Title: Separation of Kornerupine and Prismatine Abstract: Figure 1. The two stones on the far left, corresponding to the blue analytical points in figure 2, were classified as kornerupine. The center 20 stones, corresponding to the yellow analytical points in figure 2, were classified as prismatine. For the eight stones on the right, corresponding to the red analytical points, the species could not be determined. The species classifications of all the stones were based on chemistry acquired by LA-ICP-MS. The largest stone is the 11.9 ct brown oval at the top of the center group. The smallest is the light blue cushion stone at the bottom of the center group, weighing 0.93 ct. Photo by Diego Sanchez.

Kornerupine and prismatine form a solid solution series with a general chemical formula of X(□,Mg,Fe)M(Al,Mg,Fe)9T(Si,Al,B)5(O,OH,F)22 (X: cubic site; M: octahedral sites; T: tetrahedral sites). Chemically, they differ mainly in magnesium, iron, aluminum, and fluorine content, with boron content that ranges from 0 to 1 apfu (atoms per formula unit) in one of the tetrahedral sites. When the boron apfu is less than 0.5, the mineral is classified as kornerupine; above 0.5, it is classified as prismatine (E.S. Grew et al., “Prismatine: revalidation for boron-rich compositions in the kornerupine group,” Mineralogical Magazine, Vol. 60, No. 400, 1996, pp. 483–491).
GIA laboratories have recently implemented a method using laser ablation–inductively coupled plasma–mass spectrometry (LA-ICP-MS) to quantify boron concentration in kornerupine and prismatine in order to distinguish the two. The 30 stones shown in figure 1—all thought to be kornerupine—were borrowed from the GIA Museum and tested using a Thermo Fisher iCAP Qc ICP-MS, coupled with an Elemental Scientific Lasers NWR213 laser ablation system. GSD-1G and GSE-1G (U.S. Geological Survey) and NIST 610 were used as external standards. 29Si was used as an internal standard. Three 55 μm circular spots were ablated on the girdle of each stone. The data reduction was a modified version of that used at GIA for tourmaline (Z. Sun et al., “A new method for determining gem tourmaline species by LA-ICP-MS,” Spring 2019 G&G, pp. 2–17). As a result, we have slightly modified the criteria for separating the two to account for analytical error. If the boron apfu is between 0 and 0.45, the stone is classified as kornerupine. Between 0.45 and 0.55 apfu, the species cannot be determined by this method. If the boron apfu is between 0.55 and 1, the stone is classified as prismatine. For three spot analyses, if one spot has a boron apfu between 0.45 and 0.55, the species is undetermined.

Figure 2. The Al-B plot shows three sections. When the B (apfu) is between 0 and 0.45, stones are classified as kornerupine (blue spots). When the B (apfu) is between 0.45 and 0.55, the species for the stones (red spots) cannot be determined. When the B (apfu) is between 0.55 and 1.00, stones (yellow spots) are classified as prismatine. For three spot analyses, if one spot has a B (apfu) between 0.45 and 0.55, the species is considered undetermined.
All analytical points were plotted in figure 2 (full chemical results are in appendix 1). There were 2 kornerupine, 20 prismatine, and 8 undetermined species, for a total of 30 tested stones. This result suggests that, contrary to popular belief, prismatine may be a far more common gem species than kornerupine, which is also supported by the analyzed boron concentration of many production stones submitted to GIA laboratories. Interestingly, for the five green stones tested here the species could not be determined, although they slightly favor prismatine chemistry (some of the red spots in figure 2). Aluminum apfu is also a good indicator for separating kornerupine from prismatine. Boron-rich prismatine has an Al apfu around 5.8 to 6.0, compared to boron-poor kornerupine with an Al apfu around 6.6 to 6.8. Extra Al in kornerupine functions as a substitute for B in one of the tetrahedral sites in the crystal lattice.
Kornerupine is an appropriate group name for kornerupine-structure minerals of an unknown boron content or for cases where the species cannot be determined. For extreme cases, such as when boron apfu is close to 0 or 1, Raman spectroscopy could be sufficient to separate kornerupine from prismatine (B. Wopenka et al., “Raman spectroscopic identification of B-free and B-rich kornerupine (prismatine),” American Mineralogist, Vol. 84, No. 4, 1999, pp. 550–554). However, the more accurate separation for the two is determined by LA-ICP-MS analysis because the species definition is based on concentration of a chemical element, boron. Source: GIA @topic:2


Title: Natural Rubies with Glass-Filled Cavities Abstract: During recent months, natural rubies with surface cavities filled with glass-like substances that may influence both the appearance and weight of the faceted stone were examined by gemological laboratories in Thailand and England and by GIA's Gem Trade Laboratories in both New York and Los Angeles. This article reports on the examination and analysis of 15 natural rubies with notable glass-filled cavities and simple methods for identifying the presence of such filled areas. In most cases the cavities were readily detected by their distinctive luster and other visual characteristics. X-ray diffraction and chemical analysis indicated that the filler was indeed a glass; it was probably added in conjunction with heat treatment. Source: GIA @topic:3


Title: Nathan Renfro Wins Royal Microscopical Society Award Abstract: A six-rayed star of golden rutile needles radiates from a black ilmenite core beautifully preserved in smoky quartz. Photomicrograph by Nathan Renfro; field of view 18 mm. Stone courtesy of the John Koivula Inclusion Collection.
GIA Carlsbad manager of colored stones identification and G&G regular contributor Nathan Renfro took second place in the Light Microscopy–Physical Sciences division of the Royal Microscopical Society’s biennial Scientific Imaging Competition. The award-winning image (see above) shows a rutile star in smoky quartz. Source: GIA @topic:1


Title: CVD Landscape Abstract: Figure 1. GIA-grown rough CVD diamond weighing 5.8 ct, photographed under daylight conditions. Photo by Towfiq Ahmed.
Fluorescence is an integral part of diamond analysis that displays varying growth defects. Each color provides visual clues to the growth chemistries and defects formed. Gemologists use this data along with other spectroscopic features to determine a diamond’s origin and treatment history. The fluorescence features in this experimental CVD block grown by GIA (figure 1) are reminiscent of a landscape with trees reflecting into a lake during a sunset (figure 2, illuminated using a DiamondView equipped with a UV light).

Figure 2. DiamondView fluorescence image of a 5.8 ct GIA-grown CVD block measuring 7 × 7 × 7 mm. Photomicrograph by Stephanie Persaud.
CVD diamond technologies have improved vastly over the last decade. Researchers at GIA grew this CVD block over several growth runs to gain a better understanding of CVD diamonds. This block captures the essence of nature within a laboratory setting. Source: GIA @topic:4


Title: Shipley Shaped GIA Mission on Personal Experience, Commitment to Improvement Abstract: Imagine yourself in his shoes:  You are a successful businessman with the intrinsic charm and charisma of a great salesman. You have created a group of highly successful and well-regarded jewelry stores and are convinced you know all there is to know about gems – until two of your best customers challenge you and reveal your lack of expertise.

Standing in his shoes, how would you feel?

Probably just as Robert M. Shipley did: humbled. And even though his lack of expertise was typical for U.S. jewelers in the mid-1920s, those soul-searching encounters ultimately spurred him into changing the gem and jewelry industry.

First though, Shipley lost the jewelry stores in divorce and headed to Europe to recuperate from years of relentless pursuit of success. While he was there, he completed the Great Britain National Association of Goldsmiths gemological correspondence course, the foundation for his personal reinvention from jeweler to teacher and gemology expert.

Shipley returned to the U.S. in 1929 and launched his “preliminary course in gemology” in Los Angeles on Sept. 16, 1930. In the years that followed, he covered thousands of miles in secondhand cars, aggressively promoting – with the single-mindedness of a zealot – the professionalization of the jewelry industry through gemological education.

His goal was to restore the public’s trust in the jewelry trade by training “certified” jewelers who would eventually be united in a national guild.

“Like the physician, the architect and the engineer, the gemologist must complete prescribed studies and examinations in order [to be] of exceptional service to the public [in] the new profession of Gemology,” Shipley said.

His concept was the seed for GIA and would transform the gem and jewelry industry in the U.S. and, ultimately, around the world.

Shipley’s quest for expertise, his commitment to improving his knowledge and skills, and his belief that jewelry customers should know what they are buying are the central principles of GIA’s mission. Today, we apply these same principles in our daily work and in our planning for GIA’s future. Source: GIA @topic:9


Title: Year-end Chapter News and Best Wishes for 2014 Abstract: Malaysia chapter president Yihchen Ng, right, presents a gift of a Batik (wax hand painting) to a visiting Taiwanese alum and his wife. Courtesy of the Malaysia GIA Alumni chapter.

The end of 2013 is fast approaching, so I want to take this opportunity to send my good wishes for a wonderful holiday season and a joyful, healthy and prosperous new year.

I also want to remind you that one of the ways you can become more successful is to take advantage of the multitude of GIA Alumni Association chapter events available. The opportunity to network at these events ‒ whether in your home city or when you travel ‒ provides limitless possibilities for you to stay relevant with issues and to make new connections in the industry. You can visit the GIA website and the alumni Facebook page to learn what events are scheduled.

Take a quick look at the more than 40 events, listed by topic area, that were hosted by GIA Alumni Association chapters since October. There are lots of great ideas here you can use to develop your own chapter meetings or events:

Jewelry history, auctions and estates: The London chapter hosted John Benjamin, noted for his knowledge of jewelry antiquities and his BBC television appearances on the U.K.’s “Antique Roadshow.” Benjamin also shared his knowledge of fine jewelry auctions at an Ontario, Canada event. The Manhattan chapter featured Judaica jewelry history and South Florida hosted Gloria Lieberman, who spoke about antiques and estate jewelry.

Museum exhibit visits and gem/jewelry collections: California’s San Diego, Los Angeles and Orange County chapters visited the Van Cleef and Arpels exhibit at the Bowers Museum in Santa Ana and the “More is More” exhibit of Tony Duquette and Hutton Wilkinson jewelry at GIA’s Carlsbad campus. The Golden Gate chapter visited the Bulgari exhibit at the de Young Museum, and the London chapter took in the historical Cheapside Horde exhibit, recently featured in G&G, at the Museum of London. Gem collections were the feature at a Metro-Phoenix chapter meeting with a special viewing of the Rainbow Collection of gemstones and jewelry. The Washington, D.C. chapter hosted Dr. Jeffrey Post, curator of the Smithsonian Institution’s National Gem Collection for “What’s New at the Smithsonian.”

Colored gemstones, diamonds and industry news: Colored gemstone expert and author Renee Newmann spoke to the Washington, D.C. chapter. The Manhattan chapter hosted Fire Polish Diamond spokesperson Glenn Markham and Diane Warga-Arias, who shared the top 10 newsflashes from 2013, including issues in jewelry design, fashion, branding, gemology, e-commerce, manufacturing, retail and tradeshow trends.

GIA subject matter expert chapter events: Robert Weldon spoke about the characteristics of East African gems, market trends, gem sustainability and ways to promote East African gemstones in at Taita Taveta University College in Voi, Kenya. Shane McClure shared an inside view into GIA’s laboratory, including new developments in gemstone treatments and the latest in research news at the Twin Cities, Illinois/Indiana and Greater Chicago chapters. Dr. James Shigley provided insight into synthetic diamonds grown using the HPHT (High Pressure / High Temperature) and CVD processes, as well as techniques used to separate and identify synthetic from natural diamonds for the London chapter. The Colorado Mile High chapter had the opportunity to spend time with GIA researchers and gemological research and education pioneers during the Geological Society of America’s (GSA) 125th annual conference recently hosted in Denver. More than 50 attended a dinner hosted by the chapter.

Gem exploration lectures, plus field trips and activities: Jeffrey Bergman shared his adventures in Tanzania with the Golden Gate chapter. Houston hosted Dr. Marcus Origlieri, who spoke on gems and minerals of Burma and Gary Bowersox entertained North Carolina’s group with tales of his life as a gem hunter. The St. Louis and Golden Gate chapters hosted hands-on interactive sessions and three southern California chapters went on a mine adventure.

Monthly gatherings have included Mumbai’s “Last Friday” events, Ontario’s Pub Night and Malaysia’s Council and group gathering. And year-end and holiday celebrations were hosted by Seattle, Houston, Mid-Tennessee, Vancouver and North Carolina.

Quick notes from GIA

Participants in the 2013 Continuing Education Program have about three weeks to complete the eight required assignments. Access remains open until Dec. 31, so if you haven’t done so, there’s still time to finish, even in this busy season!

I want to offer my special gratitude to our alumni volunteer leaders in every chapter across the globe who commit their time to organize, arrange and bring all of you together at chapter-hosted activities. I hope each of you took the time to nominate individuals for the GIA Alumni Association Leadership and Achievement Awards, which recognize members for all they do. Recipients of the chapter awards will be announced soon and the two individuals who receive the International Alumni Awards will be recognized at GIA’s Party at the Gem Mine in Tucson, Arizona on Feb. 7, 2014.

To start a chapter or to get more involved with your local group, contact us.

Marcus J. Origlieri, Ph.D., center, speaks with attendees at a Houston GIA Alumni chapter event on Nov. 3, 2013. Courtesy of the Houston GIA Alumni chapter.

Kate Donovan, third from left, with Colorado Mile High chapter members, including some from the board, at a GSA conference dinner. Courtesy of the Colorado Mile High GIA Alumni chapter. Source: GIA @topic:9


Title: The “Montana Queen” Sapphire Abstract: Figure 1. The 31.98 ct (6.40 g) rough sapphire crystal as it was mined. Photo by Jeffrey R. Hapeman.

In September 2016, while viewing a selection of large Montana sapphires mined by Potentate Mining at their new operation at Rock Creek, one stone stood out. It possessed a beautiful medium blue-green color and a hexagonal crystal form with a blue rim and golden center (figure 1). It weighed 31.98 ct (6.40 g) and appeared to be free of major internal defects. Sapphires this large make up less than 0.25% of Rock Creek’s production, and they are typically fractured or otherwise included.

Most Rock Creek sapphires have frosted or etched surfaces, apparently as a result of partial resorption in the host rock. To assess the quality of this sapphire before cutting, a window was polished, allowing a view of the interior of the crystal; this removed just over one carat, as a surface crack was also ground away. The window revealed that the center gold spot was composed of golden rutile needles that could be cleared by heating. A mostly rehealed parting plane and a few crystal inclusions were also visible. We decided to heat the stone to dissolve the silk, hoping that the parting plane and internal inclusions would not fracture during the process. The heating, performed by Dale Siegford (The Sapphire Gallery, Philipsburg, Montana), dissolved all the silk and changed the rough’s color to a deeper, more uniform blue (figure 2). Most importantly, none of the inclusions spread or formed larger fractures.

Figure 2. The rough sapphire after heating, with a window polished to view the interior. Photo by Jeffrey R. Hapeman.
While size is always a cutting consideration, color is also a determining factor in the value of the finished gemstone. The pleochroism of sapphire crystals means that orientation is critical for the best presentation of color. This sapphire had a rich blue c-axis just slightly tinted with green, while the a-b axis was a medium shade of green. Fortunately, the crystal was shaped such that the best orientation for both color and size were the same—the table could be positioned directly on the c-axis. Our goal was to feature the stone’s natural hexagonal shape, increasing yield and preserving the crystal’s beauty. GemCad and GemRay were used to work through a series of designs, optimizing them for a combination of light return and scintillation. The intent was to use facets large enough to create broad flashes of color while concealing the minor inclusions. With a gem this rare there is no room for error, so the final design was test-cut on a smaller Rock Creek sapphire to validate the modeling.

Once we were satisfied with the result on the test stone, the cutting of the large gem began on the pavilion. Because the natural shape of the gem matched the final outline, only minor preforming was required; the rough gem weighed 30.84 ct when attached to the dop. There was a crack near one side of the gem, so it was dopped slightly off-center to ensure it would be removed in the cutting process. The gem was faceted in three steps: The facets were cut with a 600-grit sintered lap, followed by a pre-polish with 8,000-mesh diamond and an ultrafine polish using 100,000-mesh polycrystalline synthetic diamond. After completing the pavilion, the gem was transferred to a new dop and the process was repeated to cut the crown (figure 3).

Figure 3. The sapphire during the cutting process. The polished pavilion is shown on the left and the rough-cut crown on the right. Photos by Jeffrey R. Hapeman.
The finished gem weighed 12.62 ct, for a yield of 39.5% from the original rough (figure 4). The authors are aware of only two larger faceted Montana sapphires, one with similar quality. Neither of those stones is blue—one is purple and the other green—making this perhaps the largest faceted blue Montana sapphire, slightly larger than the famed 12.58 ct Big Sky sapphire. Due to its size, rarity, and beauty, this gem was named the “Montana Queen.”

Figure 4. The finished 12.62 ct Montana Queen sapphire. Photo by Jeffrey R. Hapeman. Source: GIA @topic:1


Title: Emerald Update with Arthur Groom Abstract: Figure 1. Melee goods from Eternity Natural Emerald. Photo by Kevin Schumacher.

At the 2019 AGTA GemFair in Tucson, Eternity Natural Emerald (Ridgewood, New Jersey) had emeralds up to 50 ct on display. Eternity’s president, Arthur Groom, noted that the Afghanistan emerald melee sets (figure 1) had drawn the most interest. This rough melee is particularly attractive, he said, because of its higher brilliance than stones from other sources. “The Afghanistan melee is the brightest in its natural state when it’s cut properly,” he said. “Afghanistan emerald will rival Colombian any day of the week.”
Eternity has experimented with melee from different sources but finds Afghanistan melee the most plentiful and consistent. The company currently cuts Afghanistan emeralds in sizes from 1 mm to 70 ct, disproving the perception in the trade that the country produces only small emeralds. Groom pointed out that vibrant greens are not as easy to find in gems as other colors, and tsavorite is often used for green, but Eternity’s emeralds offer the option to use one of the “Big Three” gemstones. Eternity also sources emerald rough from Ethiopia, Colombia, Brazil, and Zambia.

	Emerald update with Arthur Groom

Cutting and mounting emerald melee has traditionally been challenging because of emerald’s tendency for inclusions and fractures, and its typical enhancements. Most jewelry manufacturers do not like working with it, Groom said. Eternity has solved this problem after many years of effort, he said, producing “a finely made emerald that you can work with confidence and will never change.” Eternity’s enhancement process allows the stones to be cleaned in ultrasonic and steam cleaners with no adverse effects (traditional enhancement substances tend to alter over time).

Figure 2. A set of 15 of Eternity Natural Emerald’s calibrated emeralds ranging from 1 to 5 mm. Photo by Albert Salvato.

Figure 3. A set of calibrated emeralds (approximately 2 to 4 mm each) by Eternity Natural Emerald. Photo by Kevin Schumacher.
Eternity has cut thousands of carats of rough and developed master sets of colors and clarities. They are able to fulfill orders for thousands of stones at a time. The emeralds are cut to exact proportions; the average weight retention is about 15 percent. “You can’t be concerned with how much weight you’ll lose,” Groom said. In the past, manufacturers would buy a parcel of stones of different sizes, dimensions, and colors and find some stones unusable, but they can now buy stones of the same color, clarity, and size. Along with melee, the company offers cabochons and calibrated (figures 2 and 3) and faceted stones, in qualities from commercial-grade to very fine and at all price points. Groom showed us a set of calibrated emeralds (figure 3) ideal for a premium bracelet.
One of Eternity’s aims is to promote Afghanistan emerald and country of origin. “The miner has to benefit from this,” Groom said, “and this is one of our goals in Afghanistan.” In our 2013 interview with Groom, he said Afghanistan’s emerald resources are such that if the country were to see peace, acquire investors, and mechanize its mining operations, it would “outproduce the world.”
Groom believes in promoting country of origin not because it adds value but because it adds identity to the stone. “We all know about Colombian emerald,” he said. “But just because the emerald comes from Colombia doesn’t make it more valuable. We just manufactured a 24 ct Tajik stone that sold for close to half a million dollars. You have to take the stone on its merit.” Source: GIA @topic:1


Title: Winter 1994 G&G Book Reviews Abstract: “Humboldt's Travels in Siberia (1837-1842): The Gemstones”
By Gustav Rose, Transl. by John Sinkankas, ed. by George M. Sinkankas, 80 pp., illus.,
Geoscience Press, Phoenix, AZ, 1994. US$25.00

“Copper Art Jewelry‑A Different Lustre”
By Matthew L. Burrkholz and Linda Lichtenberg Kaplan, 160 pp., illus., Schiffer Publishing, 1992. US$49.95

“Jewelry & Gems: The Buying Guide, 3rd Ed.”
By Antoinette L. Matlins and A. C. Bonanno, 262 pp., illus., Gemstone Press, Woodstock, VT,
1993. US$23.95 hard cover, $16.95 soft cover

To view the full section, download the PDF above. Source: GIA @topic:10


Title: Multi-Generation Cutting Family from Idar-Oberstein Abstract: Figure 1. Aquamarine has long been Arnoldi International’s signature stone. Photo by Kevin Schumacher.
Idar-Oberstein, Germany is a historic agate locality that became famous over the last century as a colored stone trading and cutting center. In recent decades, though, much of the lapidary activity has moved from Idar-Oberstein to cutting centers in Asia such as Jaipur and Bangkok. The remaining businesses in Idar are focusing on highly specialized market segments, such as precision cutting and unusual stone varieties. Alexander Arnoldi explained to us the strategy of Arnoldi International and provided an update on some new high-quality materials.

The cutting business was founded in 1919, making Alexander Arnoldi a fourth-generation gemstone dealer and cutter. They process all the goods in-house, from rough sorting to final polishing. Lapidary work is still based on the traditional techniques of Idar-Oberstein, where the wheel is turned with the dominant right hand, leaving the left hand free to hold the stone. Laps are motor-driven today, but the stone is still held with the left hand. According to Arnoldi, it takes more than five years to master cutting and learn all the facet placements and correct angles for the different styles and materials.

Arnoldi International’s Gem Cutting
Fourth-generation gem cutter Alexander Arnoldi discusses his family’s business, based in Idar-Oberstein, Germany.
The company focuses on flawless stones, a challenging segment of the gemstone industry. Prices for these goods have exploded, but supply is extremely low and competition at the source is very high. Finding extremely high-quality rough that yields large clean stones is one of the main challenges they face in the current market. Nowadays, most rough suppliers bring their goods to Bangkok and Jaipur instead of Germany. This forces companies such as Arnoldi to go source their own material on site—for instance, copper-bearing tourmaline from Mozambique.

Idar-Oberstein’s first main product more than 500 years ago was agate, polished using hard sandstones found nearby. When Germany’s population began moving abroad in the early nineteenth century, Idar’s network became more global and gained access to the Brazilian deposits, which produced many quartz varieties. The German cutters became very adept at cutting and polishing the materials sourced in Brazil. Arnoldi focused on aquamarine (figure 1), a stone that remains their strong suit in 2018. Originally they worked with goods from South America, including the fabled Santa Maria deposit in Minas Gerais, Brazil. Much of the rough is now sourced in Central and East Africa, which produces deep blue material similar to Santa Maria aquamarine.

Figure 2. More recently, Arnoldi International has begun working with tourmaline from the Democratic Republic of Congo. Photo by Kevin Schumacher.
Another stone they are focusing on is tourmaline, including Paraíba, rubellite, and bicolor stones. In December 2017, they traveled to Central Africa to source the new tourmalines from the Democratic Republic of Congo (figure 2). This material comes in different shades of green, often in the same crystal. Pink crystals are occasionally found. Supply is highly irregular, and quality varies greatly.

Arnoldi International is putting their focus on high-quality, flawless goods and excellent cutting standards. This allows them to supply high-end vendors who often ask for unique, customized cutting styles. Source: GIA @topic:7


Title: Bench Tip #5: Repair a Fine Chain with a Soldering Technique Abstract: Repairing a fine chain

Chain repair is a set of fundamental skills and techniques every goldsmith needs to master, but the structure and design of the chain dictate what you need to do for a successful repair.

This bench trick focuses on fine cable and rope chains with tiny links made from extremely thin wire. It is difficult to manipulate these links, reconnect them and then solder them. Study the chain to determine how each link connects to the next and remove all damaged links, leaving only the sound links that will be joined back together.

Use a permanent marker to color some of the links near the joint so you can find the links that need to be soldered. Cut open one or more links, depending on the style of chain, and open them slightly to connect to the other section of chain. Make sure you fit the cut ends of the link together as tightly as possible to ensure a good solder joint.

The next and most important step is to solder the open links together so they are joined in an inconspicuous way. The chain should look as if it had never been damaged. So easy to say and so hard to do!

You will likely have problems if you apply flux and solder to the open link, then heat it directly with the torch:
• The solder might not flow to both sides of the joint
• A lump of excess solder will adhere to the link because it is impossible to cut solder into small enough pieces for fine gauge links
• Heating the links directly may fuse several links together, which means you must start  over on a now shorter chain
This “Sneaky Goldsmith Trick” makes it possible for you to avoid all the pitfalls and do a clean job every time.

The secret weapon is the trusty soldering pick. Normally, goldsmiths use a pick to hold a piece of solder in place or position it on the work. In this case, you will use the tip of the soldering pick to expose the clean metal and apply the flux.

Pick up a piece of easy solder about 1.0 mm square with the pick and heat it directly with the torch until it flows and covers the tip of the pick with a thin layer of solder. Be sure to choose a steel pick, because solder won’t adhere properly to titanium or tungsten.

	Use a solder pick to transfer heat and a small amount of solder to a small chain link.
Bring the solder-coated pick into contact with the open joint of the link. Instead of pointing the torch directly at the chain, heat the pick about 8 to 10 mm from the tip. The pick will act as a thermal conductor to carry the right amount of heat to the joint to be soldered. When the solder flows again, a small amount of solder will transfer to the joint. Lift the pick quickly. Allow the chain to cool, pickle and clean up as needed.

This trick simplifies the soldering process and enables the goldsmith to do better work, faster and with fewer mistakes. Source: GIA @topic:10


Title: Lead Glass–Filled Laboratory-Grown Ruby Abstract: Figure 1. This 3.53 ct laboratory-grown ruby was treated with lead-glass filling. Photo by Diego Sanchez.

The GIA lab in Carlsbad received for identification a lead glass–filled laboratory-grown ruby (figure 1). We commonly see glass-filled natural rubies, but to our knowledge only one other laboratory-grown example has ever been submitted.
This transparent to semi-transparent oval mixed cut weighed 3.53 ct and showed gemological properties of ruby: a refractive index of 1.761–1.769, a birefringence of 0.008, a specific gravity of 4.01, a uniaxial optic figure, and a characteristic ruby spectrum using a handheld spectroscope.
Examination of the stone under magnification showed a network of interconnected fractures. A pronounced blue and orange flash effect was observed throughout, proving the fractures were filled with lead glass. Also present in the fractures were dendritic patterns and coarse flattened gas bubbles (figure 2).

Figure 2. Magnification of the internal structure of the synthetic ruby; both high-relief trapped gas bubbles and blue and orange flash effects were observed in the stone. Photomicrograph by Diego Sanchez; field of view 7.19 mm.
No inclusions were observed to indicate the natural or synthetic origin of the corundum. However, this stone exhibited strong red fluorescence to long-wave ultraviolet and medium chalky (bluish white) red short-wave ultraviolet fluorescence. Chalky SWUV is typical of heated ruby and sapphire. But when viewed in synthetic pink sapphire and synthetic ruby, it generally makes it more difficult to observe diagnostic curved striae in the stone. In our sample it was much harder, since that effect was combined with interference from filled fractures.
In these cases, a stronger SWUV light source may prove helpful. The curved growth lines were seen as chalky luminescent bands in the DiamondView, proof of its laboratory-grown origin (figure 3).

Figure 3. Curved growth striations were observed in the stone using the DiamondView, conclusively proving the synthetic origin of this ruby. Image by Forozan Zandi.
Lead-glass filling of corundum is based on the same principle applied to emerald and diamond: the use of a filling material with an RI very close to that of the host material, to minimize the appearance of fractures. The treatment is very effective, and the clarity of very low-quality material can be improved, rendering it usable in jewelry. This makes it possible to market a great deal of previously unsalable material. Fortunately, this treatment is easily detected with magnification. The identifying characteristics are very low-relief fractures, flattened and rounded gas bubbles and voids (unfilled areas) in fractures, and a blue and orange flash effect (S.F. McClure et al., “Identification and durability of lead glass–filled rubies,” Spring 2006 G&G, pp. 22–33). This stone displayed an orange and blue flash effect (again, see figure 2) as well as gas bubbles trapped in fractures that were conclusive evidence for lead-glass filling of the fractures in this synthetic ruby. While it is unclear why anyone would go to the trouble to treat a synthetic ruby with lead-glass filling, gemologists should be aware that such material does exist in the trade. Source: GIA @topic:3


Title: Exceptional Gemstone Acquisitions by the Kreis Family Abstract: Figure 1. A 155 g aquamarine crystal containing a liquid and gas bubble inclusion. The crystal measures 11.9 cm long and the inclusion 4.3 cm long. Photo by Robert Weldon; courtesy of Kreis Jewellery GmbH.
Kreis Jewellery (Niederwörresbach, Germany) is known for master cutting expertise and distinctive jewelry design (see Spring 2022 GNI, pp. 86–87). At the GJX show, Stefan and Alexander Kreis showed us three recent gemstone acquisitions.

	Two-Phase Inclusion in Aquamarine Crystal

First was a 155 g aquamarine crystal containing a two-phase liquid and gas inclusion measuring 4.3 cm long (figure 1; see video). The crystal was found in the 1960s in Marambaia, Minas Gerais, Brazil, and had been part of a private collection before the Kreises obtained it in 2022.
“It would even be a cuttable crystal,” Alexander said. “Of course we would never touch it because of the specialty of the huge liquid inclusion. A liquid chamber that size in quartz would already be amazing,” he continued. “But having it in an aquamarine, which is totally intact—you have the complete termination. And look at the sheer size of that crystal.”
Marambaia was known for large quantities of aquamarine by 1900 and produced the 110.5 kg (244 lb), 552,500 ct Papamel, discovered in 1910, the largest known gem-quality aquamarine crystal. The crystal that was the basis for the Dom Pedro, the largest cut aquamarine, weighed around 45 kg (100 lb) and was also from Marambaia.

Figure 2. A 35.05 ct Sri Lankan cat’s-eye alexandrite in daylight (left) and incandescent light (right). Photo by Robert Weldon; courtesy of Kreis Jewellery GmbH.
Stefan said they had received a 35.05 ct cat’s-eye alexandrite (figure 2) that morning. He noted the size, exceptionally sharp eye, and superb color change for Sri Lankan alexandrite, which typically has a weaker color change than material from Russia and Brazil. Alexander pointed out that cat’s-eyes are less common in alexandrite than in other chrysoberyl. “A cat’s-eye alexandrite with a strong color change like this one is extraordinary,” he said. “A size of 35 carats is what makes it outstanding.”

Figure 3. A 7.08 ct padparadscha sapphire. Photo by Robert Weldon; courtesy of Kreis Jewellery GmbH.
The Kreises also showed us a 7.08 ct padparadscha sapphire (figure 3). “The color mixture of this stone is a real padparadscha color,” Stefan said. Alexander added that a range of colors fall into the padparadscha category, but “this is the perfect color.”
The cat’s-eye alexandrite and padparadscha sapphire will undoubtedly inspire exquisite jewelry designs from Sonja and Vanessa Kreis. Sonja noted, “It is a very intuitive process in which we try to bring out a gem’s natural beauty in such a way that it blurs the boundaries between jewelry and art.” Source: GIA @topic:1


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


Title: Color-Zoned Cat’s-Eye Chrysoberyl Abstract: Figure 1. A color-zoned cabochon measuring 16.33 × 16.07 × 10.27 mm set in a ring. Left: Distinct zoning with cloud-like inclusions is visible as a white band in the middle. Right: The stone displays chatoyancy when illuminated with fiber-optic light. Photos by Shunsuke Nagai.
Chatoyancy occurs when light is reflected from certain oriented inclusions in a cabochon-cut gemstone. To be chatoyant, a group of fibers or needles or other reflective inclusions must be oriented parallel to the cabochon base. Usually these fibers and/or needles are dense and included throughout the stone, but occasionally there are cases with localized distribution of such inclusions.
GIA’s Tokyo laboratory examined a brownish green cabochon set in a ring with numerous near-colorless round and marquise brilliant cut accent stones. The center stone showed pleochroism and a spot RI reading of 1.75. The spectrum observed with a handheld spectroscope clearly showed the 444 nm band, consistent with green/yellow cat’s-eye chrysoberyl. Natural inclusions were observed under the microscope, as described later. For confirmation, an FTIR spectrum was collected; it showed peaks at 2163, 2403, and 4150 cm–1 that are characteristic of natural chrysoberyl (C.M. Stockton and R.E. Kane, “The distinction of natural from synthetic alexandrite by infrared spectroscopy,” Spring 1988 G&G, pp. 44–46).

Figure 2. Dense clouds containing minute fibrous inclusions create the cat’s-eye phenomenon. Larger blurry needles are visible within the cloud inclusions in the white portion. Photomicrograph by Yusuke Katsurada; field of view 3.0 mm.
In this stone, we can see obvious color zoning with a fixed whitish band in the middle between transparent brownish green portions (figure 1, left). This white part is semi-transparent/translucent due to dense clouds with minute fibrous inclusions (figure 2)—these features typically cause chatoyancy in cat’s-eye chrysoberyl. The cloud inclusions were not only on the cabochon surface but also located below the surface. As shown in figure 1 (right), this stone displayed distinct chatoyancy in the white zone. Even when viewed from an off-center direction, reflected light striking the clouds below the surface created the weak chatoyancy in the brownish green portions, which had no clouds or fibrous inclusions.
For the purpose of showing phenomena, stones with such localized inclusions can sometimes be oriented to place the inclusions at the base of the cabochon (Winter 2017 Lab Notes, pp. 459–460). Uneven distribution of included zones requires careful observation of the inclusion to likewise produce a good chatoyancy effect. This type of localized inclusion can sometimes lead cutters to be creative to maximize the appearance of the stone and the phenomenon. Source: GIA @topic:3


Title: Color-Change Synthetic Cubic Zirconia as Peridot Imitation Abstract: This synthetic cubic zirconia imitation of peridot, with an estimated weight of 4.50 ct, is shown in daylight (left) and incandescent light (right). Photos by Igor Iemelianov; field of view 13.20 mm.

	Peridot is a common gemstone in the jewelry industry; however, it is rarely simulated using substances other than glass (Summer 2004 Lab Notes, p. 165). The State Gemological Centre of Ukraine recently received for identification an oval-cut gemstone, with an estimated weight of 4.50 ct, set in a ring. The stone was greenish yellow in daylight, as seen in the image on the left, and orangy yellow in incandescent light (right). The client who submitted the ring specifically wished to know if the center stone was peridot. The sample was transparent and isotropic, with a refractive index of 2.150 (measured by a refractive index meter) and was inert to both short-wave and long-wave UV radiation. Microscopic examination revealed no inclusions. The measured relative reflectivity (RR 65–67), obtained using a Presidium DuoTester, clearly matched that of cubic zirconia, a result in line with the other gemological observations. This allowed us to identify the stone as cubic zirconia. Chemical analysis with energy dispersive X-ray fluorescence (EDXRF) showed Zr and Y, with minor Pr and Nd. These impurities can cause color change in this stone. Using fiber-optic light with the spectroscope, we observed a complex set of absorption lines in both the orange and green-blue regions (the same measurement can be seen at http://www.gemlab.co.uk/peridot.html). This study shows the importance of studying a variety of simulants, even those for less-expensive gems such as peridot. Source: GIA @topic:3


Title: Glass Imitation of Cat’s-Eye Chrysoberyl Abstract: Figure 1. A ring mounted with an estimated 5.56 ct brownish yellow cat’s-eye cabochon resembling chrysoberyl. Photo by Johnny (Chak Wan) Leung.
The Hong Kong laboratory recently examined a ring mounted with an estimated 5.56 ct brownish yellow cat’s-eye cabochon (figure 1). The client submitted the stone as cat’s-eye chrysoberyl, which it resembled at first glance. Standard gemological testing yielded a spot refractive index of 1.57, well below chrysoberyl’s range of 1.74–1.75. Under short-wave UV radiation, the stone displayed strong chalky fluorescence. Microscopic observation revealed long parallel tubes creating a cat’s-eye when viewed from the top and a honeycomb structure when viewed from the side of the stone (figure 2). This confirmed the material was fiber-optic glass, made by fusing together very thinly spun glass fibers. Infrared spectroscopy showed two broad absorptions centered at 3500 and 2670 cm–1 associated with artificial glass, further validating our identification.

Figure 2. The cabochon displayed the honeycomb structure frequently observed in fiber-optic glass. Photomicrograph by Tsz Ying Fong; field of view 2.00 mm.
Artificial glass has been used as an imitation for different gems such as star sapphire (Fall 2021 Lab Notes, pp. 261–262), Paraíba tourmaline (Winter 2020 Lab Notes, pp. 518–520), nephrite and jadeite (Spring 2019 Lab Notes, pp. 93–94), and blue amber (Fall 2019 Gem News International, pp. 443–444). Its color and appearance can often lead to misidentification. Therefore, conducting basic gemological tests and observing the stone under a microscope is important, especially when the stone is set in jewelry. Source: GIA @topic:3


Title: Books: Ruby & Sapphire: A Collector’s Guide Abstract: By Richard W. Hughes, 384 pp., hardcover, illus., publ. by the Gem and Jewelry Institute of Thailand, 2014, $99.00.

Ruby & Sapphire: A Collector’s Guide has surpassed my grandest expectations. Richard Hughes’ eloquent prose, combined with magnificent photos, is a masterful tribute to the people from faraway lands who find and fashion these gems to brighten our world. This book is an indispensable treasure trove of information that will serve as a guide to help navigate the gem underworld. It also rivals any coffee table book, featuring beautiful photos that Hughes, his wife, and their daughter captured over many journeys together.

As Hughes notes in the foreword, his focus is on the relationship between people and gems, which he calls “humanistic gemology.” While many artisanal small-scale miners toil for years without success, he explains, some do strike it rich, instantly elevating them and their families into a new realm of existence. As Hughes points out, however, wealth does not always bring happiness and can often be fleeting. One of my favorite sidebars is the legend of Darky Garnet, who arrived in Rubyvale, Australia, with only a wheelbarrow full of worldly possessions. Garnet struck it rich, lived like a king, shared his wealth with friends and strangers, and left penniless with only his wheelbarrow and the shirt on his back. He is celebrated to this day with an annual tribute one must read to believe.

The first chapter features colorful illustrations and photos of ancient frescos, mines, and jewelry dating back hundreds and even thousands of years. Hughes suggests that Sri Lankan traders brought rubies and sapphires to Europe in early Greco-Roman times, making them the earliest stones of value tendered for international trade and commerce. Today, a gemstone’s value is defined by its beauty, rarity, durability, and transportability. This chapter continues with the varied and abundant history associated with the search for and fashioning of corundum. Ruby and sapphire were frequently mistaken for other gems such as spinel and lapis. It was not until the advancement of mineral science in the 17th and 18th centuries that these two members of the corundum family were fully understood. Another major obstacle in the understanding of gems relates to nomenclature, or “wordsmithing” as Hughes aptly puts it; these issues still exist in the trade today. Hughes states that until the early 19th century, the word “oriental” was used as a prefix to describe gems that could achieve a higher polish because of their superior hardness. Thus oriental topaz actually referred to yellow sapphire, while oriental amethyst referred to purple sapphire. In 1805 Rene Just Haüy formally combined these and other sapphires, along with ruby, into the group now known as corundum.

The chapter on source countries takes the reader on an incredible adventure to ruby- and sapphire-producing countries, providing a virtual tour of these fascinating locales. Hughes begins with a clear, concise explanation of the geologic forces that led to the conditions required for gemstone mineralization. Fascinating details are provided about the people, mining, and production in the major corundum sources: Southeast Asia, Central Asia, Australia, Africa, and North America.

Hughes then shares many secrets of the trade to help collectors make educated decisions. Details of what to look for in color, clarity, cut, and country of origin are clearly conveyed, but the reader is encouraged to always go with personal preference. In the case of ruby, the market tends to favor stones with a more intense color, but Hughes advises not to overlook those of slightly less saturation that might offer more brightness and versatility. A sidebar titled “Clarifying Clarity” provides delightful insight on how to judge a gem’s internal issues. He suggests that the budding collector “develop perspective” through research, visits to auctions and gem shows, and networking with jewelers and dealers. One of the most interesting excerpts features renowned mineral and gem dealer William Larson expounding on his vast connoisseurship of crystals. Larson shares how his passion for minerals, which began when he was just a boy, has grown into one of the finest private collections of specimens in the world. He offers his suggestions on building a meaningful collection.

One of my favorite sections examines left-brain objective pricing vs. right-brain subjective preference. A graph comparing recent auction results, coupled with gem photos, gives a colorful dimension to the author’s message. Understanding gem value is one of the most difficult things to master. Auction results, scattered throughout the book, provide the reader with tangible examples of some of the finest gems and jewelry sold over the past two decades, such as a 6.04 carat Burmese ruby which sold in 2013 for over US$3.3 million, and an 8.91 carat Kashmir sapphire which sold in 2012 for over US$1.3 million. He also includes wonderful sections on judging stars and cabochons, fancy-color sapphires, and suites.

Chapter four delves into the internal world of forensic gemology, balancing out the book’s earlier focus on people, places, emotion, and lore. Hughes explains the skills and instrumentation needed to identify synthetics, treatments, and country-of-origin characteristics. Well-deserved tribute is paid to the artistic skills and scientific knowledge required to properly capture, identify, and apply microscopic observations. The benefits and drawbacks of gem treatments are also clearly discussed.

Another valuable tool in the gemologist’s arsenal is a reference library. Chapter six gives direction on how to accumulate a useful and refined gemological library. As always, Hughes provides a generous and detailed bibliography, recommending numerous volumes and journals. In the final chapter, many of the amazing photos featured throughout the book are beautifully grouped to help communicate the subtle nuances that make up the diverse corundum family.

Throughout, Richard Hughes spices up the book with his colorful style, personal anecdotes, quotes, and fascinating sidebars. Every gemologist, dealer, connoisseur, collector, and gem enthusiast should own this indispensable work. Source: GIA @topic:10


Title: The Occurrence and Gemological Properties of Wessels Mine Sugilite Abstract: Examination of jewelry-quality sugilite shows that it consists of manganese-bearing sugilite and other minerals in a polycrystalline aggregate. The material occurs in a large stratiform manganese orebody at the Wessels mine near Kuruman, South Africa. Some 12 to 15 tons of sugilite of varying quality are estimated to occur at the mine. The attractive purple color is due to the presence of about 1-3 wt. % manganese oxide. The research reported here revealed that there are actually two types of gem materials that have heretofore been called sugilite: one that is predominantly manganoan sugilite with minor impurity minerals, and the other that is chalcedony mixed with (and colored by) sugilite. Source: GIA @topic:1


Title: Update on Trace-Element Chemical Characteristics of Golden Sheen Sapphire Abstract: Figure 1. Eighteen of the 23 golden sheen sapphires examined for their trace-element chemical characteristics. The largest stone weighs 34 ct. Photo by Shunsuke Nagai.

GIA’s Tokyo laboratory recently examined 23 sapphires displaying a “golden sheen” effect, reportedly from Kenya (e.g., T.N. Bui et al., “From exsolution to ‘gold sheen’: A new variety of corundum,” Journal of Gemmology, Vol. 34, No. 8, 2015, pp. 678–691). Bui et al. (2015) were the first to describe gemological characteristics of golden sheen sapphires from Kenya; updated characteristics of inclusions, UV-Vis-NIR spectra, and chemistry of golden sheen material was published the following year (N. Narudeesombat et al., “Golden sheen and non-sheen sapphires from Kenya,” The Gem and Jewelry Institute of Thailand, July-August 2016, pp. 282–288; Winter 2016 Lab Notes, pp. 413–414). Here we update the gemological and chemical characteristics of the recently examined material, and compare the information with various sapphire sources including other golden sheen sapphire data previously documented.
We examined 15 cabochons, three faceted, and five rough stones (figure 1). The samples were semi-transparent to opaque, with a blue and yellow bodycolor and weight range of 1.75 to 34.00 ct. The cabochons displayed a “golden sheen” effect and/or golden six-ray asterism. For the polished samples, standard gemological testing revealed refractive index (RI) values of 1.760 to 1.770 and hydrostatic specific gravity (SG) values of 3.98–4.01, except for one densely included stone with an SG of 4.04 (see Lab Notes this issue, pp. 212–213). These SG values suggested that they were all corundum. The rough stones showed SG values of 3.82–4.01 and the Raman signatures of corundum.

Figure 2. Photomicrographs (left) and Raman spectra (right) of micro-inclusions in golden sheen sapphires: zircon inclusion with intersecting needles (A), hematite and goethite inclusion (B), diaspore and siderite inclusion (C), and dawsonite inclusion (D). Darkfield illumination (A, C, and D) and reflected light (B). Photomicrographs by Makoto Miura; fields of view 1 mm (A), 0.06 mm (B), and 0.8 mm (C and D).
The inclusions were similar to those in other golden sheen sapphires described by Bui et al. (2015) and Narudeesombat et al. (2016). Characteristics included dense clouds composed of brownish needles and platelets displaying a golden sheen effect. Raman analysis identified the needles as ilmenite and hematite, although their Raman signals were weak because of their thinness. Some showed six-ray asterism caused by reflection from dense clouds of oriented needles. Inclusion-free zones like the center stone and rough stones in figure 1 contained mineral crystals and healed fissures with negative crystals (see Lab Notes, pp. 212–213). Various euhedral to subhedral mineral inclusions (figure 2) were confirmed as hematite, diaspore, and zircon. Hematite was found as needles and euhedral crystals; these euhedral hematite crystals coexisted with goethite (figure 2B). Some carbonate minerals such as siderite (FeCO3) and dawsonite [NaAlCO3(OH)2] were found as irregular inclusions with a vein-like appearance, although their primary or secondary origin was unknown (figure 2D). Additionally, magnetite and mica (paragonite and muscovite series) were identified.

Figure 3. This ternary diagram shows the relationships between Fe, Mg, and Ti in golden sheen sapphires. Note that most of samples have similar Fe, Mg, and Ti content. Some of the yellow and included zones are rich in Mg and Ti.
Quantitative laser ablation–inductively coupled plasma–mass spectrometry (LA-ICP-MS) analysis of trace elements on the 23 samples—90 spots in total—is summarized in table 1 and figure 3. Six of the samples had both blue and yellow bodycolors, and only one had a single yellow bodycolor (again, see figure 1). The other 16 contained numerous inclusions and fractures, and were not clear in color distribution. Chemical analyses were conducted on three spots for each blue, yellow, and included zone. The blue zones had high Fe content ranging 2630 to 3486 ppma and low to medium V content of 0.13 to 0.37 ppma. Their Ti concentration was higher than their Mg content. Ga/Mg ratios for the blue zones varied from 3.50 to 25.35. The yellow zones showed similar Fe, V, and Ga contents as the blue zones, with high Fe (2923 to 3846 ppma), low to medium V (0.13 to 0.40 ppma), and Ga/Mg ratios of 7.78 to 10.06. Included zones also showed similar concentrations of all elements as the blue and yellow zones, although some spots tended to be slightly high in Fe, Ti, Al, and Ga. Enrichment in these elements probably indicates compositions of dense inclusion phases, because most of the inclusion phases were Fe-Ti oxides such as hematite and ilmenite, as documented by Bui et al. (2015) and Narudeesombat et al. (2016). G&G previously published that other trace elements, such as Zr, Nb, Ta, W, Th, and U, were enriched in the included zones of some golden sheen sapphires (again, see Winter 2016 Lab Notes, pp. 413-414). Only Ta and U were detected in our samples. Elements such as Na and K that can be considered to be related to inclusions were also detected in some spots on included zones.

While golden sheen sapphires are reportedly mined in northeastern Kenya, there is no other published chemical data available from this region. We compared our chemical characteristics with those of other samples documented in the Winter 2016 Lab Notes entry; metamorphic sapphires from Sri Lanka, Myanmar, and Madagascar; and basalt-related sapphires from Thailand, Australia, Nigeria, Kenya, and Cambodia (figure 4). Compositional data for metamorphic and basalt-related sapphires are from previously published articles (J.J. Peucat et al., “Ga/Mg ratio as a new geochemical tool to differentiate magmatic from metamorphic blue sapphires,” Lithos, Vol. 98, 2007, pp. 262–274; V. Pardieu et al., “Sapphires from the gem rush Bemainty area, Ambatondrazaka (Madagascar),” GIA News from Research, Feb. 24, 2017; W. Soonthorntantikul et al., “An in-depth gemological study of blue sapphires from the Baw Mar mine (Mogok, Myanmar),” GIA News from Research, Feb. 24, 2017; Fall 2017 GNI, pp. 380–382). As shown in figure 4, the samples in this study were similar to other golden sheen sapphires in Fe, Ga, and V contents. The Fe concentration and high Ga/Mg ratio (table 1) were far from those of metamorphic sapphires but close to those of some basalt-related sapphires. Kenya, where golden sheen sapphires may occur, has two known types of sapphire deposits; one is associated with alkali basalts from the Gregory Rift, an eastern branch of the African Rift Valley, and the other is associated with syenite (Peucat et al., 2007). Both types of sapphire showed a high Fe concentration and Ga/Mg ratio, which are similar to the chemical data in this study.

Figure 4. Log plots of chemical variations of Fe vs. Ga contents (expressed in ppma) in golden sheen sapphires. Only blue sapphire data was plotted.
The similarities in inclusions and trace-element composition between our samples and other golden sheen sapphires indicate that they possibly come from the same origin. A wide variety of inclusions observed in golden sheen sapphires suggests the specific condition during the formation processes. The presence of hematite inclusions especially implied formation in a highly oxidized environment. Further gemological studies are required to construct the database for origin determination. Source: GIA @topic:3


Title: Magnesio-Axinite from Merelani, Tanzania Abstract: Figure 1. Left: A suite of eight magnesio-axinite faceted gems and one rough stone. Clockwise from top right: 1.21 g orange-yellow rough, 2.72 ct. yellow-orange pear shape, 1.14 ct bicolor marquise, 1.51 ct pair of pale pinkish blue princess-cut stones, 1.43 ct pink-blue oval, 1.83 ct light pink to light blue triangle, and at center in the pendant, a 4.22 ct. oval pink-blue gem. Right: The same magnesio-axinite gems under long-wave ultraviolet fluorescent lighting. Photos by Eric Welch; courtesy of Vance Gems.

	Colored gemstone dealer Bill Vance (Vance Gems, Newark, Delaware) showed us some transparent examples of magnesio-axinite, a rare magnesium-dominant member of the axinite group of minerals. Axinite has a general formula of H(CaFe2+MnMg)3(Al2BSi4O16). Gem-quality magnesio-axinite—also known as axinite-(Mg)—is transparent to translucent, with pale blue to pale violet, light brown to light pink, or yellow to golden yellow or orange color (figure 1, left). More intensely colored bluish violet to purple magnesio-axinite tends to have a higher refractive index (1.659–1.681) than lighter-colored pink, purple, or yellow material (1.652–1.668). Magnesio-axinite has a birefringence of 0.010–0.016, strong dispersion, and a Mohs hardness of 5.5. Stones with a blue color component display pale blue to pale violet and pale gray pleochroic colors. Fluorescence is one of the material’s most striking properties—the gem shows a dull red under short-wave ultraviolet light and a vibrant “merthiolate flame color” red under long-wave UV (figure 1, right). We intend to report on the chemistry of this interesting material at a future date.

	Bill Vance - Vance Gems

	In this video segment, gem dealer Bill Vance presents a rare gem from Tanzania—magnesio-axinite—with interesting properties, including striking fluorescence under longwave UV light. He also displays a fine 10.46 ct “Merelani mint” garnet that demonstrates similarly strong fluorescence.

	Vance said he’s attempting to name the gem “vanceite.” Besides the fluorescence, pink to blue-violet stones display a color shift: If you view it under a fluorescent light, you’re going to see a blue stone, he says, under incandescent, it’s more of a pinkish color. Yellows don’t show a color shift.

	Because of the material’s color shift and strong fluorescence, Vance believes it appeals to a wide audience. According to Vance, these examples come from a very limited occurrence in the Karo pit “D” block, Merelani Hills, Tanzania, where the chemistry and formation conditions were just right, and new material is very hard to get. It comes from the same rocks as green garnet, tanzanite, and chrome tourmaline. He remarked that while cutting of magnesio-axinite is straightforward, the biggest problem is getting clean pieces to cut as almost all have inclusions. In terms of size, he said, anything over four carats is a “monster.”

	Vance also showed us a heart-shaped 10.46 ct Tanzanian “Merelani mint” garnet. He noted that it displayed a very strong response to both long-wave and short-wave ultraviolet light (figure 2). Although such vanadium-bearing grossular garnet can come from Kenya or Tanzania, most of the Kenyan material displays no long-wave UV reaction. According to Vance, a strong long-wave UV reaction from a green grossular garnet is strong evidence of a Tanzanian stone from D block. Vance explained that supply of this material is now dwindling. In the beginning, prices ranged from $400–$500 per carat up to $800 per carat. Today’s prices for equivalent material are in the range of $2,500 per carat. For a particularly fine example over six carats, prices might be as high as $10,000 per carat. Demand is really strong, especially in China.

	Figure 2. Left: A 10.46 ct heart-shaped green grossular garnet of the color known as “Merelani mint” in the trade. Right: The same grossular garnet displays a strong orange reaction to long-wave ultraviolet light. Photo by Eric Welch; courtesy of Vance Gems. Source: GIA @topic:2


Title: Unusual Inclusions in Green Synthetic Sapphire Abstract: This 5.00 ct green synthetic sapphire showed clouds of bubbles along different directions (right, field of view 4.35 mm). Photos by Iurii Gaievskyi.
A 5.00 ct green square step cut (above left) was submitted as a synthetic sapphire to the laboratory of the State Gemmological Center of Ukraine. Standard gemological testing gave a refractive index of 1.763–1.768, with a uniaxial negative optic sign and a birefringence of 0.005, as well as a hydrostatic specific gravity of 3.94. The sample was inert to short- and long-wave UV radiation. Pleochroism was moderate green to yellowish green. Energy-dispersive X-ray fluorescence (EDXRF) spectroscopy showed only small amounts of Co (0.07 wt.% Co3O4). In the jewelry market, such synthetic green sapphires are quite rare. Microscopic examination revealed abundant gas bubbles, including some along curved lines. From these observations we can infer that the Verneuil or Czochralski method was used to create this stone. In addition to these bubbles, there were straight lines of bubbles in multiple directions (above right), which are extremely unusual in Verneuil- or Czochralski-grown synthetic sapphire. Source: GIA @topic:3


Title: Punsiri Heat Treatment on Basalt-Related Blue Sapphire Abstract: The 1.63 ct blue sapphire treated by the Punsiri method. Different views show a typical light blue to near-colorless outer layer when the stone is immersed in methylene iodide. Photos by Sudarat Saeseaw.
Heat treatment is often applied to sapphire to modify color or improve clarity. One known heat-treatment technique is the Punsiri method, typically applied to metamorphic or low-Fe blue sapphires. This treatment lightens the blue color by heating the stones in an oxidizing atmosphere to diffuse holes and aluminum vacancies into stones with low Ti levels (J.L. Emmett, lectures on corundum at GIA Bangkok, Aug. 28 and Dec. 4, 2010). The main characteristic of Punsiri heat treatment is distinct color zoning observable when the stone is immersed in methylene iodide. The stone will display a pale blue to near-colorless layer corresponding to the girdle outline that surrounds a deep blue core.

Recently, GIA’s Bangkok laboratory examined a 1.63 ct blue sapphire, identified by standard gemological testing (refractive index of 1.760–1.769 and an inert reaction under long- and short-wave UV radiation). Microscopic observation revealed only a few inclusions, consisting of stringers and small healed fractures. We then immersed the stone in methylene iodide and observed Punsiri-type color zoning (see above). Fourier- transform infrared (FTIR) spectroscopy is a common technique used in advanced gemological laboratories to determine whether a stone is heated or unheated. When the FTIR spectrum shows Punsiri features (e.g., multiband structures at 3191, 3064, 2626, and 2412 cm–1; see chapter 4 of R.W. Hughes, Ruby and Sapphire: A Gemologist’s Guide, RWH Publishing, Bangkok, 2017), this is conclusive for heat-treated metamorphic blue sapphire. However, when the FTIR spectrum does not show these features, it does not necessarily mean the stone has not been heat treated. Such was the case for this stone, which showed signs of heat treatment through its distinctive color zoning and near-colorless rim.

UV-visible near-infrared (UV-Vis-NIR) spectroscopy revealed a broadband at about 880 nm, indicating a blue sapphire of basalt-related origin. Laser ablation–inductively coupled plasma–mass spectrometry (LA-ICP-MS) showed no beryllium and limited amounts of other trace elements: 7 ppma Ti, 860 ppma Fe, and 47 ppma Ga were detected. This is the first time we have observed Punsiri heat treatment on a basalt-related blue sapphire. It was possible to perform the treatment on this sample due to the low amount of Ti, which allowed for faster diffusion. This report demonstrates the importance of the immersion technique in identifying heat treatment. Source: GIA @topic:3


Title: Lead Glass–Filled Black Star Sapphire Abstract: Figure 1. This 25.10 ct black star sapphire was enhanced with lead glass. Photo by Jian Xin (Jae) Liao.

	Fracture and cavity filling of gemstones has been practiced for hundreds of years. In recent times, this treatment has become more sophisticated and widespread, particularly with the use of lead glass, which is most often seen in rubies. The addition of lead oxide (PbO) to silica glass lowers its working temperature and viscosity while raising its refractive index from approximately 1.5 to as high as 1.8. Thus, the filler has an RI that matches many gem materials, making fractures and voids virtually disappear. But the softness and low melting point of the filler create durability issues, especially in low-quality filled rubies (S.F. McClure et al., “Identification and durability of lead glass–filled rubies,” Spring 2006 G&G, pp. 22–34).

	Common inclusion features for lead glass–filled ruby composites include blue flashes from the fractures and trapped gas bubbles. Glass features can also be detected using Fourier-transform infrared (FTIR) spectrometry and energy-dispersive X-ray fluorescence (EDXRF) spectroscopy. But if the ruby has very few areas that are enhanced with lead glass, they may not be obvious under magnification, and FTIR and EDXRF may not detect them. Real-time X-ray (RTX) imaging systems, used by GIA to identify pearl growth features and confirm filling in diamonds, can be beneficial in differentiating between lead glass and ordinary glass filling in rubies and other gemstones. This is due to opacity differences, as lead glass has a lighter appearance than glass without lead. A combination of X-ray imaging and magnification is also capable of quantifying the extent of lead glass treatment performed on a gemstone.

	A 25.10 ct opaque black star sapphire (figure 1) was submitted to the New York laboratory for identification. The stone contained a few hairline fractures and dense golden silk needles. At first glance, the sapphire had a few features that would arouse suspicion for treatment, such as round cavities on the base and a few inconspicuous fractures (figure 2). The sapphire also had a specific gravity of 4.04, which is above the normal range for corundum. Natural black sapphire may have a higher SG due to abundant asterism-causing inclusions of rutile or hematite, both of which are denser than corundum. Because of the stone’s opacity, it was difficult to observe internal inclusions under magnification.

	Figure 2. Gas bubbles visible in the sapphire’s cavities (left) and a thin fracture with different surface luster (right) indicate the possibility of lead glass filling. Photomicrographs by Akhil Sehgal; fields of view 2.10 mm (left) and 3.90 mm (right).

	Using X-ray imaging analysis (figure 3), it was clear that the fractures and multiple cavities had been filled with lead glass, and this finding was confirmed by EDXRF. These properties would have been extremely difficult to see under normal visual magnification.

	Figure 3. Face-up (left) and profile (right) RTX images of the black star sapphire. The white areas indicate higher opacity in fractures and cavities, evidence of lead glass filling. Noticeable round gas bubbles are trapped in cavity fillings.

	This is the first example of a lead glass–filled black star sapphire examined in the New York laboratory. Source: GIA @topic:3


Title: Video Feature: Emerald Sources of Brazil Abstract: Emerald Sources of Brazil Sergio Martins, Stone World

	In these videos, Sergio Martins, president of the Brazilian gemstone cutting and marketing firm Stone World, gives an overview of Brazil’s most important emerald deposits, as well as the country’s mining practices and laws.
Brazil is a major supplier of emeralds for the global market. There are a few important mining areas, and the emeralds produced at each location can have different characteristics. Overall, the supply of Brazilian emeralds remains relatively stable, despite fluctuations at individual mining locations.

	Mining Areas
The mines in the state of Bahia were among Brazil’s first emerald-producing locations, dating back to the 1960s. They continue to supply large quantities of emerald to the global market. In Bahia, there is a large production of carving, cabochon, bead, and commercial-quality facet-grade material.

In the state of Goiás, the area near the town of Santa Terezinha de Goiás has yielded large quantities of emerald, primarily in smaller crystal sizes.

The mining areas near Itabira and Nova Era in the state of Minas Gerais generate the most consistent and highest-quality supply of Brazilian emeralds. Itabira is the more stable producer, while Nova Era is known for very large emerald crystals. Montebello is one of the largest and most sophisticated mines in Nova Era. Belmont is a modern operation and an important global supplier on a steady basis. The Belmont mine often cuts its own better-quality emeralds, moving it up the value chain into cut goods. Between Belmont and Nova Era mines lies a newer mine, Piteiras. Though currently closed, it could be reopened and become an important source.

In addition to the established emerald mining areas, new production has started in the state of Rio Grande do Norte under the colored stone mine-to-market legend Lorenzo Yih.

	Mining Methods
Brazilian emeralds are extracted by mechanized mines such as Belmont, which use the most sophisticated techniques, and by cooperatives of independent miners, financed by investors. These independent miners, known as garimpeiros, use unsophisticated methods to recover gemstones or other minerals such as gold. They perform hard manual labor in search of the treasure that will change their lives. Source: GIA @topic:1


Title: Lapis Lazuli Quality Factors Abstract: The even, deep blue color of this lapis lazuli cabochon is rare and highly prized by connoisseurs.

                      Lapis lazuli is treasured the world over for its beautiful deep blue color.

Color
Variously described as indigo, royal, midnight, or marine blue, lapis lazuli’s signature hue is slightly greenish blue to violetish blue, medium to dark in tone, and highly saturated. In its most-prized form, lapis lazuli has no visible calcite, although it might contain gold-colored pyrite flecks. If the flecks are small and sprinkled attractively throughout the gem, their presence doesn’t necessarily lower lapis lazuli’s value. The lowest-quality lapis looks dull and green, the result of an excess of pyrite. Lapis with white calcite streaks is less valuable.

	This collection of beads shows the range of lapis quality, from a pale blue with an excess of calcite or pyrite to a dark blue to violetish blue without visible calcite. Top-quality lapis can contain some pyrite. – Alan Jobbins

	This collection of lapis beads displays the gem’s subtle variations in shades of blue. - Valerie Power

	This adorable carving of a baby elephant shows off a variety of blue lapis shades. – Orasa Weldon, gift of William F. Larson

	The pale color of the scarab beetle cabochon is typical of commercial-quality lapis lazuli. - Maha Tannous
Although many people associate lapis with dark blue, it’s also found in other blue shades, and even other hues. Its color can range from deep violet blue and royal blue to light blue to turquoise blue to a greenish blue. The combination of different minerals in the aggregate determines the color. For example, the presence of lazurite produces lapis lazuli’s prized royal blue color, while a mineral called afghanite creates a pale blue shade.

	The saturated royal blue of this freeform piece is an example of lapis lazuli’s finest color. The pyrite inclusions are scattered attractively in some areas, but in other areas they’re so dense that they cloud the beauty of the gem’s bodycolor. - Robert Weldon, courtesy Gary Bowersox
Lapis trade grades are based on color and the presence or absence of calcite or pyrite. Lapis types on the market today, in order of their value, are:

		Persian or Afghan—Intense, uniform, medium dark, slightly violetish blue. Contains little or no pyrite, and no calcite

		Russian or Siberian—Various tones and intensities of blue. Contains pyrite and might contain some calcite

		Chilean—Often tinged or spotted with green, with obvious calcite matrix

	The most valued lapis contains little or no pyrite and no calcite, and is an intense, uniform, medium-dark, slightly violetish blue. This quality is known in the trade as Afghan. – Bart Current

	This cabochon’s less intense color and mottled calcite content make it less valuable than a gem with deep, intense color. - Robert Weldon
A gemstone’s appearance might be described using an adjective that refers to a country or region, but that doesn’t necessarily mean the gem is actually from that area. Thus, lapis with a lot of white calcite spots and many green patches might be sold as “Chilean,” but this doesn’t mean it’s really from Chile.

Cut
For thousands of years, lapis has been fashioned to show off its rich, dark color. Typically, lapis cutting styles for use in jewelry are cabochons, beads, inlays, and tablets, as well as decorative carvings.

	Lapis lazuli beads contrast beautifully with freshwater cultured pearls in this lovely necklace. - Mike Havstad

	A lapis tablet graces this man’s ring.

	Lapis lazuli has inspired gem carvers for centuries.

	An attractive design has been carved into this ring’s lapis cabochon.
Today, lapis is frequently fashioned into freeform and nature-themed sculptures. Some of these carvings become wearable art, others are purely decorative.

	Freeform sculptures show off the beauty of high-quality lapis. - Robert Weldon, courtesy Gary Bowersox
Clarity
Lapis frequently contains varying amounts of whitish calcite matrix—the host rock that surrounds the gem—or flecks or veins of glinting yellow pyrite, or both. The gem can also have a smoothly uniform bodycolor, free of visible pyrite and calcite.

	Calcite shows up as white flecks or streaks in the aggregate (left), while the golden, metallic-looking spots are pyrite (right). - John Koivula (right)

	These lapis lazuli specimens are surrounded by their white calcite matrix host rocks. – Orasa Weldon, gift of William and Jeanne Larson

	These two blocks of lapis rough vary greatly in value. The block on the right will sell at a much lower price than the one on the left due to its high calcite presence and its lighter shade of blue. - Maha Tannous
Carat Weight
Lapis rough can be very large, so large fashioned stones are more common than with many other gemstones. Larger sizes are also more likely to be carved into art objects, used in designer jewelry, or cut into calibrated sizes.

	Large lapis rough can be fashioned into spheres or tablets. Lapis lazuli spheres are popular among collectors. - Robert Weldon

	This display of gems from Afghanistan features a large kunzite pendant suspended from
	a necklace of 18 mm lapis beads. - Valerie Power, courtesy ASMED/Gem Hunters Corp. Source: GIA @topic:1


Title: Padparadscha: What's in a Name? Abstract: For over 100 years, reference has been made to a unique sapphire, the color of a lotus blossom, the padparadscha. Yet the precise hue represented by this rare stone has been a subject of discussion, and often controversy, ever since the term was first introduced. In an effort to establish some grounds for a common understanding, the author reviews the historical references to the padparadscha sapphire, examines the modern usage of the term, and states GIA's current interpretation of the trade name padparadscha. Source: GIA @topic:7


Title: Jade Forms from Ancient China Abstract: The attraction of jade is two-fold: the nature of the material and the way it is used. The color, texture, and feel of jade are easily appreciated, but the symbolism of the motifs in which it is carved is an enigma to many of the stone's admirers. This article briefly examines some of the symbols used in jade carved in China, including an introduction to the religions on which much of this symbolism is based. By mastering these basic symbols and the philosophy behind them, collector and seller alike can gain greater understanding of the cultural and philosophical meaning of the art involved in a particular piece. Source: GIA @topic:12


Title: Zabargad: The Ancient Peridot Island in The Red Sea Abstract: Reflecting on his 1980 visit to Zabargad, the author provides an update on this relatively unknown island and the beautiful peridots for which it has gained fame. He complements his discussion of the geology of Zabargad, the peridot occurrences, the mining techniques, and the characteristics of the gemstone with a look at the ancient history of the island and the etymological changes surrounding the stone's current name, peridot. Although somewhat low on the hardness scale, this magnificent gemstone has regained popular appreciation, and the crystals from Zabargad are still among the finest in the world. Source: GIA @topic:1


Title: G&G Contributors Awarded for Best Geoscience Research Abstract: Diamond: Genesis, Mineralogy and Geochemistry, Volume 88 in the Reviews in Mineralogy and Geochemistry series, received this year’s Mary B. Ansari Best Geoscience Research Resource Award.
Several G&G authors and editorial board members are among those honored for their contributions to a recent volume in the Reviews in Mineralogy and Geochemistry series (see above). The Geoscience Information Society’s annual Mary B. Ansari Best Geoscience Research Resource Award recognizes the year’s outstanding reference publication or website. The 88th volume in the Reviews series, Diamond: Genesis, Mineralogy and Geochemistry is a comprehensive resource covering a wide range of diamond-related subjects. The publication is available for download at geoscienceworld.org and minsocam.org.
Congratulations to volume editors Karen Smit, Steve Shirey, Graham Pearson, Thomas Stachel, Fabrizio Nestola, and Thomas Moses, as well as G&G contributors Christopher M. Breeding, Jim Butler, Alan Collins, Ulrika D’Haenens-Johansson, Dorrit Jacob, Mandy Krebs, and Evan Smith for their chapters in the volume. Source: GIA @topic:7


Title: Bright Orange Sapphire from Greenland Abstract: Figure 1. A 1.28 ct heated pink round brilliant sapphire. Photo by Robert Weldon; courtesy of Greenland Ruby.
The Aappaluttoq mine in Greenland is home to the oldest known ruby-bearing rocks on Earth. These host rocks are nearly three billion years old (A. Polat et al., “New age (ca. 2970 Ma), mantle source composition and geodynamic constraints on the Archean Fiskenæsset anorthosite complex, SW Greenland,” Chemical Geology, Vol. 277, No. 1-2, 2010, pp. 1–20). This deposit was initially known for producing translucent to opaque ruby and pink sapphire, much of it cut into cabochon form. However, transparent material has always been found in this mine and makes up about 5–10% of the production.

Figure 2. A 0.89 ct heated orange oval brilliant sapphire. Photo by Robert Weldon; courtesy of Greenland Ruby.
At the AGTA show, Greenland Ruby displayed many examples of attractive transparent ruby and pink to orangy pink sapphire, including several fancy-color sapphires in sizes greater than one carat (figure 1; see also a color study of fancy sapphire from Greenland in this issue). These fancy colors are achieved by heat treating nearly colorless to slightly pink transparent material. A transparent bright orange sapphire weighing 0.89 ct and measuring 6.41 × 5.02 mm (figure 2) immediately caught our eye. Martin Viala, product manager for Greenland Ruby, shared with us a video of the original 1.07 g sapphire rough (see below). This unusual stone was mined in late 2019 and heated in May 2022. Viala noted that it was a textbook example of a chromium trapped-hole (h●–Cr3+) chromophore (E.V. Dubinsky et al., “A quantitative description of the causes of color in corundum,” Spring 2020 G&G, pp. 2–28).

	Orange Sapphire Rough from Greenland Ruby Source: GIA @topic:3


Title: GIA Museum’s “Paint the Town Ruby Red” Exhibit at TGMS Abstract: The GIA Museum’s “Paint the Town Ruby Red” exhibit at TGMS featured a Burmese ruby and diamond necklace and earrings, courtesy of Mona Lee Nesseth (Custom Estate Jewels) and a private collector. Photo by Terri Ottaway.
At the Tucson Gem and Mineral Show, the GIA Museum exhibited a Burmese ruby and diamond necklace and earrings against a backdrop of the necklace fluorescing in ultraviolet light (see above). The necklace contains 39 untreated rubies from Mogok totaling 83.73 carats and 302 diamonds totaling 42.62 carats. The largest ruby is 5.00 ct.
The exhibit highlighted the “magic ingredient”—chromium—that gives ruby not only its color but also its fluorescence. Mogok rubies are renowned for their high concentration of chromium and low concentration of iron. The latter element, if present in a high enough concentration, quenches all or part of the red fluorescence produced by the chromium. This fluorescence is an important factor in the high value of Mogok rubies.
TGMS began in 1955 and is one of the longest-running gem and mineral shows in the world. GIA Museum curator Terri Ottaway said she was thrilled at the opportunity to showcase such a gorgeous necklace and include a bit of chemistry and geology for the gem and mineral enthusiasts. Source: GIA @topic:7


Title: From the GIA Laboratory: Beryllium in Corundum – The Consequences for Blue Sapphire Abstract: Figure 1. The smaller stones in this group of sapphires (1.24–8.00 ct) were known to have been diffusion treated with beryllium. The four larger stones were identified as Be-treated during the investigations. Photo by C. D. Mengason.
 In 2001−2002, the gem industry witnessed the introduction of beryllium (Be)-diffused corundum in “padparadscha,” yellow, and orange colors. The treated “padparadscha” sapphires could be identified by their yellow-to-orange surface-related color zoning, which was easily seen with diffused light in immersion. The yellow and orange Be-diffused sapphires proved more challenging to identify, often requiring sophisticated means of chemical analysis such as secondary ion mass spectroscopy (SIMS) or laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) to detect the trace levels of Be that are indicative of this treatment; Be is a light element that is not detectable by typical analytical methods used in gemological laboratories.

As both LA-ICP-MS and SIMS require expensive and complicated instrumentation, more cost-effective alternatives were explored. Another technique that has shown promise is laser-induced breakdown spectroscopy (LIBS). Although this technique is not as complicated to use and can detect trace levels of Be, it is not as sensitive or accurate as the other two methods, and it is still relatively expensive compared to standard gemological instruments such as infrared and UV-visible spectrometers.

Figure 2. These unusually shaped and patterned clouds were seen in some of the Be-treated blue sapphires. Photomicrograph by Shane F. McClure; magnified 25×.
Blue Be Diffusion-Treated Sapphire. With the increasing availability of analytical methods that can detect Be, and the analysis of corundum for this element becoming more routine, gemological laboratories are identifying ever-greater numbers of blue sapphires in the international marketplace that have been treated by this technique. In mid-2006, the Gemological Association of All Japan reported that they had identified several blue sapphires that were treated with beryllium (click here for full report). Subsequently, a group of more than 50 Be-diffused blue sapphires were obtained by Vincent Pardieu, then of the AIGS laboratory in Bangkok, and sent to several laboratories for study.

The concentration of Be measured in these and other known Be-treated blue sapphires has varied from approximately 4 parts per million (ppm) to over 20 ppm.

The possibility of using Be diffusion to treat blue sapphires was initially investigated in 2002 by a team of GIA and other researchers working with John Emmett (Crystal Chemistry, Brush Prairie, Washington). As illustrated by Emmett et al. (“Beryllium diffusion of ruby and sapphire,” Summer 2003 Gems & Gemology, pp. 84–135), Be diffusion and subsequent heating can be used to lighten the color of dark blue sapphires.

Figure 3. Some Be-treated blue sapphires show rows and strings of circular inclusions that may resemble corkscrews. Photomicrograph by Shane F. McClure; magnified 25×.
 In light of the emergence of so many Be-treated blue sapphires, GIA initiated a broad-ranging project to determine the extent of Be-treated blue sapphire in the colored stone market. Laboratory staff used the GIA Laboratory's LA-ICP-MS and standard gemological techniques to analyze more than 500 sapphires from the New York trade; the majority were blue sapphires that had been heat treated, but the group also included some green, yellow, orange, and pink sapphires. Analysis of these 500 samples revealed four blue sapphires that showed consistently high levels of Be (over 3 ppm) throughout, proving they were diffusion treated (figure 1). Be diffusion−treated blue sapphires have indeed entered the marketplace in the U.S.

Certain inclusion scenes noted in the Be-diffused blue sapphires appear to be indicative of this treatment. These include unusually shaped and patterned clouds (figure 2), rows and strings of circular inclusions that sometimes resemble corkscrews (figure 3), and spherical clouds surrounding highly altered crystals (figure 4).  However, not all of the Be-diffused blue sapphires contained these inclusion scenes, and some contained no inclusions at all. In addition, Be was detected in some blue sapphires that did not appear to have been diffusion treated.

Figure 4. Also characteristic of Be-treated sapphires are these spherical clouds surrounding highly altered crystals. Photomicrograph by Shane F. McClure; magnified 20×.
Beryllium in Natural Sapphire? Pure corundum consists only of aluminum oxide (Al2O3), but in nature this mineral always contains minor-to-trace amounts of other elements as impurities. For example, natural untreated blue sapphires may contain roughly 1,000–10,000 ppm of iron and titanium, depending on the type of deposit in which they formed. Yellow sapphires normally contain tens of ppm of magnesium. However, beryllium has not been previously documented in untreated corundum. Therefore, it was assumed that the presence of any Be in corundum was indicative of beryllium treatment.

During its analysis of the 500 stones mentioned above, the Laboratory encountered 17 blue sapphires with Be concentrations that were highly variable from one area of the stone to the next. This is not consistent with the results obtained on known treated stones. One of these anomalies was a 2.63 ct. round brilliant-cut blue sapphire that showed clear evidence of heat treatment.

Initial LA-ICP-MS analyses of two spots on the girdle of this sapphire showed 3.5 ppm Be in one that coincided with the edge of an angular milky cloud within the stone, whereas the other spot (with no Be detected) was well away from any inclusions. Further analyses revealed up to 13.3 ppm Be in the cloud, and essentially no Be elsewhere in the stone. The cloud also showed consistently elevated concentrations of niobium (Nb) and tantalum (Ta).

Figure 5. The clouds that are associated with traces of Be often are extremely fine grained and appear milky white in darkfield illumination (left). However, they usually have a brownish appearance when viewed in transmitted light (right). The planar structure of this cloud can also be seen in the image on the right. Photomicrographs by Shane F. McClure; magnified 20×.
 The cloud in question had a distinctive appearance: a very fine particle size (so small that the individual particles could not be resolved with a standard gemological microscope), planar structures, a milky white appearance in darkfield illumination, and a brownish appearance in transmitted light (figure 5). It is important to note, however, that whereas clouds with a similar appearance were seen in other samples investigated, not all of these clouds contained Be. Due to the extremely fine size of the particles in these clouds, the phase(s) present have not yet been conclusively identified.

In addition to these 17 stones, the Laboratory has detected traces of Be (along with elevated levels of Ta and Nb) associated with such clouds in blue sapphires submitted to the Laboratory for identification reports. A few of these sapphires showed no signs of heat treatment. This was also the case for some samples collected by GIA researchers – and others obtained by AGTA’s Richard Hughes – at the deposits in Ilakaka, Madagascar.

For the heated samples examined, there does not appear to be a likely scenario in which Be diffusion treatment could produce such a dramatically uneven distribution of elements. This, and the detection of Be in sapphires with no evidence of heating, conclusively shows that trace amounts of Be do occur naturally in corundum, at least in conjunction with foreign mineral inclusions (forming the clouds). In addition to ongoing research to better understand this phenomenon and the nature of the clouds, GIA is collaborating on a project headed by Vincent Pardieu (now with the Gübelin Gem Lab in Lucerne, Switzerland) to investigate the effect of heat treatment on the Be that is naturally present in such sapphires. Careful chemical mapping by LA-ICP-MS is being conducted at the GIA Research facility in Bangkok as part of this project. Source: GIA @topic:3


Title: Russian Demantoid, Czar of the Garnet Family Abstract: Demantoid, green andradite garnet, was discovered in the Central Ural Mountains of Russia in the mid-19th century. A favorite of the Czar's court, demantoid was another victim of the 1917 Bolshevik Revolution, when mining of this and other Russian gems was halted. Today, however, independent miners are recovering notable quantities of stream-worn demantoid pebbles from two major districts: Nizhniy Tagil, about 115 km north, and Sissertsk, about 75 km south, of Ekaterinburg. As a result, these distinctive bright "golden" green to dark green garnets are re-emerging in the gem market. Although cut stones continue to be small for the most part, a number of fine demantoids over 1 ct have been seen. Source: GIA @topic:1