not finished. Cutters may use lasers to show where to cut, which features to remove, or the desired shape. The remnants usually appear as straight or sinusoidal lines along the areas to be cut or removed.
A 3.59 ct Fancy Light brownish greenish yellow diamond recently submitted to the Carlsbad laboratory for examination displayed an unusual laser feature.

Figure 1. The 0.9 mm diameter laser manufacturing remnant on this diamond showed an interesting pattern. Photo by Troy Ardon.
The table of the blocked heart shape showed a laser remnant with an interesting pattern that resembled a watch face (figure 1). Unlike the typically linear remnants, this feature was circular and located directly on the table. The cutter’s intentions for placing the 0.9 mm diameter circle on the table are unclear, but it makes for a striking pattern rarely seen on diamonds, especially finished stones. @chapter:36 @chapter:1 @chapter:36


# Publication Year: -
# Title: Summer 2020 G&G Available Now
# Abstract: The Summer 2020 edition of Gems & Gemology concludes the fancy-color diamond series with a discussion on yellow and orange diamonds and wraps up the saga of the Chivor emerald mine in Colombia. The issue also explores a surface luminescence imaging technique to separate natural from laboratory-grown diamond, the use of fluorescence spectroscopy to identify pearls that have been optically whitened and brightened, the geographic origin determination of nephrite based on isotope ratios, and more.
Naturally Colored Yellow and Orange Gem Diamonds: The Nitrogen Factor
The lead article, by Christopher M. Breeding and co-authors, investigates the four major defect groups responsible for the color in most yellow and orange diamonds. They conclude their fancy-color diamond series by focusing on yellow diamonds, the most commonly encountered colored diamonds of all, and their much rarer orange relatives.
Separation of Natural from Laboratory-Grown Diamond Using Time-Gated Luminescence Imaging
De Beers Group Technology has developed a method to easily separate colorless and near-colorless natural and synthetic diamond using an expansion of the surface luminescence imaging employed by the DiamondView. Colin D. McGuinness and co-authors explain how blue delayed luminescence can be used as an identifier for more than 99% of natural type IIa and type Ia diamond. This improved imaging technique helps eliminate the need for time-consuming and expensive testing.
History of the Chivor Emerald Mine, Part II (1924-1970): Between Insolvency and Viability
Karl Schmetzer and co-authors bring a dramatic close to the Chivor emerald mine’s rich history with part two. This story resumes after the controlling company, the Colombian Emerald Syndicate, Ltd., succumbed to bankruptcy in 1923. The tale continues with countless twists and turns involving stock market speculation, insolvency, and ownership changes.
Optical Whitening and Brightening of Pearls: A Fluorescence Spectroscopy Study
Cultured pearls often undergo a bleaching process and maeshori treatment to improve their appearance. However, the pearl trade also employs chemical compounds known as optical brightening agents to enhance the appearance of these goods. Chunhui Zhou and co-authors explore the use of fluorescence spectroscopy to quickly and effectively separate optically brightened pearls from those that are untreated or have undergone routine bleaching.
Hydrogen and Oxygen Stable Isotope Ratios of Dolomite-Related Nephrite: Relevance for Its Geographic Origin and Geological Significance
Hydrogen and oxygen stable isotope ratios can be used to distinguish the four most important origins of dolomite-related nephrite. Kong Gao and co-authors compare ratio values in samples from Russia, South Korea, and two locations in China and discuss how these ratios are related to ore-forming fluids. Combined with unique gemological characteristics such as color, luster, and transparency from specific nephrite deposits, these isotope ratios can be used to determine geographic origin.
Lab Notes
GIA laboratory staff present their latest findings in the Lab Notes section, including quench-crackled dyed blue chalcedony resembling Larimar, an exceptional purple sapphire from Montana, and HPHT-processed CVD laboratory-grown diamonds with low color grades.
Micro-World
The Micro-World section, dedicated to the inner world of gemstones, features unusually shaped rutile crystal inclusions in Russian emerald, windmill inclusions in the rare mineral sphalerite, and crystalline pyrite inside a 466.27 ct rock crystal quartz.
Gem News International
Finally, GNI correspondents from around the world report on a possible new find of purplish pink diaspore, the impact of ivory bans on the fossil ivory trade, the design and cutting of the “Fragility of the Eternal” kunzite, “rhodatrolite” from Indonesia, and a field trip to Crater of Diamonds State Park in Arkansas. @chapter:44 @chapter:1 @chapter:44


# Publication Year: 2004
# Title: Summer 2004 Gem News International
# Abstract: Colored Stones and Organic Materials
            Amethyst from California
            Green Petrified Wood from Arizona
            A Unique Quartz Sculpture from Peru
            Scapolite from Mozambique
            Update on Tourmaline and Other Minerals from Warner Springs, California
Instruments and Techniques
            Recent U.S. Patents for Diamond Fingerprinting Methods
Synthetics and Simulants
            Colored Cubic Zirconia Buddha Carvings
            “Shell Pearls” with Tridacna Clam Shell Beads
            Fake Tanzanite Mineral Specimens
Conference Reports
            ICNDST-9
            GAC-MAC 2004
Exhibits
            Pearls at the Royal Ontario Museum
            Carnegie Gem & Mineral Show
Conferences
            5th European Conference on Mineralogy and Spectroscopy
            Gems of Pacific Continental Margins
            Diamond 2004
            ICAM 2004 in Brazil
            Hong Kong Jewellery & Watch Fair
            Rapaport International Diamond Conference 2004
            CGA Gemmology Conference 2004
            Pegmatites at GSA
            Antwerp Diamond Conference

To view the full section, download the PDF above. @chapter:4 @chapter:0 @chapter:4


# Publication Year: -
# Title: Rose Quartz Care and Cleaning
# Abstract: Rose quartz is a durable gemstone. With proper care, it will provide a lifetime of jewelry-wearing enjoyment. - Photo by Robert Weldon, © GIA

                      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. With a Mohs hardness of 7, rose quartz is a gem that can provide a lifetime of wearing pleasure.

	Rose quartz ranks 7 on the Mohs scale of hardness.
Stability
Rose quartz is generally stable when exposed to light and heat.

Cleaning
Warm, soapy water is always a safe method for cleaning rose quartz. Cleaning with ultrasonic and steam cleaners should be avoided.

Treatment
Rose quartz is occasionally treated with radiation to intensify its color. @chapter:16 @chapter:1 @chapter:16


# Publication Year: 2016
# Title: Spectral Characteristics of Pinctada Mazatlanica and Pinctada Margaritifera Pearl Oyster Species
# Abstract: Figure 1. These Pinctada mazatlanica shells were obtained from Mexico. Left: The shell has a rounded outline, with a nearly equal height and width. The exterior surface exhibits alternating yellowish brown and dark greenish gray colors, with whitish blotches fanning out from the center. Right: The interior view of the shell on the left alongside a smaller example showing a yellowish green nacreous rim with a distinct orient. Photos by Lhapsin Nillapat.
Pinctada margaritifera is a well-known mollusk species of the Indo-Pacific region that produces gray to black pearls. Cultured pearls from the mollusk are often referred to as “Tahitian” in the market. Both natural and cultured P. margaritifera pearls are noted for their characteristic UV-visible spectra. The typical reflectance feature at 700 nm is a key identification attribute for this species (K. Wada, “Spectral characteristics of pearls,” Gemmological Society of Japan, Vol. 10, No. 4, 1983, pp. 3–11, in Japanese).

Pinctada mazatlanica, the so-called Panamanian pearl oyster, is a species closely related with P. margaritifera. Although P. mazatlanica was originally classified as a subspecies of P. margaritifera (R.L. Cunha et al., “Evolutionary patterns in pearl oysters of the genus Pinctada (Bivalvia: Pteriidae),” Marine Biotechnology, Vol. 3, No. 2, 2011, pp. 181–192), in 1961, the taxonomy of the Pinctada genus was revised, and P. mazatlanica was listed as a distinct species due to different shell characteristics and geographical occurrence. P. mazatlanica is extensively distributed along the western coast of the Americas from Mexico to Peru and around the Galapagos Islands. It is considered a native pearl oyster species of the Gulf of California in Mexico and around the Archipelago de las Perlas in the Gulf of Panama (G.F. Kunz and C.H. Stevenson, The Book of the Pearl, The Century Co., New York, 1908, p. 69). The spectroscopic characteristics of this species were believed to be similar to P. margaritifera (Winter 2005 Lab Notes, p. 347), yet this author was unable to find any recorded spectra in the literature.

GIA’s Bangkok laboratory recently studied three P. mazatlanica shells from Mexico (two are shown in figure 1). These shells appeared to have morphology between P. maxima and P. margaritifera mollusks (P. C. Southgate and J.S. Lucas, The Pearl Oyster, Elsevier, Oxford, 2008, p. 60). The rounded outlines were similar to those of P. maxima; in each, the shell’s height was almost equal to the width. The color of the outer surfaces alternated from yellowish brown to dark greenish gray, with rays of whitish blotches fanning out from the center. The inner nacreous rims ranged from yellowish green to dark gray with visibly iridescent overtones resembling P. margaritifera. To investigate reflectance UV-visible spectral characteristics in the dark and light nacreous areas, three pieces were cut from one of the shells (figure 2).

Figure 2. The lip area of one P. mazatlanica shell was cut into three pieces to investigate
the reflectance spectral characteristics in the dark and light nacreous areas. Photo by
Lhapsin Nillapat.
The dark gray nacre of all the samples exhibited the same spectral pattern as those recorded from naturally colored gray to black nacre of P. margaritifera shells and pearls. The reflectance feature at 700 nm was consistently present in these samples, together with a uroporphyrin feature at 405 nm (figure 3). Uroporphyrin has been established as one type of pigmentation responsible for gray to black tones in some pearl oyster species (Y. Iwahashi and S. Akamatsu, “Porphyrin pigment in black-lip pearls and its application to pearl identification,” Fisheries Science, Vol. 60, No. 1, 1994, pp. 69–71). However, the feature at 495 nm that is often displayed in natural dark-colored nacre from P. margaritifera was not present in these samples, while the spectra collected in white to silver areas lacked the 405 and 700 nm characteristics. The spectra were relatively featureless, with no significant reflectance showing in the visible region. This was in keeping with results obtained from the white to silver nacre of P. maxima and P. margaritifera shells and pearls (S. Elen, “Identification of yellow cultured pearls from the black-lipped oyster Pinctada margaritifera,” Spring 2002 G&G, pp. 66–72).

Figure 3. UV-visible reflectance spectra of the darker gray nacre areas of all three
P. mazatlanica shell samples shown in figure 2 are similar to the spectrum from a
P. margaritifera pearl. All show a uroporphyrin feature at 405 nm and a feature at
700 nm, which is diagnostic of P. margaritifera. These spectra prove the similar
spectral characteristics between P. mazatlanica and P. margaritifera.
Further studies at GIA’s New York laboratory on P. mazatlanica shells from GIA’s Carlsbad collection confirmed these findings. Additionally, the yellow-green nacre close to the dark gray nacreous rim of the shell showed a broad trough from 330 to 460 nm. This consisted of features between 330 and 385 nm and between 385 and 460 nm. A clear feature at 700 nm was observed, but the one at 405 nm was not evident. The spectra are comparable with natural yellow P. margaritifera nacre samples (again, see Elen, 2002).

Photoluminescence (PL) spectra collected on the dark gray and yellow-green nacreous areas of all the samples showed bands at approximately 620, 650, and 680 nm. These same PL bands are observed in naturally colored nacre of P. margaritifera and Pteria sterna, as well as several colors of P. maxima nacre (S. Karampelas, “Spectral characteristics of natural-color saltwater cultured pearls from Pinctada maxima,” Fall 2012 G&G, pp. 193–197).

The reflectance and PL spectra from our samples prove the close relationship between P. mazatlanica and P. margaritifera. Pearls produced by these two black-lipped oyster species therefore share similar spectral characteristics. @chapter:11 @chapter:4 @chapter:11


# Publication Year: 2022
# Title: The Year of Mineralogy at the Perot Museum
# Abstract: Figure 1. The Year of Mineralogy at the Perot Museum of Nature and Science in Dallas features 10 cases filled with fascinating samples demonstrating the importance of the mineral world around us. Photo courtesy of the Perot Museum of Nature and Science.
2022 is the International Mineralogical Association’s designated year for celebrating the history, development, and role of mineralogy, with a goal of promoting public interest in mineral studies. The association aims to emphasize mineralogy’s critical role in technology and society and to highlight the future of mineralogy through the exploration of new and environmentally conscious methods for extracting the minerals used today. To help carry out this mission, the Perot Museum of Nature and Science in Dallas has created the Year of Mineralogy exhibit (figure 1) in the Lyda Hill Gems and Minerals Hall (https://www.perotmuseum.org/exhibits/halls/lyda-hill-gems-and-minerals-hall/).

Figure 2. This striking example of lapis lazuli, a rock composed of minerals including lazurite, pyrite, and calcite, is on display in the exhibit. From the Sar-e-Sang mine in the Kokcha River area of Badakhshan Province, Afghanistan. Photo courtesy of the Perot Museum of Nature and Science; specimen courtesy of Keith and Diane Brownlee.
With more than 5,700 minerals identified to date, and more added each year, there is no shortage of specimens to display. Each of the exhibit’s 10 cases educates visitors with spectacular examples to illustrate various mineral properties. The first case defines what a mineral is, showing specimens such as lapis lazuli and lazurite (figure 2). Chemical composition and crystal structure are explained in the second case, while the remainder are dedicated to the various properties of minerals, including hardness, tenacity, streak, luster (figure 3), and color.

Figure 3. The resinous appearance of this sphalerite specimen highlights the mineral property of luster. From the Picos de Europa Mountains, Asturias, Spain. Photo courtesy of the Perot Museum of Nature and Science; specimen courtesy of Gail and Jim Spann.
“By understanding mineral characteristics, like hardness, magnetism, and specific gravity, we are able to find solutions to many modern industrial problems and improve our overall well-being,” said Kimberly Vagner, director of gems and minerals at the Perot Museum.
On display until April 24, 2023, the exhibit is an opportunity for all ages to acquire a deeper understanding of the mineral world around us. Can’t make it to Dallas before April 24? Follow the museum’s Lyda Hill Gems and Minerals Hall on Instagram for posts highlighting some of the magnificent minerals on display. @chapter:6 @chapter:0 @chapter:6


# Publication Year: -
# Title: Market Insight From a  Colored Gem Dealer
# Abstract: Bill VanceVance Gems

	Interview with Bill Vance, Vance Gems
Bill Vance, a colored gemstone dealer from Delaware, sounds the twin notes of apprehension at the increasing worldwide scarcity of high-quality colored-stone rough, and excitement at the investment opportunity this presents for the middle-range buyer. He forecasts rising demand and falling supply of gem-quality rough with no end in sight, due to mines becoming defunct and miners leaving the industry. What is selling at gem shows now, he says, is only the high end “best of the best.”

Middle-class buyers from India, China, and the Far East with disposable income are acquiring peridot, tourmaline, blue zircon, tanzanite, and other colored gemstones. Although this is driving prices higher, according to Mr. Vance it is not yet too late for buyers in this country to purchase, for example, a good-size 5- to 6-carat tanzanite for $400-$550 per carat. Such a gemstone will continue to gain in value, and thanks to currently low interest on savings and other investment instruments, is literally “better than money in the bank.”

As a GIA Graduate Gemologist himself, Vance is enthusiastic about the value of a rigorous gemological education, followed by plenty of exposure to material in the field. Since the public is increasingly knowledgeable about purchasing gems, it is imperative that gem-related businesses hire educated and ethical personnel. Credibility is everything, and those in the field with well-earned good reputations will be able to stay the course.
His advice to students?  “Always trust your instruments, never ever sight-identify, and don’t be afraid to say ‘I don’t know but I’ll find out for you.’” @chapter:38 @chapter:3 @chapter:38


# Publication Year: 2022
# Title: Red-Dyed Spodumene Imitating Ruby
# Abstract: Figure 1. A semitranslucent 5.72 ct red-dyed spodumene, presented as “red corundum.” Photo by Guy Borenstein.
A semitranslucent deep red oval faceted gem, measuring 13.88 × 9.08 × 5.88 mm and weighing 5.72 ct (figure 1), was recently submitted to Stuller Inc. by a client for a custom design. The stone was presented as “red corundum.” But initial quality control testing showed a biaxial refractive index of 1.659–1.678 with a birefringence of 0.019, which did not correspond with corundum.
Due to the incorrect identity, the stone was sent to Stuller’s gemological laboratory for further analysis. Standard gemological testing revealed a specific gravity of 3.237, with a moderate orange reaction to long-wave UV and a very weak reaction, along the fractures, to short-wave UV, typical of spodumene species. Further analysis, using a 532 nm Raman laser, also provided well-matched results for spodumene (LiAl(SiO3)2). Although the collected results clearly pointed to spodumene, the deep red color it displayed was questionable and required further investigation.

Figure 2. The unpolarized UV-Vis-NIR spectrum of the dyed spodumene shows a broad band centered at 561 nm due to the red dye. The band centered at 430 nm may be related to an intervalence charge transfer species between neighboring iron and manganese, while the band at 530 nm may be related to Mn3+.
Unpolarized ultraviolet/visible/near-infrared (UV-Vis-NIR) spectroscopy showed two merging broad bands centered at 530 and 561 nm (figure 2). The former is probably associated with the Mn3+ chromophore (H.U. Rehman et al., “An X-ray absorption near-edge structure (XANES) study on the oxidation state of chromophores in natural kunzite samples from Nuristan, Afghanistan,” Minerals, Vol. 10, No. 5, 2020, article no. 463), while the latter was previously reported as associated with red dyeing (K. Schmetzer et al., “Dyed natural corundum as a ruby imitation,” Summer 1992 G&G, pp. 112–115). A possibly iron- and manganese-related shoulder at 430 nm (R. Lu, “Color origin of lavender jadeite: An alternative approach,” Winter 2012 G&G, pp. 273–283) was also observed.

Figure 3. The FTIR spectrum of the dyed spodumene shows a series of peaks at 2954, 2924, 2872, and 2854 cm–1, associated with a typical universal paraffin oil.

Figure 4. Deep UV imaging of the spodumene’s surface showed strong luminescence of the dye within a cavity as well as surface-reaching fractures. Image by Guy Borenstein; field of view 6.25 mm.
Fourier-transform infrared (FTIR) spectroscopy revealed peaks at 2954, 2924, 2872, and 2854 cm–1 (figure 3), typical of a universal paraffin oil filler (M.L. Johnson et al., “On the identification of various emerald filling substances,” Summer 1999 G&G, pp. 82–107; L. Kiefert et al., “Identification of filler substances in emeralds by infrared and Raman spectroscopy,” Journal of Gemmology, Vol. 26, No. 8, 1999, pp. 501–520). Under deep UV illumination (<225 nm), the foreign filler in the surface-reaching fractures fluoresced strongly pink while the spodumene host rock was inert. The effect was especially prominent in a cavity near the girdle (figure 4).

Figure 5. Color concentration within surface-reaching fractures confirmed dye treatment in the spodumene. Photomicrograph by Guy Borenstein; field of view 2.66 mm.
Microscopic examination verified the FTIR, UV-Vis-NIR, and deep UV findings and revealed surface-reaching cleavages and fractures filled with a red foreign substance (figure 5), as well as natural inclusions.
The recorded results confirmed the gem as a red-dyed spodumene. Although spectroscopy identified some manganese, the lack of pink/red reaction under deep UV suggests a low concentration (Lu, 2012). Therefore, the authors assume that the starting material was either colorless or very pale pink spodumene.
Introducing red dye to intensify the color of corundum is a longstanding practice (Schmetzer et al., 1992). To the best of our knowledge, however, this is the first time a spodumene has been treated with a colored oil to imitate ruby. The result masks the true identity of the gem, and without gemological testing, an uneducated trader could misidentify it as a color-enhanced ruby. @chapter:13 @chapter:0 @chapter:13


# Publication Year: 2013
# Title: Jewels from Imperial St. Petersburg
# Abstract: Geared toward the jewelry historian, this thoroughly researched work is a window into the world of the Russian imperial Romanovs, starting with the reign of Empress Elizabeth (1741–1762), and ending with Nicholas II in 1917. The author details in chronological order the jewelry and objects d’art manufactured in St. Petersburg during this period. The book contains numerous photos of the jewels and family portraits from that era.

Reviewed by GIA Library Staff
Carlsbad, California @chapter:25 @chapter:2 @chapter:25


# Publication Year: 1983
# Title: The Rubies of Burma: A Review of the Mogok Stone Tract
# Abstract: For centuries, the Mogok Stone Tract of Burma has provided the world with its finest rubies. The mining district is situated about 700 km north of the capital city of Rangoon, with the rubies found principally in alluvial deposits weathering out of a crystalline limestone or marble. This article reviews the history of this famous locality, the geology of the area, and the mining methods that have predominated. Also covered is the gemology of these stones, including those inclusions that are characteristic of Burmese origin, and a discussion of famous rubies from Mogok. @chapter:51 @chapter:0 @chapter:51


# Publication Year: 2023
# Title: Spray of Columbite Crystals in Topaz
# Abstract: Bladed crystals of columbite radiate from a central point in colorless topaz. The mirror-like surfaces allow for reflections of neighboring blades, as seen in the top left crystal. Photomicrograph by Tyler Smith; field of view 2.90 mm.
A probable columbite inclusion in beryl was featured in a recent Quarterly Crystal, demonstrating the striking form these minerals can display (Spring 2023 G&G Micro-World, pp. 90–91). It was only fitting to follow up with a look at the same inclusion hosted by a different mineral.
The cluster of bladed columbite crystals in the figure above, identified via Raman spectroscopy, was found in an 8.91 ct colorless topaz. The thinner crystals allowed the brown bodycolor to show through, while the thicker, sword-like center crystal appeared black and opaque. Thin-film interference was observed between the host and inclusion when illuminated with oblique lighting, adding some welcome color to an otherwise featureless crystal face. While columbite has been previously described in topaz (Fall 2009 G&G Lab Notes, pp. 212–213; E.J. Gübelin and J.I. Koivula, Photoatlas of Inclusions in Gemstones, Volume 2, Opinio Publishers, Basel, Switzerland, 2005, pp. 263, 738), this is the most dramatic example observed by the author. @chapter:15 @chapter:0 @chapter:15


# Publication Year: 2016
# Title: Evidence of Focused Beam Irradiation in Treated Pink Diamond
# Abstract: Figure 1. This DiamondView image of the table of a pink diamond shows two distinct pink spots. Field of view approximately 5 mm. Image by Troy Ardon.

	A Fancy pink diamond, confirmed as natural-grown, was found to be type IIa and colored by
	NV– centers. As part of routine testing, DiamondView fluorescence images were collected to check for synthetic growth features. These images showed unusual patterning in the form of two pink spots near the edge of the table facet (figure 1). Both spots were approximately 0.9 × 0.7 mm, and the table facet was approximately 3.0 mm in diameter. The orange fluorescence throughout most of the table was likely due to NV0 centers, whereas the pink components were likely due to NV– centers.

	To further investigate the spatial distribution of the NV0/– centers, we acquired a photoluminescence (PL) image of the diamond’s table using a 532 nm laser. Figure 2 shows the distribution of the NV0 and NV– centers. The distribution of the NV centers confirms the presence of two spots on the table. Figure 3 shows the average PL spectra from inside one of the spots and the average PL spectra from the region outside the spots. Figures 2 and 3 demonstrate that the intensity of the NV centers was greater inside the spots than in the rest of the table. Inside the spots, the average peak area intensity of the NV0 center was approximately two times greater and the average peak area intensity of the NV– centers was approximately three times greater. The spots were comparable in both size and defect concentrations.

	Figure 2. Left: A PL map showing the peak area distribution of the NV0 center. Field of view is approximately 3 mm; scale is relative intensity. Right: A PL map showing the peak area distribution of the NV– center. Field of view is approximately 3 mm; scale is relative intensity.

	Figure 3. A comparison between average PL spectra from inside one of the spots and the area outside the spots. The y-axis scale is the same for both spectra, so it is apparent that the intensity inside the spot is higher for both NV0 and NV– centers.

	To determine the vertical distribution of the NV– center, a 500 µm PL depth profile was acquired through each spot. This is an automated process the instrument can perform in which a series of spectra are collected along a line spanning the diameter of the spot. The stage is then offset 5 µm in the vertical direction to focus farther into the diamond, and another series of spectra are collected. The process was repeated 100 times until the target depth of 500 µm was reached. This achieved a depth profile of NV– luminescence, indicating how deeply the irradiation beam had penetrated into the stone. One spot showed an average penetration depth of 100 µm and the other 50 µm. It is important to note that this is axial displacement, which in confocal microscopy is an approximation of the true depth of the illuminated feature. Nevertheless, this demonstrated the shallow penetration of the irradiation beam.

	The intensity variation in the NV centers strongly demonstrated that this diamond was HPHT annealed and isolated nitrogen was subsequently introduced due to disaggregation of the A-form nitrogen (pairs of nitrogen atoms) or B-form nitrogen (four nitrogen atoms around a vacancy). It also indicated that this diamond was irradiated by a focused electron beam with relatively low energy (≤1 MeV) prior to annealing. These multiple processes introduced high concentrations of NV centers into the localized shallow areas. Furthermore, an increase of electron donor defects at the incident beam area would lead to the observed patterned distribution of the NV– centers. The narrow, focused nature of the electron beam is responsible for the distribution of the defects into the two spots and therefore the reason why the pink spots are observed in the DiamondView image. The two spots may be the result of two separate beams in the irradiation setup. Alternatively, the second spot may be from an additional round of treatment designed to further enhance the color. It is also unusual for the treatment to be done through the table rather than on the culet. It is unknown what benefits the focused beam will have over wide-beam irradiation. @chapter:22 @chapter:1 @chapter:22