Publication Year: 2015 Title: Conservation Concerns over Use of Tridacna Shell in Imitation Pearls Abstract: Figure 1. Left: This white shell bead (10.08 mm) was visible after the coating was removed from one of the imitation pearls. Right: A subtle flame structure was observed on the surface of the shell bead; magnified 40×. Photos by Jessie Yixin Zhou.

              Last year the New York laboratory reported on the use of shell as a pearl imitation (Summer 2014 Lab Notes, pp. 153–154) and the improper nomenclature applied by those marketing it. We decided to delve deeper and investigate the nature of the shell beads used in such imitation pearls following correspondence with Dr. Henry A. Hänni, who previously reported on this issue (see Summer 2004 Gem News International, p. 178, and references within).

After removing the outer coating on one of the imitation pearls by immersing it in acetone, we observed a banded white bead (figure 1, left). Magnification revealed fine and subtle flame structures (figure 1, right), indicating the bead was most likely fashioned from the shell of a Tridacna (giant clam) species.

All species of the Tridacnidae family are currently listed in Appendix II of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). Some species, such as Tridacna gigas, are more vulnerable than others, such as Tridacna squamosa or Tridacna maxima. These large saltwater clams can have heavy shells fluted with multiple folds (figure 2) and colorful mantles. Their natural habitats lie in the warm marine waters of the Indo-Pacific, a fragile region that has been heavily impacted by human activities.

Figure 2. These three shells of Tridacna species are part of the collection at GIA’s Bangkok laboratory. The two largest measure approximately 33 × 20 cm each. The two larger shells were found empty by Thai divers, while the smaller shell was donated to the Bangkok lab several years ago and comes from an unknown source. Photo by Nuttapol Kitdee.
These beautiful marine animals are commonly harvested from their natural habitats or aquaculture farms for food (Center for Tropical and Subtropical Aquaculture Publication No. 114, University of Hawaii), and their shells are fashioned into beads or ornaments that are prized by some cultures. Despite their protection under CITES, these shell products are readily available on the Internet and often very inexpensive (figure 3). Imitation shell “pearls” fashioned from these endangered and protected mollusks do not offer any obvious advantages over common freshwater mussel shells, and it is extremely difficult to identify the exact Tridacna species or whether the mollusks were farmed or harvested from the wild. We urge manufacturers to stop using Tridacna shell beads when producing imitation pearls.

Figure 3. Tridacna shell beads of various sizes (4.5 to 10.5 mm) are readily available from various commercial sites. The carved beads shown on the left are marketed as “Tibetan prayer beads.” Photo by Sood Oil (Judy) Chia. @chapter:14


Publication Year: 2021 Title: Fascinating Fluid Inclusions in Chinese Ruby Abstract: Figure 1. Fluid inclusion mimicking a snake in Yuanjiang ruby from China (left). The diagram on the right shows the details of this “snake.” Photomicrograph by Wenqing Huang; field of view 0.26 mm.
Gem rubies from the Yuanjiang deposit in Yunnan Province, China, host mineral inclusion assemblages comparable with those in rubies from other marble-hosted deposits (W.Q. Huang et al., “Trace element geochemistry and mineral inclusions constraints on the petrogenesis of a marble–hosted ruby deposit in Yunnan Province, China,” Canadian Mineralogist, Vol. 59, No. 2, 2021, pp. 381–408). Moreover, the fluid inclusion scenes in rubies from all of these deposits are also similar (G. Giuliani et al., “Fluid inclusions in ruby from Asian marble deposits: Genetic implications,” European Journal of Mineralogy, Vol. 27, No. 3, 2015, pp. 393–404).

Figure 2. This Yuanjiang ruby from China contains an interesting fish-like fluid inclusion. Photomicrograph by Wenqing Huang; field of view 0.17 mm.
Two rubies from the Yuanjiang deposit showed several interesting fluid inclusions. The most impressive one strongly resembles a snake raising its head (figure 1). The other mimics a fish (figure 2). As shown in figures 1 and 2, the whole fluid cavity was split into two parts, both of which show a bubble. Raman spectroscopy analysis identified the transparent tabular crystals in the snake as diaspore (figure 1). The “snake” also hosted a solid inclusion of arsenopyrite (FeAsS); the needle on its head could not be characterized by Raman spectroscopy due to its fineness. The fluid composition was dominated by CO2 with minor components such as H2S, COS, and CH4, as revealed by Raman spectra and microthermometry. How these special inclusions formed has been speculated elsewhere (W.Q. Huang, “Fluid inclusion and titanite U–Pb age constraints on the Yuanjiang ruby mineralization in the Ailao Shan–Red River metamorphic belt, southwest China,” Canadian Mineralogist, 2021, accepted). This morphology-forming process has been explained by two mechanisms that evolved step by step. The first is morphological ripening that resulted in negative shapes of fluid inclusions; the second consists of subsequent reactions between the trapped H2O and the host corundum during the cooling of the inclusion, generating a diaspore that segregated the fluid completely.
Inclusions (mostly mineral inclusions) in gemstones that mimic scenery and landscapes are fascinating and relatively common. One novelty inclusion, an interesting “fried egg” of epigenetic residue trapped in a fissure, was recently found in rock crystal quartz (Fall 2020 G&G Micro-World, pp. 430–431). However, such novelty inclusions, especially fluid inclusions mimicking animals, are exceptionally rare. @chapter:4


Publication Year: 2019 Title: Mexican Opal with Large Fluid Inclusion Abstract: Figure 1. This 19.94 ct polished freeform opal contained a large, eye-visible three-phase fluid inclusion. Photo by Jian Xin (Jae) Liao; courtesy of Javier Lopez Ávila.

Although opals generally contain water in their structure, fluid inclusions large enough to be resolved with the microscope are rare; those that can be seen with the unaided eye are exceedingly rare. While at the JCK Show in Las Vegas, the author examined a most unusual common opal with a very large eye-visible fluid inclusion (figure 1). The fluid cavity was approximately 14 mm in diameter, and most of the space inside was occupied by a large gas bubble. An aqueous liquid could clearly be observed wetting the walls of the cavity, along with some unknown solid particles (figure 2). Since this fluid inclusion contained solid, liquid, and gaseous phases, it is appropriately described as a three-phase inclusion. According to Javier Lopez Ávila, the stone’s owner, this rare opal specimen was mined from the San Simon mine in Jalisco, Mexico, by Opalos de México. It is the first opal with a large fluid inclusion that he has observed from this deposit. This rare inclusion in Mexican opal is an interesting gemological oddity that any collector can appreciate.

Figure 2. This eye-visible three-phase fluid inclusion in a Mexican opal was just over 14 mm in diameter and contained solid, liquid, and gaseous phases. Photomicrograph by Nathan Renfro. @chapter:39


Publication Year: 2006 Title: Applications of Laser Ablation–Inductively Coupled Plasma–Mass Spectrometry (LA-ICP-MS) To Gemology Abstract: Laser ablation–inductively coupled plasma–mass spectrometry (LA-ICP-MS) is an important technique for quantitative chemical analysis. The authors have applied this minimally destructive technique to gemology to take advantage of its high spatial resolution, rapid and direct analysis of gemstones (whether loose or mounted), and precise measurement of a wide range of elements—even in ultra-trace amounts. This article summarizes LA-ICP-MS principles and describes the successful application of this technique to detecting beryllium diffusion treatment in corundum and identifying the geographic origin of emeralds. LA-ICP-MS is significantly less expensive than SIMS and more sensitive than LIBS, which is the least costly of the three instruments. @chapter:17


Publication Year: - Title: CVD-Grown Synthetic Diamonds, Part 3: Detection Abstract: This Gemesis CVD synthetic diamond shows green fluorescence to the short-wave UV radiation of the DiamondView instrument. Image by Wuyi Wang.

Part 1 of this series provided a brief history of CVD synthetic diamonds, while part 2 examined their properties.

The CVD (chemical vapor deposition) process produces gem-quality synthetic diamond of great beauty, with properties virtually identical to those of natural diamond. Because of their high purity, these CVD products are type IIa—as are only a small percentage of natural diamonds. Therefore, any type IIa diamond should be sent to a well-qualified testing laboratory for identification. Detection has advanced to the point where any CVD-grown sample can be identified with certainty.
The CVD growth process itself occurs under conditions that bring about readily detectable features, including:

1. a low-pressure, highly energetic hydrogen-rich environment
2. the presence of silicon from grower parts
3. the presence of residual nitrogen in the grower
4. the layer-by-layer addition of carbon atoms on the growing surface

The hydrogen-rich environment leads to defects known as vacancies, in which occasional carbon atoms are missing from their proper location in the diamond crystal. A carbon vacancy residing next to a silicon atom can form a silicon-vacancy (Si-V) center, which is extremely rare in nature. A carbon vacancy next to a nitrogen atom may form a nitrogen-vacancy (N-V) center, which is rarely found in nature. These two vacancy-related defects are detectable through spectroscopic measurements such as photoluminescence, ultraviolet illumination, and optical absorption. In the case of the layer-by-layer growth feature, nitrogen is non-uniformly incorporated into the layers, causing growth striations visible under a DTC DiamondView.

	The DiamondView ultraviolet imaging system allows the operator to see a sample's fluorescence patterns from different directions. These patterns are useful in identifying CVD synthesis. Photo by Kevin Schumacher.
Pink-colored CVD synthetics are also readily detected by their abundance of N-V centers. Blue CVDs have been produced by adding boron to the growth chamber, though boron can slow growth so much that only thin films are produced. But even those thin films exhibit CVD-grown features.

In summary, CVDs are readily detected in a gem lab, in specimens of any size or color. Detectable features can change under heat treatment (at low or high pressure), but these changes are well understood and can still provide unambiguous detection of CVD-grown synthetic diamonds. For a detailed scientific study and extensive bibliography of detection, see W. Wang et al, “CVD Synthetic Diamonds from Gemesis Corp.,” Summer 2012 Gems & Gemology, pp. 80–97. @chapter:15


Publication Year: 2017 Title: Exhibition Review: Colors of the Universe: Chinese Hardstone Carvings Abstract: Figure 1. Jade table screen with landscape scene. Nephrite. Gift of Heber R. Bishop, 1902; photo courtesy of the Metropolitan Museum of Art.

Hardstone carving is one of China’s oldest artistic traditions, dating back 8,000 years. As the most highly revered stone in Chinese culture, jade was preferred but other hardstones were carved as well. Access to raw materials rose and fell as dynasties changed, and the carving techniques slowly progressed. During the Qing dynasty (1644–1911) it all came together: a dependable supply of raw material, exceptional artistry and craftsmanship, and enthusiastic imperial patronage―especially by the Qianlong Emperor (r. 1735–1799)―led to a profusion of remarkable carvings.

Colors of the Universe at New York’s Metropolitan Museum of Art showcases 75 of the finest examples of Qing dynasty lapidary art, drawn from the museum’s impressive collection. In addition to jade (figure 1), there are exquisite carvings in agate, quartz, malachite, turquoise, amber, coral, lapis lazuli, and other hardstones. Filling all four walls of one large gallery room, as well as a double floor case in the center, these carvings illustrate the extraordinary imagination and technical virtuosity that was so highly appreciated by the Qing imperial court.

Many, but not all, of these carvings are from the Heber R. Bishop Collection, a portion of which is on permanent view at the museum. Bishop, a noted sugar tycoon and philanthropist of the late 19th and early 20th centuries, was an early trustee of the museum who donated his remarkable collection of jade carvings to the Met in 1902. He also sponsored one of the very earliest books on jade in the English language, a massive pair of volumes weighing 125 pounds. Only 100 copies were printed, distributed exclusively to royalty and national libraries worldwide.

One whole wall of the gallery is devoted to Bishop jades (except, oddly, for one). Here we see evidence of Heber Bishop’s unerring eye for superb carving. Favorites among this group include the large “Boulder with Daoist Paradise,” an example of yu shan or “jade mountain” and the even more massive “Jade Basin” (figure 2), modeled after the famous original in Beijing’s Beihai Park Imperial Garden, believed to have been commissioned in 1265 by Kublai Khan. The original is one of the most famous of all Chinese jades. In the mid-1700s the Qianlong Emperor recovered it from priests in a Daoist temple who were using it to store pickled vegetables. The emperor was so enthralled by this jade basin that he wrote three poems about it, had them inscribed inside, and erected a pavilion to display his treasure.

Figure 2. “Jade Basin” ca. 1774. Nephrite. Gift of Heber R. Bishop, 1902; photo courtesy of the Metropolitan Museum of Art.
The other three walls of the gallery display still more hardstone carvings with the full range of stones the Chinese utilized and even a few (soapstone, amber, coral) that do not strictly meet the definition of hardstone. Many of these are from Bishop’s collection, but several other donors are well represented. Favorites in this group include the little nephrite “Elephant Carrying a Vase” (figure 3) and its companion “Horse Carrying Books” (both inlaid with garnets), the fine agate “Pomegranates” group seen in figure 4 (even the hardwood stand is a work of art), and a lapis mountain-form “Luohan in a Grotto.”

Figure 3.“Elephant Carrying a Vase.” Nephrite inlaid with garnet. Gift of Heber R. Bishop,
1902; photo courtesy of the Metropolitan Museum of Art.

Figure 4. “Pomegranates.” Agate. Gift of Heber R. Bishop, 1902; photo courtesy of the
Metropolitan Museum of Art.
The double case in the center of the gallery features nine snuff bottles (mostly from the bequest of businessman Benjamin Altman) and 12 smaller hardstone carvings. Favorites include a rock crystal snuff bottle with tourmaline “hairs,” seen in figure 5; a jadeite snuff bottle with gorgeous apple-green color (both bottles left undecorated to best show off the material); a finely carved coral ruyi (or scepter); delicately carved pendants of jadeite and tourmaline; and a diminutive aquamarine seal (chop).

Figure 5. Tourmalinated rock crystal snuff bottle with jadeite stopper. Bequest of
Benjamin Altman, 1913; photo courtesy of the Metropolitan Museum of Art.
This exhibition affords the viewer a chance to compare similar kinds of stone. For example, several varieties of carved chalcedony and agate are displayed, as well as different types of jade, both nephrite and jadeite. The kosmochlor jadeite “Elephant with Two Boys” (figure 6) offers a rare opportunity to see a large example of this unusual material, and the green chalcedony vase makes clear the difference between that humble stone and true jade of similar color.

Figure 6. “Elephant and Two Boys.” Kosmochlor jadeitite. Bequest of Edmund C.
Converse, 1921; photo courtesy of the Metropolitan Museum of Art.
All the exhibits are well lighted and clearly labeled. It would have been interesting, though, to include a photograph or two of the carving of these masterpieces. In the Qing period these hard and tough stones would have been patiently hand-worked by slow abrasion on foot treadle powered lathes, making the artisanship all that more impressive. To spend a year or more carving a single piece would not have been unusual.

This exhibition will appeal to all who are interested in lapidary masterpieces, Chinese decorative arts, unusual gem materials, and the very finest in craftsmanship. Gallery 222 is on the third floor; one way to reach it passes through the galleries of ancient Chinese jades; visitors should take that opportunity to see how Chinese hardstone carving began thousands of years ago. Finally, do not miss the opportunity to visit the museum’s Chinese Scholar’s Garden for yet another view into Chinese glyptic arts.

Colors of the Universe: Chinese Hardstone Carvings will run at the Metropolitan Museum of Art’s Main Building on Fifth Avenue until October 9, 2017. The recommended admission is $25 for adults, $17 for seniors 65 and over, and $12 for students; this also allows same-day entry to the Cloisters and the Met Breuer. The Fifth Avenue building is open seven days a week; hours are 10:00–5:30 Sunday through Thursday, and 10:00–9:00 Friday and Saturday. The museum is closed the first Monday in May, Thanksgiving, Christmas, and New Year’s Day. @chapter:25


Publication Year: - Title: Grad Transforms Family Business, Evolves Local Gem and Jewelry Network Abstract: Yihchen Ng, known as "Y.C." to friends and colleagues, has grown his family's business and helped build an active, vibrant GIA Alumni chapter in Malaysia. Photo courtesy of Yihchen Ng

                      Yihchen Ng’s childhood home in Seremban, Malaysia is only an hour from his residence in Kuala Lumpur, the nation’s bustling capital city.

But his path to a major metropolitan area was not direct – Ng’s professional and educational journey wound through many countries and schools before bringing him home.

Ng, known as “Y.C.” to friends and colleagues, is the group executive director of Tomei Consolidated Bhd., and the executive director and CEO of Malaysia’s Oasis College.

His grandfather, a goldsmith in China, immigrated to Malaysia with his wife in the 1930s, but passed away before he was able to pass those skills to the couple’s sons. Ng’s father began his own education, and opened Tomei after finishing his collegiate work.

Ng, who completed grade school in Kuala Lumpur, high school in Singapore and attended grade 13 in Canada’s Columbia College and freshman year with Michigan Technological University, finally settled in after transferring to Iowa State University, where he majored in marketing and graduated with a B.B.A. in 1988.

He returned home and joined Tomei, where he dreamed of evolving the family company. “Those were the days of a predominantly gold jewelry industry,” he says, “when gold accounted for 90 percent of the sales revenue. Even though our business was primarily gold jewelry, I saw the potential of diamonds and gems in the future of Malaysia.”

Friends in the industry recommended that Ng pursue studies at GIA if he wanted to get serious about growth in the jewelry business; he says it was a “natural choice” and completed the Institute’s rigorous Graduate Gemologist correspondence course in 1990, in just a year.

“It was tough, especially when it came to grading and gem identification,” he says. “It was difficult to master, definitely an eye-opening and challenging experience.”

And without a local person to guide him – Ng knew of no other GGs in Kuala Lumpur at the time – or the benefit of today’s Web-based curriculum, he was largely on his own.

His diligence showed positive returns. After he earned his GG, he began to buy loose gemstones and build the first stages of Tomei’s gem and jewelry manufacturing business. He has worked in and overseen nearly every aspect of the company’s growing operations and introduced CAD and 3D prototyping in 2004.

Ng completed his MBA in finance from the U.K.’s University of Hull in 1995 and primarily focuses on corporate issues and sales. He also serves as treasurer for the Federation of Goldsmiths and Jewelers’ Associations of Malaysia (FGJAM), which has “constant dialogue sessions” with several government agencies, including the police and central bank, on security issues and new rulings.

In 2010, Ng also took over as CEO and executive director of Malaysia’s burgeoning Oasis College, which offers the first jewelry design course approved by the country’s Ministry of Higher Education. The program requires students to spend months of hands-on training in industrial manufacturing and retail environments.

But as much as Ng embraces new technologies and ventures, he believes a solid foundation is critical.

“A GIA education is a must,” he says. “It’s the ticket to the gem industry, a template and guiding tool to explore further. You gain a knowledge about gems that is mapped out systematically, and are trained with equipment for identification. This sets a firm foundation.”

Ng advises students enrolling at GIA to cover the basics: get their eyesight checked, mentally prepare for “intensive practical training,” and brush up on English if it’s not their first language. He also encourages them to join a local Alumni Association chapter and follow GIA publications to advance professional knowledge and understand new technologies after they graduate.

His own early experience taught him about the importance of that professional network, and in 2010, Ng was hand-selected by Tawfic Farah, GIA’s late vice president of international operations, to launch the GIA Alumni Association chapter in Malaysia.

Ng, who resides in Kuala Lumpur with his wife and three children, has served as president of the chapter ever since. He’s energized about the chapters’ growth and leadership, and how it can help the regional gem and jewelry business.

 “One of the main reasons for establishing a local chapter was to provide a good network for alumni – be it for academic or business support, or just friendship,” he says. “And since GIA is very active in engaging the global alumni communities, it helps local chapters connect and relate with other chapters effectively.” @chapter:36


Publication Year: 2017 Title: Growth Tube Cluster in Sapphire Abstract: Surface-reaching growth tubes within a sapphire exhibit unaltered yellowish staining, an indication that the stone has probably not been heated. Combined with other observations, this suggests a possible Madagascar origin. Photomicrograph by E. Billie Hughes; horizontal field of view 1.4 mm.

Growth tubes are a typical inclusion in corundum and often seen during examination in the laboratory. While commonplace, a stunning cluster such as the one seen above calls out to the photomicrographer. At the surface these tubes are cut through and some black debris has become lodged inside the ends, while deeper within the stone they still display a fiery glow, reminiscent of rockets launching into the sky.

Not only do these tubes spark the imagination, but they can actually tell us a lot about the identity of their sapphire host. The limonitic staining found deeper in the tubes is a yellowish orange, suggesting that they have not been altered by heat treatment. These stains often turn a darker reddish or brownish color in heat-treated stones (J.I. Koivula, “Useful visual clue indicating corundum heat treatment,” Fall 2013 G&G, pp. 160–161).

Furthermore, we have observed in the past several months that these prominent growth tubes are a common feature in Madagascar sapphire. While the tubes can be found in corundum from other origins, they seem particularly common in the Madagascar material that has been entering the Bangkok market in greater numbers recently. When taken into account along with other features, they provide a clue to the origin of these sapphires. Thus, what initially appeared to be a mundane inclusion is both visually impressive and gemologically significant, as it provides hints to the origins and treatments of corundum. @chapter:10


Publication Year: 2017 Title: New Deposits of Gem-Quality Common Opal from Michoacán, Mexico Abstract: Figure 1. Gem-quality common opal was recently discovered in Michoacán State in western central Mexico. The approximate size of this sample is 15.04 × 7.68 × 5.57 cm. Photo by M. Ostrooumov.

Recently, the author discovered new deposits of common gem opal (figure 1) in the hills near Lake Cuitzeo, in Mexico’s Michoacán State. These opals were embedded in volcanic andesitic rocks. They were generally characterized by a medium to light orange to brown color, with no visible inclusions. While these new deposits are considered “common opal” since the material does not show play-of color, some gemologists may also consider the specimens to be fire opal due to the orangy bodycolor. The samples were studied at the Institute of Earth Sciences at the University of Michoacán in Morelia.

Standard gemological testing yielded refractive indices between 1.440 and 1.457 and hydrostatic specific gravities (SGs) ranging from 2.11 to 2.14. The material was inert to both long- and short-wave UV radiation. These properties suggested common opal, which we later confirmed with scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic force microscopy (AFM), Raman microprobe, and infrared spectroscopy.

Previous research (E. Fritsch et al., “Mexican gem opals: Nano-and micro-structure, origin of colour, comparison with other common opals of gemmological significance,” Australian Gemmologist, Vol. 21, No. 6, 2002, pp. 230–233) has shown that Mexican opals with play-of-color exhibit a higher degree of organization. In these specimens, nanoparticles measuring about 10–50 nm in diameter form pseudospheres (lepispheres) of appropriate size to diffract visible light (about 200 nm) in a matrix of less acid-soluble silica particles. When examined with a scanning electron microscope, fresh broken surfaces show no particular organization, but after etching with diluted hydrofluoric acid (10% vol. HF), the microscopic arrangement of spheres is revealed. There is a continuum of structures between opals with and without play-of color. In addition to the role of particle size, rounder spheres with a more organized structure display a more noticeable play-of-color with a wider range of colors.

From SEM and AFM images, it is clear that these newly discovered common opals from Michoacán are built from a random aggregation of small, near-spherical grains, averaging 60 to 100 nm in size. (The software we used was ImageJ, an open-source image processing program designed to generate scientific multidimensional images.) The apparent diameter of some grains actually ranges from about 120 to 130 nm (figures 2 and 3). The nanostructure of this common opal explains the absence of play-of-color. In this case, we can consider the following general explanations for the lack of play-of-color:

  The spheres do not have the same size (heterogeneous structure).
  The spheres are not perfectly spherical.
  The spheres are the same size but not well organized.
  The spheres are too small (<150 nm) or too large (>300 nm) to diffract light.

Figure 2. SEM image of the heterogeneous nanostructure of a common gem opal
from the Cuitzeo area in Michoacán. The spheres are too small, irregularly sized,
and disorganized to exhibit play-of-color.

Figure 3. Distribution of particle sphere diameters in the nanostructure of the newly
discovered Mexican volcanic opal. Most of the spheres are 60–100 nm, a size too
small to diffract light.
In some cases two or more of these conditions occur in the same sample.

All Mexican volcanic CT-opals have similar Raman spectra characterized by a very strong general band (apparent maximum toward 325 cm–1) that shows a complex structure with lines of weak to medium intensity (M. Ostrooumov et al., “Spectres Raman des opales: aspect diagnostique et aide a la classification,” European Journal of Mineralogy, Vol. 11, No. 5, 1999, pp. 899–908). According to theoretical calculations, the normal modes in the 300–350 cm–1 range consist mainly of Si-O-Si bending vibrations of ring atoms. Other principal bands in the Raman spectra of opal from these new deposits are found at about 800 and 960 cm–1, 1069–1086 cm–1, and 1600 and 3200 cm–1. These bands belong to α-tridymite, α-cristobalite, α-quartz, and groups of H2O and OH.

Infrared absorption bands were observed between 4000 and 400 cm–1, which is typical for all varieties of micro- and non-crystalline opals (C, CT, and A). The three strong bands near 1100, 790, and 480 cm–1 are common to all silicates with tetrahedrally coordinated silicon (M. Ostrooumov, “A Raman, infrared and XRD analysis of the instability in volcanic opal from Mexico,” Spectrochimica Acta, Part A, Vol. 68, No. 4, 2007, pp. 1070–1076). Broadly speaking, in opal-CT only localized Si-O-Si stretching and bending vibrations remain. The distinction between opal-CT and opal-A requires careful inspection of the frequencies of the three strong Si-O bands. In particular, the band at 790 cm–1 is always at higher frequency in opal-A than in opal-CT. Broad absorption bands between 3700 and 2700 cm–1 are due to fundamental O-H stretching vibrations. For example, a very broad band is present at around 3448–3458 cm–1, with a shoulder at about 3250 cm–1 that is generally considered to be related to hydrogen-bonded molecules of water.

Based on TEM results, we have been able to prove that the orange to brown bodycolor of Mexican common opal is due to nanoinclusions of an iron-containing material. It is probably related to hematite, which is often found associated with common opal in nodules. It typically appears as needles measuring 10 to 20 nm wide by 100 to 200 nm long, seen only with TEM. @chapter:39


Publication Year: 2012 Title: Radioactive Morganite Abstract: Two strongly orangy pink morganites with residual radioactivity were studied. The dose rate of the samples, measured by a scintillation survey meter, ranged from 0.15 to 0.35 μSv/h. Although this radioactivity was likely not hazardous, it was above the recommended exposure limit set forth in 1990 by the International Commission on Radiological Protection. To identify the radionuclides, gamma rays from the samples were measured using a Ge(Li) semiconductor detector. The activation products 134Cs, 54Mn, and 65Zn were detected, proving that the samples had been artificially irradiated with neutrons. @chapter:6


Publication Year: 2024 Title: Seventh Annual Gianmaria Buccellati Foundation Award Winner Abstract: Suhan Wang’s winning necklace design sketch for the 2023 Gianmaria Buccellati Foundation Award for Excellence in Jewelry Design, featuring platinum, emerald, ruby, diamond, and tsavorite.
Suhan Wang, a graduate of GIA’s Jewelry Design program in Taiwan, received the seventh annual Gianmaria Buccellati Foundation Award for Excellence in Jewelry Design. The 18 finalists and winner were announced at the GIA Alumni Collective’s “Night at the Museum” event held during the AGTA GemFair in Tucson. Wang’s winning design, a necklace featuring platinum coils adorned with emerald, ruby, diamond, and tsavorite, stood out to the judges for its sense of movement and skill of execution (see above).
Created in partnership with the Gianmaria Buccellati Foundation in 2018, the award recognizes outstanding talent in design among GIA students worldwide. Larry French, chief officer for North American strategies at the foundation, said, “On behalf of the Gianmaria Buccellati Foundation and Rosa Maria Buccellati, we want to congratulate Ms. Suhan Wang, plus all the other designers whose work has honored this competition. We also want to send our appreciation to the talented GIA design instructors whose skill and efforts helped the students on their journey to celebrate the art of jewelry design in the highest way, an art that meant so much to Gianmaria Buccellati.”
As part of the award, Wang will travel to Italy and meet with a representative from the foundation.
The 2024 Gianmaria Buccellati Foundation Award for Excellence in Jewelry Design competition is underway and open to students in GIA’s Jewelry Design courses who meet the eligibility requirements. Visit www.gia.edu/buccellati-foundation-award-jewelry-design for more information. @chapter:36


Publication Year: 2024 Title: Two Pen Pearls from Bahrain Abstract: Figure 1. Two pen pearls from Bahrain displayed on a pen shell originating from the same waters. Both the shell and the pearls exhibit a similar color pattern. Pearl A measures 4.65 × 4.25 mm and weighs 0.65 ct (left); Pearl B measures 4.86 × 4.34 mm and weighs 0.73 ct (right). Photo by Gaurav Bera.
Pen or pinna pearls, also known as the “fan clam,” originate from the marine bivalve mollusk belonging to the genus Pinna or Atrina. They are commonly found across the Indo-West Pacific region, from southeastern Africa to Melanesia and New Zealand, extending north to Japan and south to New South Wales. Additionally, they can be found in the Mediterranean Sea, the Red Sea, and the Arabian (Persian) Gulf. Typically, the shell size ranges from 10 to 60 cm, producing pearls measuring up to 11 mm and rarely even 16 mm. Most of these pearls are non-nacreous, displaying colors ranging from yellowish orange to brown and black, while the nacreous pearls exhibit a silvery surface (CIBJO Guide for Classifying Natural Pearls and Cultured Pearls, 2021).

Figure 2. A: Non-nacreous cellular structure with a significant surface-reaching crack in pearl A; field of view 0.5 mm. B: DiamondView image of the cellular structure on the black area on pearl A. C: Cellular structure with a network of subsurface cracking on pearl B; field of view 1.6 mm. D: DiamondView image of a spectacular greenish blue reaction of the cellular structure and the subsurface cracks on pearl B. Images by Karan Rajguru (A, B, and D) and Pfokreni Nipuni (C).
GIA’s Mumbai laboratory recently received two pen pearls for scientific examination. They were recovered by a renowned Bahraini diver from the shallow waters off Bahrain, fished at a depth of 2 meters in October 2023. Pearl A was a bicolor yellowish brown and black button shape, weighing 0.65 ct and measuring 4.65 × 4.25 mm, while pearl B was a yellowish brown near-button, weighing 0.73 ct and measuring 4.86 × 4.34 mm (figure 1). Visual observation showed significant surface-reaching cracks on pearl A (figure 2A) and a network of crazing or cracking due to the columnar structure on pearl B (figure 2C). When viewed under 40× magnification with a fiber-optic light, both exhibited a translucent non-nacreous surface with a columnar calcite structure, displaying a pseudo-hexagonal cellular outline (N. Sturman et al., “Observations on pearls reportedly from the Pinnidae family (pen pearls),” Fall 2014 G&G, pp. 202–215).
The pearls showed an inert reaction when exposed to X-ray fluorescence. Energy-dispersive X-ray fluorescence spectrometry on both revealed manganese levels below detection limits and 45 ppm and higher strontium levels of 1183 ppm and 1303 ppm, respectively, confirming their saltwater origin. Under long-wave ultraviolet radiation, the black area on pearl A was inert, while the yellowish brown area showed a moderate yellowish green reaction similar to that of pearl B. Faint patchy reddish areas were also observed under the translucent surface of pearl B, a reaction linked to a type of porphyrin pigment. When exposed to short-wave UV, pearl A was almost inert and pearl B showed a weaker yellowish green reaction. When examined by the deep-UV wavelength (<230 nm) of the DiamondView, both revealed a greenish blue reaction with a mosaic of fine cellular features of the columnar calcite structure (figure 2, B and D).

Figure 3. Top: RTX imaging of pearl A shows an acicular structure with significant surface-reaching cracks (A), and μ-CT imaging reveals a minute core (B). Bottom: RTX imaging of pearl B shows an acicular structure with a few subsurface cracks (C), and μ-CT imaging reveals a small central core (D).
Real-time X-ray microradiography (RTX) and X-ray computed microtomography (μ-CT) were conducted to study the internal structures. RTX imaging of pearl A revealed a fine acicular (radial) structure with significant surface-reaching cracks (figure 3A). A minute core was visible in μ-CT imaging (figure 3B). Pearl B also exhibited an acicular structure but with broader radiating lines than those observed in pearl A (figure 3C). Similarly, μ-CT imaging revealed a small central core with a few minor cracks (figure 3D). These structures corresponded with the columnar structure observed on their surfaces (Fall 2009 GNI, pp. 69–71).

Figure 4. Left: Cross section of pearl B after grinding, revealing an acicular structure with a dark inner ring and a small central core; field of view 2.1 mm. Right: Long-wave UV image of the cross section with the dark ring and core showing a brownish red reaction. Photos by Karan Rajguru.
Raman spectroscopy using 514 and 830 nm laser excitation revealed peaks for both pearls at 280 and 712 cm–1 as well as 1085 cm–1, indicative of calcite. The surface of pearl B was ground down, exposing a dark brown ring along with the acicular structure (figure 4, left). This ring was not visible in RTX or μ-CT imaging. Raman analysis on different spots of the ground pearl showed similar calcite peaks with a weak polyenic pigment peak at around 1437 cm–1. Photoluminescence analysis for both pearls revealed very weak bands at 620, 650, and 680 nm, indicating natural coloration. These bands were more distinct on the cross-sectional areas of pearl B. In addition, the dark brown central core and ring exhibited a brownish red reaction when viewed under long-wave UV radiation (figure 4, right), linked to a type of porphyrin pigment previously recorded in partially non-nacreous and nacreous pearls from the Pteria species (S. Karampelas and H. Abdulla, “Black non-nacreous natural pearls from Pteria sp.,” Journal of Gemmology, Vol. 35, No. 7, 2017, pp. 590–592) and in a Pinctada radiata shell with a partially non-nacreous blister pearl (Winter 2023 GNI, pp. 527–529).
Non-nacreous pen pearls are often priced lower than their nacreous counterparts from the Pinctada species, mainly due to their durability issues related to surface cracks. Although not desirable for jewelry purposes, they have been used as nuclei for producing atypical bead cultured pearls. In such cases, identification becomes very challenging due to their internal structure composed of natural acicular growth features. This submission provided an interesting opportunity to study these known pen pearl samples from Bahrain, a habitat shared with the popular Pinctada radiata mollusk species. @chapter:14


Publication Year: - Title: A Tropical Paradise of Ocean-Inspired Jewelry and Gemstones Abstract: A 17 mm baroque Tahitian cultured pearl is the focal point of this whimsical octopus brooch set in black-plated 18K gold. The brooch features 374 black, 26 yellow and 169 white diamonds. Courtesy of Ron Greenidge and Emiko Pearls International. Photo by Robert Weldon/GIA

A tropical paradise conjures up images of swaying palm trees, the soothing sound of ocean waves and intoxicating floral fragrances. If this vacation is not on your agenda, you can escape to a warm-water paradise in your mind with these jewels that formed in the sea, are inspired by marine life and evoke the ocean’s essence.
Gems from the Sea
The ocean provides us with a variety of pearls, shells and coral – all top-of-mind when we think of gems from the sea, whether natural or cultured.

Urchin necklace by Evelyn Huang features two Eyris® pearls accented with color sapphires, garnets and amethysts. The Eyris® cultured blister pearl is a product of the Paua abalone shell, which is native to New Zealand. Photo by Orasa Weldon/GIA
The Pantone Color Institute named “Living Coral” its color of the year for 2019, reminding us that coral is a living member of the animal world and contributes to the health of the ocean ecosystem. Coral is a protected species and subject to regulation in the United States, requiring declaration and licensing permits from the U.S. Fish & Wildlife Service. Black coral, found in Hawaii, is the only coral that can be legally harvested in the U.S. All other corals are imported, usually from China. Gem-quality coral is primarily found in the Mediterranean and in the Pacific Ocean off the coasts of Japan and Taiwan.

“Tree Toad,” composed of pink tourmaline on a branch of coral is accented with South Sea cultured pearls and enameling. Designed by Tony Duquette and Hutton Wilkinson, courtesy of a private collector. Photo by Orasa Weldon/GIA
The warm waters of Australia, Indonesia, the Philippines and Myanmar (formerly Burma) are the pearling regions and natural home of Pinctada maxima, a large bivalve mollusk and the source of South Sea cultured pearls. South Sea pearls are known for their thick nacre, satiny luster, large size, and subtle array of colors. The silver-lipped P. maxima produces white to silver pearls and the gold-lipped P. maxima produces mostly yellow to orangy yellow pearls, called “golden” in the trade.

These golden South Sea pearl earrings glow with superb orient and luster. Sapphires, moonstones, and mother of pearl create an eye-catching combination. Designed by Dilly Kirby of Harbor Springs, Michigan. Photo by Orasa Weldon/GIA
French Polynesia is the only area with optimal conditions for the subspecies Pinctada margaritifera cumingii, the black-lipped mollusk used to culture black Tahitian pearls. Historically, black pearls were found in North America in the Sea of Cortez in the Gulf of California in pre-Columbian times. La Paz became the main commercial center for pearls in the 16th century.

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Eyris® cultured blue pearls of the abalone Haliotis iris or Paua shell native to New Zealand, form as a blister – a dome shape inside the abalone shell. It takes up to three years to culture each blister pearl. With an overall success rate of 25 percent, these cultured pearls are truly in a class of their own. With iridescent colors shimmering like the ocean waves, the pearls are sometimes tinged by rare blue colors. Their mesmerizing colors can range from blues and greens, to golds and pink, with some having splashes of red and violet.
Carvings Inspired by Sea Life
The colors, textures and movements of sea life are fascinating to observe, especially when depicted as jewelry or sculptures.

Gerd Dreher’s evocative, softly undulating carved agate emulates coral. Translucent agate gives the fish’s fins a shimmering realism. Courtesy of the William F. Larson family. Photo by Robert Weldon/GIA
The intricate patterns and romance of sea creatures, fauna and flora is masterfully rendered by gemstone carvers Patrick Dreher and his father, the late Gerd Dreher. Their dynasty has passed techniques from father to son for 13 generations over a period of five centuries. The Dreher carvings have an unsurpassed quality of realism, due in part to the advancement of diamond-sintered tools, and in greater part to their devoted observation of their subject’s nature.

This diamond-studded enameled sailfish brooch by Tiffany & Co. recalls the 1930s, an era when sportfishing became a favorite pursuit of the elite in the U.S. Courtesy of Vartanian & Sons. Photo by Robert Weldon/GIA
Warm, tropical waters are known for colorful sea life and enameling is a metal technique that offers a great opportunity to add color to a design. Louis Comfort Tiffany began exploring jewelry making and enameling, a process in which glass is fused to metal, in the early 1900s. The green and blue sailfish brooch by Tiffany & Co. recalls the 1930s when sportfishing was popular among the elite in the U.S.
Gems that Evoke the Sea
There are several gem materials whose colors remind of us the sea, and jewelry designers and gem carvers take advantage of them to create ocean-inspired pieces.

Appearing as though it was an ocean wave frozen in time, this understated 54 ct polished slice of blue papagoite overlaid by layers of quartz evokes an ocean wave. Courtesy of Rare Earth Mining, Bill Heher. Photo by Robert Weldon/GIA
Discovered in 1960 in the hot, arid desert in Ajo, Arizona, papagoite is a rare cyclosilicate mineral. It was named after the Sand Papago people who inhabit the area. This is the only known source in the United States, although worldwide it is also found in South Africa and Namibia. Its bright blue color is its most notable characteristic, and it is used as a gemstone.

This piece of polished labradorite shows great labradorescence and the shifting blue and gray colors mimic the ebb and flow of the ocean. Gift of Carol and Larry Greenfield. Photo by Orasa Weldon/GIA
Labradorite lends itself to interpretation by the jewelry artist. Its shifting blue and gray colors mimic the ebb and flow of the ocean. Because labradorite is a plagioclase feldspar, it can form fine, microscopic, intergrown layers of albite and other plagioclase feldspars. When light hits the layers, the light waves interfere with each other, creating bands of shimmering spectral color, typically blues and greens. This phenomenon is called labradorescence, named after the mineral that displays it.
Boulder opals are mined from large ironstone boulders under the ground. Thin veins of colorful opal forms in cracks and fissures in these boulders. Because these veins of color are so thin, opal cutters need to leave the ironstone on the back of the opal to form a full-sized stone. The thin layer of opal in boulder opals can display any color of the spectrum in a beautiful play-of-color.
A tropical island getaway may only be a daydream, but you can treat yourself with ocean-inspired jewelry whenever you desire. @chapter:40


Publication Year: - Title: Winter 2012 Gem News International Abstract: Colored Stones and Organic Materials
            Naturally Healed Fractures in Ethiopian Opal
            New Supplier of Montana Sapphires
Pinctada Margaritifera Cultured Pearl with Baroque-Shaped Nucleus
            Update on Ruby Mining and Trading in Northern Mozambique
Conference Report
            2012 NAG Institute of Registered Valuers Conference

To view the full section, download the PDF above. @chapter:3


Publication Year: 2023 Title: Clinochlore and Muscovite in Quartz from Colorado Abstract: Figure 1. This quartz crystal cluster from Larimer County, Colorado, contains numerous bluish green and white spherical inclusions on phantom growth planes. Photo by Annie Haynes; courtesy of Nico Jackson.
Recently the author encountered a parcel of quartz with phantom layers consisting of beautiful bluish green and white spheres (figure 1). Raman analysis identified the green spheres as clinochlore (figure 2), Mg5Al(AlSi3O10)(OH)8, a member of the chlorite group. Many of the white orbs appeared to be secondarily altered, presumably by fluids entering through fractures in the quartz host, though some showed no clear evidence of alteration. Raman analysis of one of the unaltered white spheres identified it as muscovite, KAl2(AlSi3O10)(OH)2. Minute dark brown to black spheres were also present and visually consistent with hematite, but that could not be confirmed by Raman analysis.

Figure 2. These bluish green spheres in the quartz crystal were identified as clinochlore, and the white spheres were identified as muscovite. Photomicrograph by Nathan Renfro; field of view 4.23 mm.
This material is from Larimer County, Colorado, where it was collected in 2020 by Nico Jackson. So far, three pockets of material have been discovered, with a total production of about 10 kg. While chlorite-group minerals are relatively common inclusions in quartz, the soft texture and greenish blue color of these clinochlore spheres are less common in the author’s experience. These green clinochlore spheres with contrasting white muscovite spheres are a striking addition to the possible minerals seen in the micro-world of quartz. @chapter:13


Publication Year: 2018 Title: New Technologies and Techniques Abstract: Figure 1. Left: A diamond consumer characteristics chart in which the outer squares represent characteristics beyond the Four Cs shown in the inner squares. Right: A diamond fluorescence image.

Beyond the Four Cs Basics Towards Core Diamond Values
Alexander Mosyaikin1 and Janak Mistry2
1OctoNus Software, Moscow
2Lexus SoftMac, Surat, India
Diamond grading systems continuously evolve towards more precise descriptions for relevant discussion and comparison. The basis consists of the Four Cs: carat weight, cut, clarity, and color.
Nowadays, consumers often look for clues beyond the Four Cs. The important and unique polished diamond features for end users comprise the next level of diamond description. In figure 1 (left), the central four tiles represent the Four Cs graded by the labs: pavilion color, clarity grade, polishing and microsymmetry, and carat weight. The outer tiles are the advanced diamond descriptions based on the unique core diamond features such as brilliance, fire, and table color.
These additional descriptions might provide critically important information for making decisions in cases of

Diamonds with identical Four Cs grading reports but differences in beauty and value
The design of jewelry pieces for balance in fire, brilliance, scintillation, and other factors
Uncertainty about a grading report’s authenticity
Comparing the optical performance of round and fancy cuts

The DiBox 2.0 makes users fluent in a new tier of diamond language. It generates diamond photos (figure 1, right) and videos for professional testing and specific consumer environments (e.g., office, sunlight, nightclub). Controllable long-wave ultraviolet (UV) diodes, along with full-spectrum-visible light-emitting diodes (LEDs) create different lighting conditions (indoor, outdoor, lab, UV-free), revealing the impacts of UV fluorescence on diamond transparency and color. The selection of lighting conditions includes Fire, Office, ASET/Ideal Scope, Hearts & Arrows, Fluorescence in Long-Wave UV, White Dome Lighting, Darkfield, and Brightfield. The DiBox 2.0 takes 3D videos, allowing virtual appreciation of diamonds remotely in a way that is much closer to reality. DiBox 2.0 images, along with the precise Helium Polish scanner 3D model, can be used to simplify clarity plotting.
The DiBox 2.0 also captures data for automatic assessment algorithms. Brilliance and Optical Symmetry beauty metrics are already available through the Cutwise web platform. These metrics allow the user to compare optical performance of diamonds with different sizes and cuts (round and all fancies) using core consumer values, which form the higher tier of the diamond description system.
Creating Gems Using the Zirconia Sintering Process
Etienne Perret
Ceramique by Etienne Perret, Camden, Maine
Whereas most of us are familiar with the hydrothermal and flux-melt solution methods for growing crystal forms of zirconia, these are not the only way to create gem forms from this material. Using the sintering process, zirconia powder can be baked at high temperatures to create three-dimensional objects.

Figure 1. This necklace contains 29 oval beads of sintered black zirconia measuring 12 × 17 mm apiece, with a diamond pavé clasp set in white gold. Photo by David Stewart Brown.
Sintered zirconia (figure 1), also known as zirconia ceramic, is used in many medical and industrial applications. Zirconia ceramics are now successfully used in the watch and jewelry industry. Its relatively low cost and high durability make it an ideal alternative to precious metals. A wide range of colors in addition to white and black can be achieved by adding trace elements to the zirconia powder before it is sintered. All these factors make zirconia ceramic an extremely interesting material to consider in the manufacture of jewelry.
Fluorescence Spectroscopy for Gemstone Screening and Identification
Tsung-Han Tsai
GIA, New York
Gemologists are always looking for fast, accurate, and cost-efficient methods and tools to identify gem materials. Fluorescence spectroscopy is a highly efficient way to detect a gemstone’s defects or impurities, while the characteristic fluorescence response can be used to identify the gemstone. Therefore, this rapid technology has the potential to be used to separate natural diamonds from laboratory-grown diamonds and diamond simulants, detect multi-treated pink diamonds, and identify colored gemstones. This technique can be applied to test both loose samples and mounted jewelry pieces. An experimental prototype has been built to test the concept of using fluorescence spectroscopy under room temperature for gemstone screening. The device uses a UV LED as the light source. Optical short-pass and long-pass filters are installed between the light source and the spectrometer to isolate the fluorescence from the excitation. Optical lenses are used to focus the UV source into the reflection fiber probe and then couple the fluorescence into the spectrometer. The prototype uses a reflection fiber probe to enhance the flexibility of sample positioning, allowing the user to easily target individual mounted or unmounted gemstones.

Figure 1. Characteristic fluorescence spectra of natural diamond, multi-treated pink diamond, and the most common colored stones: corundum, emerald, spinel, and zoisite.
To test the performance of the prototype and the screening software, we measured more than 10,000 samples including natural diamonds, diamond simulants, laboratory-grown diamonds, treated pink diamonds, and colored gemstones such as ruby, sapphire, emerald, spinel, and zoisite to confirm the detection rate of this device. Figure 1 shows the fluorescence spectra of natural diamond, multi-treated pink diamond, and various colored stones. The prototype detected 97% of natural diamond, and referred 100% of diamond simulants and both HPHT and CVD laboratory-grown diamonds for further testing. In pink diamond identification, 99% of natural pink diamonds were detected, while multi-treated pink diamonds and pink laboratory-grown diamonds were 100% referred. Finally, the device detected 93% of corundum, 97% of emerald, 93% of spinel, and 81% of zoisite.
From Screening to D-tection
Marleen Bouman, Ellen Biermans, and Ans Anthonis
HRD Antwerp
Screening diamonds by type is a safe way to sort potentially lab-grown colorless diamonds from natural diamonds. Nevertheless, in many cases the referral rate is too high. Therefore, HRD Antwerp has introduced the use of D-tect, a new screening device that forms a perfect complement to the M-screen+. D-tect is a nonautomated device based on UV luminescence imaging and photoluminescence spectroscopy (PL) at room temperature and liquid nitrogen (LN) temperature. In combination with M-screen+, this instrument offers the ultimate assurance of distinguishing all laboratory-grown diamonds from natural ones.

Figure 1. Example of a CVD synthetic diamond with purple fluorescence and no phosphorescence. D-tect’s PL spectra at room temperature do not reveal the SiV– doublet, but the 467 nm defect is already visible. PL measurements at LN temperatures reveal the SiV– doublet’s presence together with the presence of the 467 nm defect.
In this study, we investigated a parcel of 150 melee-sized CVD-grown diamonds, focusing on features that are challenging for up-to-date screening devices. D-tect checks the SiV– doublet and the 467 nm defect, defects typically seen in CVD laboratory-grown diamonds. At LN temperatures, it is possible to see even the weakest SiV– doublet. This feature, in combination with the presence of the 467 nm defect, identified all of the CVD specimens, even those with uncharacteristic fluorescence colors. An example of a CVD-grown diamond with purple fluorescence and no phosphorescence is given in figure 1.
Image Analysis Techniques Applied to Clarity Issues
Troy Blodgett1 and Andrew Regan2
1GIA, Flagstaff, Arizona
2GIA, New York
GIA’s research in clarity image analysis began around the year 2000 with capturing high-resolution still images to explore whether 2D images could be used as an alternative to clarity plotting. GIA also examined the potential of using image analysis and inclusion-capture algorithms for predicting a clarity grade. Based on this early research, we developed the Imaging System for Automated Clarity (ISAC), which required an operator to select a region of interest encompassing an inclusion and choose the predicted result that best represented the inclusion so that the device could predict a clarity grade. Note that this application pertained mainly to diamonds with single inclusions, although there was a supplemental entry field to adjust the predicted clarity grade if reflections or additional inclusions were reported.
From the ISAC research ending in 2007, a number of patents were filed that same year. The ISAC designs were subsequently re-engineered for a production environment, leading to the implementation of a device for producing images on the eReport in 2012. Further experiments were run on high-resolution manually “stacked” composite images using textural analysis, which showed considerable promise. GIA has undertaken extensive testing of various production-friendly imaging instruments (e.g., Keyence Microscope, Lexus-OctoNus Dibox, and Sarine Loupe) to see which ones could produce images suitable for automated clarity analysis. Artificial neural nets, a type of machine learning, were trained to recognize the shape and texture of inclusions. Examples of such plots are shown in figure 1.

Figure 1. These muted images show a comparison of hand-marked inclusion plots (left) and neural net-predicted results (right) counting inclusion reflections. In general, the predicted results matched the hand-marked plots, but a few discrepancies occurred in both examples.
In addition to plotting features, neural nets have also learned to apply clarity factors such as relative size, number, relief, and position of inclusions to calculate a clarity grade. For predicting a grade, the artificial neural nets were trained on a portion of the crown-view images and the remaining images tested the clarity grade prediction. About 70% of the predicted grades matched the clarity grades provided by graders (evaluating the images) when IF–VVS ranges were lumped together and I1, I2, and I3 were clustered. Distinguishing IF and VVS grades likely requires more information from both the pavilion and girdle views. There were not enough I2 and I3 images available to treat those grade ranges as separate categories. GIA considers 3D information important for clarity evaluation. Images of the crown tilted to varying degrees were used to estimate inclusion depth. Results from the 2D clarity plot, inclusion depth information, and a 3D wireframe model can be combined to render a preliminary 3D clarity plot. Future research will be conducted to add more 3D information from the pavilion view to improve the accuracy of the 3D clarity plot and shed more light on the most challenging IF–VVS clarity range.
Matrix-Matched Standards for Trace-Element Analysis in Ruby and Sapphire
Jennifer L. Stone-Sundberg1, Timothy Thomas2, Zachary Cole3, Yunbin Guan4, Ziyin Sun5, Troy Ardon, and John L. Emmett6
1GIA, Portland, Oregon
2Applied Materials, Hillsboro, Oregon
3Scientific Materials Corporation, Bozeman, Montana
4California Institute of Technology, Pasadena
5GIA, Carlsbad, California
6Crystal Chemistry, Brush Prairie, Washington
As reported recently (Stone-Sundberg et al., 2017), GIA has created sets of highly accurate matrix-matched corundum standards for laser ablation–inductively coupled plasma–mass spectrometry (LA-ICP-MS) analysis as an alternative to NIST glasses. These standards cover applicable ranges of the key trace elements found in natural ruby and sapphire: Be, Mg, Ti, V, Cr, Fe, and Ga. The concern with using non-matrix-matched standards to quantify trace elements in corundum is twofold: (1) Calibrating with a matrix differing in composition and structure will result in dissimilar interferences and ablation characteristics, which will negatively impact the quantification process. (2) The differences in ratios of matrix elements and trace elements of interest between the non-matrix-matched standard and the samples will result in calibration errors. Possibly the most concerning issue for applying NIST glass standards to quantifying many trace elements in corundum is the fact that they simply are not certified for most of the elements of interest.
To ensure the highest accuracy possible, we created and characterized individual ion implant standards for each trace element of interest in corundum, calibrated a secondary ion mass spectrometer (SIMS) with these implants, and then calibrated each individual corundum standard piece using SIMS. We turned to Czochralski growth to produce large and highly uniform multi-doped crystals for these standards (figure 1). The standards sets include two multi-doped pieces of synthetic sapphire to capture relevant levels of Mg, Ti, V, Cr, Fe, and Ga; a highly uniform piece of Yogo sapphire to capture a greater level of Fe than we could generate synthetically; and an ultra-high-purity synthetic sapphire “blank” with a combined total of less than 0.5 ppma of the key trace elements mentioned above. To incorporate Be, pieces from one of the multi-doped crystals were beryllium diffused for 100 hours at 1800°C in pure oxygen. Each piece for the standards set was screened to ensure high homogeneity.

Figure 1. Crystal boules grown by Scientific Materials for multi-doped corundum standards: sample 02-1032 (top) and sample 07-0687 (bottom). Both crystals were doped with Mg, Ti, V, Cr, and Ga in different amounts; only 02-1032 was successfully doped with Fe. Crystal 02-1032 is 40 mm in diameter by 150 mm in length at diameter, and crystal 07-0687 is 30 mm in diameter by 150 mm in length at diameter. Photos courtesy of Scientific Materials.
GIA has been using these standards for more than a year in its colored stones laboratories and is working to make these standards available outside of GIA. We have also been focusing on optimizing the LA-ICP-MS operating protocols throughout our labs to identify the best conditions for gemological applications. The adoption of these standards by other labs will help in creating industry-wide uniformity when it comes to reporting key trace-element data for ruby and sapphire.
REFERENCE
Stone-Sundberg J., Thomas T., Sun Z., Guan Y., Cole Z., Equall R., Emmett J.L. (2017) Accurate reporting of key trace elements in ruby and sapphire using matrix-matched standards. G&G, Vol. 53, No. 4, pp. 438–451, http://dx.doi.org/10.5741/GEMS.53.4.438
Novel Method of Diamond Color Grading by Raman Spectroscopy
Joe C.C. Yuan1, Ju-Tsung Liu2, and Gavin D.S. Pan3
1Taidiam Technology (Zhengzhou) Co., Ltd., China
2Taiwan Food and Drug Administration
3United ID Raman Lab, Taipei
A nondestructive and rapid diamond color-grading method is proposed based upon the 2030 cm–1 characteristic Raman peak. The intensity of this N-C bonding peak for natural untreated “cape” diamonds (type Ia, IIa) is strongly associated with the observed color. When the intensity of the 2030 cm–1 peak is normalized against that of the second-order diamond bond peak at 2666 cm–1, this can be used as a basis for the color grading of cape diamonds, both loose and mounted. The characteristic Raman peak of diamond at 1332 cm–1 corresponds to the vibration mode of the C-C bond. However, the C-N bond peak at 2030 cm–1 (Nyquist et al., 1997; Dana et al., 2004) can reveal information related to the diamond’s color. The 1800–2800 cm–1 spectral range clearly shows additional second-order Raman peaks at 2180, 2256, 2336, 2462, 2490, and 2666 cm–1. The coexistence of the 2030 cm–1 peak and second-order peaks in the overlaid spectrum was seen in all 50 type Ia diamonds examined in this study.
To test this approach, we examined a set of eight certified GIA color master diamonds with grades of E, F, G, H, I, J, K, and L. We collected Raman data in the spectral range between 1600 and 2800 cm–1 and normalized the 2666 cm–1 peak in each data set to 1,000 counts so that we could observe the variation in the 2030 cm–1 peak relative to it. The normalized intensity of the 2030 cm–1 peak clearly increased with increasing yellow tint. A linear relationship was observed when plotting normalized 2030 cm–1 peak intensity versus color grade.
The 2030 cm–1 Raman peak in nitrogen-containing type Ia and IIa cape diamonds is considered to be related to C-N bonding and is consistent with reports of other C-N bond vibration modes at 2030 cm–1, such as in Pb(SCN)2 (Nyquist et al., 1997; Dana et al., 2004). To date, the assignment of the 2030 cm–1 peak as N-related mode does need further research work, which is beyond the scope of this research.
This 2030 cm–1 peak may be overlooked or undetectable by conventional Raman spectrometers due to its low intensity relative to the C-C bonding mode. The instrumentation used in our study has an exceptionally high sensitivity, with S/N > 10,000, supplemented by Auto Baseline Software System, which allows us to detect and analyze this bond mode.
This method for color grading cape diamonds is rapid and nondestructive, with no requirement for sample preparation. It may serve as a novel and semi-quantitative method complementing the conventional colorimetric method. It cannot be applied to HPHT-treated diamonds because the fragile C-N bond peak at 2030 cm–1 may be totally or partially destroyed by the treatment.
REFERENCES
Mayo D.W., Miller F.A., Hannah R.W. (2004) Characteristic frequencies of molecules with triple bonds and cumulated double bonds. In Course Notes on the Interpretation of Infrared and Raman Spectra. John Wiley & Sons, Hoboken, New Jersey, pp. 85–99.
Nyquist R.A., Putzig C.L., Leugers M.A. (1997) Handbook of Infrared and Raman Spectra of Inorganic Compounds and Organic Salts. Academic Press, San Diego, California, pp. 1–14.
Quantitative Determination of Cr3+ and V3+ Contents in Rubies by Spectral Fitting of UV-Vis-NIR Spectra
Tom Stephan1,2, Tobias Häger2, Ulrich Henn1, and Wolfgang Hofmeister2
1German Gemmological Association, Idar-Oberstein
2Center for Gemstone Research, Johannes Gutenberg-University, Mainz, Germany
For this study, the ultraviolet/visible/near-infrared (UV-Vis-NIR) absorption spectra of various natural and synthetic rubies and sapphires were mathematically decomposed into Gaussian and Lorenz curves. For this purpose, we used MagicPlot Pro curve fitting software.
With the help of synthetic corundum samples that were colored respectively by Cr3+ or V3+, we developed two models that allow a comparable and reproducible description of the UV-Vis-NIR spectra (see figure 1). The applicability of the models, the transferability to the absorption spectra of natural rubies and sapphires, and the correlation with chemical analyses were successfully tested.

Figure 1. The o-spectrum of a Verneuil synthetic ruby has been fitted using MagicPlot Pro curve fitting software. Curves Cr 1–Cr 5 are then used to define the Cr3+ model.
The investigations showed that by the use of such models and knowledge of the samples’ thickness, it is possible to determine concentrations of coloring trace elements (in this case chromium and vanadium) quantitatively from the absorption spectra. Additionally, the simultaneous application of Cr3+ and V3+ models is also possible, despite the superposition of the absorption bands of both chromophores. Therefore, the detection of vanadium in rubies is made possible even at low concentrations. This allows first information on the samples’ origin.
Additional information can be obtained from the absorption spectra, such as:

Exact position and shape of the cutoff (absorption edge toward the UV region)
The strength of the Tyndall effect, to estimate the concentration and size of the light-scattering inclusions
Detection of underlying color causes

The investigations are part of the first author’s ongoing PhD thesis. The work’s aim is a model for each cause of color in corundum, which would allow a simultaneous quantification of the concentration of the involved chromophores—as well as for mixed colors. We have also tested the applicability for faceted samples. The first results show that fitting is possible, with appropriate sample orientation.
Additionally, comparable models for other gemstones incorporating Cr3+ and V3+ (e.g., emerald, tourmaline, and garnet) will be developed and tested.
A Simplified Species Classification for Gem-Quality Tourmaline by LA-ICP-MS
Ziyin Sun1, Aaron C. Palke1, Christopher M. Breeding1, and Barbara L. Dutrow2
1GIA, Carlsbad, California
2Department of Geology and Geophysics, Louisiana State University, Baton Rouge
In the trade, gems from the tourmaline species are often identified by sight based on the typical colors of the various species rather than accurate chemical analyses. However, the same color can be exhibited by several different species. In other words, tourmaline color is not species specific. Electron microprobe analysis is the most widely accepted method to determine tourmaline species. Unfortunately, it is also expensive and time-consuming. Most gemological laboratories are not equipped for it and cannot justify the overhead costs associated with outsourcing this analysis. Therefore, the electron microprobe is not a practical everyday tool for a gemological laboratory. Here, we present a comprehensive method for using LA-ICP-MS analyses to accurately determine tourmaline species. The new method allows for inexpensive, clean, fast, and largely nondestructive analysis of tourmaline chemistry. With this method, we are able to produce LA-ICP-MS data for major and minor element concentrations in tourmaline that closely match values determined by electron microprobe (within ±10% error). The ability to accurately measure the range of chemical compositions found in gem tourmaline using LA-ICP-MS allows GIA to help the colored stone industry better understand the varieties of tourmaline being bought and sold.

Figure 1. Much of the brown and yellow tourmaline on the market is sold as dravite or uvite but could just as easily be elbaite. These six tourmalines in various colors, ranging from 1.51 to 11.33 ct, are from Lundazi, Zambia. Photo by Robert Weldon/GIA, courtesy of Bjorn Anckar.
Swept-Source Optical Coherence Tomography for Imaging the Internal Structure of Pearls
Nick DelRe1, Nate Kemp2, Joey Jabbour2, and Andres Zuluaga2
1Gemological Science International, New York
2Axsun Technologies, Billerica, Massachusetts
The popularity of pearls (figure 1, left) over the centuries led to their cultivation to meet marketplace demand. This has resulted in numerous pearls and pearl imitations that at times prove to be an identification challenge, even when using X-ray tomography. Some examples include the differentiation of certain kinds of natural vs. cultured pearls. The difficulty is compounded because pearls must be tested nondestructively, a cornerstone of gemology.

Figure 1. A freshwater tissue-nucleated cultured pearl, shown in visible light (left), in an X-radiograph (center), and an optical coherence tomography image (right).
Traditionally, the internal structure of pearls has been examined by radiography. This imaging method uses X-rays (figure 1, center), which are at the higher-energy end of the electromagnetic spectrum. This technique generates two- and three-dimensional images. To get a clearer picture of the internal structure, 3D images are generated by computed tomography (CT), where multiple 2D images from different angles undergo computer processing. The time to generate an image with good resolution can vary from seconds to several minutes. While passing through the pearl, a certain amount of X-ray radiation is absorbed (dependent on the pearl’s density and structural composition) as well as scattered. Although the radiation is not harmful, there may be a slight degree of ionization occurring when the X-rays are absorbed by the pearl. In addition, the operator must take safety measures while working with ionizing radiation.
Here we present an alternate form of imaging that uses the lower-energy end of the electromagnetic spectrum, namely the near-infrared region. Optical coherence tomography (OCT; figure 1, right) is a noninvasive, micron-resolution cross-sectional scanning of visually translucent to opaque structures. It allows live 3D imaging of sample morphology without sample preparation or exposure to ionizing radiation. OCT fills the imaging gap between ultrasound and MRI (deeper coverage and lower spatial resolution) on one end, and confocal microscopy (shallower coverage, higher spatial resolution) on the other. It can be likened to sonar or medical ultrasound, but using light waves instead of sound waves. OCT has proved very successful in ophthalmology and cardiology applications.
In this technique, a beam of light (typically in the near-infrared spectrum) is used to scan the sample. Coherence refers to the fact that an interferometric, low-coherence technique is used for depth discrimination. Tomography means cross-sectional imaging. To further explain the basic optical setup, the light is split between two arms, one for the sample and one for the reference mirror. The reflected beam from the sample and the reflected beam from the reference mirror interfere with each other. That interference represents the intensity of the reflection from a specific depth in the sample. In classic time-domain OCT, scanning the position of the reference mirror in the interferometer allows the interference signals from different depths to be acquired and processed, thus forming an axial line representing the intensity of reflections from each depth in the sample. In swept-source OCT, a laser source produces a rapid sweep of wavelengths (colors). For each wavelength, an interference pattern is formed. This interference pattern can be processed with exquisite sensitivity, leading to exceptional rejection of signals from depths outside the detection window.
In the case of the 3D data presented here, a pair of galvanometer scanners were used to scan the light in two directions perpendicular to each other and both perpendicular to the depth direction (see the table for the scanning systems’ specifications). Although there have been attempts in the past 20 years to apply OCT technology for pearl examination, none have garnered sufficient interest. Part of this has to do with the cost-effectiveness of this technology for commercial use. In addition, the resulting imaging was still not suitable for pearls, since the penetration depth and sensitivity from available systems was insufficient. Our studies have demonstrated the exceptional performance of a compact and cost-effective advanced swept-source OCT system in delivering high-quality noninvasive 3D images of pearls in real time. @chapter:31


Publication Year: 2022 Title: Pressed Amber Imitation for “Root Amber” Abstract: Figure 1. This bracelet containing 12 mm beads was submitted as “root amber.” Photo by Tsung-Ying Yang.
Root amber, a commercial variety of burmite (amber from northern Myanmar), is popular in the Taiwanese market. As the name suggests, root amber resembles tree roots and usually has a dark brown to light yellow color with creamy swirls caused by the mixing of fine calcite particles and resin during the sedimentation of the amber (Y. Wang, Amber Gemology, China University of Geosciences Press, Beijing, 2018, p. 244).

Figure 2. Pressed amber imitations and natural root amber. Under white light, the pressed amber (A) appeared less homogeneous than natural root amber (C). Granular structure of the pressed amber (B) revealed under long-wave ultraviolet light, whereas natural root amber showed relatively even fluorescence (D) under the same long-wave UV lighting. Photomicrographs by Kai-Yun Huang; field of view 4.23 mm.
Recently, a bracelet was submitted to Taiwan Union Lab of Gem Research (TULAB) as root amber (figure 1). This bracelet consisted of a string of dark brown beads with light yellow creamy swirls. The refractive index of these beads was about 1.54 by spot reading, which was consistent with the RI of amber, and the beads showed uneven medium blue to faint yellow fluorescence under long-wave UV light. Microscopic observation of the beads revealed slight differences from natural root amber. First, the yellow swirls appeared to have a coarse texture rather than smooth. Second, the brown regions seemed to show a vaguely granular structure. The beads were further investigated under a microscope with long-wave UV illumination and compared with those of natural root amber. The results of fluorescence microscopy revealed that these regions did, in fact, show a granular structure with particle sizes ranging from tens to hundreds of microns, while the natural root amber appeared relatively fine-grained and homogeneous under the same lighting (figure 2). Raman spectroscopic analysis and comparison with both the RRUFF database and the internal amber references compiled by TULAB confirmed that these beads were made of amber and calcite particles (figure 3). Previous studies also pointed out that the strongest peaks at 1645 and 1450 cm–1 may respectively be assigned to ν(C=C) and δ(CH2) modes in fossil resin (R.H. Brody et al., “A study of amber and copal samples using FT-Raman spectroscopy,” Spectrochimica Acta Part A, Vol. 57, No. 6, 2001, pp. 1325–1338). To summarize, the amber bracelet should be defined as an imitation—specifically, a pressed amber mixed with calcite powder during the manufacturing process.

Figure 3. Raman spectra comparisons between the spectrum of the bead, amber reference (TULAB), and that of calcite from the RRUFF database suggested that the bead consisted of calcite and amber. The peaks at 1645 and 1450 cm–1 may be assigned respectively to ν(C=C) and δ(CH2) modes in fossil resin. The stacked spectra are baseline-corrected and normalized.
Although pressed amber has long existed in the trade, the addition of calcite powder made this sample a better imitation of natural root amber and more difficult to distinguish by standard gemological testing. The best identification method for such an imitation is observation with fluorescence microscopy. @chapter:37


Publication Year: 2023 Title: Survey of Colored Stone Preferences Among Younger Generations Abstract: Figure 1. Survey participants identified their top consideration when purchasing colored stones or colored stone jewelry.
The global colored stone market is dynamic and constantly evolving. To understand general perceptions and preferences regarding colored stones among designers and potential end consumers from the younger generations, the author conducted a survey in April 2023. The survey targeted 300 respondents under the age of 35, all followers of Donna Jewel (@donna.jewel), an Instagram community designed to champion jewelry from artisans and emerging talents worldwide. Although not scientific, the results of the survey are nonetheless revealing.
Demographics and background: The survey participants consisted of 50% Millennials (born between 1981 and 1996) and 50% from Generation Z (born from 1997 onward). All respondents were over the age of 18. Forty percent were from the United States and another 40% from Europe (specifically Italy, France, the United Kingdom, and Germany), with the remainder split between Latin America (mainly Brazil) and Asia (mainly India and Iran). Respondents identified themselves as gem and jewelry lovers (50%), designers (33%), or gem and jewelry experts (17%).
Colored stone preferences: Participants were asked to choose their single most important consideration when buying colored stones or colored stone jewelry: aesthetics, preciousness, naturalness, sustainability and ethics, symbolism, or economic value. As shown in figure 1, the top two responses were aesthetics (35%) and preciousness (30%). Naturalness was also an important consideration (receiving 20%), while sustainability and ethics was chosen by 10% of the interviewees, symbolism by 4%, and economic value by only 1%.

Figure 2. The preferences of survey respondents regarding natural vs. synthetic (lab-grown) gemstones and untreated vs. treated gemstones.
Given the choice between natural or synthetic gemstones (figure 2, left), 70% chose natural. Only 10% selected synthetic, while an additional 15% expressed no preference. When asked to explain their preferences, the participants who chose natural stones perceived them as unique, rare, and authentic products of nature, capable of evoking emotion, unlike their synthetic counterparts. Those who chose synthetic gemstones viewed them as more sustainable, ethical, and affordable. The topic of natural and synthetic gemstones remains extremely relevant.
Regarding treated vs. untreated natural gemstones (figure 2, right), 75% preferred untreated, which they perceive as more beautiful for their uniqueness and originality. They viewed natural imperfections as an added value lost during treatment. Only 15% preferred treated stones, while 10% acknowledged that they were not informed on the topic.
When asked whether they preferred “precious” or “semi-precious” stones, the participants proved generally indifferent (designers and potential end consumers alike). They associate preciousness with a broader definition more related to uniqueness, emotion, and originality.
Designer perspectives: Designers participating in this survey revealed that they follow both trends and personal inspiration. They noted several uncommon gemstones of particular interest: rainbow obsidian, red beryl, sphene, pargasite, chrysoberyl, scapolite, axinite, enstatite, and benitoite. Fifty percent indicated that they had purchased or used for their jewelry artificially manufactured materials such as glass or cubic zirconia.
At the end of the survey, participants were asked what topics they would be most interested in learning more about. They expressed a strong desire for more knowledge on uncommon and unique gemstones, original colors, treatments, history, lore, origin, and sustainability.
The survey highlighted the younger generations’ strong interest in what is unique, original, authentic, and emotional rather than alignment with traditional notions of beauty and preciousness. Naturalness emerged as an important element for the interviewees, who appreciated imperfection as a mark of authenticity and originality. Young designers favored uncommon and original gemstones with distinct and extravagant colors (especially yellows, blues, greens, and reds). While designers sought uniqueness, rarity, and extravagance, potential end customers were also looking for a gemstone with a story to tell. @chapter:33


Publication Year: 1997 Title: Winter 1997 G&G Lab Notes Abstract: Unheated Aquamarine Carving
Treated Color Beryl
Diamond Acting as a Heat Sink
Fracture-Filled Pink Diamond
Mysteriously Fractured Diamonds
A Very Dark Pyrope-Almandite Garnet
Synthetic Sapphire Sunglasses

To view the full section, download the PDF above. @chapter:32


Publication Year: - Title: Bench Tip: Discover the Benefits of CAD/CAM Abstract: CAD/CAM jewelry design rendering of a ring

                      CAD/CAM is a term that describes the two-part process of designing three-dimensional objects on a computer (CAD) and manufacturing them with a computerized machine (CAM). For many years this technology has been essential in making products from tennis shoes to automobiles, and it is rapidly gaining importance in the jewelry industry. In fact, many experts believe CAD/CAM will be the primary process of jewelry design and manufacturing in the near future.

CAD is an acronym for computer-aided design, but early on it stood for computer-aided drafting, since it was essentially a tool to make traditional technical drawings with a monitor and a mouse. As technology progressed, it became possible to create three-dimensional “models” within the computer environment. These “virtual solids” can be rotated and manipulated onscreen and examined from any angle, built up and cut away the same as a physical model, and even weighed before they are constructed.

For the bench jeweler, CAD modeling onscreen has more in common with wax carving than with pencil, paper and watercolors. Once the virtual model is completed to the designer’s satisfaction, the CAD file may be sent to a CAM machine for production. Rhino, Matrix, ArtCam, RhinoGold and Solidworks are some of the widely used 3-D modeling software in the jewelry industry today.

The advantages of CAD/CAM over traditional manufacturing methods are similar to the advantages of a word processor, such as Microsoft Word, over a typewriter. A typewriter produces “one-off” documents that aren’t easily changeable without starting over. But Word files can be modified easily, copied and pasted into other documents, and saved at each stage for later use.

CAD files can also be copied, changed and saved as often as the designer chooses. A model can be designed and saved, then redesigned to create literally endless variations on a theme. A file can be called up the next day or 10 years later and still be redesigned and sent to the CAM machine. Some manufacturers have stopped making master models since they only need to open the original CAD file and send it to the CAM machine to produce an exact duplicate of the master. Many smaller jewelers own just the CAD software and simply e-mail their CAD files to CAM service bureaus, which fabricate the models for them.

Besides its advantages in the manufacturing process, CAD software can work in tandem with high-tech rendering software such as V-Ray, Brazil and Maxwell to produce spectacular photorealistic images of virtual jewelry models before the actual piece is made. These images can be extremely effective marketing and sales tools. @chapter:34


Publication Year: 1999 Title: Clues to the Process Used by General Electric to Enhance the GE POL Diamonds Abstract: The specific details of the process used to enhance color and clarity in GE POL diamonds have not been disclosed. However, a survey of U.S. patents and European patent applications reveals that General Electric has developed a variety of high-temperature annealing techniques at different pressures for enhancing the optical properties of polycrystalline synthetic diamond films and single-crystal synthetic diamond. These methods may provide important clues to the process being used to decolorize natural type IIa (GE POL) diamonds, that is, by reducing the structural defects associated with their brown coloration. @chapter:15


Publication Year: 2008 Title: An Interesting Rose Quartz from Madagascar Abstract: Figure 36. This 3.83 ct rose quartz from southern Madagascar contains an inclusion suite that has not previously been documented in such material from any locality. GIA Collection no. 37702; photo by Robert Weldon.

              In October 2007, Fabrice Danet (Style Gems, Antsirabe, Madagascar) informed us about a new find of rose quartz from Madagascar that contained some unusual inclusions. He first saw the material in April 2007, when a local dealer offered him a few kilograms of rather small pieces said to be morganite. About half the rough contained noticeable green inclusions, and Mr. Danet subsequently purchased 2 kg. In June 2008, he obtained 10 kg from a 100 kg parcel consisting mostly of small pieces. This time it was offered as rose quartz by a man who actually mined the material. He reported that it came from several small pits in a weathered pegmatite that contained beryl, black tourmaline, mica, clay, and areas of rose quartz. According to the miner and several local dealers, the deposit is located in the Ihosy area of southern Madagascar.

So far, Mr. Danet has cut about 200 stones, the largest of which weighs 27 ct. On examining the material with a loupe, he noticed that the green inclusions had a shape and color that were typical of diopside. Also present were orange hessonite-like inclusions and some very thin needles.

Mr. Danet donated to GIA a light pink 3.83 ct oval brilliant cut (figure 36) and three pieces of rough that contained obvious dark green and bright orange transparent-to-translucent inclusions. The faceted gem was confirmed as rose quartz by standard gemological testing. It contained a relatively large green inclusion adjacent to an orange inclusion (figure 37) that were both visible through the table facet and made excellent targets for Raman microanalysis. As suggested by Mr. Danet, the green inclusions were indeed diopside and the orange crystals were grossular. While we have encountered garnets before as inclusions in rose quartz (from Sri Lanka), this is the first time this combination of inclusions has been observed in rose quartz from any locality. As an added bonus, the very small blade-like to acicular inclusions in the stone were identified as epidote.

	Figure 37. The green inclusions in this rose quartz from Madagascar proved to be diopside, and the orange crystalline masses were identified as grossular. Also present are some needles of epidote. Photomicrograph by J. I. Koivula; field of view 2.7 mm. @chapter:5


Publication Year: - Title: Exhibition Review: Maker & Muse, Women of the 20th Century Art Jewelry Abstract: Figure 1. This aquamarine necklace (c. 1890) by Mrs. Philip (Charlotte) Newman, is seen here in its original box. Newman's work inspired artists and designers of the Arts and Crafts Movement. From the collection of Tereza M. M. Driehaus. Photograph by John A. Faier, 2014, © The Richard H. Driehaus Museum.

Maker & Muse, Women of the 20th Century Art Jewelry, which opened at Chicago’s Driehaus Museum on February 14, 2015, features over 250 pieces of jewelry made during the Arts and Crafts and Art Nouveau movements from British, French, German, Austrian, and American artisans.

The exhibit, which runs through January 3, 2016, is housed in the opulent Driehaus Museum, a fairly new space housed in Gilded Age mansion, located in the heart of McCormickville and a block away from Chicago’s Magnificent Mile. Built in 1879, the Driehaus Museum was originally the home of the Nickerson family, whose patriarch, Samuel, was a distiller for the Union Army and at one-time president of The First National Bank of Chicago. Richard H. Driehaus, who founded the museum in 2003, spent five years restoring it, opening it to the public in 2011. These ever-changing galleries are filled with furnishings, chandeliers, and decorative art from the 19th century to early 20th century Driehaus Collection.

The exhibit is housed on the second floor hallway and in bedrooms that were once inhabited by the Nickersons. At the top of the landing is a case of four pieces of distinctive jewelry, including an aquamarine necklace (figure 1), by Charlotte Newman (1840–1927), who broke through the glass ceiling of women jewelers. After the death of her mentor, John Brogden, Newman continued producing pieces in her own workshop. At the 1889 Paris Exposition, just as the Arts and Crafts movement was beginning she was the only woman listed as a collaborator on the jewelry exhibited.

The first room of the exhibit is titled “With A Hammer in Her Hand: British Arts and Crafts Jewelry.” As the Arts and Crafts Movement (1890–1910) took hold, simpler designs became the fashion for clothing, and the jewelry was made to compliment this change. Brooches, necklaces, clasps, and buttons were became common accoutrements, while earrings and bracelets fell out of favor. The movement away from industrialization allowed time for handmade items with natural materials, colored gems, and enamel which was affordable for many economic classes. Famous British jewelry designers included in this room are Charles Ashbee, Liberty & Company and its designers, Archibald Knox and the Guild of Handicraft, Child & Child, Sybil Dunlop, and Dorrie Nossiter. Husband and wife teams such as the Gaskins and Dawsons also gained acclaim. Notable pieces in this room include the silver blue enameled winged tiara set with a central citrine made in 1990 by Child and Child and a pair of life-like horn lily pad hair combs with moonstone drew drops made in 1906 by Ella Naper (figure 2).

Figure 2. English designer Ella Naper completed these lily-pad hair combs circa 1906. From the collection of Richard H. Driehaus. Photograph by John A. Faier, 2014, © The Richard H. Driehaus Museum.
Tiffany & Company and Marcus & Company, who were in fierce competition, are shown in the next room, themed “American Art Jewelry.” After his father’s death in 1902, Louis Comfort Tiffany became Tiffany & Co.’s first official design director. He established Tiffany Studios on the sixth floor of the 5th Avenue building at Madison and 45th Streets in New York, which was supervised by artists Julia Munson from 1902 until 1914 and Meta K. Overbeck from 1914 until 1934. Louis Tiffany himself left the studio in 1918.

As a leader of the Art Nouveau movement, Louis Comfort Tiffany is best known for his stained glass windows and lamps, several of which are exhibited here. Since he was inspired by nature, color, and design, his move into jewelry, particularly his smaller enameled works, was a natural progression, resulting in beautiful pieces encrusted with opals, garnets, moonstones, and jade. The most notable piece by Louis Comfort Tiffany is in the central case, the 1918 platinum, blue zircon, diamond, chrysoberyl, amethyst, and demantoid garnet necklace. Marcus and Company rivaled this piece with it 1900 gold, natural pearl, demantoid garnet and enameled necklace. In Germany, the Arts and Crafts movement was known as Jugendstil. In Vienna it was founded by Josef Hoffman of the Wiener Werkstätte as a cooperation of designers, artists and architects best known for their work on the Fledermaus Caberet (1907-1913). This movement is encompassed in “Jewelry as Art, Germany and Austria in the Early 20th Century.” Jewelry and objects in this gallery include boxes, dishes, and vases mostly made by Josef Hoffman and Karl Rothmuller. One striking piece on display is a silver, opal, and mirrored glass pendant created by Josef Hoffman in 1904 (figure 3).

Figure 3. Austrian artisan Josef Hoffmann, of the Wiener Werkstätte, completed this silver, opal, and mirrored glass pendant in 1904. From a private collection. Courtesy of the Richard H. Driehaus Museum.
The awe-inspiring pieces in “Metamorphosis, The Female Figure in Art Nouveau” are all about the muse: curves, folds, winged sylphs, femme fatale, Medusa. This room is filled with nature-inspired objects. Beautifully crafted art pieces were made for wealthy clients by men such as Rene Lalique, Alphonse Mucha, Louis Aucoc Fils, Georges Fouquet, and Maison Vever. Rene Lalique’s stunning gold, enamel, glass, diamond and baroque pearl chrysanthemum pendant/brooch is found in this room (figure 4).

Figure 4. Rene Lalique’s chrysanthemum pendant/brooch, completed c. 1900. From the collection of Richard H. Driehaus. © 2014 Artists Rights Society (ARS), New York / ADAGP, Paris. Photograph by John A. Faier, 2014, © The Richard H. Driehaus Museum.
The final room, “Beautiful, Useful, and Enduring, Chicago Arts and Crafts Jewelry”, is filled with Chicago-based jewelers such as LeBolt & Company, Elinor Klapp, Madeline Wynn, Florence Koehler, Frances Glessner, and the now-defunct Kalo Shop. The Christia Reade crown for the Queen of the Lombard (Illinois) Lilac Festival, still used every year, and made from donated silver spoons, is also on display.

This exhibit is a must see for anyone interested in the Arts and Crafts and Art Nouveau periods. It is a rarity that all of these exquisite pieces are open to public viewing in the same place and time.

The admission fee to the museum is $20.00 which includes the special exhibit. Audio and guided tours are also available for an additional $5.00 each. The museum, located at 40 East Erie, is open every day, except Monday, from 10am to 5pm. @chapter:16


Publication Year: 2023 Title: Nickel-Diffused Spinel, Vietnamese Augite, Brown Mammoth Ivory, and More… Abstract: Welcome to the Summer 2023 issue of Gems & Gemology! Loaded with noteworthy content, the articles in this volume cover timely topics, such as a new treatment process identified in natural spinel, a recent source of augite in Vietnam, and research identifying the origin of the surface color of brown mammoth ivory.
“…an undisclosed diffusion treatment process for spinel that is being used to convert lightly colored gems to hues ranging from green to blue.”
In our lead article, Dr. Michael Jollands and fellow GIA researchers report on an undisclosed diffusion treatment process for spinel that is being used to convert lightly colored gems to hues ranging from green to blue. Testing a set of spinel samples represented as “cobalt diffused” revealed that the stones were actually diffused with nickel. With this treatment now present in the gem market, the authors suggest identification criteria for spinel samples within the green to blue color range.
Next, a team led by Le Ngoc Nang investigates a variety of gem-quality augite from Dong Nai, Vietnam. The magnesium-rich augite, characterized by its intense dark orangy brown or dark green color under transmitted light, has potential use in jewelry and as a carving material.
Another carving material, mammoth ivory, is typically found with a brown surface color. Our third article, from Zhaoying Huang and coauthors, examines the origin of this color. They determine that iron oxides and sulfides and manganese oxides and hydroxides crystallized on the mammoth ivory’s surface while underground, causing it to turn brown.
Our regular columns offer a host of interesting finds from all over the globe, including an aquamarine displaying asterism, a CVD-grown diamond over 34 carats, and an exceptionally large South Sea cultured pearl in the Lab Notes section. Explore the inner wonders of gemstones in Micro-World, with a feather inclusion resembling a mountain range in natural diamond, metallic platelets in Brazilian Paraíba tourmaline, an intriguing metal sulfide crystal in garnet, and more. Colored Stones Unearthed returns in this issue, covering gemstones that formed through metamorphic processes. Highlights from the Gem News International section include the characteristics of treated rubies from Greenland as they become more common in the market, the 2023 Sinkankas Symposium, and the latest auction season. Also in this issue, we put fire obsidian In the Spotlight. Tom Dodge’s impressive lapidary work reveals the vivid spectrum of iridescent colors in this rare volcanic glass found only in the Glass Buttes region of Oregon.
Lastly, we invite you to join the G&G Facebook group (facebook.com/groups/giagemsgemology). Since its launch in February 2020, our growing community has surpassed 35,000 members. Thank you for your continued support and interest in Gems & Gemology! @chapter:3