Publish Year: - Title: Fall 2021 G&G Available Now Abstract: The Fall issue presents the second article in a three-part series on Pinctada maxima with a detailed documentation of the internal structures of cultured pearls. The next two articles present unique findings: the first identification of sudoite in as a lapidary material and the first reported example of specific chromophores causing a purple color in spinel. Lastly, a field report highlights the current state of mining and production at Neyshabur, Iran’s largest turquoise mine.
Internal Structures of Known Pinctada maxima Pearls: Cultured Pearls from Operated Marine Mollusks
The lead article, by Artitaya Homkrajae and co-authors, studies the internal structures of 74 non-bead cultured (NBC) and 12 bead cultured (BC) pearls harvested directly from farmed mollusks off the coast of Western Australia. Characteristic internal features of most NBC samples allowed separation from their natural counterparts, with a few exceptions that proved challenging and could result in an inconclusive call in a laboratory.
First Identification of Sudoite in Caribbean Ceramic-Age Lapidary Craftsmanship
A research team led by Alain Queffelec examines nine sudoite artifacts from several archaeological sites in the French West Indies. This material was previously unknown in sizes large enough for carving and has never before been identified in lapidary craft.
Purple Gem Spinel from Vietnam and Afghanistan: Comparison of Trace Element Chemistry, Cause of Color, and Inclusions
Philippe Belley and Aaron Palke investigate the chromophore combinations responsible for the purple coloration in two spinel samples from Vietnam and Afghanistan. This article presents the first reported example of chromium and cobalt causing the saturated purple color in a gem spinel.
Persian Turquoise: The Ancient Treasure of Neyshabur
This field report by Bahareh Shirdam and co-authors describes the current state of the Neyshabur turquoise mine, located in northeastern Iran. The authors highlight the local geology, mining techniques, and turquoise production from mine to market.
Lab Notes
GIA laboratory staff members present their latest findings in the Lab Notes section, including multiple fossilized shells composed primarily of emerald, a parcel of manufactured glass masquerading as blue star sapphire, and a batch of large CVD-grown diamonds with high clarity and color for as-grown material, which offers insight into potential new growth conditions.
Micro-World
The Micro-World section, dedicated to the inner world of gemstones, features an apatite crystal suspended over a cloud of rutile silk in a blue star sapphire, a diamond cut to showcase an octahedral-shaped cloud inclusion, a fractal-like hematite inclusion resembling a rose in aquamarine, and Chinese ruby with fluid inclusions in the shape of a snake and fish.
Gem News International
Finally, GNI correspondents from around the world report on the first rough Mozambican ruby auction held by Fura Gems, the identification of pink aventurine quartz with alurgite inclusions, spectroscopic characteristics of blue to violet spinel heated at low temperature, and the announcement of the GIA Library and Museum Facebook group. @topic:5


Publish Year: 2021 Title: GIA Library and Museum Facebook Group Abstract: The GIA Library & Museum Facebook page stimulates spirited discussion among gemologists, bibliophiles, and gem enthusiasts. Photo composite by Robert Weldon/GIA.
Dedicated to the beauty and fascination of gemological books and mineral exhibits, the Richard T. Liddicoat Gemological Library & Information Center and the GIA Museum launched a Facebook group on August 2, 2021.
The group has attracted over 600 bibliophiles, museum curators, gemological enthusiasts, students, researchers, and experts worldwide. It aims to provide greater digital access to our library and museum and stimulate enthusiastic discussion of the many themes covered in our collection of books, periodicals, and exhibits (see above). These subjects include gemology, geology, mineralogy, jewelry manufacturing, design, jewelry history, localities, and the gem industry.
Features include library-curated video segments and book reviews, commentary on rare bookplates or covers, and short interviews with notable library patrons. The Facebook group also highlights specific rare books from the library’s digital collection on the Internet Archive (https://archive.org/details/gialibrary). A growing proportion of the library’s notable rare books and manuscripts are digitized and offered to the public—free of charge. Over 700 books have been digitized, and the project is ongoing. The museum provides unique glimpses and the stories behind some of the amazing gems and minerals from GIA’s collection.
To become a member of this group, please visit https://www.facebook.com/groups/gialibraryandmuseum @topic:6


Publish Year: - Title: Summer 2021 G&G Available Now Abstract: The Summer issue bursts with exciting topics. We open with an important question in the diamond industry—how fluorescence intensity impacts diamond appearance and how to quantify those effects scientifically. Pearls are the focus of the next two articles, which identify the color origin of Chinese “Edison” freshwater pearls and present a classification system based on size, shape, color, luster, surface, matching, and nacre quality, respectively. Lastly, a field report highlights the bustling gemstone trading hub in Peshwar, Pakistan, known as the “intersection of anxiety.”
Measurement and Characterization of the Effects of Blue Fluorescence on Diamond Appearance
The lead article by Yun Luo and co-authors studies the effects of blue fluorescence on diamond appearance, particularly when it comes to perceived transparency and color. Results show that fluorescence intensity only occasionally impacts visible color and does not cause haziness by itself. The authors present methods to quantify these effects instrumentally.
Detection of Color Treatment and Optical Brightening in Chinese Freshwater “Edison” Pearls
A research team led by Chunhui Zhou provides an in-depth study on a group of 23 freshwater “Edison” pearls to distinguish their color origin. Various gemological and advanced instrumental techniques identified the use of color treatment and optical brightening agents in these popular cultured pearls.
Pearl Classification: The GIA 7 Pearl Value Factors
Affectionately known as “The Queen of Gems,” pearls have been cherished throughout history, and their popularity continues to grow in the market. Joyce Wing Yan Ho and Sally Chan Shih discuss the GIA 7 Pearl Value Factors for classifying various appearances and qualities. A beautiful wall chart accompanies this article.
Namak Mandi: A Pioneering Gemstone Market in Pakistan
This field report by Habib Ur Rehman and co-authors describes Namak Mandi’s transformation a salt market in Peshawar to Pakistan’s largest rough gemstone trading hub. The authors highlight pricing and trading techniques, the local gemstone supply chain, and traditional cutting practices to save weight.
Lab Notes
GIA laboratory staff members present their latest findings in the Lab Notes section, including a social media–worthy Melo pearl with an intense natural color, a beaded opal strand displaying striking play-of-color, and a flux-grown ruby containing chrysoberyl inclusions.
Micro-World
The Micro-World section, dedicated to the inner world of gemstones, features an iridescent abalone shell reminiscent of a topographic map, a polished quartz crystal displaying unusual bent rutile needles, and blue beryl crystals with heavily etched surfaces that are reportedly from Khyber Pakhtunkhwa in Pakistan.
Gem News International
Finally, GNI correspondents from around the world report on natural freshwater pearls from three European countries, mobile inclusions in quartz, multi-color Kenyan sapphires, and the reopening of the Mignone Halls of Gems and Minerals at the American Museum of Natural History in New York. @topic:10


Publish Year: - Title: Sapphires from Anakie, Australia: A Closer Look at Blue, Yellow, Green and Bicolor Sapphires Abstract: Some of the studied samples from Australia. Colors ranged from blue to dark blue, yellowish green, yellow, and greenish yellow to brownish yellow. Photo by Lhapsin Nillapat. Courtesy of Fura Gems.

Though long underappreciated, Australian sapphires could see a resurgence with the arrival of Fura Gems, a major mining and marketing company. A team of GIA researchers recently took a deeper look at the colors and causes of color of these sapphires, as well as the internal inclusion scenes observed.
The results are available in a study titled “Sapphires from Anakie, Australia: A Closer Look at Blue, Yellow, Green and Bicolor Sapphires.” The authors concluded that these sapphires are relatively high in Fe, resulting in their blue-green-yellow colors. Advanced statistical techniques can often help separate Australian sapphires from those in other deposits worldwide. @topic:2


Publish Year: 2021 Title: Peter Ngumbi (Vter Young) Abstract: Gemstone trader Peter Ngumbi examines rough at the sapphire mining area near Garba Tula in northern Kenya. Photo courtesy of Vter Young.

The pandemic has been felt throughout the entire jewelry industry, from the miners who are the first to see gems come out of the ground to the local traders and the end consumers. To get a better understanding of the situation in East Africa, we spoke to Peter Ngumbi, a third-generation Kenyan gemstone trader who sources rough from local markets and directly from the miners (see above). Mr. Ngumbi sells stones from his offices in Nairobi and Voi to visiting international merchants, as well as directly to consumers and hobby cutters via social media. The main focus of his business is garnet, primarily tsavorite. His broad perspective allows us to gain some insights into the East African gemstone scene during 2020.
The Kenyan government was quick to impose actions to contain the virus, such as a ban on interprovincial travel, which allowed for strong control of local outbreaks, and closed its borders to avoid importing cases while implementing a strict curfew. Mask wearing and contact tracing quickly became routine. While these measures affected daily life, they kept COVID-19 rates relatively low. Similar measures were enforced in Rwanda and Uganda with positive results.
The situation is vastly different in the neighboring country of Tanzania, where the existence of COVID-19 is officially denied and many people are losing friends and relatives. This has significantly impacted local production, which fluctuates heavily. Areas like Mahenge produce almost no material, while material is abundant in other areas because foreign buyers are no longer present.
Even though the local Kenyan restrictions were strong, Mr. Ngumbi notes some positive aspects. Most foreign buyers were forced to leave the country, and many of the local buyers were hesitant to invest large sums in the gem trade during these economically uncertain times. Suddenly he had access to larger volumes of stones with only a fraction of the usual buying public. On top of that, he returned from the 2020 Tucson shows and saw some exceptional tsavorite production, which allowed him to replenish depleted stock.
Normally, Mr. Ngumbi travels regularly to other countries in the region such as Rwanda, Malawi, Mozambique, and Tanzania to source rough. Since he has done this for many years, he has a strong network in these countries, which he relied on heavily during times of limited travel.
He feels that many traders have dramatically expanded their network into source countries over the last decade and are now relying on these established, trusted connections to supply them with rough remotely.
While this was an excellent opportunity for African traders to buy rough, selling was not so rose-colored. No foreign traders came to the continent to source rough. Luckily, many of the African rough traders had established an online presence, which compensated for the decreased in-person sales. Mr. Ngumbi estimates that he sold more than three times the value he usually sells through social media, adding that the public has fully accepted this method of buying. In fact, customers in the United States were so hungry for rough that he could not keep up with orders. This includes some regular customers he sees at trade shows or in his Nairobi office, but a significant portion are unknown buyers he has never met in person. A growing number of online customers are independent jewelers who source their rough as close to the mine as possible and have it cut by contracted cutters.
Artisanal mining was also impacted by COVID-19. Kenyan authorities suspended mining operations where more than 20 people were working to avoid large gatherings. This only lasted for a few months, although it was strictly enforced by officials. These temporary suspensions affected the amount of material available in the market, but keep in mind that the number of buyers was also significantly reduced due to the absence of foreigners. Once the mining restrictions were lifted, there was an influx of artisanal miners trying their luck. This resulted in increased availability of rough in the local markets compared to other years. Availability was balanced out toward the end of the year by the reopening of international borders and the return of foreign buyers with a strong desire for rough.
In summary, the pandemic has had varying effects on the trading situation in East Africa, with local regulations having a major impact on the local supply and access to that material. The absence of foreign buyers has augmented the supply of available rough in the markets, while COVID-19 has locally disrupted production by artisanal and small-scale miners. The combined effect of this could turn out positive in some regions, while other areas are adversely affected. @topic:11


Publish Year: 2021 Title: Jeff Hapeman (Earth’s Treasury) Abstract: Figure 1. A 2.04 ct blue brilliant-cut unheated Rock Creek sapphire. Photo by Jeff Hapeman.

How does one prepare for a global pandemic on a scale unlike anything seen in recent history? While it would have taken an extraordinary act of foresight to predict how significantly the world has changed since March 2020, one trend was set in motion several years ago. Increased online presence, especially with social media, proved enormously beneficial to many in the gem and jewelry industry. Jeff Hapeman of Earth’s Treasury in Westtown, Pennsylvania, was at the forefront of this social media trend and shared his views on its impact on the trade since the pandemic and beyond. Mr. Hapeman got his start faceting gemstones (figure 1). However, he has grown his business over the last few years by hiring several designers and bench jewelers and developing what he calls his “mine to finger” approach. By building close relationships with the people producing rough material at gem mines around the world and moving the jewelry-making process in-house, he is able to capture more of the value-added chain in getting rough stones to the end consumer (figure 2).

Figure 2. A ring sourced, designed, and manufactured by Earth’s Treasury displaying a 2.14 ct heated Rock Creek sapphire alongside melee-sized unheated sapphires from Rock Creek. Photo by Jeff Hapeman.
In March, when Pennsylvania went into strict lockdown, all employees of Earth’s Treasury were sent home and asked to continue working on any projects they could. His bench jeweler sorted and graded melee stones, while his designer created new stock pieces. Fortunately, given Mr. Hapeman’s heavy online involvement, Earth’s Treasury was classified as an e-commerce retailer and allowed to open again after only about a month. Of course, there was an immediate plunge in sales in March and into April, but by May sales were picking up. In June, everything took off and business was much stronger than usual. This uptick in gem and jewelry sales is likely related to delayed purchases. As the uncertainty of the early days of the pandemic began to recede and the economy started coming out of the hard lockdown seen in much of the country, consumers had discretionary funds for jewelry purchases that would have ordinarily been set aside for travel or other luxuries. E-commerce jewelers did especially well last summer as the country slowly reopened with new safety restrictions that made in-person shopping at traditional brick-and-mortar shops more difficult.
Of course, this move to online jewelry sales did not happen in a vacuum. As social media continues to take an expanding role in our lives, modern consumers have become increasingly comfortable buying gemstones online at higher price points. Since the pandemic, Mr. Hapeman has noticed that customers are becoming more comfortable with the online purchasing process. Because Earth’s Treasury offers free returns for gems and jewelry by FedEx or UPS, customers are willing to purchase and try something before settling on exactly what they want. In fact, he has stopped private showings at his offices for now and is moving more toward video consultations with potential clients.
The pandemic has dramatically affected not only the way we buy and sell gems but also the supply chains for the colored stone industry. While Mr. Hapeman deals a lot in domestically sourced Montana sapphire, it has become increasingly difficult to source gem rough internationally. In particular, rough exports from Africa have apparently dried up recently, given difficulties in exporting this material to locations such as Bangkok where it could be further distributed around the world. Some major gem cutting centers have also seen a decline in business as their international buyers can no longer visit. As a result, it has become much easier to purchase Sri Lankan stones for recutting. Interestingly, he has seen an enormous amount of tanzanite become available recently, which he speculates may be related to the material being rerouted from the badly stricken cruise industry.
The biggest potential impact of the COVID-19 pandemic on the industry concerns trade shows. While the rise of online sales had been felt by global gem and jewelry shows such as Tucson for several years, the ability of the industry to survive, and perhaps even thrive, for more than a year without a major gem show may cause many to question whether the events are crucial for their business. As we pull out of this pandemic world, it remains to be seen how major international gem shows will react and adapt. @topic:11


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

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

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

Figure 3. The “Rhapsody in Blue” suite (145.2 carats total) is composed of 17 gems: nine greenish blue cushion-cut aquamarines from Brazil, four oval-cut tanzanites, and four intense blue oval-cut Mozambique aquamarines. Photo © Constantin Wild.
During this time, Mr. Wild has been able to work on a book commemorating the firm’s 175th anniversary next year. Titled Gems, Colours, and Wild Stories… 175 Years of Constantin Wild, the book will explore the history of the company and provide many entertaining stories and high-quality images to capture the unique emotions associated with colored gems.
Mr. Wild looks forward to returning to Tucson in 2022 and predicts that demand will focus on vibrant colors to celebrate the end of the pandemic. @topic:11


Publish Year: - Title: Spring 2021 G&G Available Now Abstract: A variety of topics are in store for you in the Spring issue of G&G. First up is a study of the internal structures of natural pearls collected from wild marine mollusks. The second article explores the effectiveness of resin as a pore-filling treatment to improve the appearance of rough turquoise specimens. Next, visible spectroscopy and a mathematical function are used to predict the color of a uniaxial gem material when viewed in any direction. And spinel, which has become increasingly popular among jewelry artisans and aficionados, inspires a colorful chart displaying the many types of inclusions found in this fascinating gem.
Internal Structures of Known Pinctada maxima Pearls: Natural Pearls from Wild Mollusks
This issue’s lead article, by Artitaya Homkrajae and fellow pearl researchers from GIA, spotlights the importance of reliably sourced natural pearl samples. With the help of the Paspaley Pearling Company, the GIA team collected wild P. maxima mollusks off the coast of Australia to compare their internal structures with those of pearls from other sources. This study adds to gemologists’ understanding of natural pearl identification.
Technical Evolution and Identification of Resin-Filled Turquoise
China’s Hubei Province has long been a source of commercial turquoise production. Using a variety of detection techniques, Ling Liu and a team from the Gemmological Institute, China University of Geosciences in Wuhan researched the widespread treatment of filling porous turquoise with resin. Their conclusion was that this is an effective method of improving rough turquoise quality and, like any treatment, should be disclosed to consumers.
How to Calculate Color from Spectra of Uniaxial Gemstones
Understanding the color characteristics of a gemstone can provide a scientific basis to guide its cutting. This study uses visible spectroscopy and a mathematical method to determine the unpolarized spectra of a uniaxial material from the polarized spectra (o-ray and e-ray) in order to predict the color of a uniaxial gem material when viewed in any direction.
Micro-Features of Spinel
Nathan Renfro and co-authors add to the G&G series of micro-feature charts with this lovely display of inclusions found in spinel, a previously under-appreciated gem that is now gaining in popularity due in part to its wide range of colors. The chart is included in every printed copy of this issue, and a laminated version is available for sale in the GIA Store.
Lab Notes
GIA laboratory staff present their latest findings in the Lab Notes section, including two diamond cabochons displaying rare asterism, a precious cat’s-eye opal with patches of color producing distinct chatoyancy, and a lead glass-filled laboratory-grown ruby.
Micro-World
The Micro-World section, which highlights the inner world of gemstones, includes a remarkable cloudlike inclusion resembling a faceted brilliant diamond situated inside a polished diamond, a Mexican opal featuring a rare fluid inclusion with a mobile gas bubble, and a blue sapphire whose strikingly iridescent “play-of-color” along large partially healed fissures demonstrate thin-film interference typical of heat-treated corundum.
Gem News International
GNI correspondents from around the world offer a virtual report on the state of the gem and jewelry trade more than a year into the COVID-19 global pandemic. Other highlights include a geode with a striking resemblance to the Cookie Monster character, a historical hand-drilled briolette diamond, and a stunning photo gallery from the collection of the Alfie Norville Gem and Mineral Museum in Tucson, which reopens in 2021.
The Spring issue also contains the 2021 Gems & Gemology Challenge. Score 75% or better and you’ll receive a certificate of completion (PDF file); earn a perfect score and your name will be listed in the Fall 2021 issue. Online entries for the Challenge must be submitted by Monday, August 2, 2021. @topic:5


Publish Year: 2018 Title: Opal with Agate-Like Banding Abstract: Figure 1. This opal from the Shewa region of Ethiopia, weighing just over 10 ct, shows areas of agate-like banding. Photo by Diego Sanchez and Robison McMurtry.

Recently, author SC purchased an interesting Ethiopian opal (figure 1) that displayed a most unusual growth structure. A portion of the orangy brown opal displayed a small patch of wavy “varve” banding much like one would expect to see in an agate (figure 2). The banded area was composed of layers of translucent dark brown material alternating with lighter opaque material. It was also evident that the dark layers were much harder than the lighter layers, which had significant undercutting on the polished surface. These lighter areas also showed play-of-color, which made it obvious that they were precious opal layers. The dark areas did not show play-of–color, leaving it unknown if they were also opal or perhaps chalcedony, consistent with their banded pattern. It was also interesting to note that the lighter areas readily absorbed water and became transparent, an indication of hydrophane opal.

Figure 2. Prominent agate-like banding was seen in the opal. Photomicrograph by Nathan Renfro; field of view 8.22 mm.To test the composition of the various layers, we polished a flat surface on the back of the stone in order to accurately measure the refractive index (RI). Two measurements were resolvable with the refractometer, at 1.43 and 1.47. Further testing revealed an extremely low specific gravity measurement of 1.42 (compared to a typical SG of about 2.00 for opal), implying that the hydrophane areas were very porous. Further testing by Raman spectrometry was unable to detect the presence of quartz in either the light or dark brown bands, a finding consistent with the RI measurements.

Figure 3. Left: A crack running diagonally across the banding exhibits an offset shifting indicative of a strike-slip type of “micro-fault.“ Right: A second area in this stone also shows “micro-faulting“ with movement along the banding and no movement across the photonic crystal, indicating that opalization of the chalcedony was a secondary process. Photomicrographs by Diego Sanchez and Robison McMurtry; fields of view 2.50 mm (left) and 2.62 mm (right).
Careful microscopic observation yielded some interesting conclusions. A few small healed cracks in this stone were naturally repaired with opal infilling. Some of these cracks showed a lateral offset as they cut across the banding (figure 3, left). We also observed that the fractures that showed an offset in the banding showed no offset in the “photonic crystal” (B. Rondeau et al., “On the origin of digit patterns in gem opal” Fall 2013 G&G, pp. 138–146), or in the single play-of-color patches (figure 3, right). These observations are important in revealing the order of events that took place to produce such a specimen. First, the deposition of chalcedony had to occur in order to produce the crenulated (wavy) banded pattern. Second, stress cracks were introduced into the agate and then laterally shifted, creating several “micro-faults.” These micro-faults were subsequently “healed” with a secondary deposit of opal. This secondary opal deposition also replaced the chalcedony while preserving the original agate-like banding, which was apparent since there was no offset along the micro-faults in the patches of play-of-color.

This is one of the most unusual opals the authors have encountered to date. The microscopic observations tell an interesting story about the formation of a unique gem. @topic:13


Publish Year: - Title: Winter 2020 G&G Available Now Abstract: The Winter issue covers an array of insightful topics, including treatment detection, geographic origin separation, and more. We open with a characterization study of Madagascan pink sapphire before and after low-temperature heat treatment and the techniques used to detect such treatment. Two articles investigate various advanced analytical methods used for origin determination of blue amber and Vietnamese sapphire, respectively. And faceting patterns of from a bygone era see renewed interest with a historical examination of rose-cut colored stones.
Low-Temperature Heat Treatment of Pink Sapphires from Ilakaka, Madagascar
The lead article, by Sudarat Saeseaw and co-authors, studies the effects of low-temperature heat treatment on inclusions, particularly zircon and monazite crystals, in pink sapphire from this locality. Results show that Raman and Fourier-transform infrared spectroscopy are useful techniques to detect low-temperature heat treatment and may help laboratories set criteria for detecting treatment of this nature.
Baroque-Era Rose Cuts of Colored Stones: Highlights from the Second Half of the Seventeenth Century
Karl Schmetzer provides an in-depth profile on the faceting patterns of colored stones from the Baroque era. In this study, five gem-encrusted objects originally belonging to the archbishops and prince-electors of Trier and Cologne are systematically evaluated to shed light on the variety of rose-cut facet arrangements available during the latter half of the seventeenth century.
Fluorescence Characteristics of Blue Amber from the Dominican Republic, Mexico, and Myanmar
Amber showing very strong blue fluorescence under sunlight is highly sought after in the Chinese gem market. A research team led by Zhiqing Zhang shows that a combination of visual features, UV-Vis-NIR spectroscopy, and excitation-emission mapping can aid in identifying “blue amber” from each of the three principal localities.
Mineral Inclusions in Sapphire from Basaltic Terranes in Southern Vietnam: Indicator of Formation Model
Southern Vietnam plays host to four main sapphire-producing areas, including Dak Nong, Di Linh, Binh Thuan, and Krong Nang. Utilizing advanced analytical techniques, Doan Thi Anh Vu and co-authors study the chemistry of mineral inclusions to reconstruct the formation model of sapphire in this volcanic area. The results of this work are useful for origin determination.
Lab Notes
GIA laboratory staff members present their latest findings in the Lab Notes section, including an “all-American” diamond from Crater of Diamonds State Park in Arkansas, a striking purplish pink unheated Montana sapphire, and the largest CVD laboratory-grown diamond submitted to GIA yet.
Micro-World
The Micro-World section, dedicated to the inner world of gemstones, features a pyrope-spessartine garnet proudly displaying an unusual inclusion of blue apatite, a Mogok ruby paired with a rare bright blue lazurite inclusion, and a Mong Hsu ruby containing a partially healed fissure with a snowflake-like pattern of flux residue.
Diamonds from the Deep
Karen Smit and Steven Shirey examine the large-scale tectonic processes that have produced a critical carbon reservoir where the majority of diamonds are stored. Age-dated diamonds from the lithospheric mantle help us better understand continent evolution and carbon cycling between Earth’s crust and mantle.
Gem News International
Finally, GNI correspondents from around the world report on a new emerald locality in Southern California, distinctive dendritic inclusions in Chinese nephrite from Dahua, laser-engraved rock crystal as a new imitation of phantom quartz, and chemical analysis of rhodium-plated etched iron meteorites. @topic:2


Publish Year: - Title: Fall 2020 G&G Available Now Abstract: This issue features a unique glimpse into the overwhelming majority of diamonds submitted to GIA: those on the D-to-Z color scale. It also includes a detailed study of emeralds from Pakistan, a fascinating historical look at auctions of gems and jewels of Europe’s royal families, analysis of a rare raindrop pattern in Chinese turquoise, and a firsthand account of shell nuclei production and pearl farming in Vietnam.
Natural-Color D-to-Z Diamonds: A Crystal-Clear Perspective
The lead article, by Sally Eaton-Magaña and co-authors, examines a large dataset of colorless to near-colorless diamonds from GIA’s 2017 intake. The statistical evaluation of grading quality factors and diamond type properties has never been presented in such comprehensive detail for natural-color D-to-Z diamonds.
Inclusion and Trace Element Characteristics of Emeralds from Swat Valley, Pakistan
Hongshu Guo and coauthors provide a detailed study characterizing the various properties and chemistry of emeralds from Swat Valley, Pakistan. The researchers analyze regular and trapiche-type emeralds separately and posit that their distinct properties can be useful for geographic origin determination.
A History of European Royal Jewel Sales, Including Sotheby’s 2018 Auction of Marie Antoinette’s Jewels
Russell Shor delivers a fascinating retrospective on the accumulation of gems and jewels by the most prominent European royal houses, culminating with Sotheby’s historic Bourbon-Parma auction in 2018. This remarkable sale garnered worldwide attention as 10 lots featuring items that once belonged to Marie Antoinette faced the auction gavel.
Unique Raindrop Pattern of Turquoise from Hubei, China
Hubei Province in China produces about 70% of the turquoise available in the Chinese gem market. Hubei turquoise possessing blue and blue-green spots resembling raindrops is very popular in China and very rare. Ling Liu and coauthors use an array of spectroscopic techniques to analyze the differences in the raindrops, veins, and substrates while identifying the formation mechanism of this unique pattern in turquoise.
Vietnam: Shell Nuclei, Pearl Hatcheries, and Pearl Farming
A team from GIA’s Bangkok laboratory was granted behind-the-scenes access to two pearl farms and a shell nucleus manufacturing factory in Vietnam. In this field report, Nicholas Sturman and coauthors detail how high-quality bead nuclei are produced from raw shell and subsequently used to culture pearls on a commercial scale.
Lab Notes
GIA laboratory staff members present their latest findings in the Lab Notes section, including “fire and ice” fluorescence in a novelty cut diamond, color-change cat’s-eye diaspore, the discovery of a 15.53 ct pearl in an edible oyster, and magnetite inclusions in star peridot.
Micro-World
The Micro-World section, dedicated to the inner world of gemstones, features several creatively manufactured inclusions, epigenetic residue mimicking an “egg,” a beautiful tuft of blue needles, and metal sulfide “tree” patterns, all found within their quartz hosts.
Gem News International
Finally, GNI correspondents from around the world report on bead cultured pearls embedded with near-field-communication technology, Maxixe beryl with an unusual violet color, oiled spinel, and an overview of the research presentations at the annual Geological Society of America meeting.
The Fall issue also contains the list of winners from the 2020 Gems & Gemology Challenge. @topic:8


Publish Year: 2020 Title: Spinel on Sapphire Abstract: Figure 1. This 4.8 cm pale blue sapphire crystal contained numerous purple spinel crystals on the surface. Photo by Angelica Sanchez; courtesy of Steve Dubyk.
Recently the authors examined a 4.8 cm tall pale blue sapphire crystal (figure 1) that featured numerous purple spinel crystals up to 8 mm in size on the surface (figure 2), a rather uncommon association. Steve Dubyk of Albuquerque, New Mexico, had acquired this specimen and doubted the accuracy of the accompanying label, indicating aquamarine from Tres Pozos in Baja California, Mexico. Raman spectroscopy confirmed Mr. Dubyk’s suspicion that the specimen was in fact corundum and identified the associated purple crystals as spinel. LA-ICP-MS chemical analysis suggested that the specimen was from Sri Lanka based on the trace elements present, which indicated an average of 130 ppma iron (Fe), 38 ppma titanium (Ti), and 37 ppma magnesium (Mg). The trace element chemistry is also notable, as the magnesium will preferentially charge compensate the titanium, leaving very little excess titanium to pair with iron to produce a blue color. The chemistry measurements were consistent with the very pale blue color observed in this stone. The chemistry of the spinel was also interesting in that its reasonably saturated purple color would indicate it was at least partially caused by chromium. However, the spinel was inert to long-wave UV light, suggesting no chromium was present. LA-ICP-MS testing confirmed the absence of chromium but showed relatively high iron (10,566 ppma) and some cobalt (2.75 ppma average) which together are likely responsible for the purple color (A. Palke and Z. Sun, “What is cobalt spinel? Unraveling the causes of blue color in blue spinel,” Fall 2018 G&G, p. 262). While spinel is uncommon in sapphire, a spinel inclusion has been previously reported in a Sri Lankan yellow sapphire (Winter 2015 Micro-World, p. 444). This sapphire is one of the more unusual examples the authors have encountered.

Figure 2. Purple spinel crystals were intergrown on the outermost layer of the sapphire crystal, which appears to be from Sri Lanka based on trace element chemistry. Photomicrograph by Nathan Renfro; field of view 13.42 mm. @topic:3


Publish Year: 2020 Title: Unusual Violet Maxixe Beryl Abstract: Figure 1. This 26.72 ct Maxixe beryl has an unusual violet color. Photo by Diego Sanchez.

Recently examined in the Carlsbad laboratory was a 26.72 ct transparent violet modified cushion mixed-cut stone (figure 1). Standard gemological testing revealed a refractive index of 1.583–1.592 and a specific gravity of 2.78, both consistent with beryl. Using plane-polarized light, pale purple and saturated blue pleochroic colors were observed. A uniaxial optic figure was seen at the girdle, and the optical orientation of the stone showed the stronger blue pleochroic color down the optic axis direction. The stone was inert to long-wave UV light and fluoresced weak greenish yellow to short-wave UV. Viewed with fiber-optic light during microscopic examination, it displayed a few scattered blocky crystals, platelets, and needles, confirming natural growth origin. No coatings were seen on the surface under reflective light. Other than the unusual violet color, these properties were consistent with Maxixe beryl.

Figure 2. The violet beryl showed a typical UV-Vis-NIR spectrum for Maxixe beryl. Pleochroic colors were calculated from the spectra and revealed a blue (o-ray, dark blue trace and color swatch) and light violet (e-ray, pale purple trace and color swatch) pleochroism.
Advanced testing by LA-ICP-MS revealed that the stone lacked iron. This result was consistent with Maxixe beryl, in which iron is too low to be measured (I. Adamo et al., “Aquamarine, Maxixe-type beryl, and hydrothermal synthetic blue beryl: Analysis and identification,” Fall 2008 G&G, pp. 214–226). Maxixe beryl normally has a blue to violet blue bodycolor, but this stone showed an unusual violet color. The UV-Vis-NIR spectrum (figure 2) showed absorption bands between 500 and 700 nm and a broad band near ~690 nm. This spectrum was consistent with Maxixe beryl (again, see Adamo et al., 2008). While Maxixe beryl has been found to be colored by natural irradiation, it can also be produced by artificial irradiation. Some of these “Maxixe-type” beryls produced by artificial irradiation are known to fade when exposed to “mild heat or strong light” (see Winter 1997 Lab Notes, p. 293). However, there is no conclusive test to determine whether Maxixe color results from natural or artificial irradiation, and as such, beryl in the blue to violet color range that shows the type of visible spectrum previously mentioned is designated simply as the Maxixe variety of beryl by the GIA laboratory.

Figure 3. From the violet beryl material provided for this study, a wafer was fabricated in order to directly measure the absorption spectra while conducting a fade test by placing the sample four inches away from an intense 150-watt halogen light source. The results, normalized to a 25 mm path length, confirmed that the color became less saturated over time with exposure to light. Most of the color loss came from the o-ray direction (left).

Figure 4. The polarized visible spectra were used to produce color swatches of the ordinary-ray (E ⊥ c) and extraordinary-ray (E || c) color normalized to a 25 mm path length to illustrate the change in color during fade testing over a period of 32 hours at four-hour intervals.
A small sample cut from the same rough as the 26.72 ct violet beryl was provided by lapidary Nolan Sponsler for destructive testing in order to evaluate the color stability of this material. An optically oriented wafer, 4.45 mm thick and normalized to a 25 mm path length in order to better observe the change in color, was fabricated from this sample with parallel polished windows that are parallel to the optic axis to allow measurement of the o- and e-rays. UV-Vis-NIR spectra were collected on the sample prior to fade testing and at four-hour intervals of exposure to a 150-watt halogen bulb at a distance of approximately four inches from the bulb to avoid any significant heating (figure 3). The results showed fading of the sample until its color was very pale (figure 4), confirming that this material may fade. One should avoid prolonged exposure to light and store it in a dark environment to preserve the color.
This violet Maxixe beryl was purported to be from Santa Maria de Itabira, Minas Gerais, Brazil. It is notable for its unusual color and its fantasy cut design. In addition to this violet Maxixe beryl, another violet beryl group mineral named “johnkoivulaite” was documented in 2019 (see Fall 2019 GNI, pp. 454–455); that new beryl is from the Mogok mining area in Myanmar. However, standard gemological properties clearly separate the two violet beryl minerals. Even though this beryl owes its appealing violet hue to what would be considered an unstable color center, the color should remain intact if prolonged exposure to intense light sources is minimized. @topic:3


Publish Year: 2020 Title: The “Fragility of the Eternal” Kunzite: Origin, Cutting, and Identification Abstract: Figure 1. The pronounced pleochroism of the rough spodumene crystal weighing 2,950 grams, seen here in two orientations, was one of the properties that had to be considered during fashioning. Photos by Arjuna Irsutti.
Lapidary, the art of colored stone fashioning, is an art that requires a keen eye, talent, and great patience. Different gem materials have their particular quirks that must be considered when planning the various steps required to reach the ultimate goal of obtaining the most aesthetic stone while usually also optimizing weight yield.
Spodumene is known to challenge even the most experienced cutter owing to its high fragility, perfect cleavage planes, and unpredictability in different cutting directions. This is further magnified when the rough is exceptionally large and the cutter’s goal is to produce the largest faceted kunzite in the world.
This was author VT’s aim as he prepared to work on a piece of rough spodumene that weighed 2,950 g. The untreated crystal (figure 1) originated from Kunar Province in Afghanistan. Although a wide crack was visible at one end and about 30% of the opposite end contained numerous inclusions, the removal of both sections still left more than 1.5 kg of relatively clean rough after 20 hours of wire sawing (the safest method under the circumstances). Since the rough was oversized, some of the routine cutting accessories such as dops and transfer holders, as well as the cutting tactics, had to be adapted for the job.
Prior to the start of the process came the design element. No journey can be completed without knowing the destination, and so rather than playing it safe and opting for a simple design, the artist, VT, chose a truly challenging facet pattern of his own design that incorporated 914 facets. The “Fragility of the Eternal” design is based on the stained glass window of the iconic Notre Dame cathedral in Paris. The stone is the fifth in a series of six cut designs that fall under VT’s “World Heritage” project.
VT would also have to revise his usual strategy due to the size. So instead of cutting the pavilion first, followed by the girdle, crown, and finally the table facet, it was necessary to start with the table facet for this masterpiece. This presented its own challenges since the faceting required specialized equipment belonging to a friend in Moscow. The choice of equipment was also dictated by the material’s fragility and perfect cleavage, which prevented the use of coarse laps. This combined to make the work time-consuming, especially since large facets were the order of the day.

Figure 2. A working diagram showing the facet positions. These helped estimate the final weight of the finished stone before work began on the rough. Photo by Victor Tuzlukov.
The next step required the rough to be rounded in order to achieve the basic outline of the stone in its face-up position. This meant that sufficient pressure had to be applied to the 1.5 kg preform using both hands. Eventually the correct shape resulted. The diameter measured approximately 85 mm, while the table facet came in at 65 mm. This allowed the final weight to be approximated using formulas and the facet plan shown in figure 2. The result, between 2,500 and 3,000 ct, indicated that it would supersede the largest known faceted spodumene, an 1,800 ct green spodumene cut by John Sinkankas in 1959 that was destined for the Royal Ontario Museum in Toronto.
Although the rest of the preforming could not be done traditionally by hand, VT managed to use his faceting unit with custom-made dops provided by his friend and former student Danial Hu. The pre-faceting step took considerable time to complete because the goal was to create an important piece of art and each facet needed to be cut in a pattern that matched the stained glass window in the Notre Dame cathedral with a precision of tenths of a millimeter. Perhaps the most complex part of the process was creating 16 mains and 16 additional lines extending from the center (culet) to the girdle, each containing eight (main) and five (additional) parallel-sided facets, continuous with one another. An equally challenging task was ensuring the proportions were correct while cutting 18 rows of facets of different sizes and shapes, where one often does not depend on another, and finally making the last row of facets correspond exactly with the girdle, which was already pre-shaped. It was impossible to change the width of the final facets without breaking the pattern, which meant that the pavilion had to finish precisely where the girdle started. In other words, the width of all 18 rows had to be exactly proportional to the diagram. Another look at figure 2 is enough to show that the girdle does not simply separate the crown from pavilion as in traditional faceted stones: It is an essential element of the design.
Many chances for something to go awry existed during the cutting process. Only a slight error in judgment or calculation would result in disaster. For example, if the rows of facets were just a bit too wide, there would not have been enough space for the design and the pavilion would have required a complete recut. If some were too narrow, the girdle would have needed recutting, resulting in a smaller stone, which would also have meant recutting the table facet. Fortunately, the final facet positions aligned perfectly around the girdle, and the stone’s final diameter (83.7 mm) was off by just over 1.0 mm from the initial calculations.

Figure 3. The polishing step on the stone’s pavilion begins to show the intricate optical effects of the completed piece. Photo by Victor Tuzlukov.
The next steps, pre-polishing and polishing of the pavilion facets (figure 3), were straightforward in comparison. Yet, as mentioned previously, the sheer size meant that the vertical pressure had to be applied equally over the whole stone during pre-polishing, requiring modification of the technique used for routine work on smaller stones. If too much force was applied to the left or right side, or back and forth, the facets would become too large and the pattern would be broken. To overcome this, the stone’s own weight provided sufficient force on the rotating lap so that the pressure was always equally distributed.
After more than two months of daily work, the pavilion was polished. The next step was transferring the stone to a new dop to polish the crown. Unlike traditional lapidary procedures, directly heating the stone as part of the transfer was not an option, as the process could crack the stone along the twin plane in the direction it needed to be dopped, and because the size was once again a factor when it came to how evenly the heat warmed the stone. This resulted in the application of a technique that the late Jeff Ford from Michigan shared with VT in 2006, using a combination of wax and superglue. The wax is placed on the hot dop, which is softened by the heat. The cold stone is then placed, pavilion first, in contact with the wax, and an impression of the surface is made in it. One drop of superglue is enough to secure the stone firmly in position, and it can be removed by reapplying a little heat to warm the wax again.

Figure 4. The 3,051 ct “Fragility of the Eternal,” containing 914 facets, is believed to be the world’s largest cut kunzite. Photo by Adisorn Wattanavanich.
After three months of work, the final polishing step was completed. The gem’s removal from the dop was an exciting moment, and it was wonderful to finally see the end product in all its glory (figure 4). The finished piece weighed 3,051 ct, very close to the maximum estimated weight of 3,000 ct.
The final step in the stone’s journey was its submission to GIA’s Bangkok laboratory for examination and a report. The gemologists were excited to study such a large kunzite, although the size, 83.75–83.79 × 65.00 mm, presented challenges that limited the testing equipment that could be used. Hence, basic gemological techniques came to the fore, with Raman spectroscopy the only advanced technique used as a final confirmation. The stone was found to be anisotropic with a loupe and microscopic observation up to 70× magnification, and this property was also apparent in terms of the strong pleochroism that could be easily seen as the stone was turned. The same purple and green colors are also clearly evident in figure 1.
The RI readings of 1.660–1.676 (birefringence of 0.016) together with the trichroic colors seen through a dichroscope showed it was optically biaxial. Inclusions such as growth tubes, transparent crystals, negative crystal fingerprints, and a “natural” retained on the girdle all proved the stone was natural. Combined with the weak and moderate orange zoned long-wave ultraviolet fluorescence reaction, the data were consistent with spodumene, kunzite variety.
Since the stone was cut and submitted by VT with a series of photographs documenting this fact, the GIA report (dated May 27, 2020) also mentioned that it was represented as cut by him. Since it was the largest known faceted kunzite examined by GIA at the time, and indeed the largest faceted example of its kind known to exist, a GIA Notable Letter was issued to accompany the report. @topic:2


Publish Year: 2020 Title: Purplish Pink Diaspore Reportedly from Afghanistan Abstract: Figure 1. This purplish pink diaspore is reportedly from a new deposit in Afghanistan, discovered in February 2020. The faceted stones weigh 0.57 to 1.60 ct; courtesy of Donald Hofler. The rough stones range from 4.15 to 17.52 ct; courtesy of Salman Khan. Photo by Diego Sanchez.
Diaspore, an orthorhombic aluminum oxide hydroxide mineral with the formula AlO(OH), is a relative newcomer to the jewelry scene, with some stones possessing a captivating ability to change color between pale green, yellow, pink, and purple when viewed in different sources of light (C. Shen and R. Lu, “The color origin of gem diaspore: Correlation to corundum,” Winter 2018 G&G, pp. 394–403). Here we document a new find of purplish pink gem diaspore reportedly from Nangarhar Province, Afghanistan (figure 1).
Previously, transparent crystals of diaspore in sizes suitable for jewelry purposes were only recovered from mining operations on Ilbir Mountain near the village of Pinarcik, Milas District, Muğla Province, Turkey (M. Hatipoğlu and S. Chamberlain, “A gem diaspore occurrence near Pinarcik, Mugla, Turkey,” Rocks & Minerals, Vol. 86, No. 3, pp. 242–249). Gem diaspore from Turkey has been reported since the late 1970s (K. Scarratt, “Faceted diaspore,” Journal of Gemmology, Vol. 17, No. 3, 1980, pp. 145–148), but it was not until commercial mining began in 2005 that a consistent supply became available and was subsequently marketed under various trade names including Zultanite and Csarite (S. Kotlowski and L. Rosen, “A short history of diaspore and its trade names Zultanite and Csarite,” International Gem Society, www.gemsociety.org/article/short-history-diaspore-trade-names-zultanite-csarite). Additionally, alluvial deposits in Myanmar near Mong Hsu have yielded limited amounts of chromium-colored gem-quality crystals in small sizes since 2004 (U Hla Kyi and K.K. Win, “A new deposit of gem quality colour-change diaspore from Möng Hsu, Myanmar,” Australian Gemmologist, Vol. 22, No. 4, pp. 169–170).
Dealers Salman Khan (ARSAA Gems & Minerals) and Noshad (Noshad Gems Enterprises), both based in Peshawar, Pakistan, reported that in March 2020, a purplish pink diaspore from a new deposit had reached the gem market. The new material was reportedly coming from the Goshta district of Nangarhar Province near the village of Ragha. The authors obtained several samples from Salman Khan and Donald Hofler, a gem dealer in Texas, to perform gemological and advanced testing to characterize this material. These samples would be classified as F-type samples (collected in the international market) according to the classification scheme used by GIA’s field gemology department (W. Vertriest et al., “Field gemology: Building a research collection and understanding the development of gem deposits,” Winter 2019 G&G, pp. 490–511). It was also reported by the Peshawar-based dealers that preliminary experiments with gamma irradiation resulted in samples becoming an undesirable dark brownish orange color, but this was not tested further by the authors.

Figure 2. Microscopic examination of the diaspore revealed numerous elongate fluid inclusions (A) and planes of fluid inclusions (B). Also observed in two rough samples were fine black rutile needles (C), and one stone contained an unidentified brown hexagonal crystal (D). Photomicrographs by Nathan Renfro; field of view 1.88 mm (A), 1.44 mm (B), 4.47 mm (C), and 1.41 mm (D).
Microscopic examination showed that the dominant type of micro feature in the material is fluid inclusions, typically consisting of a gas bubble, liquid, and occasionally a solid phase. Fine curved black rutile needles were also observed in two of the samples (confirmed by Raman analysis), while one diaspore crystal contained a brown hexagonal crystal that the authors were unable to identify (figure 2). Brown epigenetic staining and cleavage cracks were observed in several samples. Strong doubling from birefringence was also characteristic of the material.
Gemological testing revealed a biaxial positive mineral with refractive indices of nα = 1.700, nβ = 1.721, and ng = 1.749, and a specific gravity of 3.38. The maximum birefringence observed was 0.049. Examination with a dichroscope showed three distinct pleochroic colors, consistent with a biaxial mineral: dark purplish pink, pale yellow, and pale pink. The diaspore showed a very weak red fluorescence under long-wave ultraviolet light and an irregular chalky yellow fluorescence reaction under short-wave UV. When the samples were examined with daylight-equivalent illumination and compared to incandescent illumination, a slight color shift was observed. The samples appeared less purplish, going from purplish pink in daylight-equivalent lighting to a nearly pure pink hue in incandescent lighting, but no distinct color change of the dominant hue was observed in the faceted samples.

Figure 3. UV-Vis-NIR spectra were collected from an optically oriented sample to resolve the alpha, beta, and gamma vibrational directions in the Afghan diaspore. All three spectra showed a broad absorption band centered between 560 and 580 nm resulting primarily from vanadium and chromium. In this sample, the average concentrations were 57 ppma vanadium, 20 ppma chromium, 205 ppma iron, and 84 ppma titanium.
Advanced spectroscopic instrumentation was used to further characterize the new diaspore material. One sample was optically oriented into a polished cube with parallel faces polished perpendicular to the crystallographic axes (T. Thomas et al., “Device and method of optically orienting biaxial crystals for sample preparation,” Review of Scientific Instruments, Vol. 85, No. 9, 2014, 093105). The ultraviolet/visible/near-infrared (UV-Vis-NIR) absorption spectra of the polished cube revealed broad absorption bands centered in the range of 560 and 580 nm for alpha, beta, and gamma polarizations (figure 3). Under daylight-equivalent lighting, the saturated purple-pink color was consistent with the alpha vibration direction, pale greenish yellow for the beta direction, and light purplish pink for the gamma direction. Under incandescent light, the pleochroic colors were saturated purple-pink for the alpha color, orange-pink for the beta color, and light pink for the gamma color. Color swatches were calculated using the measured spectra to produce a representative color for each pleochroic color and also to show how the colors mix relative to their crystallographic axes (figure 4).

Figure 4. One diaspore sample was fabricated into a crystallographically oriented block in order to measure the polarized spectra, which were used to analyze the color. This figure shows the relationship of the polarized spectra measured parallel to each crystal axis and the resulting colors produced when the polarized spectra are mixed together under daylight (top) and incandescent (bottom) conditions, which is what the viewer would observe using unpolarized light transmitted through the sample normalized to a 1 cm path length. Under daylight-equivalent lighting, the alpha color was saturated purple-pink, the beta color was light greenish yellow, and the gamma color was light pink. Under incandescent light, the alpha color was a saturated purple-pink, the beta color was orange-pink, and the gamma color was light pink. The acute 2V angle, or angle between the two optic axes, was measured as 85° in this sample. Both axes lie in the optic plane that is perpendicular to the b crystal axis.
Observations under the microscope showed the cleavage direction in the faceted stones to be nearly parallel to the table (it is inclined slightly, presumably to avoid cleaving when polishing the table facet). This orientation places the b-axis approximately perpendicular to the table facet, which will facilitate the best color face-up, composed primarily of a mixture of the alpha and gamma rays.

Figure 5. The purplish pink gem material from Afghanistan showed a Raman spectrum (left) that matched diaspore, with a dominant peak at 449 cm–1 and smaller peaks at 334, 500, and 669 cm–1. Its FTIR spectrum (right) was consistent with diaspore, with absorption features at approximately 2115 and 1990 cm–1 and broad absorption bands at approximately 4080 and 3000 cm–1.
Raman analysis confirmed the material’s identity as diaspore (figure 5, left). Fourier-transform infrared (FTIR) spectroscopy showed absorption features at approximately 2115 and 1990 cm–1 and broad absorption bands at approximately 4080 and 3000 cm–1, all of which are consistent with diaspore (figure 5, right). Chemical analysis of seven samples showed a bulk composition consistent with that of diaspore, and average notable trace element concentrations showed 27 ppma chromium (ranging from 14 to 48 ppma), 31 ppma vanadium (from 14 to 59 ppma), 213 ppma titanium (from 67 to 428 ppma), and 252 ppma iron (from 137 to 350 ppma).
This exciting discovery of purplish pink diaspore from Afghanistan may prove to be a significant new deposit. While production volume is currently unknown, several kilograms of material have been reported and large faceted stones of nearly 50 ct have been described on social media (Mark Smith, @thailankagems). The color of this diaspore can be attributed mainly to trace element concentrations of chromium and vanadium. The concentrations of these elements are generally different from those in Turkish diaspore, which has significantly lower vanadium, and those in Burmese material, which generally has much higher chromium. This new attractive color of gem-quality diaspore will certainly be a welcome addition to the gem trade. @topic:2


Publish Year: 2020 Title: Fossil Ivory Update with Lee Downey Abstract: Figure 1. Fossil walrus ivory carvings by Artifactual. The base of the octopus carving is chalcosiderite. Photos by Kevin Schumacher.
Lee Downey, owner of Artifactual (Tucson, Arizona), spoke with us in early 2020 about his 35 years in the fossil ivory carving trade and the impact of ivory bans on his business. Until recently Downey carved fossil ivory from mammoth and walrus tusks thousands of years old; he has never used elephant ivory. But legislative measures banning all ivory in response to the poaching of African elephants have diminished ivory demand.
Downey got his start in silver and turquoise and established Artifactual in the late seventies. Since then, he has lived and worked in an ivory carving village in Bali with artisans he calls “the most talented carvers in the world.” When he first arrived in Bali, they were carving bone and coconut shell. His task was to carve animals and animal skulls out of fossil ivory. “We created a trade,” he said. He showed us two of Artifactual’s current offerings (figure 1). “But now the material has become flat-out illegal in eight states.”
Since 2014, California, Hawaii, Illinois, Nevada, New Hampshire, New Jersey, New York, and the District of Columbia have enacted prohibitions against trade in ivory. (Two other states, Oregon and Washington, have banned only ivory from living elephants.) Downey said that Hawaii’s ban in particular “tanked” the trade. Customers even in states where ivory remains legal are reluctant to purchase fossil ivory, he said.
“I understand why they’re doing it,” Downey told us. “I’d rather save all wildlife if there was a way.” But he said the effect of the bans on his business has forced him to prepare to exit the fossil ivory trade. He is selling his current ivory inventory at lower prices and not buying additional material.

Figure 2. A mammoth tusk carved with sea life by Lee Downey. Photo by Kevin Schumacher.

Figure 3. A selection from Artifactual’s inventory of fossil ivory. Clockwise from top left: belt buckle with mammoth ivory, knife with mammoth tooth handle, belt buckle with mammoth ivory, and frog carving of fossil walrus ivory. Photo by Kevin Schumacher.
Downey showed us a mammoth tusk carved with sea life (figure 2) as well as two belt buckles featuring mammoth ivory (figure 3). All of them use material sourced from Alaska. “This washes up on beaches and comes out of gold mines,” he said. “It’s highly sought after by the knife makers. It’s got colors that elephant ivories will never have. It just keeps weathering out of the dirt.” Downey added that this ivory is at least 10,000 years old.
Mammoth ivory can be differentiated from elephant ivory by a simple field test to observe its natural grain lines. But there is no test to determine whether a specimen of walrus ivory comes from a fossil or a modern animal. According to Downey, this is a problem in the trade.
Artifactual uses fossil walrus ivory from St. Lawrence Island, Alaska. This ivory is 500 to 15,000 years old and dug by the native Yupik people. “It’s part of their income, and they own the island,” he said. “For us it’s a legitimate and ethical trade.”
Downey added that the legislation on ivory also prohibits mammoth tooth because it comes from an ivory-bearing animal. He showed us a knife with a carved mammoth tooth handle (figure 3). Knife makers are some of the biggest buyers of mammoth tooth, he said, and the bans have dramatically impacted their business.

Figure 4. Left: “Alpha,” a stainless steel foundry-cast skull by Artifactual, one of six in a series. Right: “Gaia,” the second skull Downey carved from a piece of the Gibeon meteorite, has a tridymite crystal inclusion in the forehead. The geometric pattern on its surface was caused by the slow process of cooling as the meteor moved through space. Photos by Kevin Schumacher.
As a result of the decreased demand for ivory, Artifactual is moving its business to other materials, including jet, natural American turquoise and variscite, steel (figure 4, left), and meteorite. “Gaia” (figure 4, right) is carved from a piece of the Gibeon iron-nickel meteorite, which landed in prehistoric times in Namibia and is believed to be around four billion years old. The company also does a lot of business in silver.

Figure 5. A moose antler carving of a horned toad by Lee Downey. Photo by Duncan Pay.
Downey has also sought out materials similar to ivory but without the ethical and legal challenges. He has begun carving moose antlers naturally shed by the animals (figure 5). “The moose antler has been a really good substitute for the ivory,” he said. He also recently began carving vintage billiard balls. “We’ll carve anything that’s carvable,” he said.
Watch our video interview with Lee Downey.

	Interview with Lee Downey @topic:6


Publish Year: 2010 Title: Developments in Gemstone Analysis Techniques and Instrumentation During the 2000s Abstract: The first decade of the 2000s continued the trend of using more powerful analytical instruments to solve gem identification problems. Advances in gem treatment and synthesis technology, and the discovery of new gem sources, led to urgent needs in gem identification. These, in turn, led to the adaptation of newer scientific instruments to gemology. The past decade witnessed the widespread use of chemical microanalysis techniques such as LA-ICP-MS and LIBS, luminescence spectroscopy (particularly photoluminescence), real-time fluorescence and X-ray imaging, and portable spectrometers, as well as the introduction of nanoscale analysis. Innovations in laser mapping and computer modeling of diamond rough and faceted stone appearance changed the way gemstones are cut and the manner in which they are graded by gem laboratories.

	DATA DEPOSITORY

Additional References
	August 15, 2010 @topic:8


Publish Year: - Title: Behind the Scenes of a Gemological Field Expedition Abstract: Field gemologists need to take preparation seriously if they are going to be ready to hike in jungle conditions. Andrew Lucas and Ahmadjan Abduriyim, of GIA in Japan, climb a trail covered with wet, slippery vegetation on marble pinnacles of rock to get to a ruby mining area of Vietnam. Photo by Vincent Pardieu/GIA

                      How do you mount a successful field expedition? Make sure you have the right people in place for the trip.

“Never go on a serious field expedition with people you don’t know. Make sure your team is ready and that they have the right attitude,” said Vincent Pardieu, senior manager for field gemology at GIA.

Gemology in the field is not the same as in a lab, he says. There are long stretches of communal living with nearly constant interaction with your traveling companions and reliance on local people to point you in the right direction.

Contrast that with a lab job where you get to go home every night and communicate with colleagues on your own terms, and you see that the challenges of fieldwork go well beyond gemological expertise.

“There is no way I will ask my boss to hire a person to work with me in the Field Gemology department based on a resume and few interviews,” Pardieu said. “To know if I can go on a serious expedition with a person, we need to spend time together in the field. Then I will be able to judge his skills and his attitude.”

Each member of the team needs to know precisely what he is expected to do, including how to interact efficiently with the other members of the team, Pardieu said. “Furthermore, a field expedition is about the gems, the place they are mined from and the people who mine them. The people are the key, because without their support you will not get where you want to go or get what you want to get.”

That is the context from which Pardieu, who is based in Bangkok, and Andrew Lucas, manager of field gemology for GIA Education in Carlsbad, broached the idea of traveling on a field expedition together when they met for dinner at a global GIA research meeting in late 2012.

Both gemologists have traveled extensively for their work: Pardieu to collect reference samples from gem mining areas to be used in laboratory work and Lucas to collect the details of the mine to market story for GIA’s education courses. Although their approach to gemology in the field is different, they soon found out they could learn from each other.

“During that evening we decided to try to combine our enthusiasm and our experience to build an efficient team that will benefit the lab and education,” said Pardieu, who asked Lucas to join his basic training program.

“Where do we start?” Lucas asked.

“Well, we already did,” Pardieu said. “It all starts with a good discussion around lunch or dinner. That’s the first time you get a sense of whether or not you have good rapport with each other.”

Trial Runs in Chanthaburi and Vietnam

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Pardieu suggested that Lucas travel to Bangkok for a weekend field expedition to Chanthaburi (Thailand) and Pailin (Cambodia) to visit ruby and sapphire mines so he could see first-hand how Pardieu and his team works in the field for the lab. Next would be a 10-day trip that included Vietnam.

“Vietnam is one of the most beautiful and challenging place I know,” Pardieu said. “The jungle-covered mountains of the Luc Yen district, where rubies and spinels are mined, is also home to a lively cutting and trading industry. But it is dangerous terrain. If you are not careful you might fall, be wounded or even die.”

Pardieu told Lucas to expect the unexpected and to physically prepare his 57-year-old body for the expedition.

“If you survive Vietnam, then we will be ready to travel on longer expeditions to places as challenging as Central Asia or Africa,” he said.

	Field gemology has significant risks. Pardieu, right, had a serious fall in a very treacherous and slippery ruby mine in Vietnam and suffered a significant fractured arm. This photo right after the accident shows his remarkable good spirit as he laughs with Lucas and still discusses the logistics of the trip. Photo by Clara Jennifer Haggai

Lucas did well on the May 2013 trip. Ironically, it was Pardieu, the younger man who warned everyone else about the rugged terrain of the mountains, who had an accident. He broke his left arm after losing his balance on some slippery marble pinnacles at the end of a long day of walking.

But what could have been a disaster turned out to be an interesting field experience for each member of the group, who banded together to immobilize Pardieu’s arm and carry him to help.

Ready to Explore Mogok
Pardieu and Lucas met again in November 2013, just after Pardieu had completed a successful scouting expedition in Mogok, Myanmar (formerly known as Burma), a legendary gem locale in an area known as Upper Burma. The region opened to foreign visitors in June 2013 after being closed for many years. Pardieu felt he had recovered well enough from his accident to go for some serious exploring there, including some underground adventures using ropes and wooden ladders.

Lucas has previously visited Myanmar several times, but had never been able to visit Mogok, and jumped at the opportunity to collect information about it for GIA Education. The time was right, the feeling between the two gemologists was good, so they decided to partner up for a field expedition to Mogok, Pardieu said.

The idea was to build a small, efficient team composed of a lab field gemologist to find ways to access the mines and collect reference samples; an education field gemologist to help take photos, work on a report and collect data for education; and finally, a videographer to document the whole adventure.

Although Mogok is accessible again, people are not free to go there. The Myanmar government requires travelers to get a permit to visit the gem-producing and trading area. A government-accredited guide must also travel with the group. Pardieu asked one of his friends, Jean Yves Branchard from Ananda travels in Yangon, to deal with the permits, guide and hotels.

He asked Jordan, one of his oldest friends in Mogok, to make arrangements to visit the mines. He met Jordan met in in 2000 when he studied gemology in Yangon and the two visited Mogok several times together until January 2005 when the Myanmar authorities stopped allowing foreigners in Mogok and the other gem-producing areas in Myanmar.

	“Traversing a rock wall in a ruby mine in Mogok that reaches a depth of 300 meters, gives you have a heightened sense of focus,” said Lucas, in red helmet. He found the activity much different from his desk work in Carlsbad. Photo by Vincent Pardieu/GIA
Pardieu, Lucas and their cameraman Didier Gruel focused on improving their stamina for the physically grueling trip. The challenge in Mogok is not about long hours walking in jungle or remote mountain areas, Pardieu said, it is in navigating the underground ruby mines that could be several hundreds of meters deep. Places like Kadoke Tad consist of an impressive network of wooden ladders that look like the underground Goblin kingdom in the movie “The Hobbit,” he said.

“Just take your time. Don’t try to move like the locals move: Each step, make sure you get a sure footing before you make the next step,” Lucas said after visiting these mines. “It’s better to be slow and sure than have a fast fall.”

The group visited numerous mines, markets and cutting areas practicing what Pardieu calls “‘doing gemology with your eyes and not your ears,” meaning getting the information yourself at the source, not secondhand from others. They also absorbed the culture and personality of the people and the beauty of their temples and pagodas.

“The time we spent together on previous field expedition was useful to improve our team’s efficiency,” Pardieu said. “Communication was easy and efficient. We were ready for the Mogok experience and everyone went home safely with great samples, thousands of photos, hours of video footage and wonderful memories.”

This is success by any definition of a great field expedition.

View Gallery @topic:9


Publish Year: - Title: Spring 2020 G&G Available Now Abstract: After being delayed by the global pandemic, the Spring 2020 edition of Gems & Gemology is available now. This issue features two articles that quantitatively analyze the causes of color in corundum and blue to yellow beryl, respectively, with a focus on chromophores. It also offers an exciting look back at the evolution of jade carving craftsmanship in China, the rediscovery and early production of the Chivor emerald mine, an analysis of Swiss rhodonite, coverage of the Tuscon gem shows, and more.
A Quantitative Description of the Causes of Color in Corundum
The lead article, by Emily Dubinsky and co-authors, investigates the quantitative relationship between corundum’s color and chemistry. Using quantitative visible absorption spectroscopy and chemical analysis by SIMS, the authors are able to calculate the absorption cross section of six major chromophores that cause a wide array of color in corundum. Data is presented in the form of spectra and color circles.
The Evolution of Chinese Jade Carving Craftsmanship
China’s oldest and most important art form, jade carving, is steeped in history going back thousands of years. Mingying Wang and Guanghai Shi explore the evolution of jade carving tools and their impact on carving craftsmanship. With advancements in technology, jade carving has increased in complexity and delicacy while still reflecting Chinese philosophy and culture.
Color Characteristics of Blue to Yellow Beryl from Multiple Origins
Yang Hu and Ren Lu use quantitative spectroscopy and trace-element analytical techniques to study color characteristics and chromophores in blue to yellow beryl. This article also discusses the complex roles alkali ions and water have in beryl, though their influence on the blue to yellow color was found to be indirect.
History of the Chivor Emerald Mine, Part I (1880-1925): From Rediscovery to Early Production
Karl Schmetzer and co-authors dig deep into the history of the Chivor emerald mine in the first part of a two-part article. Their extensive research seeks to clarify historical inconsistencies, starting with the rediscovery of the site by Colombian mining engineer Francisco Restrepo, to mining title transfers and mining company formations, the impact of World War I, and the eventual bankruptcy of the Colombian Emerald Syndicate, Ltd.
Rhodonite-Pyroxmangite from Tanatz Alp, Switzerland
Swiss rhodonite is typically used to make cabochons, beads, and ornamental objects. Franca Caucia and co-authors analyze the chemical, physical, and gemological properties of this pale pink to purplish pink material. Rhodonite deposits can be found all over the world and have been widely investigated, but material from the Tanatz Alp is less well known.
Lab Notes
GIA laboratory staff members present their latest findings in the Lab Notes section, including the “Matryoshka” diamond from Siberia, corundum inclusions in diamond, an “electronic device” in an atypical bead cultured pearl, and the use of fluorescence spectroscopy for colored pearl treatment screening.
Micro-World
The Micro-World section, dedicated to the inner world of gemstones, features reversible twinning in neodymium pentaphosphate, a pallasitic peridot with iridescent needles, and sapphire with a phenomenon resembling play-of-color.
Diamonds from the Deep
Karen Smit and Steven Shirey examine the dissolution features that occur on diamond during storage in the mantle and transport to the earth’s surface. These unique surface features, influenced by the composition and temperature of the dissolving fluid/melt, help scientists better understand when diamond grows or dissolves.
Gem News International
Finally, GNI correspondents from around the world report on the Tucson 2020 gem shows, sapphires from Montana and Australia, sunstone from Ethiopia, and the new mineral dutrowite, named after well-known researcher, professor, and GIA governor Barbara Dutrow.
The Spring issue also contains the 2020 Gems & Gemology Challenge. Score 75% or better and you’ll receive a certificate of completion (PDF file); earn a perfect score and your name will be listed in the Fall 2020 issue. Online entries for the Challenge must be submitted by Friday, October 9, 2020. @topic:2


Publish Year: 2020 Title: Tucson 2020 Overview Abstract: Figure 1. A busy booth on the first day of the AGTA show. Photo by Tao Hsu.
In early February, despite the early phase of the COVID-19 outbreak, the Tucson shows were well attended and sales were brisk. Several vendors indicated that they had their biggest single day of sales ever this year (figure 1). This anecdotal evidence was supported by the strong demand for identification and origin services reported by the GIA Show Service Lab. This year, it was hard to identify any one particular item leading demand or any game-changing new gem material finds. Instead, we found that vendors were carrying high-quality material in terms of color, clarity, and cut. In fact, many were carrying items that had been meticulously carved, fantasy-cut, or recut for ideal proportions (figure 2).

Figure 2. A 72 ct gem silica carving by Nick Alexander showing a highly desirable intense shade of blue. The material is from the Ray mine in Arizona. Photo by Kevin Schumacher; courtesy of Nick Alexander.

Figure 3. A suite of the popular teal blue Montana sapphires from Rock Creek. The center stone is 11.03 ct, and the other 14 stones total 8.38 carats. Photo by Jennifer Stone-Sundberg; courtesy of Pala International.
Surpassing its strong momentum from the past few years, teal blue sapphire from Montana was a prominent and well sought-after item (figure 3). Sapphire was doing very well at the shows, including parti-colored, fancy-colored (electric colors such as fuchsia and pinks as well as pastels such as lavender), and slabs displaying zoning or trapiche-like patterning (figure 4).

Figure 4. Left: This set of 110 Australian sapphire “fancies” in 3 mm sizes was collected over several years. Right: A pair of trapiche-like Australian sapphire slices. Photos by Jennifer Stone-Sundberg; courtesy of Terry Coldham.

Figure 5. A 0.33 ct emerald from Malysheva, Russia, offered by Dudley Blauwet at the AGTA show. Photo by Kevin Schumacher.
Emerald from around the world could be found, including some untreated smaller sizes from Russia (figure 5), melee and small-sized finished stones from Pakistan, attractive material from Ethiopia, and an abundance of material in a wide variety of color, clarity, and size from Colombia, Brazil, and Zambia.
Outstanding brilliant green garnets in both demantoid and tsavorite varieties were available, including several larger-sized, ideally colored Russian demantoids (figure 6).

Figure 6. A 6.73 ct round brilliant Russian demantoid of top quality showing a horsetail inclusion. Photo © Christian Wild.

Figure 7. Deep blue aquamarine from Nasarawa, Nigeria (left to right: 1.94, 2.84, and 1.84 ct). Photo by Emily Lane; courtesy of Jeff Hapeman.
As “Classic Blue” is the Pantone color of the year and varieties of blue gemstones are very popular in general, gems prominently displaying a blue hue could be found throughout the shows. Along with sapphire, deep blue aquamarine from Nigeria (figure 7) was particularly popular, and many vendors displayed blue zircon, gem silica (again, see figure 2), apatite, cobalt spinel, blue topaz, haüyne, turquoise, blue moonstone, and lapis in their cases.
Electric-colored accent stones and melee in materials such as sapphire, spinel, apatite, and garnet varieties tsavorite and demantoid were easy to find both loose and in finished pieces (figure 8).

Figure 8. Sea star pendant by Paula Crevoshay featuring 4.04 carats of ruby, 5.06 carats of lavender sapphire, 9.40 carats of purple sapphire, 3.87 carats of fuchsia sapphire, 6.79 carats of crystal spinel, and 0.43 carats of amethyst, set in 18K yellow gold. Photo by Emily Lane; courtesy of Paula Crevoshay.

Figure 9. Parti-colored sapphire slices from Montana (left) and Australia (right). Photos by Jennifer Stone-Sundberg; courtesy of Warren Boyd (left) and Terry Coldham (right).
As has been the case for the past couple of years, gem slices in a variety of materials, shapes, and price points were very popular in both the AGTA and GJX shows. These are attractive to many designers, whether they are working with higher-price-point material such as parti-colored sapphire (figure 9), diamond, and trapiche emerald, or more moderately priced material including amethyst, rhodochrosite, and petrified wood.

Figure 10. Fluorescent hyalite opal flower pendant by Loretta Castoro, photographed in daylight-equivalent (left) and lower-power daylight-equivalent light with added short-wave UV light (right). The 12.63 ct fluorescent opal is from Zacatecas, Mexico. It is set in 18K yellow gold and has 48 yellow diamond accents (1.14 carats total) and 72 white diamond accents (1.27 carats total). Photos by Robert Weldon; courtesy of Loretta Castoro.

Figure 11. An extremely diverse selection of unusual stones was on display at the GJX show. Left: Bright green fluorite offered by a European vendor; photo by Tao Hsu. Right: Bicolor chrysoberyl carried by United Colour Stone Co. from Bangkok; photo by Jennifer Stone-Sundberg.
As always, Tucson was the place to find the unusual and phenomenal, with several vendors carrying exotic gem materials such as fluorescent hyalite opal (figure 10), star peridot, brilliant green fluorite (figure 11, left), hackmanite, triphylite, grandidierite, axinite, and an array of bicolor stones in materials such as garnet, chrysoberyl (figure 11, right), tanzanite, and sphene.

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An Inside Look at the 2020 Tucson Shows
2020 also marked the first Tucson edition of the Ethical Gem Fair. The exhibitors showed a wide range of gemstones, prices, and origins. They were all united in their commitment to responsible sourcing, traceability, transparency, and social awareness. The variety of exhibitors reflected the different approaches taken to address these diverse challenges around the world. During its inaugural Tucson show, the Ethical Gem Fair mainly attracted young independent jewelry designers looking for gems with a transparent chain of custody from the mine to their use in finished jewelry. @topic:11


Publish Year: 2020 Title: Bicolor Synthetic Sapphire Abstract: Figure 1. Split boules of bicolor synthetic sapphire grown by flame fusion. Photo by Jennifer Stone-Sundberg; courtesy of RusGems.
At the JOGS show, a wide selection of synthetic gem materials was offered by the Bangkok office of RusGems, a synthetic crystal growth company out of Russia. Olga Tanskaia showed us their extensive color range of synthetic sapphire, spinel, beryl, garnet, and other lab-grown crystals produced using a variety of crystal growth methods. She noted that blue and red synthetic gems are always their best sellers.

Figure 2. Left: Bicolor 14.83 ct synthetic sapphire showing popular teal blue and purple colors. Photo by Kevin Schumacher; courtesy of RusGems. Right: Wisps of presumably CoAl2O4 at the boundary of the teal and purple colors in the crystal. Photomicrograph by Nathan Renfro; field of view 7.05 mm.
As we found with natural sapphire this year, bicolor synthetic sapphire, both rough and cut, was also available and popular (figure 1). This material is grown by flame fusion, and the chromophore component of the powder composition is altered during the growth process at the desired length. Many different color combinations were available, including some with the popular teal blue and purple hues (figure 2, left). The inspiration for applying this method of color zoning to these flame-fusion grown crystals came from historical work on synthetic ruby laser rods where colorless (or “undoped”) regions were desired for the ends of the rods (figure 3). A process to grow a single crystal having pure aluminum oxide for a certain length, then adding the desired level of chromium to the growth for the laser rod portion of the length, and then returning to pure aluminum oxide was developed to achieve this.

Figure 3. Synthetic ruby rod grown by the flame-fusion technique showing chromium-free ends. Photo by Jennifer Stone-Sundberg; courtesy of RusGems.
We took the step-cut bicolor synthetic sapphire in figure 51 back to the GIA lab to determine the trace element chemistry responsible for generating the teal and purple hues. Using laser ablation–inductively coupled plasma–mass spectrometry (LA-ICP-MS), we found that the teal end contained no Be, Mg, Ti, V, Mn, Fe, or Ni but did contain small amounts of Cr and Ga (approximately 4 ppma and 0.5 ppma, respectively) and a substantial amount of Co (approximately 140 ppma). The purple end similarly contained no Be, Mg, V, Mn, Fe, or Ni but did contain small amounts of Ti (0.6 ppma) and Ga (0.4 ppma), with substantial amounts of Co (120 ppma), and Cr (470 ppma). Cobalt is giving this crystal the greenish blue component of its color, and chromium is modifying the hue to purple. We used UV-Vis spectroscopy to detect absorption peaks that could be used with the trace element chemistry to explain the two differently colored regions. We identified chromium peaks at approximately 400 and 560 nm responsible for the red color component in the purple half. We also identified an additional peak in the purple half at around 640 nm, likely due to Co3+. In the teal half, we did not find the Cr3+ peaks but did identify Co3+ peaks at 640 nm and at around 440 nm, and a peak around 600 nm due to Co2+ (K. Schmetzer and A. Peretti, “Characterization of a group of experimental Russian hydrothermal synthetic sapphires,” Journal of Gemmology, Vol. 27, No. 1, 2000, pp. 1–7).
In inspecting the inclusions at the boundary between the two differently colored portions, we discovered bright blue wisps of what we believe to be CoAl2O4 (figure 2, right), a spinel-structure material referred to as “cobalt blue” that is used to impart a blue color to glass, ceramics, and plastics.
The ability to generate just about any hue in sapphire, including color zoning, was readily apparent when looking through the offerings of RusGems. It was fascinating to see evidence of the direct influence of the high-tech laser industry on these synthetic gems. @topic:3


Publish Year: 2020 Title: New Blue Sapphire from Rakwana, Sri Lanka Abstract: A 49.99 ct rough sapphire crystal (5.8 cm in length) and a 33.16 ct cut stone with exceptional color from the 2019 Rakwana find. Photo by Robert Weldon/GIA.
The town of Rakwana, in southern Sri Lanka, has been known for decades as a premier source of royal blue sapphires. Often, a simple mention that a gemstone is from Rakwana will immediately explain the price and quality. In August 2019 a small pocket yielding numerous large sapphire crystals was discovered in the nearby Sinharaja Forest area of the Ratnapura District, Sabaragamuwa Province. What was unique about this find was the quality and size of the lustrous crystals. The 49.99 ct rough crystal in the figure above, measuring 5.8 cm in length and 1.6 cm at its widest point, was one of about 60 found in August 2019. It was also the largest complete crystal found. The beautiful 33.16 ct gem beside it was cut from a 207 ct piece of rough, the end of a large portion of a crystal. This crystal and cut gem rival the famous ones from Kataragama found four years ago. @topic:2


Publish Year: 2020 Title: Investigations into Corundum and Beryl Color, Jade Artistry, the Chivor Emerald Mine’s History, and Swiss Rhodonite… Abstract: Welcome to the Spring Gems & Gemology! Publication was significantly delayed by the COVID-19 pandemic, but we’re very proud to present this issue, which offers a blend of science, art, and history. In our lead article, authors Emily Dubinsky, Jennifer Stone-Sundberg, and John Emmett illuminate the chemistry behind gem corundum’s rich array of colors to reveal the influence of the concentrations of the six identified chromophores found in natural corundum on the depth of color. The authors use quantitative visible absorption spectroscopy and chemical analysis by secondary-ion mass spectrometry (SIMS) to study specially chosen synthetic and natural corundum samples to calculate each chromophore’s absorption cross section. This information is presented as spectra and color-circle arrays, which we hope practicing gemologists will find informative.
“This article provides insight for the practicing gemologist on the influence of six specific chromophores and their concentrations on depth of color in corundum.”
In our second paper, Mingying Wang and Guanghai Shi of the China University of Geosciences (Beijing) present a study of Chinese jade carving artistry ranging from time-honored, traditional techniques to state-of-the-art computer numerical control and 3D replicate engraving. Using data from almost 2,500 contemporary pieces, the authors demonstrate the art’s rich heritage and its continuing innovation.
Next, two more authors from the China University of Geosciences (Wuhan), Yang Hu and Ren Lu, examine the chromophores in blue and yellow beryl using quantitative spectroscopy and trace-element analysis to explore their color-causing characteristics. The authors show that different concentrations of iron ions with various valences and occupancies are most responsible for the gem’s blue to green to yellow colors.
Our following paper offers a change of topic. Karl Schmetzer, Gérard Martayan, and Jose Guillermo Ortiz provide the first of two installments detailing the checkered history of Colombia’s Chivor emerald mine: its abandonment, rediscovery, and intermittent operations by a fascinating cast of characters, including German gem merchant Fritz Klein.
In our final feature article, a team of Italian researchers led by Dr. Franca Caucia offers a study of the chemical, physical, and gemological properties of attractive rhodonite-rich rocks from Switzerland’s Tanatz Alp.
Our regular sections have much to offer, too. In Lab Notes, we describe diamonds with graphitic cavities and corundum inclusions, a clarity-enhanced glass imitating emerald, a large grandidierite, and curious pearls. Micro-World also provides intriguing curiosities, including a diamond with a mobile green diamond inclusion and a pallasitic peridot with iridescent needles. In Diamonds from the Deep, regular contributors Karen Smit and Steve Shirey demonstrate that diamonds are not necessarily forever with an exploration of the dissolution many diamond crystals suffer during transport in kimberlite magma. Our Gem News International section surveys gem materials and events from the 2020 Tucson gem shows, including star peridot, demantoid garnet, emerald, sapphire, trapiche gems, Tucson’s first ethical gem fair, and the results of the 2019 Buccellati jewelry design competition. Please also see the winners of our Dr. Edward J. Gübelin Most Valuable Article Award and this year’s G&G Challenge quiz.
Finally, do make sure you visit our new G&G Facebook group at www.facebook.com/groups/giagemsgemology. Since our February 2020 launch, over 7,000 of you have joined, so if you haven't seen it yet, please check it out. Thank you all for your support and interest! @topic:2


Publish Year: 2020 Title: Exceptional Rough and Cut Blue Sapphire from Rock Creek, Montana Abstract: The 17.65 ct “Lucky Sapphire” rough crystal and 3.92 ct oval cut using the custom “Helena” design, both from Rock Creek, Montana. Photo by Robert Weldon/GIA; courtesy of Jeffrey Hapeman.

The Rock Creek sapphire deposit in Montana has been active since the 1890s and is known as the state’s most fruitful deposit (T. Hsu et al., “Rock Creek Montana sapphires: A new age of mining begins,” https://www.gia.edu/
gia-news-research/rock-creek-montana-sapphires-new-age-mining-begins, August 29, 2016). This year in Tucson, Jeffrey Hapeman of Earth’s Treasury showed the authors a very fine untreated blue sapphire rough with a yellow spot in the center, as well as a top-quality faceted light teal blue untreated stone with some yellow zoning (see above). Since 2014, Mr. Hapeman has been focusing on Rock Creek material in these nontraditional lighter blues to greens. They have proven to be very popular, as several AGTA vendors this year reported strong demand for these colors, not only in Montana sapphire but from other sources as well. When it comes to unheated material, only about 5% of the rough from Rock Creek is cut without treatment, and most of these are either fancy pinks, yellows, or lighter blues. In the past year Mr. Hapeman has seen a shift in demand to parti-colored and green sapphires, particularly deep bluish green. @topic:2


Publish Year: - Title: Alexandrite History and Lore Abstract: A 43-carat alexandrite in the collection of the British Museum.

                      Abundant alexandrite deposits were first discovered in 1830 in Russia’s Ural Mountains. Those first alexandrites were of very fine quality and displayed vivid hues and dramatic color change. The gem was named after the young Alexander II, heir apparent to the throne. It caught the country’s attention because its red and green colors mirrored the national military colors of imperial Russia.

	Alexander II was still a youngster in 1830, when a never-before-seen color-change gem
	was discovered in the Ural Mountains of Russia. - Corbis
The spectacular Ural Mountain deposits didn’t last forever, and now most alexandrite comes from Sri Lanka, East Africa, and Brazil. The newer deposits contain some fine-quality stones, but many display less-precise color change and muddier hues than the nineteenth-century Russian alexandrites. You’ll still find estate jewelry set with some of the famed Ural Mountain alexandrites. They remain the quality standard for this phenomenal gemstone. @topic:1