Publication Year: 2018 Title: Lepidocrocite in Boulder Opal Abstract: Figure 1. This boulder opal contains a layer of needle-like lepidocrocite inclusions along the interface between the opal and the ironstone matrix. Photomicrograph by Nathan Renfro; field of view 0.96 mm.

The term “boulder opal” is used to describe gem-quality opal that fills in the pore spaces and cracks of its ironstone host. When cut, some of that ironstone matrix is included in the finished stone, often to add structural support to delicately thin veins of opal (R.W. Wise, “Queensland boulder opal,” Spring 1993 G&G, pp. 4–15). The authors recently examined a boulder opal, presumed to be from Australia, that showcased some interesting inclusions along the interface between the opal and ironstone matrix. Microscopic observation revealed a carpet of minute needle-like inclusions radiating outward from the ironstone into the surface opal layer (see above). Where some of the inclusions broke the surface, they showed a submetallic luster in reflected light. In order to identify these unusual inclusions, we used Raman spectroscopy to analyze some of the surface-reaching needles. Raman spectroscopy and comparison with the reference spectra from the RRUFF mineral database showed that these inclusions were the iron hydroxide mineral lepidocrocite. Energy-dispersive X-ray fluorescence (EDXRF) testing revealed only the presence of iron, which was consistent with the Raman results. This is the first time the authors have encountered a lepidocrocite inclusion in boulder opal. @chapter:39


Publication Year: 2013 Title: Aviat Diamonds: A Window into the Deep Lithospheric Mantle Beneath the Northern Churchill Province, Melville Peninsula, Canada Abstract: The Aviat kimberlites are located in Melville Peninsula in northeastern Nunavut. They are part of the Rae craton, which is composed of Archean granitoid rocks, supracrustal belts, and Paleoproterozoic metasedimentray rocks. The carbon isotopic composition, nitrogen concentration, and nitrogen aggregation state of 70 samples from these kimberlites were analyzed to help understand the composition of diamond-forming fluids, paragenesis of diamond source, mantle residence history, and thermal history of the subcratonic lithospheric mantle. The colors of samples were colorless, gray, brown, and green.

FTIR analysis revealed that the majority were type IaAB, including IaA and IaB. Total nitrogen content ranged from 13 to 1467 ppma. The Aviat diamonds were relatively rich in hydrogen. Absorption bands at 3107, 2786, and 1404 cm–1, caused by bending and stretching of the vinylidene group (C=CH2), were observed in most samples. An additional hydrogen-related band at 3237 cm–1 was also detected.

SIMS analysis revealed nitrogen content ranging from 1 to 1724 ppma. The δ13C isotopic analysis suggested that these diamonds were precipitated mainly from carbonate-bearing fluids. Large variations in nitrogen content and δ13C values, though they were not correlated, were observed in growth sectors, suggesting multiple events of fluid derivation from different sources, mainly ecologitic and also probably peridotitic. But the relationship between CL and carbon isotopic composition suggested that non-luminescent diamond may have been formed during one episode of growth. The Aviat diamonds were possibly formed from diamond-forming fluids or melts from several orogenic events, such as transportation of graphitized organic matter and marine carbonates into the deep mantle via subducting oceanic slabs.

Catastrophic platelet degradation was suggested by the positive correlation between platelets and B aggregates of nitrogen. This phenomenon was probably caused by transient heating events or deformation or both during mantle residence. Blue luminescence of nitrogen-rich samples may be related to intense degradation of platelets. The residence temperature of most samples was extrapolated to ~1050–1150°C, suggestive of a diamond source near the top of diamond stability field at ~150–170 km.

Abstracted by Kyaw Soe Moe @chapter:29


Publication Year: 2011 Title: Demantoid and Topazolite from Antetezambato, Northern Madagascar: Review and New Data Abstract: An important deposit of andradite, containing demantoid and topazolite varieties, has been mined near the village of Antetezambato in northern Madagascar since early 2009. Most of the activity took place from April through November 2009, and yielded a large quantity of rough material in a wide range of colors. The deposit has a skarn origin, related to contact metamorphism between Cenozoic magmatic intrusions and Mesozoic calcareous sediments. The garnets’ internal features consist mainly of fluid inclusions, fractures, wollastonite needles (or their remnant channels), and diopside aggregates. The chemical composition is close to pure andradite, with negligible Cr and V contents; thus, iron is likely the main chromophore. LA-ICP-MS analysis showed a relatively high content of light rare-earth elements.

	DATA DEPOSITORY

Rare-Earth Element Composition
	May 2, 2011 @chapter:5


Publication Year: 1998 Title: Spring 1998 G&G Lab Notes Abstract: Emerald: an Interesting “Daughter” Crystal
Rough and Fashioned Hemimorphite
Jadeite with Inclusions of Zircon
Mother-of-Pearl Doublet
Cat’s-Eye Opal
Ruby with Surface Evidence of Treatment
Internal Diffusion Revisited in Sapphire
Scapolite Showing Asterism
Natural-Color Green Topaz

To view the full section, download the PDF above. @chapter:17


Publication Year: 2019 Title: Largest Square Cushion-Cut Tsavorite Abstract: This 283.74 ct rough tsavorite (left) was mined in Merelani, Tanzania, by Bridges Tsavorite and yielded a 116.76 ct square cushion cut (right). Photos by Robert Weldon/GIA, courtesy of Bruce Bridges.
At the AGTA show, Bridges Tsavorite unveiled the largest known square cushion-cut tsavorite, weighing 116.76 ct (see above). The 283.74 ct rough stone was mined by the company in Merelani, Tanzania, in September 2017. Bangkok-based gem cutter Victor Tuzlukov cut the stone at Bridges Tsavorite’s Arizona office over the course of a month in 2018.
The tsavorite could be a once-in-a-lifetime stone, said Bruce Bridges, the company’s CEO and son of the late Campbell Bridges. Despite seeing most of the finest tsavorites in the world above 20 carats, he had never seen one comparable to this size in a square cushion cut. The square cushion and round cuts are the rarest shapes for tsavorite because the rough typically lends itself to other shapes.
Size and cut were not the only factors contributing to this tsavorite’s rarity. The rough was extremely clean for its size. It had several very well-terminated euhedral faces, unusual for tsavorite, which typically has more fragmented face formation. The tsavorite also has the distinction of being the largest gemstone cut in the United States.
Bridges said that the public is much more concerned about ethical sourcing than in the past and wants to know where a gemstone came from; in keeping with Bridges Tsavorite’s mine-to-market tradition, the stone’s process from mining to finished product was completely documented. “My father would be very happy that we’re doing this and that we’re carrying on his legacy,” he said.

	Bruce Bridges tells us about the square cushion-cut tsavorite.

In March 2018, a GIA team traveled to Arizona to document the cutting of the stone. Find out more about this rare tsavorite, and how Victor Tuzlukov approaches the cutting process, at https://www.gia.edu/gia-news-research/angel-in-stone-cutting-largest-square-cushion-cut-tsavorite @chapter:1


Publication Year: 2016 Title: Separation of Black Diamond from NPD Synthetic Diamond Abstract: Figure 1. The 0.70 ct Fancy black pear-shaped diamond in the left photo closely resembled two NPD synthetic diamonds submitted earlier (the 1.51 ct round and 0.9 ct marquise, right). Photos by Jian Xin (Jae) Liao.
In two recent Lab Notes, we reported on a new type of synthetic diamond: nano-polycrystalline synthetic diamond, known as NPD (Spring 2014, pp. 69–71; Winter 2014, pp. 300–301). Submitted for identification in April 2016 was a 0.70 ct pear-shaped Fancy black diamond (figure 1). The diamond’s infrared absorption spectrum was strikingly similar to that of the two NPD identified specimens mentioned above. It displayed very similar absorption peaks in the one-phonon region (figure 2), which can probably be attributed to nitrogen.

Figure 2. IR spectra of the three black samples (offset for clarity) show unusual broad
peaks in the 760–1500 cm–1 region (highlighted in gray): 0.70 ct natural black diamond
(A), 1.51 ct NPD (B), and 0.90 ct NPD (C).
Microscopic examination revealed an abundance of dark graphitized crystal and fracture inclusions, features often associated with black gem-quality diamonds but not unlike those observed in the NPD samples (figure 3). The challenge for gem laboratories, then, is how to separate black NPD synthetic diamonds from their natural black diamond counterparts.

Figure 3. Natural inclusions in black diamond (left) are compared with various inclusions previously observed in NPD synthetic diamond (center and right). Photos by Paul Johnson; field of view 6.24 mm (left) and 1.76 mm (center and right).
DiamondView imaging offers a quick and definitive solution to this problem. NPD synthetic diamond has a distinct fluorescence pattern and structure that are obvious in the DiamondView images (figure 4). This technique can provide an instant positive identification for NPD synthetic diamond, which can be supported with further testing.

Figure 4. These DiamondView images show the fluorescence pattern and color for natural diamond (left and center) and NPD synthetic diamond (right). Photos by Paul Johnson.
The 0.70 ct pear-shaped diamond was issued a report with a Fancy black color grade and a natural origin of color. @chapter:15


Publication Year: 2015 Title: Attractive Composite Quartz Beads Abstract: Figure 1. This string weighing 145.70 carats consists of attractive blue and golden brown beads measuring approximately 7.91–8.48 mm in diameter. The beads were identified as composites fashioned from pieces of dyed quartzite held in a polymer matrix. Photo by Gagan Choudhary.

              The Gem Testing Laboratory in Jaipur recently received a 145.70 carat string of attractive blue and golden brown spherical beads (figure 1) measuring approximately 7.91–8.48 mm in diameter. The beads were readily identified as artificial by their appearance, which consisted of metallic golden brown veining and concentrations of blue color against a whiter body. Further tests were performed to identify the blue areas.

The measured RI was approximately 1.54. The beads displayed a patchy chalky blue reaction to short-wave UV and were inert to long-wave UV. Their Chelsea filter reaction was red, and under the desk-model spectroscope they displayed a band at approximately 650 nm. Under magnification, the blue areas displayed fluid inclusions that gave the beads a cloudy effect. In addition, the abundant fractures showed the presence of dye (figure 2) that was responsible for the beads’ blue color. Such features are commonly observed in dyed quartzite, but these were not sufficient to prove its identity. The golden brown areas, which consisted of fine flakes (again, see figure 2) held in a soft polymer, were later identified by EDXRF spectroscopy as copper and zinc composites. Similar composites in which the components are held together in a polymer matrix have been known in the trade for several years now (see G. Choudhary, “A new type of composite turquoise,” Summer 2010 G&G, pp. 106–113). Also present were thick layers of polymer along the edges of the blue and golden brown areas, which appeared green due to the overlap of the blue dye with the golden flakes. Raman spectroscopy confirmed that these blue portions were quartz.

Figure 2. Color concentrations of blue dye were easily visible along the fractures against a white background, while the golden brown areas were composed of copper-zinc based fine flakes. Also note the greenish polymer along the edge of the golden brown and blue areas. Photomicrograph by Gagan Choudhary; magnified 48×.
Recognizing these beads as composites was straightforward, but identification of the components required Raman and EDXRF spectroscopy. Although these beads were obviously created to offer something fancy and attractive to consumers at a low price, clear and complete disclosure remains imperative. @chapter:5


Publication Year: 1983 Title: Summer 1983 G&G Lab Notes Abstract: Diamond Flights of Fancy
Painted Pink Diamond: The Big Switch
Diamond Rose Cuts
Diamond Simulants
Treated Yellow Diamond
Synthetic Emerald
Dyed Blue Jadeite
Black and White Opal
Black Non-Nacreous Natural "Pearl"
Early Mabe Pearls
Green Quartz
Color Restoration of Sapphire
Taaffeite
Imitation Turquoise

To view the full section, download the PDF above. @chapter:35


Publication Year: - Title: Tourmaline Care and Cleaning Guide Abstract: Tourmaline ranks 7 to 7.5 on the Mohs hardness scale.

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

Tourmaline ranks 7 to 7.5 on the Mohs scale. Its toughness is considered Fair.

Stability
Tourmaline is generally stable to light and isn’t affected by exposure to chemicals, but heat can damage a tourmaline. High heat can alter the color, and sudden temperature change (thermal shock) can cause fracturing.

Some tourmalines might have been treated to improve their color. The two most important tourmaline treatments are heating and irradiation.

	The stone on the left was heat-treated to give it its desirable Paraíba color. The violetish stone on the right couldn’t be heated because it contains liquid inclusions. - Courtesy Nomad's Company
Changes resulting from heat treatment are stable and undetectable. Gems with abundant liquid inclusions can’t withstand heat treatment.

Color changes due to irradiation can fade with exposure to heat or bright light.

Cleaning
Warm, soapy water is the best method for cleaning tourmaline. The use of ultrasonic and steam cleaners is not recommended. @chapter:0


Publication Year: 2015 Title: Impregnated and Dyed Turquoise Abstract: Figure 1. Spectroscopic analysis of this 15.21 gram turquoise reveals that the material has been both impregnated and dyed. Photo by Wen Han.

Turquoise has a cryptocrystalline structure, which gives rise to the gem’s porosity. Its vulnerability to body oils, ordinary solvents, and dirt can induce variation of color. This porous gemstone’s appearance and durability can be enhanced by various treatment techniques, such as dyeing, impregnation (with polymer, wax, or plastic), and the proprietary Zachery process (E. Fritsch et al., “The identification of Zachery-treated turquoise,” Spring 1999 G&G, pp. 4–16).

Turquoise, often featured in vintage jewelry pieces, is becoming increasingly popular in the Chinese market. Recently, the NGTC Beijing lab received for identification a 15.21 gram turquoise sphere with green color (figure 1). The specimen measured approximately 3.5 cm in diameter; its spot refractive index value was 1.59 and its hydrostatic specific gravity value was 2.58. The test sample was inert, except for several lines and a cavity with moderate white fluorescence under both long-wave and short-wave UV radiation (figure 2), suggesting impregnation. Magnification showed some filling materials were also present in the cavities. Additionally, green color concentration was observed in the material’s cavities and cracks.

Figure 2. Some lines, along with the cavity, fluoresce white when exposed to long-wave
UV radiation, indicating the presence of filling material. Photo by Wen Han.
Infrared reflectance spectroscopy revealed complicated peaks containing turquoise and impregnated materials. The bands at 1118 and 1050 cm–1 were assigned to the asymmetric stretching vibrations of phosphate units, while the 835 cm–1 was caused by the bending vibration of OH units. Other features from approximately 647 to 482 cm–1 were due to the phosphate bending modes of turquoise. The 2918 and 2850 cm–1 peaks were attributed to wax; additionally, a series of small peaks from 1800 to 1350 cm–1 indicated the presence of organic matter. To identify this organic material, we scraped off some powder from the edge of one of the cavities with a blade. The resulting infrared transmittance spectrum indicated the presence of three kinds of polymer (figure 3). The 1731 and 1013 cm–1 peaks were attributed to acrylic polymer, and the 1611 and 1510 cm–1 peaks were due to epoxy resin; both are commonly applied to various gem materials for impregnation. Peaks at 1410, 1260, and 797 cm–1 were characteristic absorption features of silicone. Silicones are polymers consisting of repeating units of siloxane (a functional group composed of two silicon atoms and one oxygen atom, often combined with carbon and hydrogen). The 1410 and 1260 cm–1 peaks were caused by asymmetric and symmetric deformation vibrations of Si-CH3, respectively, and the 797 cm–1 was assigned to the Si-C stretching vibrations of the silicones.

Figure 3. The infrared transmittance spectrum of small amounts of powder scraped from
the sample shows that the turquoise was impregnated with three components: epoxy resin,
acrylic polymer, and silicone.
EDXRF chemical analysis detected mainly P, Al, Cu, Fe, and Si. The first four are consistent with the chemical composition of turquoise, while Si was suspected to be a byproduct of silicone impregnation. The UV-Vis spectrum showed two absorption bands: a band centered at about 428 nm caused by Fe3+ d-d electronic transition, and a sharp band centered at approximately 677 nm (figure 4). Natural-color turquoise does not show the 677 nm band; many Chinese labs consider this feature characteristic of dyed material.

Figure 4. When compared with the spectrum of a known natural turquoise sample, the
677 nm band of the UV-VIS spectrum indicates that the sample in this study was dyed.
Turquoise is usually impregnated with acrylic polymer or epoxy resin for stabilization in addition to the dyeing process to change its color. This is the first time we have encountered turquoise that was dyed and impregnated with three components. Our investigation reinforces the need to identify any and all treatments. @chapter:6


Publication Year: 2009 Title: Cutting Diffraction Gratings to Improve Dispersion (“Fire”) in Diamonds Abstract: A new microlithography process developed to create high-resolution diffraction grating patterns on portions of certain facets can improve the dispersion of light and thus the amount of “fire” in a diamond. These Nanocut plasma-etched diamonds can be identified with magnification by the presence of small, unpolished-appearing areas on the facets where the grating pattern has been created. Round brilliant–cut diamonds displaying such patterns will be classified by the GIA Laboratory as modified round brilliants; as such, they will receive color and clarity grades, but not a cut grade.

	DATA DEPOSITORY

Additional Data
	Winter, 2009 @chapter:31


Publication Year: 1986 Title: Spring 1986 G&G Book Reviews Abstract: “Cartier: Jewelers Extraordinary”
By Hans Nadelhoffer, 312 pp., illus., publ. by Harry N. Abrams, New York, NY, 1984. US$50.00

“The Great American Sapphire”
By Stephen M. Voynick, 212 pp., illus., publ. by Mountain Press Publishing Co., Missoula, MT, 1985. US$16.95 cloth, $9.95 paper

“Pearls: Their Origin, Treatment, and Identification”
By Jean Taburiaux, 247 pp., illus., publ. by Chilton Publishing Co., Radnor, PA, 1985. US$24.95

“Larousse Des Pierres Precieuses”
By Pierre Bariand and Jean-Paul Poirot, 264 pp., illus., publ. by Librairie Larousse, Paris, France.
US$45.95

“The Tourmaline Group”
By R. V. Dietrich, 300 pp., illus., publ. by Van Nostrand Reinhold, New York, NY, 1985. US$29.95

To view the full section, download the PDF above. @chapter:21


Publication Year: - Title: Bench Tip #1: How To Sharpen A Drill Bit Abstract: How to Sharpen a Drill Bit

Small, fine drill bits used for jewelry making will become dull with normal use. Worn cutting edges make tasks more difficult and time-consuming and can cause costly accidents, including damage to jewelry and gemstones or even injury. Maintaining the cutting surfaces on your tools will ensure clean, consistent work at the bench.

This installment will teach you how to sharpen the cutting edges of a fine drill bit. There are different styles of bit tips, but this example features a chisel tip. Let’s begin with a look at its anatomy.

A drill bit has two cutting surfaces, one on each side of its center axis, that are cut at an angle of approximately 60 degrees.

	The parts of a drill bit.
Notice that each of these angled surfaces is also cut at a slightly narrower angle, creating another plane. This plane creates the cutting edge as well as a relief area behind that edge. This relief area prevents contact with the metal being cut as a hole is drilled, which reduces drag and friction.

The helical groove in the drill bit is called the flute.  It acts as a channel to guide the cut material out of the hole created by the two cutting edges.

We will file each of the relief areas to sharpen the drill bit, maintaining the same angle as these planes, which is important for the drill bit to perform properly after sharpening. The cutting edges will be honed by reducing a small amount of metal from each surface.

	The cutting area and the angle of the relief area plane.
Begin by inserting and tightening a silicon carbide separating disk in a No. 30 hand piece of a flex shaft. Secure the worn drill bit in a screw mandrel and brace against the bench pin as you position the bit to be filed on the relief area.

Carefully lower the separating disk to lightly touch the targeted surface. Without changing the angle, rotate the bit in the holding device and repeat on the opposite relief area plane. Once this is complete, you will have a newly sharpened bit. This may take a bit of practice, but it’s a valuable technique that can save time on the job.

	Always maintain the angle of the relief area plane when sharpening. @chapter:28


Publication Year: 2023 Title: Quarterly Crystal: Dravite in Fluorapatite Abstract: Figure 1. Dark yellowish to brownish green needle-like inclusions dominate the interior of this 21.36 ct Portuguese fluorapatite on siderite matrix. Photo by Adriana Robinson.
Growing from an angular matrix plate of brown siderite, a doubly terminated hexagonal crystal weighing 21.36 ct with a very light purplish blue color (figure 1) was identified as fluorapatite by Raman analysis. As the photo shows, the semitransparent crystal clearly hosts a number of randomly arranged, eye-visible, translucent acicular inclusions. The fluorapatite thumbnail specimen, from the Panasqueira mine in the Castelo Branco district of Covilhã, Portugal, was acquired by author JIK from the collection of Dr. Vasco Trancoso at auction in June 2023. When the specimen was examined microscopically, the acicular morphology and dark yellowish to brownish green bodycolor of the inclusions, as well as their behavior in polarized light, suggested they might be tourmaline. Laser Raman microspectrometry was able to pinpoint their identity as dravite (figure 2), a member of the tourmaline group.

Figure 2. Raman analysis was used to identify the acicular inclusions in the fluorapatite host crystal as dravite tourmaline. Photomicrograph by Nathan Renfro; field of view 7.37 mm. @chapter:13


Publication Year: 2016 Title: Tucson 2016 Abstract: Figure 1. Tucson’s GJX show saw considerable traffic this year, including a higher number of American buyers. Photo by Andrew Lucas.

	For decades, buyers and sellers from every aspect of the gem and jewelry industry have flocked to the gem fair in Tucson, a town in the heart of Arizona’s Sonoran Desert that is rich in cultural and natural heritage. The annual shows are widely considered a forecast for the rest of the year. While the shows of the past few years have reflected a sluggish industry, the atmosphere in 2016 was dramatically different, with an increase in both attendance and business. The 34th AGTA GemFair saw record pre-registration numbers, and more than 300 exhibitors greeted a full house of buyers on the opening day. Gabrièl Mattice of Pala International (Fallbrook, California) said that sales were very strong this year, even on the first day of the show. The energized interaction between exhibitors and buyers was evident throughout the convention center. Though diamond sales have slowed, colored stones have gradually gained momentum among jewelry customers, and designers are responding in kind. Although the overall market share for colored stones is still small compared to the diamond sector, efforts to promote them have had very positive results.

More Serious Buyers. After the surge of foot traffic on the opening day, attendance remained stable at the shows for the rest of the week (figure 1). Vendors saw fewer Chinese buyers than in 2014, though Josh Saltzman of Nomad’s Co. (New York) indicated that those who came were serious buyers picking up high-quality goods. Gaurav Shah from Real Gems Inc. (New York) confirmed that his company has seen greater demand for emerald in mainland China since 2007, a market that slowed in 2015. He said that the Chinese are more cautious and specific in their purchases, and he predicted an upswing in Chinese buying activity in the near future. Joseph Nakamura of Shogun Pearl (White Plains, New York) said that 95% of his customers were from the United States, while Gabrièl Mattice also saw many Europeans on the floor, especially French buyers. Many new buyers attended, possibly due to the stabilized prices and heightened interest in colored stones (figure 2). Mr. Shah observed three categories of clients in Tucson: buyers from television and Internet companies, retailers, and designers.

Figure 2. A customer examines some calibrated emeralds at the Real Gems booth in the AGTA show. Photo by Tao Hsu.

	David Bindra of B&B Fine Gems (Los Angeles) noted that the number of transactions relative to the attendance was much higher than in previous years. He felt that this year’s AGTA show was much better than the September 2015 Hong Kong Jewellery and Gem Fair, where many sellers felt the slowdown of the mainland Chinese market.

Calibrated Goods. Though high-end colored gems continue to set auction records, the market for these stones remains slow. As a result, the colored stone trade still mainly consists of goods in standard calibrated sizes rather than custom-cut material (figure 3). Many cutting factories are able to provide a greater selection of sizes that fit their clients’ requirements. This especially benefits the jewelry manufacturers in China and India, as setting calibrated gems is the bulk of their workload. Thus, mid-priced colored goods were the overall best sellers in Tucson. Nirmal Bardiya of RMC Gems (Bangkok) informed us that calibrated goods of various millimeter sizes are best sellers in the American market, while Arthur Groom Jr. of Eternity Natural Emerald (Ridgewood, New Jersey) noted that Afghan emerald melee is one of his biggest sellers. Guarav Shah reported that the most popular calibrated cuts are oval, emerald, and pear shapes; these goods generally range from $200–$2,000 per carat.

Figure 3. Assorted goods in calibrated sizes sold very well at the shows. Photo by Tao Hsu.

Classics. No single stone stole the show this year. Some relatively new varieties were available, but their potential is still hard to evaluate. Some people asked about the color-change pink pyrope garnet that has recently been covered by multiple trade magazines, including the Winter 2015 G&G. Ms. Mattice said it will take time to educate people about this stone, and it is not easy to predict the market potential. Mr. Bardiya informed us that morganite (figure 4), aquamarine, and blue topaz were popular among RMC’s American clients. According to Joseph Nakamura, white pearls still dominate, while other colors come and go with different fashion trends. According to multiple dealers, Paraíba tourmaline is still in high demand (figure 5).

Figure 4. Morganite attracted many American buyers this year. Photo by Andrew Lucas.

Figure 5. According to many exhibitors, Paraíba tourmaline remained one of the shows’ best sellers. Photo by Andrew Lucas.

	Even so, the “big three” of ruby, sapphire, and emerald still dominate the market and fetch higher prices, which was reflected in this year’s shows. Corundum is still the most popular material in the high-end sector. David Bindra and Gabrièl Mattice both said that sapphires sold very well, and Mr. Bindra thinks that blue and green material will be especially strong this year, though yellow sapphires drew more interest than at previous shows. Pink and pastel-colored sapphires also attracted many buyers, perhaps because they evoke rose quartz and serenity blue, Pantone’s colors of the year for 2016.

Interest and Demand for Color. As one of the best platforms to trade and promote colored gemstones, the Tucson shows provide buyers with the finest goods sourced from all over the world. Some one-of-a-kind stones debut here, such as the 332.24 ct Imperial Flame topaz carving. Spectacular stones such as these usually attract immediate attention.

	Mr. Bindra tied the increase in sales to a growing awareness of colored stones. Once-daunted consumers are becoming more knowledgeable about different varieties and are better prepared before they purchase. This interest in learning was reflected at the AGTA GemFair seminars, which saw a 30% increase in attendance.

	Greater appreciation for colored stones motivates designers and retailers to source more of them (figure 6). Mr. Shah did business with more designers than in previous shows. The authors themselves saw materials in more unique cuts that seemed intended to capture the designers’ imagination (figure 7). Mr. Shah said that even though Real Gems is a wholesaler, the company does not have a minimum order requirement for any buyers. This is very helpful for many designers, especially the young ones. This exhibitor feels that it is worthwhile to do business with people who are willing to work with and promote colored stones in their own work.

Figure 6. Colored stone jewelry is becoming increasingly popular among consumers, as designers such as Paula Crevoshay use colors in more creative ways. Photo by Tao Hsu.

Figure 7. Some pieces offered excellent options for designers who wish to create a unique look. Photo by Tao Hsu.

Summary. Based on their own observations, the authors were not surprised to hear vendors say that this was one of the strongest Tucson shows in recent history. People were encouraged by the renewed momentum of the American market, even though high-end buyers were still cautious. Relatively stable prices also contributed to increased sales, although the price of sapphire, ruby, and emerald remained high. With the positive forecast from Tucson, the trade is expecting a prosperous 2016.

	We thank the many exhibitors who provided insight, photos, and materials. @chapter:33


Publication Year: 2004 Title: Spring 2004 Gem News International Abstract: Tucson Report
Colored Stones and Organic Materials
	            Yellow Cat’s-Eye Beryl from Brazil
	            Update on Demantoid and Cat’s-Eye Demantoid from Iran
	            Blue Omphacite from Guatemala
	            New Ruby Production from Malawi
	            Pink to Pink-Orange Spinel from Tanzania
	            Large Tsavorite and Green Grossular from Tanzania
Synthetics and Simulants
	            Color-Change Glass, Imitating Alexandrite
Treatments
	            Commercial Production of HPHT-Treated Diamonds Showing a Color Shift
Conference Reports
	            Accredited Gemologists Association Conference
GNI Regular Features
Diamonds
	            Update on Proprietary Diamond Cuts
	            A Diamond Exhibiting a Spectacular Phantom
Colored Stones and Organic Materials
	            Black Horn Coral Coated with Artificial Resin
	            Petroleum Inclusions in Quartz from Pakistan: A Photoessay
Instruments and Techniques
	            New Swarovski Triplet Loupe
Conference Reports
	            Diamond Presentations at the Australian Diamond Conference
	            “Science of Gem Materials” Session at the MRS Meeting
	            Sinkankas Tourmaline Symposium
Announcements
	            Dr. Henry A. Hänni Receives AGA Bonanno Award
	            Dr. George R. Rossman Receives Feynman Prize
Conferences
	            JCK Show Las Vegas
	            Jewelry Camp 2004
	            Geoscience Africa 2004
	            International Geological Congress
	            5th European Conference on Mineralogy and Spectroscopy
	            Gems of Pacific Continental Margins
	            Diamond 2004
	            ICAM 2004 in Brazil
	            Hong Kong Jewellery & Watch Fair
Exhibits
	            GIA Museum Exhibits in Carlsbad

To view the full section, download the PDF above.

	DATA DEPOSITORY

Table of Proprietary/Patented Diamond Cuts
	Submitted by Thomas W. Overton
	Spring 2004 @chapter:23


Publication Year: 1991 Title: Sunstone Labradorite from the Ponderosa Mine, Oregon Abstract: The Ponderosa mine is now producing commercial quantities of the gem-quality labradorite feldspar known as sunstone. This gem material exhibits unique optical and physical properties that include a wide range of saturated body colors, aventurescence, and strong pleochroism. The feldspar is An70 labradorite, a high calcic plagioclase; the aventurescence-causing inclusions have been identified as pure native copper. Microprobe analyses conducted on colorless, red, and green samples did not reveal any obvious causative mechanism for the exhibited colors, although ongoing research is investigating intervalence charge transfer, possibly involving colloidal copper. Gemological identification involves the use of R.I., S.G., and microscopy. Locality determination (Oregon) is based on the copper inclusions and a distinct pleochroism. @chapter:6


Publication Year: 2019 Title: Recycled Gemstones from Perpetuum Jewels Abstract: Figure 1. This 2 ct Old European cut diamond has a color grade of N and a clarity grade of VS1. The faceted girdle is not original to the stone; originally this would have had a bruted girdle. Photo by Albert Salvato, courtesy of Perpetuum Jewels.

The Tucson shows were busy for Perpetuum Jewels (New York and San Francisco), a wholesaler specializing in post-consumer recycled diamonds and colored stones in original, antique cuts. They also work with mine-to-market gemstones and estate jewelry. Co-founder Jared Holstein spoke to us about the importance of recycled gems to the industry (figure 1).
Perpetuum works mainly with designers and jewelry stores in the bridal market. The company originally sought to provide alternatives to newly mined material, focusing on stones cut before 1940. They are active on social media and with organizations such as the Women’s Jewelry Association and Ethical Metalsmiths, which drives traffic their way. Holstein and his partner, Jay Moncada, enjoy working with antique stones because each one is different. Rather than achieving a “mathematical ideal of what a stone should look like,” each is cut to different proportions and has a history and character all of its own. Holstein teaches his clients the progression from the first point cut (with eight facets) to today’s multifaceted cuts. While they have a good deal of stock for center stones, they also have antique melee for eternity bands and other pieces.

	Recycled gemstones from Perpetuum Jewels

Their clients seek the smallest possible environmental footprint—as Holstein points out, “Diamonds are the ultimate recyclable material, because they are so hard,” allowing them to be used in jewelry again and again—or choose, for other reasons, to avoid newly mined gems. Many simply love the appearance and mystique of large antique-cut diamonds. The oldest one in stock was a Peruzzi-cut diamond with a double-cut bottom and a triple-cut top; the diamond came from a Victorian ring that it clearly predated. Diamond’s hardness allows a long journey through many cuts and several mountings. Holstein explained, “I like to think that there is probably a modern brilliant, which was a transitional cut, which was an Old European cut, which was an old cushion, which was a Peruzzi, which was a Mazarin, which was a table cut, and which was a point cut.”

Figure 2. This 3.74 ct unheated sapphire was removed from a vintage 1960s platinum pendant. The sapphire was refaceted by Jean-Noel Soni of Top Notch Faceting. Photo by Albert Salvato, courtesy of Perpetuum Jewels.

Figure 3. This 1.28 ct blue-green sapphire is from Montana’s Eldorado Bar deposit. Photo by Kevin Schumacher, courtesy of Perpetuum Jewels.
With the emergence of the “alternative bridal market,” Holstein and Moncada see designers choosing to work with colored stones instead of diamonds. In these cases, they work with a large supply of corundum. While they carry fine classic and antique blue sapphire (figure 2), their clientele gravitates toward softer blues, teals, and greens (figure 3); Montana and Australian bi- and parti-color sapphire are also popular. Holstein would like to see a move toward spinel and garnets by their bridal clients.
Perpetuum is the only company to achieve the SCS Recycled Gemstone Standard, a third-party certification for 100% post-consumer recycled diamonds and gemstones. The SCS annually audits all aspects of a business to ensure it is a responsible source before awarding this certification. A company must prove, for instance, that its environmental footprint decreases every year while recycled inventory increases annually. The latter has become difficult for Perpetuum, as they now carry recently mined Montana and Australian sapphire to meet their clients’ needs. Doing so has lowered their level of recycled gemstones to below 100%.
Holstein said he has never been able to separate the jewelry pieces he loves from the issues endemic to the industry. He has always been aware that the makings are “from someone else’s backyard.” He considers it his responsibility to engage in ethical, environmentally sustainable and responsible practices because they are better for the communities that mine and cut the metals and stones that help him make a living; this is at the core of his business practices. Perpetuum’s booth in Tucson allows him to meet with new and existing clients and educate them on these matters that are close to his heart. @chapter:24


Publication Year: 1992 Title: Unstable Radiation-Induced Yellow-Green Color in Grossular Garnet Abstract: Although conventional wisdom has been that irradiation will not alter the color of garnets, exposure of some colorless to pale-hued African grossulars to either 60Co or 137Cs gamma rays turns them light yellow-green. The resulting color is unstable and fades within hours to days in sunlight, and within weeks in the dark. The spectra of the radiation-enhanced garnets differ from those of similar-appearing naturally colored grossulars. In the dark, the irradiation-related absorption features undergo two stages of fading: an initial period of relatively rapid fading, followed by a longer period of slow fading. In daylight, a single rate of even faster fading is observed. @chapter:9


Publication Year: 2021 Title: Asterism in Natural Diamond Cabochons Abstract: Figure 1. Photos show internal cloud inclusions in profile view (left) and asterism in top view of the polished cabochons using fiber-optic illumination (right). The diameters of the two cabochons are 11.33 mm (top) and 11.32 mm (bottom). Photos by Christopher Vendrell.
The New York laboratory received two cabochon diamonds from Hong Kong, both displaying asterism. Gemologists initially questioned whether these stones were in fact diamond because of the cabochon cutting style and the white four-rayed “stars” observed using fiber-optic illumination. The polished cabochon is a popular cutting style in colored stones but rarely attempted with diamond due to its hardness. This cutting and polishing technique yielded two semitransparent to translucent round cabochon diamonds with a very light yellow color, weighing approximately 6.29 ct and 6.07 ct (figure 1).

Figure 2. FTIR spectra reveal natural type Ia diamonds with strong hydrogen concentrations in the 3000–4000 cm–1 region and aggregated nitrogen in the one-phonon region at 1400–800 cm–1. The 6.29 ct diamond cabochon spectrum is denoted in red and the 6.07 ct diamond in blue.

Mid-infrared spectroscopy revealed strong hydrogen-related absorption bands (e.g., 3107 cm–1) and those attributed to aggregated nitrogen in the one-phonon region, evidence of natural type Ia diamonds (figure 2). Microscopic observation from the base of the cabochons revealed prevalent clouds distributed throughout the diamonds. The clouds were composed of small whitish pinpoints, and when aligned linearly formed small needle-like internal inclusions (figure 3).

Figure 3. Cloud and needle-like inclusions observed in bottom view of the two very light yellow round cabochon diamonds: 6.29 ct (left, field of view 1.8 mm) and 6.07 ct (right, field of view 6.5 mm). Photomicrographs by Christopher Vendrell.
Fluorescence images collected using the DiamondView revealed yellowish green fluorescence in the sectors with clouds. The cloud-free sectors were inert to UV radiation. Symmetrical fluorescence patterns were observed in both stones with nearly mirror images (figure 4).

Figure 4. DiamondView images of the very light yellow round cabochon diamonds reveal the location of asterism using ultra-short-wave illumination, approximately 225 nm. The top view is shown on the left in each pair of images, the bottom view on the right. Images by Christopher Vendrell and Kyaw Soe Moe.
Natural diamonds are dominated by {111} octahedral growth sectors, but occasionally the {100} cubic sector is well developed, forming a crystal with mixed growth habits. The cubic growth sector could preferentially contain a significant amount of pinpoint cloud inclusions. This feature occurs quite often in diamonds from Zimbabwe. Unlike other diamonds with clouds, these clouds concentrated in the {100} growth sectors linearly aligned to form needle-like inclusions. The distribution of these needle-like inclusions within the {100} growth sectors generated the asterism feature seen in these gem diamonds.
Gemological and spectroscopic features strongly indicated that these diamonds were cut from the same large rough diamond crystal. The crystal was very likely cut through the center along the (100) plane and then polished into two relatively large cabochon diamonds. Taking advantage of the widespread needle-like inclusions in this otherwise well-included large diamond crystal was a clever design choice to produce two cabochons displaying the rare asterism phenomena. @chapter:11


Publication Year: - Title: US Government to Industry: Know Your Supply Chain; De Beers, Alrosa Cut Rough Sales Abstract: Leading diamond producers have cut rough sales way back as credit tightens and inventories build. Photo courtesy of Rio Tinto

The U.S. State Department told jewelry industry representatives in April to tighten chain of custody reporting on all materials – gemstones, diamonds and metals – used in their products.
Last week, the department came back and told the industry it was not doing a very good job.
According to a JCK report, the industry is still lagging on adopting “Know Your Customer” rules that require businesses to file “Suspicious Activity Reports” on transactions using large amounts of cash or where criminal activity is suspected. State Department officials told attendees that “very few” such reports have been filed and that everyone up and down the supply chain needs to do more.
The State Department said these regulations are necessary to prevent funds from going to “malign” regimes, such as Iran, Venezuela and several African nations.
The industry voiced concerns after the April meeting about a new round of restrictions placed on its supply chain that require documentation of every step of every colored gemstone or diamond in the pipeline.
Attendees agreed last week that cooperation is beneficial for all sides and called for greater due diligence moving forward.
ROUGH DIAMOND SALES
De Beers, Alrosa and other diamond mining companies severely cut rough sales in an effort to reduce inventories in diamond manufacturing centers and to help temper the softening of rough and polished prices. Sales will likely remain low for the rest of the year because there is no sign of a quick resolution to the diamond manufacturers’ credit problems or high inventories.
De Beers and Alrosa said the banks’ cutting credit to diamond manufacturers and the prospects of an increased trade war between the U.S. and China were the main reasons for the difficult rough diamond market today.
De Beers announced its smallest allocation in three years – $250 million – and allowed clients to defer purchases of a wider range of goods. Rough revenues are down nearly 25% for the year compared to last year.
Alrosa reduced its rough sales by more than 50% to $169 million against June 2018 levels. Its sales are down more than one-third for the year. Rough prices have declined about 6% this year, while polished prices for diamonds one carat and under have declined 1.5% to 3.5%, with larger drops coming in the smaller sizes.
In addition, Rio Tinto reported a $5 million loss in its diamond division for the first half of the year, compared to a profit of $55 million for the same period of 2018. While the loss is due in part to the company shifting mining activities to lower ore grades (a means of trimming production in a soft market without disrupting operations), sales of rough diamonds were down 16% for the period. The company will close its largest diamond operation, the Argyle mine in Australia, next year.
Demand for diamonds, while not depressed, remains mired in very slow growth worldwide and is not sufficient to absorb excess inventories. Part of the reason for the slow demand growth is the unsettled political and economic climate around the world. In addition, young people seem less interested in jewelry than their parents. A study of the U.S. market, conducted by Harris Poll for TD Ameritrade, found that Gen Z and millennials place much less value on an engagement ring than their parents – two-thirds believe a ring should cost less than $2,500. @chapter:30


Publication Year: - Title: DNA Techniques Applied to the Identification of Pinctada Fucata Pearls from Uwajima, Ehime Prefecture, Japan Supplementary Data Abstract: Supplementary Figures. From K. Saruwatari et al., “DNA Techniques Applied to the Identification of Pinctada Fucata Pearls from Uwajima, Ehime Prefecture, Japan,” Spring 2018 Gems & Gemology, pp. 40–50.

Supplementary figure S-2
Supplementary figure S-2 @chapter:14


Publication Year: 2021 Title: Glass Imitation of Star Sapphire Abstract: Figure 1. Glass cabochons with weights ranging from 0.47 to 1.29 ct were obtained by the author. The stones displayed white six-ray stars across their domes, resembling star sapphire. Photo by Jessa Rizzo.
The market for sapphire simulants and synthetics is plentiful, as sapphire is likely the most popular of all colored stones. The high cost of natural, gem-quality sapphire means it is not obtainable for much of the world’s population. This has opened the doors of creativity to produce blue stones with high luster resembling the natural material. Recently, the author obtained a parcel of blue cabochons with an unusual star pattern resembling star sapphire (figure 1). After a series of tests were performed, the material was identified as manufactured glass.

Figure 2. A vertical cross section of the glass cabochon showcases the internal structure and diagnostic flow lines imitating star sapphire. Photo by Nathan Renfro.
Gemological investigation revealed an average specific gravity of 2.46 and a refractive index of 1.40. The cabochons were inert to long-wave ultraviolet radiation but exhibited strong chalky blue fluorescence under short-wave ultraviolet radiation. Observation under a microscope revealed gas bubbles shallow to the surface within the blue regions of the stones and small conchoidal fractures along the girdles. One cabochon was cut in half vertically for further scientific investigation (figure 2). This cross section uncovered a large core of white glass raised to the surface of the dome in a star pattern. Flow lines were also visible within the white glass core. Finally, a thin layer of blue glass around the perimeter of the cabochon was seen in the cross section, creating the bodycolor of the stone (again, see figure 2).
Asterism is an optical phenomenon that can be defined as a star-shaped concentration of reflected or refracted light from inclusions within a gemstone cut en cabochon. Genuine asterism is also mobile if the stone and/or light source is moved. These glass imitation star sapphires, however, do not exhibit genuine asterism, as their stars were simply molded into shape and are fixed in place.
Glass imitations span the gamut of gemstones. Faceted transparent colorless glass is one of the oldest and simplest diamond simulants. Glass beads coated with pearlescent paint are a common pearl imitation, and colored glass of various opacities is capable of imitating almost any colored gemstone. Recent G&G articles on colored stone imitations include “Artificial glass imitating a Paraíba tourmaline” (Winter 2020 Lab Notes, pp. 518–520), “Greenish blue glass imitating gem silica” (Summer 2020 Gem News International, pp. 314–315), and “Glass bangles” imitating jadeite and nephrite (Spring 2019 Lab Notes, pp. 93–94). @chapter:12


Publication Year: 2015 Title: Rubies from a New Deposit in Zahamena National Park, Madagascar Abstract: Figure 1. Rough rubies from Zahamena National Park with a combination of good shape, transparency, and attractive color. Photo by Vincent Pardieu/GIA.

	In July 2015, news circulated through the trade about a ruby discovery south of Andilamena, near Lake Alotra (figure 1). Photos of clean, attractive stones of over 10 carats were shared on social media by Malagasy and Sri Lankan gem merchants. Several thousand unlicensed miners quickly descended on the area, creating serious conservation concerns as the new deposit was located inside Zahamena National Park. In August 2015, the Malagasy government sent soldiers to close the mining site. But because the area is very remote, they could not maintain their presence longer than a month. As soon as the soldiers departed, the miners returned in numbers.

	Gem-quality rubies and sapphires are not unknown in northeastern Madagascar: They were first found in 2000, east of Andilamena and west of Vatomandry (Summer 2001 GNI, pp. 147–149). These discoveries were followed by a blue sapphire deposit near Andrebabe, a few kilometers south of Andilamena, in 2002 (www.ruby-sapphire.com/madagascar_ruby_
	sapphire.htm). Ruby mining was limited until 2004, when demand for the heavily fractured material from Andilamena dramatically increased with the advent of the lead-glass filling treatment developed in Thailand between 2001 and 2004. Visiting the deposit in June and September 2005, author VP could see that more than 10,000 miners were living and working in the jungle (www.rwwise.com/madagascar1.html). In 2011 and 2012, two new discoveries occurred in the region. The first was a pink and blue sapphire deposit near Mandraka village, north of Toamasina. In 2012, a deposit was discovered east of Didy (www.giathai.net/pdf/Didy_Madagascar_US.pdf). That deposit produced some large, clean, and attractive rubies and blue sapphires. More discoveries followed—near Bemainty, north of Didy, for instance—but either the gems were ordinary or the rush was short-lived. In 2015, a new blue sapphire rush occurred near Andrebabe in February, followed by a ruby discovery near Ambodivoangy village in July (http://lotusgemology.com/index.php/library/articles/322-blood-red-rubies-from-madagascar-lotus-gemology).

	From September 23 to October 6, 2015, a GIA field expedition team collected samples at the mines. After three days of walking in the jungle, the team was able to visit the new mining sites (figure 2), located about four hours’ walking distance from Ambodivoangy. There they witnessed some illegal ruby mining activity by artisanal miners at two different sites, located in a valley at 17°37'60''S 48°52'19''E and along a creek in a forested area at 17°38'26''S 48°52'38''E. They confirmed that the deposit was indeed located inside Zahamena National Park. Approximately 500 people were seen at the lower mining site, while about the same number worked in the forest along a stream where ruby-rich gravels were collected (figure 3).

Figure 2. A young Malagasy miner searches for rubies in Zahamena with simple homemade tools: a pierced plastic oil can used as a sieve and an empty water bottle to store his gems. Photo by Vincent Pardieu/GIA.

Figure 3. Artisanal Malagasy ruby miners wash gem-rich gravels in the stream that runs through the jungle of the Zahamena National Park. Photo by Vincent Pardieu/GIA.

	The local trading center was in Andrebakely, with mainly Malagasy buyers, while foreign buyers (typically from Sri Lanka) waited for local miners and businessmen at Tanambe and Andilamena. In both towns, more than 20 Sri Lankan buying offices were visible, mostly in houses with painted signs for the different companies.

	The new deposit is located about halfway between the old ruby deposit in the jungle east of Andilamena (discovered in 2000) and the rush that occurred at Didy in 2012 (www.giathai.net/pdf/Didy_Madagascar_US.pdf). The rubies from Zahamena share obvious similarities with those from Andilamena, such as their inclusions (mainly zircon and rutile crystals associated with rutile needles) and trace-element composition. Therefore, it is likely that these deposits are related, and a huge ruby and sapphire deposit could be hidden under the jungle in northeastern Madagascar.

	Back at GIA’s Bangkok lab in October 2015, the samples were fabricated and data was collected from them; a more extensive study is in progress. At this point it is interesting to note that the rubies from the Zahamena deposit have a very similar aspect to those from amphibole-related African deposits such as Montepuez in Mozambique, Chimwadzulu in Malawi, and Winza in Tanzania. Their iron content is indeed much higher than that of the marble-type rubies mined in Myanmar, Vietnam, Afghanistan, or Tajikistan. The shape of the crystals is generally tabular but not as flat as what is commonly found in Mozambique, meaning that faceted stones with good proportions can be produced. The new material is on average more included than the ruby from Montepuez. But ultimately the limiting factor for this deposit is its location inside Zahamena National Park, where gem mining is illegal. @chapter:37


Publication Year: 2015 Title: Wonders Within Gemstones II Abstract: By Anthony de Goutiere, softcover, 72 pp., publ. by FriesenPress, Victoria, British Columbia, 2014, Can$23.99.

              In his second book on photomicrography, Wonders Within Gemstones II, Anthony de Goutiere presents remarkable photos of gem inclusions. De Goutiere reveals the natural beauty of these features by applying various lighting methods to a wide range of gemstones, including amber, beryl, corundum, diaspore, feldspar, garnet, malachite, meteorite, peridot, quartz, spodumene, and topaz. Readers will get a thorough overview on how to use these approaches to find “invisible” inclusions. It is a great resource for both the general public and those working in the jewelry trade and in gemological laboratories.

de Goutiere has mastered the use of oblique illumination, polarized illumination, and diffused illumination to reveal the most amazing aspects of many inclusions, such as iridescent color in fractures, cleavages, parting planes, thin films (like liquid inclusions), and voids. In one notable photo, the whitish mosaic thin film inclusions in aquamarine become remarkably colorful because of the excellent use of oblique illumination. The author demonstrates how darkfield and transmitted oblique illumination exhibit the sharp euhedral crystal faces of the syngenetic crystals inside gemstones. de Goutiere also uses diffused reflected oblique illumination to reveal distinctive surface etch markings and crystal growth markings, and shows how polarized illumination exposes internal graining and strain as well as birefringent spectral colors. It is such a vivid use of oblique illumination, which can be a very useful but challenging lighting technique for gemologists. The description of each photograph is concise, clear, and well organized. It covers stone information, inclusion detail, and lighting method. Some photos look like abstract art, and some are reminiscent of nature scenes such as mountains, rivers, and animals. These beautiful images are all strikingly rainbow-colored due to the effect of the light.

A Graduate Gemologist with over 50 years of experience, de Goutiere has filled his book with gemological knowledge, a persistent passion for gemstones, and an impressive aesthetic standard. Each photo is enhanced by his unique and artistic perspective. Wonders Within Gemstones II is an enjoyable read for anyone interested in gemstones. It is a valuable reference for any enthusiast who would like to start their photomicrographic adventure. @chapter:8


Publication Year: 2015 Title: Maine Pegmatite Workshop Abstract: Figure 1. Workshop attendees at the Havey Quarry, which has produced some of the finest Maine elbaite tourmalines. The mine was originally opened in 1902 and worked for feldspar. This view shows the Havey pegmatite body, with three pockets visible. Photo by Duncan Pay/GIA.

              The 2015 Maine pegmatite workshop took place at the Poland mining camp, May 29–June 6. As readers know, many important colored gemstones including tourmaline, beryl, topaz, garnet, quartz, and spodumene are mined worldwide from pegmatites, and these rocks are the source for most fine gem crystals. Maine pegmatites have been mined for many decades (some back as far as the 1820s) and are renowned for their fine tourmaline, beryl, and quartz crystals. The workshop’s website is at pegworkshop.com.

The workshop is conducted by Dr. William “Skip” Simmons, Dr. Karen Webber, and Alexander Falster—all formerly of the University of New Orleans—and Ray Sprague, a local pegmatite miner. Simmons, Weber, and Falster were the core of the university’s mineralogy, petrology, and pegmatology (“MP2”) research group. Following the closure of the university’s mineralogy department, they relocated to the new Maine Mineral and Gem Museum in Bethel (www.mainemineralgemmuseum.org).

The workshop has taken place annually since 2001. The 2015 workshop had a total of 26 attendees, including six undergraduate mineralogy students from University of New Orleans, one postgraduate mineralogy student from the University of the Basque Country (Bilbao, Spain), a well-known mineral dealer, a variety of mineral collectors, and interested members of the public.

The workshop is structured with morning presentations and lectures, followed by excursions to mines and quarries in the afternoon. Given the breadth of participants (rockhounds from mineral clubs, undergraduate and graduate geology students, mineral dealers, gemologists, and PhD-level researchers), the content varied from introductory to quite complex—and sometimes contentious— topics, such as pegmatite genesis (fractional crystallization from granite vs. anatexis) and crystallization time. In particular, the relationship of pegmatites to tectonic settings was well explored, as was the current consensus on cooling time and the formation of large crystals. Nonetheless, the presenters did an excellent job and encouraged plenty of debate. Some of the best questions came from the mineral collectors in the group, many of whom have visited these quarries repeatedly.

The selection of field excursions (figures 1 and 2) varies from year to year and is dependent on which mines are available or being worked at the time. This year’s destinations included the following quarries: Western Mount Apatite, Tamminen, Waisanen, Bennett, Orchard, Havey, Mount Mica, and Emmons. Around noon each day, participants would caravan in a stream of cars to the “quarry du jour.” The workshop organizers enjoy excellent relationships with local mine owners, dependent on the good conduct of the attendees.

Figure 2. Colorful mineralogy at the Havey quarry. Pink and green tourmaline, clevelandite, lepidolite, and “salmon”-colored feldspar all indicate the presence of a nearby pocket. Photo by Duncan Pay/GIA.
At each quarry, Simmons or Falster explained pegmatite mineralogy and miners Frank Perham or Ray Sprague outlined current or past mining history at the site. The remainder of the time could be spent mineral collecting, which was a focus for a good portion of the group. Those interested in more depth could talk with members of the MP2 research group about the exposures, or with Perham and Sprague about the practice of mining pegmatites. Indeed, this is the workshop’s strong suit: The theory from the morning presentations is applied to real rocks in the afternoon.

Besides the quarries, workshop attendees also visited the new Maine Mineral and Gem Museum in Bethel. There they could see the progress of the exhibits and view the MP2 research group’s laboratory in the basement, which includes an electron microprobe, scanning electron microscope, X-ray diffraction equipment, and other advanced instrumentation.

Following an evening lecture on pegmatite mineralogy complemented by numerous hand specimens, the opening session kicked off with a general introduction to pegmatites, the earth’s chemistry, and phase equilibria. Throughout the week, the presentations delivered by Simmons, Webber, and Falster built on the basics to cover the relationship of granites to pegmatites, magmatic differentiation, pegmatite classification, magma genesis, and the influence of tectonic setting. Some of the more complex topics covered included crystallization dynamics, such as the influence of volatiles and fluxes (water, lithium, fluorine, boron, and phosphorous), pegmatite textures, aplites (“line rocks”), pocket formation and indicators, and regional and internal zonation of pegmatites.

Besides these instructional sessions, workshop attendees were also treated to a variety of other presentations, including:

Myles Fetch (Maine Mineral and Gem Museum, Bethel) described the garnet line in Oxford County pegmatites. He explained that the garnet line marks the lower edge of the pegmatite’s productive zone. It might swell upward close to a pocket, serving as an important indicator.

Dr. Encar Roda-Robles (University of the Basque Country and a member of the MP2 pegmatite research group) presented on pegmatites from the Iberian Massif and the central Maine belt, covering the differentiation of granitic melts vs. anatexis. Dr. Roda-Robles also delivered a talk on tourmaline, mica, and garnet as sensitive indicators of pegmatite evolution in the Berry-Havey pegmatite. This last talk was very relevant, as the afternoon’s field trip was to this quarry.

Idoia Garante-Olave (University of the Basque Country) delivered a presentation on mineralogy and geochemistry of micas from the Tres Arroyos pegmatite field in Badajoz, Spain.

Frank Perham, a noted Maine pegmatite miner, reminisced on the remarkable Newry tourmaline discovery, which produced an estimated $30 million worth of gem and specimen-grade tourmaline crystals in 1972. Perham also delivered a talk on Maine feldspar mining.

Dr. Skip Simmons presented previous work on the chemistry and a calculation of volume, by mineral, for the Mt. Mica pegmatite. The volume of tourmaline was estimated at 1%.

Jim Nizamoff (a mineralogist with Omya AG and former University of New Orleans research associate) and mineral collector Don Dallaire discussed the pegmatite mineralogy of the Conway and Osceola granites from the White Mountains of New Hampshire.

Ray Sprague (pegmatite workshop organizer and miner) presented on the mineralogy of specimens from the Emmons pegmatite in preparation for the all-day visit to that quarry. @chapter:0


Publication Year: 1984 Title: The Chemical Distinction of Natural from Synthetic Emeralds Abstract: The chemical characteristics of natural and synthetic emeralds were studied in order to identify differences that could be used to separate them from one another. Thirty-eight natural emeralds from 20 localities and 11 synthetic stones from six manufacturers (flux and hydrothermal growth processes) were analyzed by microprobe and X-ray fluorescence. The results revealed a complex collection of chemical constituents that reflect the different environments in which natural and synthetic emeralds form. The present study agrees with the limited number of analyses previously reported for both materials. Thus, a new method of distinguishing natural from synthetic emeralds is now available for use in gemology when more conventional methods prove inadequate. @chapter:8


Publication Year: 2022 Title: A “Galaxy” within a Diamond Abstract: Figure 1. This particle cloud, a typical inclusion in diamond, shows an iridescent appearance and is grouped in a triangular shape viewed in fiber-optic illumination. Photomicrograph by Aprisara Semapongpan; field of view 2.8 mm.
The 2.01 ct, D-color, I1-clarity type IaB diamond in figure 1 reveals an intriguing cloud of particles grouped in a triangular shape. These tiny crystal and particle cloud inclusions resemble a galaxy, as if seeing the Milky Way at night.

Figure 2. DiamondView imaging of the type IaB diamond reveals a fibrous pattern and a hazy triangular cloud area with blue fluorescence. Image by Aprisara Semapongpan.
The DiamondView image in figure 2 reveals blue fluorescence with a hazy triangular glowing area that matches perfectly with the position of the particle cloud in figure 1. Furthermore, this type IaB natural diamond displays a fibrous pattern in the DiamondView instead of the tree-ring pattern that is typical in type Ia diamond. This fibrous pattern is related to a weak B-aggregated (B-center; 4N+V) signal in Fourier-transform infrared spectroscopy.
Finding and analyzing inclusions in diamonds is fascinating, as you never know where the next diamond will lead you—perhaps you will even discover your own galaxy. @chapter:11


Publication Year: - Title: Morganite Description Abstract: One of the advantages of beryl is its wide color range. These crystals show pastel shades: aquamarine's green and blue and morganite's pink. -photo credit Alan Jobbins.

                      Like many gems found in pegmatites, morganite can form large crystals. Miners in Brazil have found crystals as large as 22 lbs. (10 kg). The Smithsonian Institution in Washington, D.C., includes two faceted gems weighing 236 cts. and 250 cts. in its collection. Although morganite is rarer than aquamarine, large cut stones are readily available on today’s market. That’s probably because morganite hasn’t been promoted to the jewelry-buying public nearly as widely as aquamarine or emerald.

Most of the morganite on the market comes from pegmatite mines in Minas Gerais, Brazil. Afghanistan, Mozambique, Namibia, and the US have been minor and inconsistent sources. While it’s only a minor producer today, the original Madagascar deposit still sets the standard for the best material. That location’s yield of magenta-colored rough was superior to crystals from other sources.

This impressive morganite crystal from the Serra do Urucum mine, Galileia, Minas Gerais, Brazil, is 11 cm high. The faceted stone is 84.88 carats. - Jeff Scovil

This morganite mine is in the Brazilian State of Minas Gerais, near Govenador Valderas. Morganite is usually mined from solidified magma-released fluids called pegmatites. - Eric Welch/GIA. @chapter:0


Publication Year: 2011 Title: Ruby and Sapphire from the Tan Huong-Truc Lau Area, Yen Bai Province, Northern Vietnam Abstract: Primary and secondary deposits in the Tan Huong–Truc Lau area of northern Vietnam’s Yen Bai Province have supplied rubies (especially star rubies) and some sapphires—mostly of cabochon quality—for more than a decade. The gems are typically translucent to semitransparent and pink to purplish or brownish red, with rare color zoning. The most distinctive features of this corundum after polishing include growth zoning and asterism. The samples contain relatively high amounts of Fe and variable Ti and Cr. The geologic origin and gemological properties of this corundum are distinct from that of the adjacent Khoan Thong–An Phu area. @chapter:3


Publication Year: 1995 Title: The Yogo Sapphire Deposit Abstract: Yogo Gulch, discovered more than 100 years ago, is one of four major sapphire-producing areas in Montana, United States. Yogo sapphires are known for their uniform, well-saturated blue color; relative absence of inclusions and zonation and high luster and brilliance in both artificial and natural light; they do not require heat treatment. Rough crystals, usually flat with low cutting retention, generally weigh less than one carat (but have been reported up to 19 ct). Unlike the other Montana deposits, which are secondary, Yogo sapphires are mined directly from a lamprophyre host rock. There are at least six known dikes, five sapphire-bearing, at Yogo. From 1895 to 1994, the Yogo deposit produced an estimated 18.2 million carats of rough that are believed to have yielded more than 500,000 carats of cut stones. Considerable reserves remain. @chapter:20


Publication Year: 2024 Title: Ukrainian Pegmatitic Heliodor and Topaz Abstract: Figure 1. Left: This 109.68 ct heliodor and 80.62 ct bicolor topaz are from the Volyn deposit in Ukraine. They are cut to leave natural etch faces on the pavilion/culet, while the crown and table are faceted. Right: A 162.22 ct pear-cut heliodor. The natural etching patterns are retained on the pavilion and are well displayed through the polished table. Photos by Robert Weldon; courtesy of Nomad’s.
This year in Tucson, exceptionally large, clean, and attractively colored topaz and beryl from the Volodarsk-Volynskii pegmatite field in Ukraine (also known as the Volyn deposit) were very popular at multiple shows.
The Volyn deposit is in the northwestern portion of Ukraine, about 190 km from Kyiv. This deposit has been worked for more than 100 years and was initially mined for piezoelectric quartz with topaz as a byproduct. More recently it has been known for producing large and fine-quality topaz and beryl crystals as well as phenakite (Be2SiO4) and fluorite. The topaz ranges in color from blue to a golden-red sherry color, while the beryl ranges from mainly yellow heliodor to green beryl to greenish blue aquamarine. The large, beautifully etched heliodor crystals brought international notice to this deposit in the 1980s (G. Franz et al., “Etch pits in heliodor and green beryl from the Volyn pegmatites, northwest Ukraine: A diagnostic feature,” Fall 2023 G&G, pp. 324–339).
At the GJX and Pueblo shows, Nomad’s (New York City) had high-quality heliodor and topaz that were carefully cut to retain the beautiful rough etching patterns characteristic of this material (figure 1, left). These intricate etching patterns were retained in each gem’s pavilion and visible face-up through the polished table (figure 1, right). The founders and owners are from Ukraine, and they started Nomad’s in the 1990s with pegmatite minerals from Volyn.

Figure 2. Exceptionally large and clean blue and bicolor topaz from the Volyn deposit. The blue triangular cut is 113.86 ct, the middle blue cube cut is 87.82 ct, and the blue and golden bicolor rectangular cut is 55.70 ct. Photo by Robert Weldon; courtesy of Dudley Blauwet Gems.
At the AGTA and Pueblo shows, Dudley Blauwet Gems (Louisville, Colorado) featured topaz, heliodor, and phenakite from Volyn, which they have successfully been carrying for three years. This year, however, the demand for these Ukrainian gems has grown. In fact, Ukrainian topaz was one of their best sellers, with much of the material gone by the first day of AGTA. The bicolor blue to sherry topaz was a particularly strong seller, followed by blue topaz (figure 2). They noted that the miner they work with has been reworking old pockets for the last 20 years, and all of the topaz stones they offered in Tucson this year were from the same pocket at a depth of about 35 meters in the central part of the Volyn deposit.
The beauty, size, and availability of the gem crystals from these pegmatites bodes well for the continued presence of this material in the marketplace. @chapter:0


Publication Year: 2019 Title: Possible Natural Abalone Shell Blister Abstract: Figure 1. This intriguing abalone sample, shown in three different orientations, weighed 3.00 ct and measured 10.73 × 8.82 × 6.23 mm. Photo by Diego Sanchez.
An intriguing item was sent by KC Bell to GIA’s Carlsbad laboratory for examination. Mr. Bell stated that it was found among a group of natural abalone pearls off the coast of Southern California in the Pacific Ocean. The sample (figure 1) weighed 3.00 ct, measured 10.73 × 8.82 × 6.23 mm, and was appealing because “pearl” layers appeared to have formed around a piece of rock. However, its natural or cultured origin and the mollusk species that produced it needed to be determined.
The sample consisted of two main components: an opaque dark body and a translucent cap formed of nacreous layers. The main body looked like a stone with a typical angular baroque shape expected of unfashioned natural material. The exposed areas exhibited a bumpy surface texture, and a strong fiber-optic light revealed a dark greenish bodycolor and some black areas of a different composition. Subsequently, Raman spectroscopic analysis with an 830 nm diode laser verified the dark greenish body was composed of a rock-forming feldspar mineral when the spectrum was matched with the RRUFF mineral database (RRUFF-R040129).
The thin layers partially covering the stone displayed vibrant blue, green, and purple-pink hues. At higher magnifications, a fine platelet structure was clearly visible, together with a characteristic underlying botryoidal-like structure that has been observed through the translucent surface layers of many abalone pearls (Fall 2015 Lab Notes, pp. 319–320). Raman analysis of the surface layers using a 514 nm argon-ion laser revealed peaks at 701, 705, and 1085 cm–1, proving the nacre was composed of aragonite. In pearl testing, the higher excitation power of this laser is generally used in the identification of calcium carbonate polymorphs as well as natural pigments or artificial coloring agents. The 830 nm laser is used to obtain spectra in some situations, such as when high fluorescence is encountered with the 514 nm laser.
Energy-dispersive X-ray fluorescence (EDXRF) analysis showed that the nacreous surface layers contained low levels of manganese and confirmed a saltwater origin. Moreover, 221 ppm of iodine was detected, typical of many abalone shells and pearls since abalone is an iodine-rich organism (H.S. Doh and H.J. Park, “Speciation of bio‐available iodine in abalone (Haliotis discus hannai) by high‐performance liquid chromatography hyphenated with inductively coupled plasma‐mass spectrometry using an in vitro method,” Journal of Food Science, Vol. 83, No. 6, 2018, pp. 1579–1587). GIA has often detected iodine in abalone samples examined (Fall 2015 Lab Notes, pp. 319–320). Surface observation and chemical data confirmed that the nacre layers were produced by a univalve abalone gastropod (Haliotis genus), allowing us to confidently identify the mollusk species. Furthermore, EDXRF analysis of the rock surface revealed that it was composed of sodium-rich feldspar.

Figure 2. The overlying nacre tightly conformed to the underlying rock’s surface, and a small opening was visible on the face, exposing the material beneath. A translucent brown layer between the two main components is possibly an organic substance, likely conchiolin. Photomicrograph by Artitaya Homkrajae; field of view 7.19 mm.
Closer examination of a small surface opening on the face of the sample (figure 2) and the edge of the nacre where it did not cover the underlying rock (figure 1, center and right) revealed a tight connection between the two main components. No gas bubbles or other features such as flow lines indicating an artificial bonding agent were observed in the translucent brown layer between them. The brown layer appeared to be an organic substance—likely conchiolin, an essential natural substance secreted by mollusks during the formation of pearls, blisters, and shells. The internal structure revealed by real-time X-ray microradiography (RTX) supported the observational findings that the thin nacreous overgrowth adhered to the rock’s surface in all directions and did not appear to have formed from any culturing process (figure 3).

Figure 3. RTX images of the sample’s face (left) and side (right) revealed that the thin nacre layer conformed very well to the underlying stone’s surface.
Abalone are known to produce natural pearls and are also used commercially to produce cultured shell blisters in order to fashion assembled cultured blister “pearls” (mabe). Shell blisters can form naturally when a foreign object accidentally enters the mollusk’s body and becomes trapped in between the shell’s interior surface and the mantle tissue. If the mollusk survives this experience, the cells within the mantle tissue continue to secrete nacre (commonly biogenic aragonite) to increase the layers and cover the intruder, possibly to ease any discomfort. The intruder eventually becomes a part of the inner shell, resulting in a natural shell blister. Based on this formation mechanism and the gemological evidence obtained, this sample appears to be an unusual natural shell blister in which a small piece of rock acted as the irritant that initiated formation. Since abalone mollusks inhabit rocky areas and attach themselves to rocky surfaces, this scenario is not out of the question. @chapter:14


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

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

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

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

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

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

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

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

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

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

“Where do we start?” Lucas asked.

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

Trial Runs in Chanthaburi and Vietnam

View Gallery

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

View Gallery @chapter:22


Publication Year: 1982 Title: The Jade Enigma Abstract: Jade is one of the most misunderstood gemstones. It is actually two separate materials: jadeite and nephrite. Together, these materials have more simulants than most other gems. Thus, it is important to know the various simulants, and to understand how to separate them from jade. This article examines the key identifying properties of green jade (jadeite and nephrite) and contrasts them with the properties of the 10 most common green jade simulants. Simple visual techniques are emphasized as well as the appropriate gemological tests. @chapter:37


Publication Year: - Title: Colored Gem Supply and Market Update Abstract: Dudley BlauwetDudley Blauwet Gems

Interview with Dudley Blauwet, Dudley Blauwet Gems
Dudley Blauwet, a colored gemstone dealer from Colorado, has been traveling throughout Asia and parts of Africa for three decades, hunting down good, saleable gem material. He has witnessed firsthand the dramatic constriction in availability as global market forces have made their impact. If Blauwet’s lengthy, wide-ranging exclusive interview with GIA at the 2013 Tucson Gem Show had to be reduced to one word, that word would be: China.

As the interview moves over the map from Thailand to Pakistan to Afghanistan to Sri Lanka to Kenya, it always comes back to China. As the interview touches on an array of gems from tourmaline to topaz to sapphire to spinel to morganite and zoisite, availability always comes back to China.  According to Blauwet, everywhere you go looking for gemstones you find the Chinese have either gotten there first or with more hard cash to corner the various markets.

Other factors do come in to play in creating scarcity in the world gem market for what Blauwet describes as “bread and butter” dealers like him who make their living off the stones rather than amass fortunes. Among them are energy costs to run the drilling equipment, tribal battles over digging sites, and reduction of source material to prohibitive depths and locations. @chapter:28


Publication Year: 2012 Title: Tsavorite and Other Grossulars from Itrafo, Madagascar Abstract: Since 2002, tsavorite and other grossular varieties have been recovered from a primary deposit at Itrafo, a village in the Andrembesoa area of central Madagascar. Twenty-two samples from this locality were investigated by classical gemological methods, chemical analysis, and UV-Vis-NIR and mid-IR spectroscopy. The garnets’ chemical composition was nearly pure grossular (92 mol. %), with iron and vanadium as the main chromophores. Their iron content and Fe2O3:V2O3 ratio were higher than those generally found in tsavorite from well-known deposits. Although the Itrafo deposit is relatively large, and new veins could be discovered, future production will be limited by access difficulties and security concerns. @chapter:5


Publication Year: 2017 Title: Chlorapatite in Quartz Abstract: Figure 1. This 57.56 ct rock crystal quartz hosts two large euhedral chlorapatite crystals. Photo by Kevin Schumacher.

We recently examined a 57.56 ct rock crystal quartz (figure 1) that came from Luciana Barbosa (Gemological Center, Asheville, North Carolina). Said to be from Bahia, Brazil, the transparent and colorless rectangular step-cut gem measured 31.91 × 19.01 × 11.83 mm and hosted two relatively large translucent euhedral crystals. When examine under magnification, these inclusions appeared to be hexagonal prisms, the larger one measuring approximately 7.0 mm in length. Rotation of the microscope’s analyzer clearly displayed the crystals’ dichroism, which changed from blue to pale yellow (figure 2). Laser Raman microspectrometry was used to identify the inclusions as chlorapatite. This is the first time that we have encountered chlorapatite as a inclusion in quartz.

Figure 2. The blue and pale yellow dichroic colors of a chlorapatite inclusion in quartz are clearly seen in these microscopic views. Photomicrographs by Nathan Renfro; field of view 14.16 mm. @chapter:13


Publication Year: 1986 Title: Winter 1986 G&G Lab Notes Abstract: Amethyst with Brazil Twinning Visible without Polarized Light
Synthetic Amethyst with Inclusions Typical of Hydrothermal Origin
Andalusite with Growth Bands
Faceted Clinohumite
Saint Valentine's Diamond
Imitation Emerald: Synthetic Spinel-and-Glass Triplets
Synthetic Emerald with a "Breadcrumb" Inclusion
Imitation Lapis Lazuli
Eroded Natural Pearls
Imitation Pearls
Cat's-Eye Petalite
Pyrite in Quartz

To view the full section, download the PDF above. @chapter:9


Publication Year: 1981 Title: Emeralds of Colombia Abstract: There has been more activity in emerald mining in Colombia in the last few years than at any other time in the four centuries since the Spanish first discovered the deposits. This article combines a comprehensive review of the literature on the history and geology of Colombian emeralds with the author's own insights into the current marketing and mining of these stones. Of particular concern are the harsh methods now being used to extract the emeralds and the impact these methods will have on future production in Colombia. The past, however, has yielded many fabulous gems, the most famous of which are also described here and placed in historical perspective. @chapter:1


Publication Year: 2016 Title: Charting the Increasing Availability and Quality of CVD Synthetic Diamonds Abstract: Welcome to the Fall 2016 Gems & Gemology! This issue brings together synthetic diamonds grown by the chemical vapor deposition (CVD) process, a reversible color modification of zircon, and a rich vein of locality articles including sapphires from Russia, a new Madagascar deposit of the rare gem grandidierite, Vietnamese peridot, and Indonesian cultured pearls.

	Our lead article, by Drs. Sally Eaton-Magaña and James Shigley, reviews the characteristics and key identifying features of CVD synthetic diamonds based on the study of several hundred faceted examples examined by GIA between 2003 and 2016. This comprehensive summary shows how the volume and quality of CVD diamonds changed from what the authors term the “pre-commercial” phase prior to 2008, to the range and color of material available in today’s jewelry marketplace.

		GIA researchers review several hundred CVD synthetics produced between 2003 and 2016.

	Our second paper, by Nathan Renfro, might be of great use to jewelers wishing to restore blue zircons that clients have inadvertently altered to unattractive brown. This “ugly duckling” transformation results from accidental exposure to long-wave ultraviolet radiation from tanning beds or other UV lights. The author explores the nature of this change using spectroscopy to confirm whether exposure to visible light might restore the zircons’ blue color.

	Next, a team of Russian researchers headed by Svetlana Yuryevna Buravleva describes a new deposit of translucent to semitransparent, blue to pinkish blue sapphire crystals and corundum-bearing rocks at Sutara, in the Jewish Autonomous Region of the Russian Far East. The authors postulate that this deposit formed by metasomatism of the contact zone between carbonate rocks and pegmatite veins.

	In our fourth article, lead author Dr. Delphine Bruyère reports on a new occurrence of the rare gem grandidierite in southern Madagascar and provides a gemological characterization of the material, which occurs as bluish green to greenish blue crystals measuring up to 15 centimeters in length. Their analysis confirms that this new locality provides some of the purest grandidierite yet found and will likely be of great interest to museums and collectors.

	In our penultimate paper, Dr. Nguyen Thi Minh Thuyet and colleagues review the gemological and geochemical characteristics of peridot from Vietnam’s Central Highlands, noting similarities with material that originates from xenoliths in alkaline basalts from other localities.

	In our final article, visit a pearl farm in the pristine waters off the Indonesian island of Lombok, where a team of researchers and industry professionals led by GIA’s Nicholas Sturman capture the recovery of bead-cultured and non-bead-cultured pearls from gold-lipped oysters.

	As always, our Lab Notes, Micro-World and Gem News International entries are filled with the latest updates from around the world.

	You can also meet the editors and take advantage of special offers on subscriptions and back issues at the G&G booth in the publicly accessible Galleria section (middle floor) of the Tucson Convention Center during the AGTA show, January 31–February 5, 2017. We would be delighted to see you.

	We hope you enjoy our Fall issue! @chapter:35