Publication Year: - Title: 6 Tips for the Best Gem Photos Abstract: Robert Weldon captures the vibrant color of the 79 natural rose color sapphires and 24 round pink and purple heated sapphires in this bracelet set in 18K rose and white gold accented with round diamonds. Courtesy of Omi Privé, photo by Robert Weldon/GIA

                      Robert Weldon, manager of photography and visual communications for GIA, has photographed some of the most extraordinary pieces of jewelry and gem specimens in the world. He has refined the art of gemstone photography through years of careful experimentation and persistence in capturing every detail of each piece. He knows how to use the best tools, environments, lights and props to showcase the beauty of the gems and jewels he sees through his camera lens.

He offered these six photo tips at the 2014 JCK Show in Las Vegas.

Tools

Camera and lenses – Use a high-end digital Single Lens Reflex (SLR) camera capable of shooting images 16 mega pixels and above. A 60-80 mm macro lens capable of 1:1 magnification makes it possible for you to focus on your subject matter from a distance of 5 inches or more. Weldon traditionally uses a 105 mm lens.

	This Victorian gold snake bracelet (circa 1875) features woven, stamped and engraved gold set with diamond eyes. Gift of Mona Lee Nesseth, photo by Robert Weldon/GIA
Lighting – Studio strobe lights, continuous lighting, LED lights and simple flash units give you a variety of lighting options. The investment in a system can be significant, so carefully consider how gems or jewelry will be lit, and how light interacts with them.

Stage – Create a platform or area where your subject will be photographed. Many photo supply companies sell pre-fabricated light boxes, or you can use a white cloth tent or cocoon made of translucent plastic, to control the environment and create diffused lighting, which scatters light, softens shadows and provides uniform lighting for your subject.

A consistent light arrangement and staging is ideal for appraisers and jewelers who want to catalog what they have worked on or record inventory in an environment that does not change. This provides consistency in the way the images look, but little in the way of creativity or artistic license.

	This large, 201.06 carat ametrine is from Bolivia. Courtesy of Michael M. Dyber, gem designer, photo by Robert Weldon/GIA
Tripod – A tripod will help eliminate camera movement, especially with continuous lighting systems, and make it easier to compose the best possible photograph.

Tweezers, sticky wax or tape and gem cloths – Sticky wax and tape help the photographer address minute details, such as placement of the object on a stage. As in gemology, gem cloths are invaluable to clean a gem or remove fingerprints and dust. Tweezers are used to avoid getting new or more fingerprints on the gems, especially after they have been wiped with a gem cloth. Because items are magnified through macro photography, make sure such details to do not detract from the object.

Beautiful Objects
Choose the best-cut stone or the most beautifully made jewelry. A well cut stone that doesn’t show light leakage take less time to prepare for the photo and is easier to position in a flattering manner. That said, it is always good to change the position of a jewel, and remember to document a piece from the front and back.

	Left: Jeffrey Appling designed this bicolored tourmaline ring with green and pink gold, tsavorite garnet, pink sapphire and natural yellow diamonds. Courtesy Jeffrey Appling. Right: These diamonds – 22.32 ct macle, left, and 1.01 ct round brilliant – are from the Oppenheimer Collection. Gift of DeBeers. Photos by Robert Weldon/GIA
Background
Carefully choose the material that will act as a background to your subject matter. You want to make sure you choose a material – fabric, stone, tile, glass, or wood – whose texture or color doesn’t compete with the object. A good rule of thumb: if the subject matter is light, choose a dark background and if it is dark, choose a light background. This will ensure there is high contrast between the object and the background, which is always appealing to the eye. Also, white backgrounds tend to have a more clinical feel, while black often adds a dramatic touch.

Successful is when a viewer likes the “mood” of an image but is not distracted by the background. Remember, your gem or jewel is the focal point and most import aspect of the photo.

Props
Use props to tell the story of the piece. A cameo placed on ancient books, for example, conveys a sense of history. Make sure the colors of your props are different enough that the piece stands out from them or is complimented by them. You can also use props to establish the scale of the object.

	Left: Weldon used rare books from “Tablet to Tablet,” a library museum exhibit in Carlsbad, as a background for this cameo brooch. Courtesy of Elise Misiorowski. Right: The rectangular cushion-shaped amethyst and pearl brooch is displayed on blue fabric. Courtesy of KCB Natural Pearls. Photos by Robert Weldon/GIA
Post-Shot Processing
Most images can be enhanced with a little bit of Adobe Photoshop work. This photo-editing software makes it possible for you to clean dust and remove glue or sticky-wax that may be showing. While this software can be used to change color, it should only be used to correct the color to match the actual gemstone. In some cases, items can be cut out of a background, or a halo-lighting effect can be used to create a mood or spotlight a special aspect of the piece. Photoshop can also be used to convert the format of the photo for various media (print, email and web).

Never use Photoshop to change the “truth” of a photo. For example, don’t take out inclusions, abraded facet junctions or dramatically change the color of a stone, such as altering a pink stone to a deep red. It is unethical to make such significant changes without disclosing that you have done so.

Be Patient
Keep trying. Author Malcolm Gladwell often refers to the "10,000-Hour Rule" in his book “Outliers,” saying the key to success in any field is due, to a large extent, to practicing a specific task for a total of around 10,000 hours. Applying that adage to photography, consistent “perfection” comes after your 10,000 image.

	Designed in New York by Max Halpels for Bulgari, this floral platinum brooch is set with 47 natural, fancy colored and fancy cut diamonds that weigh a total of 29.38 carats. Courtesy of the Royal Ontario Museum in Toronto, Canada, photo by Robert Weldon/GIA @chapter:26


Publication 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. @chapter:3


Publication Year: - Title: Soweto Jeweler is a Symbol of Hope for South Africa Abstract: Nkosi at his studio in Soweto, South Africa. Photo by Robert Weldon, © GIA 2012

Robert Weldon, manager of photography and visual communications for GIA, met Nqobile Nkosi on a trip to South Africa in 2012. Nkosi is a self-made jeweler from Soweto, South Africa, who is hoping to create jobs and opportunities in his township.

	Soweto’s first home-grown jeweler has set his goals high and his aspirations even higher.

	Nqobile Nkosi, who is a jewelry designer, manufacturer and retailer, embodies the spirit of entrepreneurship that is characteristic of the new South Africa.

	His story focuses as much on jewelry education and innovation as it does on the dismantling of social barriers. It is the story of a man who simply does not recognize impediments, be they financial or social. Instead, his vision is clear: to build a business, create new jewelry, disseminate his ideas globally through cooperation and friendships, and most importantly, to create jobs locally.

	Soweto, southwest of Johannesburg, was formed at the intersection of repression, activism – and now – hope. Home to an agglomeration of townships that coalesced in 1961 as a sprawling suburb of South Africa’s capital, its population of more than one million includes many African miners who toil daily in the nearby gold and diamond mines.

	Soweto, site of the now-famous uprising that eventually helped bring an end to the apartheid system, was also home to Nelson Mandela and other leaders of the anti-apartheid movement. Though enormously underdeveloped still, entrepreneurship and business creation is on the rise, and Soweto is slowly emerging as the country’s breathing symbol of hope and freedom.

	“Everyone can rise above their circumstances and achieve success if they are dedicated to and passionate about what they do,” Mandela has said.

	Nkosi has translated those words into action.

Cakes, Biscuits, and a Window

	Nqobile Nkosi, like hundreds of thousands of South Africans in 2004, found himself at a crossroads.

	“I was unemployed, at home, and it came to a point where I really had to do something with my life,” he said. A friend suggested taking courses at the Soweto Jewellery Training School, which Nkosi immediately pursued.

	“Some months before the training ended, I started selling cakes and biscuits at school to make ends meet and to be able purchase my first polishing motor and ultrasonic cleaner. I made small space in my bedroom for a torch and a small bench,” he said. “I was a one-man-band jeweler.”

	As improbable as it might seem for a jeweler to set up shop in the township, Nkosi said there was no shortage of business, even before his studies were concluded.

	The requests came steadily: “Could you please size this ring for me?” “Could you polish this, or do that?”

	Nkosi seized the opportunities as they arose. Talking with people, being introduced to the trade, and being able to contribute to his community was a turning point for Nkosi. “It is really all about what you want to achieve. For me, the jewelry business was different. It opened a new window in my life and I just wanted to go further with the experience.”

		This Cornerstone design, left, called a “vuvuzela,” or a fanfare, is used in stadiums to make noise while rooting for a favorite soccer team. South Africa hosted the 2010 FIFA World Cup in soccer. The Silver Flame ring, right, is set with citrine. Photos courtesy of Cornerstone.

		Success followed, and he began to earn local awards and recognition: a South African Breweries Kickstart Award (a cash prize given to young entrepreneurs), a Jet Community Award and a nomination as a Gauteng local business leader. Other forms of recognition followed as well.

	He invested all of his cash prizes in the business, making it possible for it to grow and for him to be able to hire additional people.

	“For me, success isn’t driving a new car,” Nkosi said. “I see success as being able to move this business from one generation to the next.”

	Nkosi’s studio is small and bursting at the seams. As he reaches towards an international audience for his jewelry, Nkosi’s space considerations, tools, security and further training for his workers become his principal focus. Photo by Robert Weldon, © GIA 2012.

Growth and Future

	Nkosi established a new company, NQ Jewellery, in 2007, and its success soon required additional support. “My brother came to help out, and soon I was training yet another colleague,” he said. “Now we have six people working for the studio.”

	The main challenge he now faces is logistical: he needs a new space in which to grow and needs training for his workers.

	Nkosi has also begun to establish connections internationally. Award-winning U.K. jeweler Paul Spurgeon met Nkosi on a business trip to South Africa and the two became immediate friends and business partners. Together they formed a separate international company called Cornerstone, and soon thereafter Nkosi traveled to Birmingham, U.K. to train at Spurgeon’s manufacturing facilities. The plans are for additional workers at Nkosi’s studio to do the same in coming years.

	This design features a Pagoda pendant with oxidized chain detail. Paul Spurgeon, an award-winning designer based in the UK, is business partner with Nkosi in a separate company called Cornerstone. Photo courtesy of Cornerstone.

	Spurgeon wrote about his partnership with Nkosi in the UK-based trade magazine Professional Jeweller: “My personal commitment to Cornerstone is based on my desire to help provide skills and jobs to a people that have so often been marginalized and forgotten, in a continent that has given us in the trade all the materials needed.”

	The Cornerstone collaborative project and jewelry brand launched their first products at the Springfare trade show in Birmingham, and a new international line of products was shown to GIA when we visited Nkosi in Soweto in late 2012.

	Spurgeon’s and Nkosi’s Cornerstone initiative has gathered steam in the U.K. community as well: In February, 2012, Spurgeon organized a sponsored bike ride from Goldsmiths’ Centre in London, to Paris. Weston Beamor, a precious metals casting house in Birmingham, offered free casting services to the group so the first international collection could be launched.

	Nkosi poses with the team at Weston Beamor, a precious metal casting house located in Birmingham, UK. Photo courtesy of Cornerstone.

	Nkosi is ready to launch his full collection of South African-inspired motifs in 2013. “Our products aim to have a unique African look, but with a European appeal,” he said. “This is the launch of a brand.”

	Nkosi met with GIA’s late Vice President of International Operations, Tawfic Farah, as well as a few members of GIA’s Board of Governors, in 2013. GIA provided Nkosi with an AJP education scholarship, which he completed soon after and has taken on the role of president for GIA’s Alumni Africa chapter.

	Nqobile Nkosi, the first designer and jeweler from Soweto is clearly not looking back. He is joining the international community of jewelers, with an eye towards furthering his and his team’s education – and creating much-needed jobs at home. @chapter:33


Publication Year: 2018 Title: Green-Blue Maxixe-Type Beryl Abstract: Figure 1. This 54.21 ct green-blue specimen was identified as Maxixe-type beryl. Photo by Gagan Choudhary.

Recently, a transparent greenish blue pear-shaped mixed-cut sample (figure 1) was submitted for identification to the Gem Testing Laboratory in Jaipur. The 54.21 ct specimen (40.00 × 20.14 × 12.63 mm) was relatively clean to the unaided eye. Its refractive index (RI) of 1.582–1.590, birefringence of 0.008 with a uniaxial negative optic sign, and hydrostatic specific gravity (SG) of 2.71 suggested a beryl, which was later confirmed with Fourier-transform infrared (FTIR) and Raman spectroscopy. The specimen’s natural origin was established by zones of fine growth tubes, planes of platelets (usually ilmenite, although not identified here) oriented along the basal plane, and birefringent crystals.

Figure 2. The Maxixe-type beryl displayed an intense dichroism, with a deep saturated blue o-ray (left) and a yellow e-ray (right). A combination of these blue and yellow components resulted in a greenish face-up appearance. Photos by Gagan Choudhary.
Identification of the stone as beryl was straightforward, but its unusual color and striking dichroism invited further study. It displayed deep blue and yellow as the two principal colors (figure 2); the deep saturated blue resembled the color of top-quality sapphires. Such strong dichroism was reminiscent of Maxixe-type beryls, although their dichroic colors are usually deep blue and colorless. Careful examination of the specimen showed a deep saturated blue o-ray and a yellow e-ray. Maxixe-type beryls are known to display deep blue color absorption along the o-ray direction (R. Webster, Gems, 5th ed., Butterworth-Heinemann, London, 1994, pp. 124–127) and colorless along the e-ray direction. An opposite pattern of deep blue (e-ray) and pale greenish blue (o-ray) absorptions was reported previously in an aquamarine by this author (Fall 2014 GNI, pp. 244–245).

Figure 3. Polarized Vis-NIR spectra of the green-blue Maxixe-type beryl displayed a series
of bands between 500 and 700 nm (o-ray) that are associated with radiation-induced color
centers.
Further analysis with UV-Vis-NIR spectroscopy confirmed the cause of color. Polarized spectra (figure 3) revealed a series of bands between 500 and 700 nm along the o-ray direction, but only a broad absorption feature at ~690 nm along the e-ray; these features are typically associated with the radiation-induced color centers observed in Maxixe-type beryl (see I. Adamo et al., “Aquamarine, Maxixe-type beryl, and hydrothermal synthetic blue beryl: Analysis and identification,” Fall 2008 G&G, pp. 214–226).
Gemological properties along with absorption spectra and the pleochroic color directions were sufficient to establish the identity of this submitted specimen as Maxixe-type beryl. This was the first time we had encountered a green-blue Maxixe-type beryl, although there exists a previous report of such a beryl (see K. Nassau et al., “The deep blue Maxixe-type color center in beryl,” American Mineralogist, Vol. 61, 1976, pp. 100–107). On the basis of pleochroic colors, it can be deduced that the greenish face-up appearance of this specimen was due to the overlap of blue and yellow color components. The supplier of the specimen informed us that the specimen is reportedly from Mozambique. @chapter:19


Publication Year: 1988 Title: Pastel Pyropes Abstract: Pyrope garnets occur in near-colorless to light orange and pink, as well as the familiar red. Because the pale-hued pyropes are unfamiliar to gemologists, their low refractive index usually results in their misidentification as grossular. This note clarifies the means by which these unusual garnets, predominantly from East Africa, can be properly and easily identified with a refractometer and a spectroscope. @chapter:4


Publication Year: 2021 Title: Radioactive Green Diamond Abstract: Figure 1. Green diamond treated with radioactive salts. Photo by Diego Sanchez.

The rarity of naturally colored green diamonds has created the demand for artificially irradiated green diamonds. One 2.42 ct green diamond recently examined by the author showed signs of radiation treatment by the use of radioactive salts (figure 1).

Figure 2. A mottled green appearance was visible on the table facet of the green diamond treated with radioactive salts. Photomicrograph by Nathan Renfro; field of view 4.70 mm.
Microscopic analysis revealed telltale green mottled and shallow radiation stains over large areas of the stone, causing its green bodycolor (figure 2). These radiation stains were produced by exposing a cut and polished diamond to radioactive salts for an extended period. The inert to ultraviolet light radiation stains were easily visible against the diamond’s blue fluorescence seen in the DiamondView (figure 3).

Figure 3. This diamond’s blue fluorescence provides strong contrast to the inert radiation stains, as shown by the DiamondView. Image by Michaela Stephan; field of view 8.265 mm.
Treatment using radioactive salts (such as radium) is not often used anymore, as this method may produce dangerously radioactive diamonds. Today, most artificially irradiated diamonds are treated with a low-energy electron beam (Spring 2013 Lab Notes, pp. 46–47). When tested with a Geiger counter, this stone was revealed to be weakly radioactive. @chapter:11


Publication Year: - Title: Sunstone Quality Factors Abstract: This 11-ct. bicolor sunstone is highly desirable for its color alone. An attractive display of aventurescence and a unique cut make it even more valuable. – Robert Weldon

Color
Most sunstones have yellow, orange, or brown bodycolor. Green is extremely rare. Small inclusions create a reddish or golden sheen on top of any bodycolor, while larger inclusions create attractive, glittery reflections. Sunstone inclusions can be hematite, copper, or some other mineral.

	The 2.40-ct. faceted bicolor gem displays an unusual green and yellow combination. Gem cutters seek ways to display unusual colors from rough like the 9.36-ct. specimen. – Robert Weldon

	These fine-quality gems display some of the sunstone colors found in the Plush, Oregon, mining area. – Jeff Scovil, courtesy Jeff Scovil
Oregon sunstone is a transparent feldspar with copper inclusions. It comes colorless as well as in a wide variety of colors, including pale yellow, pink with brilliant aventurescence, orange, red, green, and blue-green. The red version is often marketed as “spinel red,” and its vivid hue—if not its hardness—rivals spinel or even ruby.

	Deep red sunstone from the Ponderosa mine is marketed as spinel red. Although it’s not as hard as spinel or ruby, this sunstone type has a vivid scarlet hue that can be equally lovely. – Bart Curren
Some Oregon sunstones are either bicolored or tricolored, and a rare few display color change. Currently, the top deep green, deep red, and intensely bicolored sunstones are considered extra fine.

	Some sunstones are bicolored, which makes them ideal for free-style designer cuts
	(bottom). They might also be tricolored, like this lovely 32.80-ct. Oregon sunstone (top).
	The cut is a spectacular example of the sculptor’s artistry. – Tino Hammid (bottom); Maha
	Tannous, courtesy Dust Devil Mining Company, Beaver, Oregon (top)
Cut
Sunstone is available in a wide range of shapes and sizes, from exquisite fantasy cuts for designer jewelry to precise caliber cuts for manufacturers.

	This “Dreamscape” fantasy-cut sunstone was created by gem designer John Dyer. – Lydia Dyer, Gem courtesy of John Dyer & Co.

	Caliber-cut sunstones are available for mass-market production or custom jewelry designs. – Valerie Power, courtesy Desert Sun Mining & Gem Co., Inc.
Clarity
All Oregon sunstones have an extra sheen that’s caused by copper inclusions. The sheen is there even if the inclusions aren’t large enough to create actual aventurescence.

	A photomicrograph shows inclusions in a gem from Oregon’s Ponderosa Mine, magnified 12 times. – Shane F. McClure, courtesy Dr. E. J. Gübelin Collection

	These oligoclase sunstone cabochons display an attractive adventurescent sparkle. – Edward Gubelin, courtesy Dr. Edward J. Gübelin Collection
Carat Weight
Sunstone can be found in relatively large sizes, but most caliber-cut stones weigh one carat or less.

	The unusual size of this 146.07-ct. oligoclase sunstone dwarfs the sunstones, moonstones, and other gems in the background. – Terri Weimer, courtesy Blue Moon Enterprise @chapter:2


Publication Year: 1990 Title: The Legendary Dresden Green Diamond Abstract: The approximately 41-ct Dresden Green diamond is the largest, and perhaps the finest, green diamond known to have a color of natural origin. A diamond so rich in history is well worth studying for that reason alone, but the Dresden Green offers the unique opportunity of adding valuable data to the quest for means to distinguish natural from laboratory-irradiated green diamonds. In November of 1988, two senior GIA staff members visited the Green Vaults with this goal in mind. The Dresden Green diamond proved to be not only of extraordinary quality but also a very rare type IIa – one of the purest forms of diamond. In addition, the spectral characteristics of this stone were found to overlap those of k n m treated diamonds. The history locality origin, and properties of the Dresden Green diamond are discussed in detail in this article. @chapter:35


Publication Year: 2022 Title: Identification of Natural, Reconstructed, and Imitation Root Amber Abstract: Figure 1. Left to right: Reconstructed root amber (assembled from small fragments and from powders), natural Burmese root amber, and plastic imitation. Photos by Yilei Feng.
Natural root amber is a variety of Burmese amber with a distinct appearance, good luster, and deep color (Y. Wang, Amber Gemology, China University of Geosciences Press, Beijing, 2018, p. 145). Root amber was named for its similarity in color and structure to tree roots. Root amber beads are popular in the Chinese market, and the Guangzhou Gemstone Testing Center receives many of them for identification. Recently we have noticed three different types submitted for identification (figures 1 and 2): natural root amber, reconstructed root amber (assembled from either pressed powders or small fragments), and plastic imitations.

Figure 2. Natural Burmese root amber beads (N-1 through N-3), root amber beads reconstructed from pressed amber powders (M-1 through M-3) and small fragments (M-4 through M-6), and plastic root amber imitations (P-1 through P-3). Photos by Yilei Feng and Zhaoyi Li.
Specific gravity (SG) was measured for three natural Burmese root amber samples (N-1 through N-3), three samples reconstructed from pressed powders (M-1 through M-3), three samples reconstructed from pressed fragments (M-4 through M-6), and three plastic imitations (P-1 through P-3). The SG of most varieties of regular Burmese amber samples is within 1.020–1.050, except for root amber and reddish amber (1.060–1.110). Overall, the natural root amber had higher SG (1.044–1.107) than that of regular Burmese amber and much lower SG than that of the reconstructed root amber from pressed amber powders (1.133–1.137) and the plastic imitations (1.161–1.167). The root amber reconstructed from pressed fragments, meanwhile, had an SG of 1.075–1.077. The variations in SG of the reconstructed amber were due to differences in internal structure and/or gas porosity.

Figure 3. Row 1: Internal features of natural Burmese root amber beads: cellular or porous structures (A), red-brown dots in both transparent and opaque zones (B), and the lamellar flow-like pattern with a natural color transition (C). Row 2: Root amber beads reconstructed from pressed amber powders: a flow-like pattern formed by an accumulation of powders (D and E) and a granular texture (F). Row 3: Root amber beads reconstructed from small fragments of pressed amber: clear and rigid borders of the fragments (G and H) and a small granular texture seen in a larger patch structure (I). Row 4: Plastic root amber imitations showing ribbon-, string-, or ring-like patterns (J–L, respectively). Photomicrographs by Yilei Feng and Zhaoyi Li. Fields of view: 10.6 mm (A), 9.0 mm (B), 5.6 mm (C), 2.80 mm (D), 10.4 mm (E), 7.7 mm (F), 11.3 mm (G), 10.7 mm (H), 9.3 mm (I), 5.6 mm (J), 5.0 mm (K), and 4.9 mm (L).
Most importantly, the internal features of the samples were quite different. There were some cellular or porous structures in the natural Burmese root amber (figure 3A). The typical red-brown dots of Burmese amber could be detected in both transparent and opaque zones (figure 3B). The flow-like pattern of natural Burmese root amber can be lamellar, annular, or flocculent, and there are natural transitions between varying colors (figure 3C). The internal features of the root amber reconstructed from pressed powders displayed an unnatural flow-like pattern similar to the veins of a leaf (figure 3, D–E). Under higher magnification, these samples displayed a granular texture (a sugar- or sand-like pattern with apparent broken particles), confirming that small amber micro-particles had been pressed (figure 3F). There were very clear and rigid borders in the root amber reconstructed from fragments (figure 3, G and H). Some granular texture could still be found in these samples (figure 3I). The flow-like pattern of plastic imitation is mostly ribbon-, string-, or ring-like, with a sense of separation between the brown matrix and the obvious boundaries (figure 3, J–L).

Figure 4. FTIR spectra of natural, reconstructed, and imitation root amber in the mid-infrared range (3500–500 cm–1). Spectra are offset vertically for clarity.
Using Fourier-transform infrared (FTIR) spectroscopy, the plastic imitations were quickly identified in the mid-infrared range (3500–500 cm–1). The extremely strong peak at 1731 cm–1, three peaks of increasing intensity (1240, 1192, and 1148 cm–1), and other peaks suggest that the material is an amino resin (figure 4, blue line). The vibration peaks of functional groups of natural root amber mainly appear at 2928, 2860, 1720, 1458, 1375, 1227, 1141, 1028, and 974 cm–1, consistent with the main FTIR peaks of Burmese amber (figure 4, green line). The obvious “Baltic shoulder” (Y. Wang et al., “Characteristics of hydrothermally treated beeswax amber,” Fall 2019 G&G, pp. 370–387), composed of a broad and weak absorption shoulder at 1265 cm–1 and a sharp peak at 1158 cm–1 as well as an absorption peak near 887 cm–1, appeared in two reconstructed root amber specimens (figure 4, pink and purple lines). It can be inferred that these two reconstructed samples were pressed from rough Baltic amber. @chapter:37


Publication Year: - Title: Morganite History and Lore Abstract: Morganite was named to honor American financier and gem enthusiast J.P. Morgan. - Corbis

                      Following the discovery of a new locality for rose beryl in Madagascar in 1910, George Kunz proposed the name morganite at a meeting of the New York Academy of Sciences on 5 December 1910 to honor his friend and customer J.P. Morgan for his financial support for the arts and sciences, and his important gifts of gems to the American Museum of Natural History in New York and  to the Museum of Natural History in Paris.  Morgan was one of the most important gem collectors in the early 1900s – his collection was partly assembled by Tiffany and Company and their chief gemologist, Kunz.

One of the interesting properties of morganite noted by Kunz was its intense red-colored fluorescence when exposed to X-rays, but no phosphorescence when the X-ray source was turned off.

On October 7th, 1989, one of the largest specimens of Morganite was uncovered. It was found in the Bennet Quarry of Buckfield, Maine, and it was somewhat orangish in hue and about 23 cm long and 30 cm across. This well-formed crystal weighed in at just more than 50 pounds, and was called ‘The Rose of Maine’.

	Miners discovered the first morganite specimens in Madagascar in 1911. Magenta-colored rough from those deposits still sets the color standard for the variety. This sample weighs about 12 oz. (349 g). - Maha Tannous @chapter:1


Publication Year: 2016 Title: Metallic Chromium Inclusions in Industrial By-Product Ruby Abstract: Figure 1. Photomicrograph of a petrographic thin section of ruby (purplish red)-diaoyudaoite (grayish green) slag, shown in transmitted light. From Sorokina et al. (2010).

	Technogenic corundum contained in metallurgical slag represents a potentially unique source of gem material. Since the 1950s, slags have been studied for their secondary uses. Their mineralogical and petrographic attributes have been documented, but to date there have been virtually no studies from a gemological standpoint.

	X-ray powder diffraction analysis (XRD) was performed on two slag samples taken from the waste products of chromium ore processing by thermite reaction at a refinery located in Russia’s Ural Mountains. These specimens showed the presence of corundum (α-Al2O3), the rare phase diaoyudaoite NaAl11O17, and a spinel-group mineral. For the spinel-group mineral, electron microprobe analysis (EPMA) indicated significant amounts of Mg, Cr, and Al. As seen in figure 1, the corundum contains transparent purplish red crystals up to 2.5 cm in length embedded in a diaoyudaoite matrix. The crystals may be elongated and prismatic, irregularly formed, or rounded. Gemological testing including refractometry, specific gravity measurements, and reaction under short-wave (254 nm) and long-wave (365 nm) UV. The UV reaction (figure 2, left) was consistent with natural and synthetic ruby (for in-depth analytical procedures and results, see E.S. Sorokina et. al., “On the question of technogenic ruby in the slags of Cr-V production,” Mine Surveying and Using of Mineral Resources, Vol. 2, 2010, pp. 33–35, in Russian). Microscopic examination of the samples showed features such as gas bubbles and irregular growth lines, both of which are inconsistent with natural corundum. Most significant was the presence of a metallic-phase chromium that appeared in several forms, such as needles, dendrites, and rounded or irregularly formed black solid inclusions with metallic luster. The metallic chromium was most frequently observed along the ruby parting planes (figure 2, right); it is an inclusion that has never been detected in naturally occurring corundum or in any synthetic analogues.

	Figure 2. Left: Intense red photoluminescence typical of ruby observed under long-wave UV; field of view 8.34 mm. Right: Strongly reflecting rounded and irregularly shaped metallic chromium inclusions within the technogenic ruby, surrounded by greenish gray diaoyudaoite matrix. Shown in reflected light; field of view 0.288 mm. Photomicrographs by Elena S. Sorokina.

	Laser ablation–inductively coupled plasma–mass spectrometry (LA-ICP-MS) and EPMA showed high Cr content (4.3–7.7 wt.%), most likely linked to the capture of micron-sized metallic chromium inclusions during the measuring process. We also found 135–270 ppmw of Mg, 30–70 ppmw of Ti, and 5–10 ppmw of V. Fe, Ga, Ni, Pb, and Pt were found to be below detection limit by both methods. This was the first time LA-ICP-MS had been applied to technogenic ruby.

	The identification of metallic-phase chromium inclusions, coupled with trace-element chemistry, will serve to separate these ruby slag materials from natural and other artificial analogues. @chapter:6


Publication Year: - Title: Bench Tip #11: Turn an Old Brush into a Whip Burnisher Abstract: Transform an old brush

A worn-out bristle brush can easily be recycled into a useful tool called a whip burnisher or rotary hammer to improve or even eliminate minor imperfections and surface porosity in castings and other metal surfaces.

You’ll need the following supplies, which are available at most jewelry shops, to make a whip burnisher:

		worn-out bristle brush wheel

		flex-shaft and handpiece

		bench grinder with a coarse grit wheel and a medium grit wheel (such as a cratex wheel)

		jeweler’s saw

		sanding sticks – 320, 400 and 600 grit

		polishing machine with tripoli and rouge buffing wheels

The first step is to use the jeweler’s saw to cut off the worn-out bristle brush. This will leave just the shaft of the former brush wheel -- a piece of mild “soft” steel about an inch and a half long. This type of steel works well because it’s not hardened or tempered. It’s strong, but you can still bend it easily without breaking it.

Use the coarse grinding wheel on the bench grinder to round the end steel piece. Remove coarse grinding marks with the medium wheel, then insert the steel into the flexshaft handpiece and spin it against 320, 400 and then 600 grit sandpaper sticks to make a smooth, rounded end. Finally, polish the rounded end with tripoli and rouge.

The last step is to make a slight bend about 6-7 mm from the end you have rounded and polished. The further you bend the stock, the more aggressive the burnisher will be when you use it. You can adjust the tool to suit your preferences.

To use the whip burnisher, insert it in the flexshaft handpiece and spin it at medium speed. Bring a metal surface against the spinning end, and it will hammer the surface and smooth out imperfections, such as porosity. A touch of burr lubricant will improve the performance of the whip burnisher.

Lightly sand the surface of your piece with 400 and 600 grit sandpaper after burnishing it, then polish as usual.

	This is what your final whip burnisher will look like. @chapter:22


Publication Year: - Title: Diamond Cut: The Wow Factor Abstract: The round brilliant is the most popular diamond cut. Because of its popularity, assessment of this cut has been the subject of considerable research. Courtesy of Harold & Erica Van Pelt.

Ask anyone what the most important characteristic of their diamond is and they’re likely to say it’s the “Wow” factor. You want your friends and family to stop, stare and admire the stone dancing on your finger or from your ears.

Carat weight, color, clarity, and let’s face it, price, help you decide which diamond you like best, but you might not understand how your diamond’s cut – how its facets and angles are cut and polished − affects its overall appearance – its “Wow” factor.

A beautifully finished (cut) diamond is dazzling; every facet displays the craftsman’s skill and care. When it interacts with light, each facet and angle affects the amount of light returned to the eye. This is what gives a diamond its face-up appearance and what makes it appealing – or not.

That is why for many people, cut is the most important of the 4Cs − the system developed by GIA to describe a diamond’s quality. Those four factors – color, clarity, cut and carat weight  – are the basis of the International Diamond Grading System that GIA created in the early 1950s as the universal standard of diamonds. The GIA Cut Grading System, introduced in 2005 and validated by thousands of observations by retailers, manufacturers and the public who looked at real diamonds and described why they thought certain diamonds were the best looking, can help you understand what to look for in a well-cut diamond.
The Basics
The GIA Cut Grading System applies to the most popular cutting style – the standard round brilliant – and all clarities across the D-to-Z color range. There are five cut grades: Excellent (EX), Very Good (VG), Good (G), Fair (F) and Poor (P).
A diamond with an Excellent cut grade is very bright. It shows an even pattern with good contrast between light and dark areas, so the reflections appear crisp and well-balanced. This tells you that the cutter made the best possible use of the rough.

The Good cut grade diamond isn’t quite as bright – reflections aren’t as sharp and there’s more darkness or dullness in the diamond.

The Poor cut grade diamond has much more prominent dark areas or dullness. Given the choice, most people would pick either of the first two diamonds instead of this stone.

If you look at the photo above, you can see how diamonds with Excellent, Good and Poor cut grades, from left to right, compare to each other.

If all else is equal, an Excellent cut grade pretty much guarantees an extremely attractive diamond. Diamonds in the Very Good and even Good cut grades are also beautiful; they only suffer by comparison with the very best stones.
Words that Describe Diamond Cut
Words like “sparkle,” “fire,” “brightness” and “pattern” are used when talking about a finished diamond’s appearance. You might hear: “Isn’t it beautiful? See how much it sparkles. See how much life this stone has.”

There are optical effects that make a beautiful diamond look the way it does; together, they give the diamond life and determine its visual appeal – especially when you move it. Optical terms include:

Brightness – often called brilliance – is the effect of all the diamond’s internal and external reflections of white light, best observed under diffused lighting. Well-cut diamonds are brighter than poorly fashioned ones, even if they’re of equivalent size, color and clarity. In general, the brighter a diamond is, the higher its grade will be.
Fire results when white light traveling through the diamond is dispersed into its rainbow of spectral colors. Look for red, blue, yellow or orange flashes as you rock and tilt it under store spotlights.
Scintillation is a combination of sparkle and pattern. Sparkle refers to the spots of light that flash when the diamond, you or the light source moves. In an attractive diamond, the reflections should appear even and balanced in size.
Pattern is the relative size, arrangement and contrast of bright and dark areas that result from a diamond’s internal and external reflections. There must be enough contrast between the bright and dark areas to give the pattern a crisp, sharp look, but no distracting dark areas.

Proportions: Everything Works Together
The whole is greater than the sum when it comes to a diamond’s proportions, which are the dimensions and angles of a polished diamond’s facets and how they relate to one another. There is no set “formula” or set of proportions that result in a perfectly cut diamond. All of the numbers you might have heard other people referring to – table size, crown angle, pavilion angle – work together to create the spectacular stone sitting in front of you.

That’s one of the surprising things GIA researchers discovered in the course of the 70,000 observation tests they conducted as they developed the cut grading system. There are a range of proportions that fall within each cut grade, and each specific diamond within that grade may look slightly different in terms of attributes like brightness, fire or pattern. For this reason, a specific stone may be more appealing to one customer than another, even though both may perform equally well.

The GIA system places more emphasis on the overall appearance of the diamond, as opposed to any single set of proportions.

Diamond Cut: What to Look For
Your eye sees those proportions working together – for better or worse – when you look at a diamond face-up. Dark areas in the center, under the table or around the girdle could mean that the shape of the rough forced some compromise. Conversely, bright, even patterns signify a cutter’s attention to detail and precision.

The GIA system downgrades diamonds that carry excess weight in extremely thick girdles, steep crowns or deep pavilions. Diamonds with features that make them vulnerable to damage – like extremely thin “knife-edge” girdles – also tend to receive lower GIA cut grades.

Carefully observe diamonds that have high cut grades. They are often a little different from each other; you may even prefer a diamond with a lower cut grade.

One last tip: A grading report used in conjunction with your own visual observation will confirm what your eye is seeing. But, ultimately, beauty is in the eye of the beholder, so make sure you pick out a diamond that is most appealing to you. @chapter:31


Publication Year: - Title: After a Century, Riches Still Flow from Cullinan Mine Abstract: A 29.6 carat blue diamond was recovered from the Cullinan Mine in January 2014. Photo courtesy of Petra Diamonds

	South Africa’s Cullinan Mine could be called the greatest treasure trove the world has ever known and, 111 years after its first diamonds were found, it is still yielding major gems.

	Last week, Petra Diamonds, which acquired the mine from De Beers in 2008, unveiled a 29.6 carat “exceptional” blue diamond expected to result in a “diamond of great value and importance,” according to the company.

	The Cullinan Mine (known as the Premier Mine until 2005) first made news in 1905 when workers found a 3,106 carat stone. Named the Cullinan Diamond after the mine’s discoverer, the gem is – to this day ‒ the largest piece of diamond rough ever found.

	The largest diamond cut from it was the Cullinan I, a 530 carat pear shape, probable D color, internally flawless diamond that rests atop the scepter in the crown jewels of Queen Elizabeth II. Through the years, the mine has yielded such famous diamonds as the Premier Rose (353.9 carats rough/137.02 carats polished), The Taylor-Burton (240.8 carats rough/69.42 carats polished), the Niarchos (426.5 carats rough yielded two polishes stones of 128.25 and 39.99 carats) and the Golden Jubilee (755.5 carats rough/545.67 carats polished).

	A number of major blue diamonds have also come from the mine: De Beers’ 27.64 carat (polished weight) Heart of Eternity and 11 other fancy blue diamonds that formed De Beers’ Millennium Collection.  In all, the Cullinan Mine has produced 750 stones weighing more than 100 carats.

	More recently, the Cullinan mine yielded a 26.6 carat blue diamond, cut into a GIA-graded Fancy Vivid blue of 7.0 carats, which sold for $9.49 million, or $1.35 million per carat.

	Petra Diamonds CEO Johan Dippenaar holds the 29.6 carat blue diamond, one of many notable diamonds recovered from the South African mine. Photo courtesy of Petra Diamonds

DIAMOND MARKET: After reasonably successful holiday sales of diamond jewelry in the U.S., De Beers allocated a large sight of about $750 million, with prices of medium quality goods rising 3-5%, higher in some cases. The price increases were apparently based on the assumption that demand for certain goods will increase in the spring when U.S. retailers will need to restock.

	As soon as the news of the price increase reached the markets, premiums on existing rough supplies also began to rise, causing concern that a new round of speculative buying – and subsequent price increases unrelated to demand – may be in the offing.

	Additional buzz from the sight, held in Gaborone, Botswana Jan. 21-24, came from De Beers’ CEO Philippe Mellier’s address that hinted of possible major changes for the sight term that will begin in 2015. He told sightholders De Beers was looking at ways to give them more flexibility, simplify the process and “make sightholder status more meaningful.”

	Diamond dealers take this to mean that De Beers will likely build in more ability for sightholders to adjust the quantities of rough stones in various quality ranges they want to purchase, and make the complex application process much easier. A number of sightholders have publically proclaimed their dissatisfaction with the system and indicated they may not re-apply for a new term.

	Since 2009, De Beers has adjusted to the realities of the post-economic crisis market by allowing clients to defer purchases, but has remained relatively inflexible over whether clients could refuse or defer partial lots of certain categories of goods. The sight application process also requires clients to provide extremely detailed analyses of their businesses.

	Whatever changes may be coming in 2015, the market will have to adjust to a continually challenging environment, especially as far as bank financing is concerned.

	Last year, ABN Amro, the industry’s leading lender, announced it would limit credit to 70% of rough purchases, a break from past policy when they would finance the full amount. In short, diamond manufacturers and rough dealers must put 30% of their own capital up for each purchase, a move the bank feels will limit the speculative buying that has created an extremely volatile rough market during the past four years. In addition, the manufacturers must invest their own funds into rough that is much less profitable to cut in the current environment.

	Bank Leumi’s U.S. subsidiary announced this week that it was exiting the U.S. diamond business, a year after it closed out its Israeli diamond industry portfolio.  A banker quoted in JCK said the industry’s continued lack of transparency, coupled with the stringent regulatory requirements of Basel III, along with other risks, has increased the banks’ reluctance to finance the diamond industry.

	Additionally, some bankers claimed that excessive finance created an unsustainable credit bubble that will ultimately cause some large firms to default. @chapter:28


Publication Year: - Title: ‘Perfect Storms’ Cloud BaselWorld Business Abstract: The BaselWorld show attracts tens of thousands of visitors each year to see the new offerings from leading watch, jewelry and gem companies. Photo by Russell Shor/GIA

                      The world’s turmoil has begun to catch up with the superrich, who comprise most of the demand for the top gemstones, diamonds and designer jewelry pieces offered at BaselWorld 2015.

On display in the gemstone hall: several 200 carat (ct.) plus Sri Lankan sapphires; a stunning necklace fashioned from 30 fancy Vivid Pink diamonds and 23 fancy Vivid Blue diamonds, all ranging from 0.75 ct. to 0.90 ct.; a collection of nine D color Type IIa diamonds ranging from 16 ct. to 41 cts.; and many designer collections featuring top Burmese rubies, Colombian emeralds and collection color diamonds.

In the past, many of these rarified goods would find buyers at BaselWorld, typically a crossroads for the global wealthy, many from Russia, the Middle East and China. However, the Russian ruble has lost 40% of its value since last year’s show; oil prices have nosedived; the Chinese economy is showing signs of strain; and the Euro has weakened about 30% against the Swiss Franc and U.S. Dollar, raising the prices of already costly items even higher.

“This ‘perfect storm’ has conspired to reduce demand, especially for the buyers who are looking to acquire gems for investment,” said one exhibitor. “Their buying power is down by a considerable percentage, while their costs have gone up just as much.”

Few dealers were willing to make concessions on these high-end items because they believe demand will return once these issues stabilize and prices will resume rising.

The market for “normal” pieces, especially diamonds, was beset with problems of its own. Dealers at this show, and the nearby Diamond Show run by Martin Rapaport, noted that credit to the diamond industry continues to tighten − by some estimates there is a $3 billion shortfall in the amount of funds available to the industry from what it currently owes to banks.

Banks also have forced diamond manufacturers to sharply curtail or end the memo programs, which they traditionally used to conduct a majority of their business with retailers, especially in the U.S. With rough prices still higher than comparable polished for many sizes and qualities of goods, manufacturers are unable to build up cash reserves to compensate for the diminished credit.  And, finally, the banks themselves are under strong regulatory pressure to restrict credit to clients who, in their opinion, cannot meet transparent dealing standards.

Another dealer also used the phrase “perfect storm” to describe this confluence of events.

There is some good news: colored gemstones. Bold colors are coming into fashion and demand for emerald, peridot, sapphire and tanzanite pieces, as well as tutti-fruitti styles, was quite strong.

BaselWorld is traditionally the showcase for the world’s luxury watch industry and, as usual, tourist crowds flocked to see the new offerings from brands like Hublot, Breitling, Tissot and jewelers like Graff and Winston, but demand also slowed from last year. The Federation of the Swiss Watch Industry reported that sales of luxury watches made in that country increased only 1.9% last year to CHF 22.2 billion, with declines in all major markets except the U.S. and Japan. @chapter:30


Publication Year: 2017 Title: Preliminary Observations on Facet-Grade Ruby from Longido, Tanzania Abstract: Figure 1. Sixteen samples of facet-quality ruby (0.8–7.1 ct) from Longido, Tanzania. Photo by Sasithorn Engniwat.
With rubies discovered about 100 years ago, the Longido district of Tanzania is one of the longest-known occurrences in Africa. The deposit is famous for its “ruby-in-zoisite,” consisting of large red corundum crystals in a striking green zoisite matrix, often speckled with black amphibole spots. The majority is used for carving, but occasionally facet-quality material is discovered (D. Dirlam et al., “Gem wealth of Tanzania,” Summer 1992 G&G, pp. 80−102).

For this study, 16 transparent rubies (figure 1) were collected during a July 2016 field expedition. The stones were acquired at the Mundarara mine in Longido and from a dealer in a nearby trading post. Most of the rough material ranged from 1 to 3 ct, although one heavily fractured piece weighed about 7 ct. Colors ranged from red to purplish red, very similar to the color of high-quality Mozambican ruby. Fluorescence was medium red under long-wave UV and weak red under short-wave UV.

The inclusion scenes (figure 2) had features similar to those of rubies from Mozambique: short needles, particle banding, and reflective platelets (V. Pardieu et al., “Rubies from the Montepuez area, Mozambique,” GIA News from Research, Oct. 1, 2013).The most common inclusions were thin films (figure 2A), a combination of needles and reflective platelets (figure 2B) and particle banding (figure 2C). In addition, dense particulate planar clouds were arranged mostly parallel to each other and associated with short and long needles (again, see figure 2C). Internal growth zones (figure 2D) and twinning features were also found. Several types of crystals were identified by Raman spectroscopy, including amphibole, mica, and feldspar. Undetermined opaque metallic inclusions were also observed.

Figure 2. Internal features of ruby from Longido, Tanzania. A: A group of irregular thin films, field of view 1.6 mm. B: An array of reflective platelets with needles, field of view 0.9 mm. C: Short and long needles together with thin films; bands of fine reflective particles are also seen. Field of view 2.0 mm. D: Angular internal growth, field of view 4.0 mm. Photomicrographs by Boodsakorn Kongsomart.
Various advanced analytical techniques were used to characterize the properties of the studied rubies. Fourier-transform infrared (FTIR) spectroscopy revealed strong absorption features consistent with boehmite in all samples. Other minerals that are normally present in ruby, such as diaspore or kaolinite, were not detected in the studied rubies.

The trace element concentrations of these rubies were analyzed with laser ablation–inductively coupled plasma–mass spectrometry (LA-ICP-MS) and compared to ruby from other East African sources (table 1). The rubies from Longido were extremely rich in Cr and fairly low in Fe compared to other African sources. The only East African deposit producing ruby with similar concentrations of chromophores is Maninge Nice in Mozambique, but the facet-grade material from Longido has lower magnesium content on average. Other deposits can be separated from Longido based on other trace elements (again, see table 1), although minor overlap cannot be excluded.

While Longido is traditionally known for large ruby-in-zoisite specimens, facet-grade rough is also produced and can yield attractive gemstones. Chemical analysis revealed an extremely high chromium concentration in both facet- and carving-grade ruby. While the internal features of the rubies from Longido are quite similar to those of other African deposits, trace element composition can aid in positively identifying their origin. @chapter:37


Publication Year: - Title: An Inside Look at the 2015 Tucson Shows Abstract: Many sellers at Tucson were displaying very large, fine, or unusual gems that had been held in inventory for years. Photo by Duncan Pay/GIA; courtesy of Noor Gems Japan Ltd.

                      Every year in February, colored stone miners, dealers, cutters, and retailers from around the world converge at the several major gem and mineral shows in Tucson, Arizona. In 2015, GIA once again interviewed industry professionals who presented spectacular gems and provided revealing insights on the global market. Links to these interviews are listed below.

New Production of Brazilian Emerald from Minas Gerais – Tucson 2015
Marcello Ribeiro of the Belmont mine showed emeralds from Belmont’s underground mine, including one especially fine 9.22 ct stone. As a GIA team visited Belmont in April 2014, it was interesting to see the gems from this relatively new part of the mining operation for sale at the show.
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Exceptional Red Spinels and Fine Aquamarine – Tucson 2015
Axel Henn of Idar-Oberstein, Germany, showed superbly colored 61.29 ct Tanzanian red spinel, including two pear-shaped gems cut from similar rough, and a spectacular 450.08 ct aquamarine with pure blue "Santa Maria" color.
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Fine Tsavorite and Spinel – Tucson 2015
Bruce Bridges of Tsavorite USA Inc. said that fine stones often return to his inventory after years in a collector’s possession. At the AGTA show, he showcased a vivid, top-quality 12.46 ct cushion-shaped tsavorite fashioned some 15 years earlier, which made its way back into the market in the last two years.
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Fine Corundum, Demantoid Garnet – Tucson 2015
Dave Bindra of B&B Fine Gems showcased fine pink and yellow sapphire, Mozambique ruby, and a superb suite of Russian demantoid garnet. He explained how increased consumption in markets outside the U.S. and Europe is affecting gem supply and forcing many colored gem dealers to turn to the “recirculated” market for their clients.
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High-End Colored Gems – Tucson 2015
Idar-Oberstein’s Constantin Wild displayed a unique 290 ct multicolored suite of specimen-quality gems from all over the world, rare “canary” tourmaline from Zambia, fine rubellite from Brazil and Nigeria, and an array of sets aimed at enterprising jewelry designers and manufacturers.
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Tsavorite Garnet and Mahenge Red Spinel – Tucson 2015
Daniel Assaf of the Tsavorite Factory provided a detailed market update for tsavorite garnet. In this interview, he explains how unprecedented Asian demand for this rare gem has drastically affected availability and pricing for his customers.
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Oregon Sunstone Update – Tucson 2015
Reviews the Oregon sunstone seen at the Tucson gem shows, provides an update of the current market and demand for the gem, and explains an initiative to set up an Oregon sunstone miners’ association.
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Large and Unusual Gems – Tucson 2015
The inventory of Noor Gems Japan Ltd. was characterized by large and unusual gems, including a fine selection of rare blue and pink gemstones: afghanite, hauynite, hemimorphite, and pezzottaite.
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Ginger Garnet, “Fancy” Tanzanite – Tucson 2015
Kobi Sevdermish of Advanced Quality introduced a new pinkish orange to orangy red “ginger” garnets that remains bright in larger sizes. He also outlined the trials and tribulations of sourcing and cutting the unique “fancy” tanzanite crystals his company specializes in.
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Gem Artistry in Smaller Sizes –Tucson 2015
Alexander Kreis displayed his most recent designs: tourmalines in organic fluid shapes resembling the leaves in a tropical forest, citrines evoking the essence of sunrays, and icy blue topaz that mimic the cool brilliance of arctic ice.
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Larger Optic Disks –Tucson 2015
Brian Cook of Nature's Geometry explained the latest step in the evolution of his innovative "wheel of light" optic disks: larger pieces that display more intriguing reflective effects, including a striking rainbow of concentric color bands.
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Unusual Carved Tourmaline Suite – Tucson 2015
Jan Goodman had an exquisite 303 carat suite of particolored tourmaline depicting Snow White and the Seven Dwarfs, carved in Idar-Oberstein in the 1970s and kept in his personal collection for more than 30 years.
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Gemstones and Jewelry Inspired by Nature – Tucson 2015
Award-winning cutter and designer Jeff Bilgore exhibited two pieces that departed from the norm of colored stones: an exquisitely carved leaf brooch of moss agate highlighted with diamonds, and a platinum pendant panel and chain featuring natural-color fancy diamonds that appeared to float within the frame.
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Rare Stones in Demand – Tucson 2015
Coast-to-Coast’s Brad Wilson explained that rare gems also have a place in jewelry. Innovative designers seek out rare materials such as sphalerite, sphene, apatite, and even afghanite for clients who appreciate the unusual.
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Color-Change Garnets from Tanzania – Tucson 2015
Introduces striking color-change pyrope garnets from Tanzania. Originally thought to be rhodolite garnets when found in the 1980s, these gems turned out to be predominantly pyrope, and the best examples show a strong red-to-purple color change.
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Bold Color Combinations – Tucson 2015
For retailers and designers overwhelmed by the endless rows of gemstones lined up in trays, inspiration could be found at the booth of Stephen M. Avery, which featured brightly colored "statement"-sized gemstones.
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Chrysocolla in Quartz – Tucson 2015
The Rare Earth Mining Company booth displayed a specialized inventory of unique and rare materials, including clear and near-colorless quartz containing blue spots of chrysocolla.
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Cultured Pearl Market Update – Tucson 2015
Fran Mastoloni provided a market summary from his own business perspective. He emphasized surging demand in the Chinese domestic market for all cultured pearl types, plus the need to introduce innovative styles and pearl combinations in contemporary jewelry.
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Chinese Freshwater Pearl Culturing, Overall Market Summary – Tucson 2015
Jack Lynch offered his perspective on Chinese freshwater cultured pearl products and styles, as well as fine South Sea and Tahitian goods.
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Diamond Slices – Tucson 2015
The popularity of gem slices, particularly diamond, is on the rise, as reflected at the 2015 Tucson gem shows.
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Large Namibian Demantoid Garnet – Tucson 2015
The Green Dragon mine yields exceptional demantoid, including a round brilliant seen at Tucson’s GJX show.
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Green Nephrite Jade Attracts Buyers in Tucson – Tucson 2015
An update on the nephrite jade market from the 2015 GJX show.
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Baroque Pearls – Tucson 2015
Baroque pearls were ubiquitous at the Tucson 2015 gem shows.
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Crimson Prince Ruby from Namya – Tucson 2015
An exceptional ruby is discovered in Namya, Myanmar.
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Update on Rock Creek Sapphire Deposit – Tucson 2015
An overview of recently expanded sapphire production at the Gem Mountain mine near Philipsburg, Montana.
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Unique Tourmaline Necklace – Tucson 2015
An unusual parti-color tourmaline necklace and clasp are seen at the 2015 AGTA show in Tucson.
Learn More @chapter:28


Publication Year: 2018 Title: Trapiche-like Amethyst from Brazil Abstract: Figure 1. Left to right: 16.73 ct, 14.50 ct, 17.03 ct, and 27.75 ct trapiche-like amethysts. The four cabochons were cut with the base perpendicular to the c-axis (optic axis). Photo by Diego Sanchez.

Minerals such as corundum, beryl, tourmaline, and quartz, which belong to either the trigonal or the hexagonal crystal system, can show a trapiche-like texture with a hexagonal core and six extended arms when viewed down the c-axis. Four trapiche-like amethyst cabochons (figure 1) were submitted to GIA’s Carlsbad laboratory by L. Allen Brown (All That Glitters, Methuen, Massachusetts) for scientific examination. Each was characterized by a hexagonal black core and six brownish arms with pale purple color zoning in between. Magnification revealed that the black core was composed of dense metallic dendritic inclusions (figure 2, left). The brown color of the arms was caused by numerous tufts of tiny inclusions (figure 2, right), some of which resembled either brushes or bullets.
Raman spectra were collected with a Renishaw inVia Raman microscope system. The confocal capabilities of the system allowed inclusions beneath the surface to be analyzed. The black core was identified as an FeS2 (iron sulfide) mineral, likely pyrite. The brownish tiny inclusions in arms could not be identified but were likely goethite (E.J. Gübelin and J.I. Koivula, Photoatlas of Inclusions in Gemstones, Vol. 2, Opinio Verlag, Basel, Switzerland, p. 558) based on appearance and occurrence in quartz matrix.

Figure 2. Left: Metallic dendritic inclusions compose the hexagonal black core in the amethysts; field of view 19.27 mm. Right: Brownish and yellowish brush-like and bullet-like fibrous inclusions in the trapiche-like arms; field of view 2.34 mm. Photomicrographs by Jonathan Muyal.
The texture of trapiche-like amethysts is often caused only by the distribution of color-inducing elements (K. Schmetzer and B. Williams, “Gem-quality amethyst from Rwanda: Optical and microscopic properties,” Journal of Gemmology, Vol. 36, No. 1, 2018, pp. 26–36). The fact that the texture was caused by two sets of distinctly colored inclusions makes these four gemstones unique. @chapter:4


Publication Year: 2018 Title: A Repaired Diamond Abstract: Figure 1. A face-up photo of the repaired diamond. Photo by Robison McMurtry.

A 1.38 ct marquise-cut diamond (figure 1) was submitted to the Carlsbad lab for colored diamond grading services. It was initially noted that large fractures and a large cavity were present on the table. Careful examination of the stone with a gemological microscope revealed that it had previously broken in half and been repaired with an unknown adhesive. The first clue was a large fracture from the crown to the pavilion that showed a sizeable gap present throughout the stone. Furthermore, the facets the fracture passed through all showed slight to moderate misalignment, which cannot happen during polishing (figure 2). Finally, large trapped air bubbles could be seen in the fracture when viewed at an angle. These clues proved that the diamond had broken and been put back together again, though not perfectly. Polish lines on the pavilion facets showed a pattern that would line up if not for the fracture separating them, demonstrating that the breakage occurred after the diamond had been at least partially polished. Beyond that, it is impossible to tell when the damage occurred.

Figure 2. A bezel facet of the repaired diamond as seen in reflected light. The wide fracture can be seen cutting across the facet, and the upper edge of the facet does not form a straight line. Photo by Troy Ardon; field of view 3.3 mm.
Diamonds have been adhered together with glue to form a diamond-diamond doublet (E. Barrie and E. Biermans, “A different type of deception: ‘Diamond-diamond’ doublet,” HRD Antwerp, 2014, www.hrdantwerp.com/en/news/a-different-type-of-deception-diamond-diamond-doublet), but a broken diamond that has been repaired was not something previously reported by GIA. The fracture in the item was not a flat, straight surface but very irregular, indicating that it was not two separate diamonds glued together to make a larger diamond, but rather a repair. Since the item was simply two pieces of diamond joined together, it was not eligible to receive a diamond grading report. None of the 4Cs apply to a composite such as this (e.g., the carat weight of the item was actually the sum of the weights of two diamonds plus the weight of the adhesive). The decision to repair a diamond in this manner is unusual. Careful gemological examination will, however, reveal the repair work done. @chapter:31


Publication Year: 2017 Title: Ametrine Optical Dishes: Windows into the Effects of Crystal Structure Abstract: Figure 1. Left: An 85 × 25 mm ametrine crystal from Bolivia’s Anahí mine exhibits the deeply etched prism faces typical of this quartz variety. Right: The crystal’s termination, viewed in the direction of its c-axis, displays a rare “Y”-shaped manifestation of the crystal’s trigonal symmetry. Slices made perpendicular to this direction will reveal this symmetry with alternating amethyst and citrine sectors. Since the optic axis parallels the c-axis located at the intersection of the “Y” arms, all paths of light found across this termination face will be along the optic axis. Photos by Elise A. Skalwold.

	During exploration of a gem’s interior, it is important to understand how crystal structure affects the incorporation and orientation of inclusions, how an inclusion can affect its host, how interpretation of observations can depend on point of view, and the nature of light as it passes through a crystal—host or inclusion. As proposed earlier in this column (Spring 2016, p. 81), polished inclusion study blocks are ideal for showcasing, studying, and reviewing basic concepts relating to the micro-world. Here we take a look at light and crystal structure.

	Of all the varieties of quartz, ametrine is perhaps the most fascinating to observe. While its stunning color zoning makes it a popular designer gemstone, it also encompasses several optical properties unique to different quartz varieties that can all be explored in one specimen. Almost unrecognizable as quartz, ametrine crystals are deeply etched (figure 1, left) and have abundant healed fractures. The only clues to the trigonal symmetry typical of quartz are occasional rhombohedral faces and, very rarely, an enigmatic flat termination manifesting a three-armed figure (figure 1, right). Only when a basal section is made by cutting a slice perpendicular to the c-axis is the improbable yet beautiful combination of citrine and amethyst revealed.

	Beauty and function are married in an ametrine study block oriented so that the view through its two largest faces is directly along the optic axis of a crystal, as seen in figure 1. The innovation of adding a set of concave dishes for sampling each color zone, as well as the borders between them, reveals truly remarkable optical phenomena (figures 2 and 3). These optical dishes allow the viewer to see light passing through the specimen in many directions, as does the strain-free glass sphere familiar to gemologists for use with a polariscope (figure 4). When viewed between crossed polarizing filters, these dishes dramatically display the different uniaxial optic figures unique to quartz, which vary depending on thickness and placement in the sectors: the classic “bull’s-eye” optic figure seen in the untwinned citrine sectors, an Airy’s spiral in the amethyst sectors, and a distorted figure produced in a border region. All of these observed phenomena are produced by optical activity (i.e., the rotatory dispersion of light as it travels along the optic axis direction within the quartz crystal). By analyzing these figures, we can determine handedness and the effects of thickness, while observations of the amethyst’s Brazil-law twinning may help distinguish natural versus synthetic origin.

	Figure 2. An ametrine study block with concave dishes cut and polished into its surface, including one on the opposite side. Viewed in transmitted light along the optic axis direction (i.e., all paths parallel to the c-axis), as in figure 1 (right), the trigonal symmetry of the crystal defines the citrine and amethyst sectoral zoning and allows observation of the effects of the optic axis on light. This specimen was fashioned by Nathan Renfro. Photo by Kevin Schumacher.

	Figure 3. Placing the study block between crossed polarizing filters in transmitted light results in a variety of bull’s-eye optic figures that form in the divergent light produced by the concave dishes. The citrine sectors under the minor rhombohedral faces (z) are free of twinning and show a classic bull’s-eye optic figure with varying colors due to slightly different thicknesses. The amethyst sectors display an Airy’s spiral (middle row, right dish) produced by the alternating layers of left- and right-handed quartz of the Brazil-law twinning that formed under the crystal’s major rhombohedral faces (r); broadly angled colors in these latter areas are also indicative of this twinning. The dish on the upper right is a distorted figure on the border of the sectors. Photo by Kevin Schumacher.

	Figure 4. Left: A section through part of the study block. The dish serves as a concave (negative) lens that causes the light rays to diverge. Right: A gemologist’s strain-free glass sphere is used to observe an interference figure. Although the rays first converge at the base of the sphere, they ultimately diverge just like the rays in the figure on the left. Illustration by William A. Bassett.

	For an in-depth analysis of the phenomenon of optical activity and the origin of quartz’s optic figure, see E.A. Skalwold and W.A. Bassett, Quartz: A Bull’s Eye on Optical Activity, Mineralogical Society of America, 2016, www.minsocam.org/msa/OpenAccess_publications
	/Skalwold/Quartz_Bullseye_on_Optical_Activity.pdf. @chapter:10


Publication Year: 2019 Title: Lazurite in Spinel Abstract: This light gray spinel from Mogok, Myanmar, contains a vibrant blue inclusion of lazurite. Photomicrograph by Nathan Renfro; field of view 1.59 mm. Courtesy of Mark Smith, Thai Lanka Trading Ltd.

Spinel is often inclusion free but occasionally showcases unusual inclusions. This was the case with a 1.02 ct light gray Burmese spinel from Mogok, courtesy of Mark Smith (Thai Lanka Trading Ltd., Bangkok), that was recently examined by the authors. A striking vibrant blue inclusion reached the surface of the pavilion, making Raman analysis straightforward (see above). The identity of the blue inclusion was confirmed to be lazurite. The mineral has previously been found as an inclusion in Burmese ruby (Spring 2012 Lab Notes, pp. 51–52), but this is the first instance of a lazurite inclusion in spinel that we are aware of. @chapter:5


Publication Year: 2009 Title: Spectral Differentiation Between Copper and Iron Colorants in Gem Tourmalines Abstract: The authors used Vis-NIR spectral measurements combined with LA-ICP-MS data to investigate the usefulness of absorption spectra for differentiating between copper and iron as sources of greenish blue coloration in gem tourmaline. While both Cu2+ and Fe2+ produce absorption bands with maxima near 700 nm, Cu2+ also has a strong band with a maximum near 900–925 nm, where absorption due to Fe2+ is typically at a minimum. In addition, Vis-NIR spectroscopy successfully identified Cu in pink/purple and violet stones that could be candidates for heat treatment. For the blue, green, and violet Cu-bearing tourmalines of pale-to-moderate color intensity in this study, weight percent of CuO could be estimated from the absorbance at 900 nm. This relatively inexpensive identification method may prove to be a valuable screening tool for Cu-bearing tourmaline.

	DATA DEPOSITORY

Additional Spectra
Average LA-ICP-MS Data (ppm by Weight) of the Tourmaline Samples
	Summer, 2009 @chapter:4


Publication Year: 2017 Title: A New Discovery of Emeralds from Ethiopia Abstract: Figure 1. This suite of untreated emeralds is from a new find in Ethiopia’s Seba Boru district. The largest faceted stone weighs 10.64 ct. The largest rough crystal weighs 63.12 g. Photo by Robison McMurtry, courtesy of Michael Nemeth Inc.

In recent years Ethiopia has gained considerable attention in the gem trade for large amounts of high-quality opal from an area near Wegel Tena (B. Rondeau et al., 2010, “Play-of-color opal from Wegel Tena, Wollo Province, Ethiopia,” Summer 2010 G&G, pp. 90–105). Apart from opal, emeralds have been sporadically mined, near Dubuluk, for more than a decade. This deposit is located about 80 km from the Kenyan border. Gemfields has been exploring this deposit since July 2015 (Fall 2012 GNI, pp. 219–220).

A new deposit of high-quality emeralds (see figure 1) has been found in the rural villages of Kenticha and Dermi, in the Seba Boru district (figure 2). In November 2016, author MN and business partner Daniel Kifle visited the local trading town of Shakiso, where Ethiopian gem merchants gather to legally buy and sell emeralds that are mined several kilometers away. Shakiso is located about 160 km north of the Dubuluk emerald deposit. The mining area is divided into a few “associations.” Each consists of a manager and several members who control the actual mining and distribution of the emerald rough. After the rough has been sorted, it makes its way first through Shakiso before being sold to dealers in the capital city of Addis Ababa, about a 12-hour drive from the mining area.

Figure 2. The new deposit of Ethiopian emerald is located near the town of Shakiso,
about 12 hours from Addis Ababa.
According to Tewoldebran Abay, the mineral marketing director of the Ministry of Mines, Petroleum and Natural Gas, more than 100 kilograms of emerald rough have been produced to date. Mining still is done the traditional way using hand tools, without heavy machinery.

Samples from the new deposit, acquired from multiple independent sources, were examined at GIA’s Carlsbad and Bangkok laboratories. Even though most of the material is commercial grade, lighter in saturation, and moderately to heavily included, fine gem-grade crystals of exceptional size, color, and clarity (see figures 1 and 3) are obtainable and can produce stones that do not require clarity enhancement. Many of the rough crystals were completely covered in dark biotite crystals, but had an extremely pleasant green color when examined with transmitted light. However, these Ethiopian crystals often do not yield large clean stones because their interior is riddled with dense, dark biotite mica crystals. Some show a double termination, but most are broken and heavily included on one end. Usually only one end of the crystal is clean enough to yield faceted gems. The matrix minerals attached to some of the emeralds were identified as dark brown to black biotite flakes, quartz, and kaolinite.

Figure 3. Author Michael Nemeth sorts through parcels of gem-quality rough emeralds from the open market in Shakiso. Rough crystals can weigh more than 20 g, with reports of some weighing almost 100 g. Photo by Michael Nemeth.
These emeralds are very similar in appearance to other schist-hosted emeralds—in particular, those from Brazil and Zambia. Among the faceted and rough samples examined, blocky multiphase inclusions and irregular biotite crystals were the most common microscopic features observed (figure 4). Otherwise, the gemological properties were very consistent with emeralds, including an average specific gravity of 2.73 and a refractive index of 1.581–1.589. These emeralds were generally inert to long- and short-wave UV exposure due to their moderately high iron content, which is typical of schist-hosted emeralds. UV-Vis-NIR spectroscopy results (figure 5) were consistent with emeralds colored by chromium and vanadium. The Fourier transfer infrared (FTIR) spectrum was consistent with beryl, as expected, but did not reveal any other diagnostic features.

Figure 4. Microscopic observation of the Ethiopian emeralds revealed (A) biotite crystals; (B) blocky multiphase inclusions; (C) multiphase inclusions containing a liquid, gas, and multiple daughter crystals seen parallel to the c-axis; and (D) a multiphase fluid inclusion showing liquid and gaseous CO2 phases and an immiscible aqueous liquid (parallel to this inclusion are several growth tubes). Photomicrographs by Nathan Renfro (A and B) and Victoria Raynaud (C and D). Field of view 2.04 mm (A), 1.79 mm (B), 1.07 mm (C) and 1.03 mm (D).

Figure 5. The characteristic UV-Vis-NIR spectra of the new emerald production from Ethiopia.
Quantitative trace element chemical analysis was performed with a Thermo Scientific iCap Q inductively coupled plasma–quadrupole mass spectrometer combined with a New Wave Research UP-213 laser ablation unit. The analyses were compared to data from other known sources using GIA reference samples, including Zambian and Brazilian schist-hosted emeralds. Based on the results, it was possible to separate the new find of Ethiopian emeralds from other sources by comparing trace alkali metals and some transition metals (figure 6).

Figure 6. LA-ICP-QMS quantitative trace-element composition analysis of alkali and some transition metals (measured in ppmw) proved useful in separating this new deposit of Ethiopian emeralds from Brazilian and Zambian schist-hosted deposits.
Due to heightened tensions and fear of price instability, most of the mine area was temporarily closed by a joint effort of the mining associations and the local government from early November through December 2016. It has been reopened, but now all dealers, including Ethiopian dealers, need written permission to enter the Shakiso area for buying. The law is vigorously enforced, and penalties are severe.

This exciting discovery in Ethiopia will provide a new source of large, high-quality emeralds for the gem and jewelry trade. So far, this deposit appear to be quite promising, as significant production was seen in the recent gem shows in Tucson, Bangkok, and Hong Kong. Only time will tell how significant this deposit will be. @chapter:18


Publication Year: - Title: Banks Move to Curb Rough Speculation Abstract: Rough diamond crystal. Photo courtesy of De Beers.

	The leading diamond banks have moved to dampen speculative rough buying in their latest round of credit cutbacks. Banks will only finance 70% of client rough purchases, instead of fully funding them.

	The banks believe rough prices have soared far beyond those of comparable polished diamonds, making diamond cutting unprofitable and creating a liquidity crisis throughout the industry.  At the same time, they have further reduced lending across the board by another 10%, lowering it to 65-70% of  client receivables.

	Banks, which had supported the diamond industry through the economic crisis of 2008-9, say credit reductions are necessary to bring rough prices and manufacturing activities more in line with  market forces. By some estimates, manufacturing significantly exceeded demand for some sizes and qualities, sometimes resulting in large, unbalanced inventories.

	The credit reductions have hit most diamond manufacturers, but they do applaud measures to reduce the growing gap between rough and polished prices. The International Diamond Manufacturers Association issued a call on Oct 10 to diamond mining companies asking them “to face reality” and rein-in the out-of-control speculative rough buying.

	The banks’ action puts De Beers and other diamond producers in the middle because, while manufacturers have been buying very cautiously, some rough dealers have been paying the higher prices, which has kept prices high.

	De Beers’ sightholders, for example, have been leaving 10-15% of their allocations on the table for much of this year. De Beers executives have reportedly stated that a client’s “purchase history” will be reviewed in their applications for the next sight term that begins in 2015. De Beers and other producers have not significantly lowered rough prices despite the stagnant state of polished prices.  Additionally, De Beers’ executives, according to press reports, have told clients who complain about high rough prices that other clients would be happy to pay their prices for rough.

	Russia’s Alrosa and Rio Tinto also have been reluctant to lower prices, particularly as the former is in the midst of an initial public offering and the latter is funding an extremely costly retooling of its Argyle mine. Tender sale prices have also held up, but some analysts believe speculative dealers have been leading the bidding.

	Whether the banks’ actions help bring rough prices more in line with the polished market will become apparent by year’s end.

SYNTHETIC DIAMONDS: Recent reports of undisclosed synthetic diamonds mixed into parcels of natural diamonds have rattled the industry. Several manufacturers of natural diamonds in Surat have allegedly begun to grow CVD synthetics; press reports indicate that synthetics from existing producers have been showing up in parcels.

	GIA has seen no significant increase in the number of synthetics submitted to its laboratory for grading. According to the press reports, most of the undisclosed activity appears to be concentrated in the melee and small stones that generally are not submitted to gemological labs for grading. @chapter:30


Publication Year: 2023 Title: Zeki Karaca Jewelry: Luxury Pens Abstract: Figure 1. These handcrafted jewelry pens are created with silver, embellished with 24K gold, and inlaid with diamond, sapphire, and crushed emerald. Left: The peacock design is a miniature painting coated in clear enamel. Right: A pen with fine metal engraving and dimming just below the 24K gold nib. Photo by Robert Weldon; courtesy of Zeki Karaca.
Some of the most original work we saw at the GJX show included bejeweled pens made by Turkish designer Zeki Karaca (figure 1). These intricate pens feature exquisite details and fine craftsmanship in metalworking, enameling, engraving, inlay, and stone setting. In addition to pens, Karaca also creates other desk items such as letter openers and magnifying glasses (figure 2).

Figure 2. Silver magnifying glass with 24K gold embellishments, inlay, carvings, and diamonds. Photo by Robert Weldon; courtesy of Zeki Karaca.
Born in Istanbul, Karaca has 41 years of jewelry-making experience, originally designing jewelry to sell in the Grand Bazaar. To apply his experience and creativity to different designs and styles, he began making luxury pens and products three years ago. He first ventured into these new products by crafting silver gemstone handles for Damascus steel knives. After finding success there, he expanded to meet the demand for luxury pens, letter openers, and magnifying glasses.
Each pen takes about six months to design and craft. All production steps are done by hand, making each item one of a kind. After designing an item, Karaca creates a silver body using fold forming, with the folds created using emery sheets. Engraving is executed by a master engraver using different nibbed steel pens, and dimming is used to emphasize the engraving. Karaka incorporates diamond, sapphire, emerald, and ruby into the designs and uses 24K gold for design highlights. Miniature paintings, such as the peacock on the pen cap in figure 1 (left), are created by hand with a small brush and then coated with a transparent enamel for protection. For micro-mosaics, gemstones such as emerald are crushed and added to the pen body, as seen in both pens in figure 1. The pen parts are welded together with a laser, and then the 24K gold nibs are added.
With high demand for his products from collectors, Karaca continues to explore additional high-end objects as well as custom designs for some clients. @chapter:16


Publication Year: 2015 Title: Polished Freeform Topaz Imitating Diamond Rough Abstract: Figure 1. The 13.70 ct topaz under daylight-equivalent light. Note the triangular features on each of the octahedral faces. Photo by Jian Xin (Jae) Liao.

Topaz is one of many near-colorless diamond simulant materials that may be faceted to bear a closer resemblance to diamond. Although most diamond simulants in the marketplace are faceted, every now and then, one comes across what appears to be a near-colorless octahedron diamond rough (see Lab Notes: Fall 1996, p. 205; Fall 1997, pp. 217–218; Fall 2007, p. 250; Fall 2009, pp. 230–231). A near-colorless 13.70 ct stone (figure 1) was recently submitted to the New York laboratory as a rough diamond from an alluvial source. At first glance, even with a well-trained eye, this stone could easily be misidentified. It bore a striking resemblance to diamond rough, with a “well-formed” octahedral shape and trigon-like formations on the surface of each of the faces. To further complicate the identification of this stone, topaz and diamond have the same heft due to overlapping specific gravities: 3.52 (+/-0.10) for diamond, 3.53 (+/-0.04) for topaz. The material was doubly refractive, with a spot RI reading of 1.61, properties consistent with topaz. Final confirmation came from Fourier-transform infrared (FTIR) spectroscopy, which revealed the distinctive topaz absorption spectrum shown in figure 2, with peaks at 4802 and 3650 cm–1 (K. Shinoda and N. Aikawa, “IR active orientation of OH bending mode in topaz,” Physics and Chemistry of Minerals, Vol. 24, No. 8, 1997, pp. 551–554).

Figure 2. Many absorption peaks related to the hydroxide ion in the crystal structure of
topaz are detected in this infrared absorption spectrum, including those at 4802 and
3650 cm–1. These have never been documented in any diamond absorption spectrum.
Although topaz can be easily shaped and polished into an octahedral shape, the trigon-like figures observed on the surface require an additional fabrication step and are not typically seen in octahedral-shaped simulants. Intentional material processing steps to mask a stone’s identity remind gemologists of the caution and care that need to be taken when dealing with gemstone identification—even when the identity of the material initially seems obvious. @chapter:32


Publication Year: 2002 Title: Spring 2002 Gem News International Abstract: Special Report
            A New Corundum Treatment from Thailand
Tucson 2002
Conference Reports
            Highlights of the Tucson Diamond Symposium
            8th Symposium on the Gems and Minerals of Afghanistan
            Gemological Presentations at the 23rd Annual FM-TGMSMSA Symposium
Colored Stones and Organic Materials
            Amethyst from Afghanistan
            Fossilized “Stingray” Coral
            Canadian Emerald Discovery in the Yukon
            Red Andesine Feldspar from Congo
            Fluorite from Afghanistan
            Green Fluorite from the Rogerley Mine, England
            Demantoid Garnet from Iran
            Blue, Biaxial Positive Kyanite from Nepal
            Pargasite from China
            Cultured Pearls with Gem Inlays
            Ruby from Northern Kenya
            Black Spinel from Mexico
            More on Cuprian Elbaite Tourmaline from Nigeria
            Vesuvianite from Kenya
Synthetics and Simulants
            Star Opal Triplets
Miscellaneous
            Interesting Etch Features and Cavities in Beryl and Quartz
GNI Regular Features
Colored Stones and Organic Materials
            Recent Emerald Production from Hiddenite, North Carolina
            Star Emerald from Madagascar
            Tourmaline “Slider” in Quartz
Miscellaneous
            Illusion Mount™ Stone Holders
Exhibits
            GIA Museum Exhibits in Carlsbad
Announcements
            The JCK Show—Las Vegas
            3rd World Diamond Conference
            Jewelry 2002: A Celebration of Jewelry
            11th Quadrennial IAGOD Symposium and GEOCONGRESS 2002
            JA New York Summer Show
            FIPP 2002
            IMA2002
            Colorado Gems
            AGTA Spectrum Awards Competition

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