Publication Year: 2016 Title: Preliminary Study on Rubies Reportedly from Pokot, Kenya Abstract: Figure 1. These eight rubies (0.36–4.38 ct) are reportedly from Pokot, Kenya. Photo by Lhapsin Nillapat.

	In July 2016, Christine Muthama and David Pkosing from Pokot Gems Ltd. in Nairobi submitted eight faceted rubies (figure 1) to GIA’s Bangkok laboratory. The material came from a new operation in the Pokot area, a marble-type deposit in western Kenya that has been largely inactive since the 1960s. This new production could prove to be an interesting source of cabochon- and facet-grade rubies from East Africa.

	The submitted rubies ranged from 0.36 to 4.38 ct and were semitransparent to translucent, with a very fine, milky appearance. Their gemological properties were consistent with ruby from marble-type deposits. The samples displayed strong red fluorescence under long-wave UV radiation and a medium red reaction under short-wave UV. They contained unhealed fractures, planes of negative crystals, fingerprints, and different mineral inclusions such as  apatite, calcite, orange and black rutile, chlorite, pyrite, zircon, and amphibole (figure 2), the last of which is uncommon in marble-hosted rubies. Short needles, boehmite, and clouds of reflective particles were also observed.

	Figure 2. The rubies reportedly from Pokot contained a variety of internal features, including (A) reflective particles, field of view 2.4 mm; (B) very fine short needles, field of view 1.3 mm; (C) very fine milky bands, field of view 4 mm; and (D) an amphibole crystal, field of view 1.3 mm. Photomicrographs by Charuwan Khowpong.

	Since the samples had inclusion features similar to those seen in marble-hosted rubies from Myanmar or Luc Yen, Vietnam, this interesting new Kenyan material could present a challenge in future origin determination studies. Nevertheless, spectroscopy and chemical composition analysis can be used to separate rubies from these deposits. FTIR spectroscopy of all eight samples from Pokot showed the presence of boehmite. LA-ICP-MS analysis revealed a distinguishing trace element composition. The rubies from Pokot had low Fe content (60–252 ppma), along with the following trace element contents: V: 6–11 ppma; Ga: 5–10 ppma; Ti: 29–135 ppma; and Cr: 678–1773 ppma. This combination is quite different from that of known Vietnamese rubies, showing once again that trace element composition is a useful tool for determining the origin of rubies. @chapter:3


Publication Year: - Title: Aquamarine Description Abstract: An aquamarine crystal in its natural state shows why these specimens are prized for their beauty. - Courtesy Daniel Trinchillo, Fine Minerals International

                      Aquamarine is the green-blue to blue variety of the mineral beryl. (Emerald is the green to bluish green variety of the same mineral.) Its color is usually a light pastel greenish blue.

	This 20.83-carat stone from Africa represents the large size and attractive color that make aquamarine a much-prized gem. - De'ev Dvir/ICA, courtesy Gemstar Ltd., Israel
Heat treatment usually gives it a more bluish appearance.

Aquamarine crystals are known to be large in size and relatively clean and well-formed, making them particularly valuable to collectors of mineral specimens. @chapter:9


Publication Year: 1989 Title: Mildly Radioactive Rhinestones and Synthetic Spinel-And-Glass Triplets Abstract: Low levels of radioactivity were found in some greenish yellow to yellow-green (peridot-like) synthetic spinel-and-glass triplets, mirror-backed glass rhinestone chatons, and fully fashioned glass rhinestones. Uranium was detected in the radioactive stones. Although individual stones in jewelry carry virtually no risk, it is recommended that parcels of such stones not be carried on one's person for prolonged periods. @chapter:23


Publication Year: 2015 Title: The Beauty and Value of Inclusions, Plus Double Stars and Corundum from Tajikistan Abstract: We hope you enjoy this edition’s unusual and distinctive cover image. It’s especially fitting, as a number of contributions in this issue deal with aspects of gem inclusions: their documentation using modern digital photography and image-processing software, how some interact with light inside a fashioned gem to produce asterism, and the straightforward instructional value that might be gained through their study.

Our cover article, by Nathan Renfro, analytical manager of the gem identification department at GIA’s Carlsbad laboratory, focuses on digital photomicrography for gemologists. Renfro’s article builds on the landmark 2003 paper by his longtime mentor and master of gem-inclusion photography John Koivula, to offer a highly practical and relevant guide covering equipment and current techniques for the gemologist.

In the lead article, we present a paper by a team of researchers headed by Dr. Karl Schmetzer, a frequent contributor to Gems & Gemology during the 1980s and 1990s. We are delighted to welcome Dr. Schmetzer back to our journal. He and his coauthors offer a comprehensive description of a largely unappreciated form of asterism: the dual-color “double stars” observed in some natural sapphire, ruby, and quartz, as well as synthetic corundum, including diffusion-treated examples. The authors discuss the mechanism by which double stars are formed and present a historical summary of the manufacture and improvement of synthetic star corundum by diffusion treatment.

		We invite gemologists to take a closer look at the astounding beauty and variety of the micro-world of gems.

Our third article, by Russian researcher Dr. Elena Sorokina and her coauthors, provides an update on the geology, mining, and internal and external features of ruby and sapphire from Snezhnoe, Tajikistan. This is a welcome summary of a marble-hosted deposit with significant potential, one that has seen little study or previous coverage in the gemological literature.

After these three feature articles, you’ll find our regular Lab Notes and Gem News International sections, which include further entries from the 2015 Tucson shows and a report of the recent Maine pegmatite workshop.

In addition, we present a new quarterly column on inclusions entitled “Micro-World.” With this new regular feature, section editors Nathan Renfro, Elise Skalwold, and John Koivula aim to foster the wider appreciation of inclusions and to bolster practicing gemologists’ observational skills by providing concise reports accompanied by stunning photomicrographs of specially chosen specimens. The authors invite gemologists to take a closer look at the astounding beauty and variety of inclusions in gems.

Finally, I'd like to thank Stuart and the entire G&G editorial and production staff. Due to the unexpected death of a close family member, I have been out of the United States for a period of weeks. As a result, I have come to appreciate the hard work and dedication of the entire G&G team even more.

All of us at G&G hope you enjoy the Summer issue! @chapter:2


Publication Year: - Title: New Treatments and Imitation Gems Abstract: Rajneesh BhandariRMC Gems Thai Co. Ltd.

	Interview with Rajneesh Bhandari, RMC Gems Thai Co. Ltd.
In an exclusive interview with GIA conducted at the 2013 Gem Show in Tucson, Rajneesh Bhandari pulls back the curtain on the too-often secretive world of gemstone treatments. Bhandari is with RMC Gems Thai Co. Ltd., which specializes in gem treatments, synthetic gemstone processes, and the creation of imitation gemstones.

In the interview Bhandari speaks professionally and proudly about this important aspect of the gem trade. He is a strong advocate for these products with the stipulation that they are fully disclosed to customers so they know exactly what they’re getting. Rather than view disclosure as a burden on his business, Bhandari sees it as a necessity that allows the gem trade to meet its necessity to treat in order to produce more pleasing products. He compares gem treatments to treatments that are done across a wide cross section of industries where new technologies increasingly make natural products better in numerous ways.

He explains in some detail what some of those technologies are that allow RMC to create imitation morganite beryl, bi-color tourmaline, unusual quartz triplets and thin film coatings for increased durability. People in the trade should find Bhandari’s disclosures both informative and reassuring as they struggle to deal with the always-tricky subject of treatments. As for customers--if you have no idea what electron vapor deposition has to do with the shimmering gold drusy you just purchased as a gift on the home shopping channel, this interview will prove to be a fascinating eye-opener. @chapter:20


Publication Year: 2014 Title: Rare Faceted Wurtzite Abstract: Figure 1. This 3.97 ct faceted wurtzite has an adamantine luster and brownish red bodycolor.

              Recently the Carlsbad laboratory examined a 3.97 ct transparent brownish red pear-shaped modified brilliant for identification service (figure 1). Standard gemological testing revealed a refractive index that was over the limit of the RI liquid and a specific gravity (obtained hydrostatically) of 3.96. There was no fluorescence observed with exposure to long- and short-wave UV light. The stone also displayed an adamantine luster and a uniaxial optic figure when examined with polarized light. Microscopic examination with a fiber-optic light source showed fine needles and a large reflective decrepitation halo surrounding a negative crystal. Examination also revealed that the decrepitation halo was perpendicular to the optic-axis direction, suggesting the stone had basal cleavage (figure 2).

	Figure 2. A decrepitation halo surrounds a negative crystal in the faceted wurtzite. Photomicrograph by Nathan Renfro; field of view 2.15 mm.
Raman spectroscopy and X-ray powder diffraction conclusively identified the stone as wurtzite. EDXRF analysis detected zinc and sulfur, which further supported this identification.

Wurtzite, a polymorph of sphalerite, commonly occurs in hydrothermal vein deposits associated with barite and sphalerite. Facet-grade wurtzite has been reported to occur in Merelani, Tanzania (Winter 2013 GNI, p. 261). This is the first wurtzite examined by the GIA laboratory. @chapter:5


Publication Year: 2001 Title: Summer 2001 G&G Lab Notes Abstract: Diamond “Banded” Twinned Crystal
Diamond with a Carbonate Inclusion
Diamond with Unusual Mineral Inclusions
Feldspar with Chrome Diopside Inclusions
Gibbsite Dyed to Imitate Nephrite
Devitrified Glass Resembling Jade
Early Japanese Assembled Cultured Blister Pearls
Dyed Black Faceted Cultured Pearls
A New Imitation: “Shell Pearls” with a Calcite Bead

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


Publication Year: 2019 Title: Gray Spinel: A New Trend in Colored Stones Abstract: Figure 1. Spinel with nearly perfectly neutral gray color with only a slightly bluish tinge, 24.15 ct. Photo by Robert Weldon/GIA, courtesy of 3090 Gems, LLC.

In recent years, the colored stone world has seen a growing appetite for unusual colors. Ruby, sapphire, and emerald with strong saturation but not overly dark tones have always been the mainstay of the colored stone market. But now there is stronger demand for stones in nontraditional colors that might have been difficult to move a decade or two ago. Especially notable is the growing popularity of lighter-toned, lower-saturation pastel stones such as garnets from East Africa or Montana sapphires.
Gray spinels were one of the obvious new trends at the Tucson shows this year. It was not hard to find exhibitors showing off their gray spinel, and everyone who had them commented on how quickly they were selling. The story is remarkable in that the colored stone market has accepted a gemstone that by definition has an unsaturated color—a gray color, no less. Most gray spinel has a minor blue or violet secondary color component. It is relatively rare to find a spinel with a perfectly neutral gray color. These stones have the most value, which increases as the depth of the gray increases. Most of the specimens on display in Tucson were under a carat. Stones larger than a few carats were relatively rare, but we were able to document some with exceptional color, such as the 24.15 ct bluish gray spinel cut by 3090 Gems, LLC in figure 1 or the slightly bluish gray matched pair (10.34 carats total) from Nomad’s in figure 2.

Figure 2. Matched pair of slightly bluish gray spinels with a combined weight of 10.34 carats. Photo by Robert Weldon/GIA, courtesy of Nomad’s.
Gray spinel’s success is due in large part to strong marketing. Of particular note is the influence of social media in bringing this material to the market. In the last year or so, these spinels became quite popular in gemstone circles on Facebook and Instagram. In our interview with cutter Jeff Hapeman, he noted how social media has fundamentally altered the industry by allowing gem dealers to satisfy more eclectic desires and by giving consumers power to find and purchase novel and unusual stones that were traditionally unavailable. As we continue to witness the disruptive power of social media in the industry, gray spinel will not be the last story we hear of a once unmarketable color being embraced by the colored stone world. @chapter:3


Publication Year: 2013 Title: Corundum Carving Coated with Colored Polymer Abstract: Figure 1. This 444 g dark violetish blue carving of Lord Mahaveera, submitted as sapphire, was identified as corundum coated with a blue polymer. Photo by Gagan Choudhary.
Coating, one of the traditional forms of enhancement, is still widely used on a number of gem materials. This contributor alone has reported on recent examples (e.g., Spring 2011 GNI, pp. 71–72; Summer 2012 GNI, pp. 154–155). The latest is a dark violetish blue carving of the early Jain spiritual leader Lord Mahaveera, submitted as sapphire (figure 1), that turned out to be corundum coated with a blue colored polymer.
The 444 g opaque carving measured 10.00 × 8.00 × 4.50 cm. Although it had the heft of sapphire, its dull, vitreous to waxy luster (again, see figure 1) raised doubts. Examination from different directions using a fiber-optic light revealed substantial color variation in different parts of the carving; some areas appeared pale blue, others dark violetish blue. This patchy, concentrated color variation is associated with dyes. Parallel whitish crisscross lines were also observed, consistent with the twinning planes associated with corundum. Further microscopic observation revealed color concentrations within cavities, large fractures, and twinning planes, confirming the material had been dyed (figure 2, left). Finer fractures appeared whitish, however. When the carving was rotated, some areas also displayed a chipped bluish layer on the surface (figure 2, right), an attribute typically found in coated materials. This layer was easily indented with a metal pin, suggesting the presence of a polymer. In addition to these features, the carving possessed a granular texture in many places, as commonly seen in rocks. These grains were also identified as corundum on the basis of the crisscross pattern of their twinning planes, which is consistent with corundum.

Figure 2. Color concentrations within cavities, large fractures, and twinning planes (left) confirmed the presence of a dye. The chipped layer of blue polymer (right) indicates a coating; this polymer layer was easily indented by a metal pin. Photomicrographs by Gagan Choudhary; magnified approximately 20×.
Under UV light (long- and short-wave), the carving displayed patchy white and chalky green fluorescence, mainly on the surface. A desk-model spectroscope revealed weak absorptions at 540, 610, and 640 nm, confirmed with UV-Vis-NIR spectroscopy. Such bands are associated with cobalt-based dyes. RI and SG could not be measured because of the piece’s large size, though visual features were sufficient to identify the carving as corundum. @chapter:37


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

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

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

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

Abstracted by Kyaw Soe Moe @chapter:29


Publication Year: - Title: Bench Tip #18: How To Modify a Wooden Ring Clamp Abstract: Modify a Wooden Ring Clamp

One persistent daily challenge a bench jeweler faces is trying to figure out the best way to hold onto tiny, delicate objects while performing mechanical operations such as sawing, filing or burring bearings for stone setting.

There are dozens of tools available for this purpose, some centuries old and some that are modern, sophisticated and often quite expensive. An alternative is to make a simple modification to a wooden ring clamp—which holds rings and other jewelry items—that turns it into a useful, multi-function holder.

The ring clamp is usually braced against the bench pin as you work. Trouble can develop if the clamp slips while you are applying pressure. When you push downward on the ring with a prong pusher, for example, the clamp can slip out of place—even slightly—and cause a sudden movement that results in a chipped stone, damaged prong or injury to your finger or hand.

	The inset shows the original shape of the ring clamp. Grinding a groove to modify it will help brace the clamp more securely and give you a greater range of motion as you work.
If you grind a channel in the ring clamp, however, you can lock it in place with the bench pin. This provides more stable support for the work in progress and enhances your accuracy and safety.

	The groove in the ring clamp locks it into place against the bench pin for safety and stability as you work.
An 80 grit ½” x ½” abrasive band and mandrel (drum arbor) works well for this modification. Draw a reference line on the ring clamp about 10mm from the end. Use the abrasive band to create a two-millimeter indentation around the ring clamp. Test the groove against your bench pin(s) and make adjustments as necessary so the clamp locks in place.

This simple modification will make your tool more stable and reduce the chance of damaged jewelry or injury. @chapter:28


Publication Year: 1995 Title: Winter 1995 Gem News International Abstract: THE 25TH INTERNATIONAL GEMMOLOGICAL CONFERENCE
Diamonds
            Fluid Inclusions in Diamonds
            Some Historical Trends in the Diamond Industry
Colored Stones
            New and Unusual Inclusions in Amber and other Gems
            Green Beryl and Emerald from Central Nigeria
            Red Beryls from Utah
            Gem Localities in China
            Colored Stones Seen by CISGEM Laboratory
            New Gem Deposits in Shan State, Myanmar
            New Emeralds from Southern India
            Natural Glass: Tektites
            Jade Market in Mandalay
            Jadeite Lapidaries in Myanmar
            Freshwater Natural Pearls from the Lac St. Jean Area, Quebec
            Unusual Pearls
            Rubies from the Barrington Volcanic Field, East Australia
            Ruby Market in Taunggyi
            Sapphire Mining in Laos
            The Sapphire Deposit in Southern Madagascar
            Scapolites from New Discoveries in Sri Lanka
            Tanzanites and other Zoisites from Merelani, Tanzania
Synthetics and Simulants
            Russian Flux-Grown Synthetic Alexandrites
            GGG as a Corundum Fake
Instrumentation
            The Lapidary as a Gemological Resource
            Nuclear Microscopy of Rubies
            Raman Spectrometers
            Brewster Angle Refractometer
Miscellaneous
             Gems in Ancient Jewelry
Announcements
Gems & Gemology Wins Again

To view the full section, download the PDF above. @chapter:0


Publication Year: 2024 Title: Out of Our Mines Abstract: Figure 1. Extremely rare Black Web Gem mine turquoise nuggets and cabochons from Nevada. These pieces are natural with no treatments except for the backings added to the cabochons. The center oval is approximately 16 × 12 mm. Photo by Richard Shull; courtesy of Out of Our Mines.
As noted in the overview turquoise was one of the most prolific gems in Tucson this year, found in a variety of jewelry, cut stones, and rough throughout the shows. Richard Shull and Helen Constantine-Shull of Out of Our Mines (Dyer, Nevada) reported strong sales at the AGTA show, where they had an impressive variety of mainly American stones, particularly turquoise and variscite from Nevada. They also offered other popular materials, including Oregon chalcedony, California tourmaline, Oregon sunstone, Nevada golden opal, and Arizona amethyst.
Childhood visits to trading posts during trips to the Southwest sparked Richard’s fascination with turquoise and jewelry. His family’s gold mining activities in California and Nevada inspired his own interest in mining. Helen similarly traveled throughout the Southwest as a child, developing a strong appreciation for the local rocks and plants. Both Shulls have extensive lapidary and jewelry-making experience. They began mining their own material in the late 1980s and became mine owners in the 1990s. Currently, they own and operate several turquoise and variscite claims in Nevada.

Figure 2. Natural Nevada turquoise from the Nevada Blue mine (stone farthest to the right, the pear shape on top, and the large center triangle); the Double Eagle mine (freeform triangular stone on center right and the geometric freeform below that); the Northern Lights mine (green stone); the Black Widow mine (two tight spiderweb stones on the left); and calibrated stones from the Supernova and Aztec mines at Royston (clear gem material without patterning). Sizes range from 2.12 ct to 24.62 ct. Photo by Robert Weldon; courtesy of Out of Our Mines.
Helen attributed her passion for turquoise and variscite to their great variety of patterns and colors. Their highest-end turquoise is material with tight, distinct spiderweb patterning from their Black Widow and Black Web Gem mines. Only about two pounds of material has been recovered to date from the Black Web Gem mine, and it is some of the finest natural black web turquoise in the world (figure 1). Also popular are greens from the Northern Lights mine, bright greenish blue material with striking reddish brown matrix from the Double Eagle mine, blues with strongly contrasting matrix from the Nevada Blue mine, and pattern-free clear gem material from the Supernova and Aztec mines at Royston (figure 2).

Figure 3. Stabilized Nevada turquoise from the Supernova mine. Sizes range from 5.61 to 13.09 ct. Photo by Robert Weldon; courtesy of Out of Our Mines.
Turquoise with distinct matrix patterning is a strong draw for those seeking one-of-a-kind pieces, a very popular trend in jewelry today. However, there is still solid demand for clear gem material, which the Shulls sell from both vintage sources (1950s Persian) and from their own Dyer Blue and Supernova mines in Nevada, which both produce webbed and clear turquoise (figure 3).

Figure 4. Variscite with matrix (left) and clear gem variscite without patterning (right). Photos by Jennifer Stone-Sundberg; courtesy of Out of Our Mines.
Variscite, a non-copper-containing aluminum phosphate mineral closely related to turquoise, is gaining popularity as consumers learn more about this mineral. Variscite comes in a range of greens and can exhibit the same fascinating matrix patterns found in turquoise (figure 4).
The Shulls described how some buyers form a personal connection with the material. For these customers, the stone they acquire is more than simply a piece of turquoise; it is a stone from a known location, uncovered by a known person, with a clear story of how it reached the final form in front of them. @chapter:18


Publication Year: 2018 Title: Colored Stones and Pearls Abstract: Figure 1. 3D reconstructions of the internal structures of two bead-cultured pearls with atypical nuclei. Left: A flower-shaped bead nucleus. Right: A small gastropod shell used as a nucleus.
3D Reconstruction of the Internal Structures of Pearls
Emiko Yazawa and Chunhui Zhou
GIA, New York
Pearl testing involves a variety of tools and techniques, most notably X-ray imaging. GIA applies both real-time X-ray microradiography (RTX) and computed X-ray microtomography (μ-CT) to reveal the internal structures of pearls and draw conclusions on their identity. These images help gemologists determine whether a pearl is natural, bead-cultured, non-bead cultured (NBC), and so forth. The identification of some pearls remains challenging for even the most well-equipped laboratories. Researchers sometimes find surprises hidden within—a piece of shell or some other interesting object that is difficult to visualize with two-dimensional images.
Here, we present a range of interesting internal three-dimensional structures (figure 1), using specialized software and μ-CT slice images for the reconstruction. These include unusual internal growth features such as bivalve and gastropod shells, foraminifera, flower-shaped bead nuclei, and plastic bead nuclei, as well as non-bead-cultured features such as voids and linear structures. This powerful research tool makes it possible to virtually explore, manipulate, extract, and reconstruct specific areas inside a pearl for analysis. It also gives the operator the ability to enhance the existing μ-CT data to view the details more clearly, thus revealing the fascinating world within pearls that gemologists routinely encounter.
Atypical “Bead”-Cultured Pinctada Maxima Pearls Nucleated with Freshwater Non-Bead-Cultured Pearls
Promlikit Kessrapong and Kwanreun Lawanwong
GIA, Bangkok
At present, most of the freshwater shell bead nuclei used in the cultured pearl industry originate from mussels from the Mississippi River in the United States. However, shell beads are not the only material used as nuclei in the culturing process. Cultured freshwater pearls have also been used as nuclei to produce atypical bead-cultured (aBC) South Sea pearls (Scarratt et al., 2017).
GIA researchers sourced several aBC samples from Orient Pearl Ltd. in Bangkok. Two samples were selected, one “golden” and one white (figure 1), both showing an unmistakable saltwater appearance. Standard testing methods as well as macro photography, microradiography, X-ray luminescence (Hänni et al., 2005; Kessrapong et al., 2017), Raman and photoluminescence (PL) spectroscopy and ultraviolet-visible spectrophotometry (UV-Vis) were applied to the samples prior to cutting them in half. After they were sawn, further data was collected through photomicrography, X-ray fluorescence (XRF) images, and laser ablation–inductively coupled plasma–mass spectrometry (LA-ICP-MS) analysis.

Figure 1. Photographs of the “golden” (left) and white (right) atypical bead-cultured pearls. Photos by Kwanreun Lawanwong.
As expected, the results of the examination confirmed their aBC nature. While their appearance, baroque shapes, and white to strong yellow (golden) colors indicated they were typical saltwater Pinctada maxima pearls, their internal structures revealed clear boundaries where the outlines of freshwater NBC pearl nuclei could be seen in the microradiographs. Raman, PL, and UV-Vis spectra for the golden sample indicated it formed within a P. maxima mollusk. Also, in keeping with their freshwater NBC nuclei structure, a weak to moderate fluorescence was observed, which would not be the case to such a degree if they were entirely saltwater in origin. The golden pearl showed a yellow-orange fluorescence to X-ray luminescence, while the white sample exhibited a yellow-green reaction, similar to the result one would expect to see in cultured saltwater pearls incorporating freshwater mussel shell nuclei.
Examining the halves, we observed more detail: the demarcation between the two parts (nuclei and surrounding nacre overgrowth), small void/linear features (proving the NBC origin of the nuclei), the different colors/structures between the saltwater and freshwater nacre components, and some other indications of their cultured origin (i.e., small voids within the demarcation zones). The X-ray luminescence reactions were similar to those seen in the whole samples, only more intense since the inner freshwater nuclei were now directly exposed to the X-rays and not masked by the saltwater nacre that covered them prior to cutting. LA-ICP-MS analysis clearly revealed the nature of the outer saltwater layers and inner freshwater pearls, through significant differences in the concentrations of Sr and Mn among other elements. The Mn levels in the center were higher while the Sr levels were lower compared to the overgrowth layers, where the opposite was true, as expected in saltwater material.
Although cutting the pearls in half was a nice way to reveal the features in more detail, it is worth noting that gemologists do not need to go to such extremes to prove the identities of such pearls in laboratory conditions. Standard testing methods permit the straightforward identification of aBC pearls. Cutting them in half is a useful exercise to carry out for scientific examination of their structures and to allow more detailed analysis that would not otherwise be possible.
REFERENCES
Hänni H.A., Kiefert L., Giese P. (2005) X-ray luminescence, a valuable test in pearl identification. Journal of Gemmology, Vol. 29, No. 5/6, pp. 325–329.

Kessrapong P., Lawanwong K., Sturman N. (2017) Pinctada maculata (pipi) bead-cultured blister pearls attached to their shells. GIA Research & News, Apr. 25, https://www.gia.edu/gia-news-research/pinctada-maculata-bead-cultured-blister-pearls-shells

Scarratt K., Sturman N., Tawfeeq A., Bracher P., Bracher M., Homkrajae A., Manustrong A., Somsa-ard N., Zhou C. (2017) Atypical “beading” in the production of cultured pearls from Australian Pinctada maxima. GIA Research & News, Feb. 13,  https://www.gia.edu/gia-news-research/atypical-beading-production-cultured-pearls-australian-pinctada-maxima
Chinese Freshwater Cultured Pearl Industry at a Crossroads
Qishen Zhou and Ren Lu
Gemmological Institute, China University of Geosciences, Wuhan
During the past 15 years, China has made tremendous progress in the quality and output of freshwater cultured pearls (see figure 1). Innovative technologies have facilitated a variety of colors and high-quality nacre within a shorter culturing cycle. Large-scale culturing has boosted the annual output to a high of 2,200 tons, and China has become an undisputed freshwater pearl empire.

Figure 1. Tea set decorated with Chinese freshwater pearls from the 2016 G20 Summit held in Hangzhou, China. Courtesy of Angeperle Corp.
However, the expanded production has been accompanied by considerable damage to the environment. With a more forceful implementation of the Chinese government’s environmental policy, there have been many strict bans in the main producing areas of freshwater cultured pearls during the past three years. The pearl culturing area decreased from approximately 250 km2 in 2005 to 100 km2 in 2016, and output has also dropped from a peak annual output of over 2,200 tons to less than 1,300 tons in 2017. Production is predicted to decline by about 50 percent in the next year or two.
The number of Chinese lakes with Grade IV–V water quality (Grade IV water is used in general industrial and recreational water areas and Grade V water is employed in agricultural and general landscape water areas; see New York Water Quality Standards, 2016) increased from 16.67% in 2000 to 58.5% in 2016. It is worth emphasizing that about 20% of all lakes are still Grade V. At the same time, water eutrophication has become a common phenomenon. It is caused by the discharge of excess nutrients (mainly nitrogen and phosphorus), resulting in abnormal reproduction and growth of various aquatic organisms and plants. Since 2003, the proportion of eutrophic lakes and reservoirs in China has increased from 50% to an average of 77.93%, while the proportion of eutrophic reservoirs alone has nearly doubled from 15.05% to 28.8%. Among the lakes monitored by the government in 2013 and 2015, many of the eutrophic lakes are also leading areas for pearl culturing.
As a result of the Chinese government’s strict environmental regulations, the extensive feeding model with massive fertilization is no longer permitted. The government has carried out the forced demolitions of some pearl culturing areas during the past three years, and the three largest freshwater pearl-culturing provinces/regions also have implemented strict bans on cultured pearls. Meanwhile, the central and eastern provinces such as Hubei and Zhejiang began compulsory demolition of freshwater pearl culturing in 2017, which caused a dramatic decline in pearl output.
This has been a major setback for freshwater pearl farmers, aquaculture companies, and pearl workers. The Chinese government at all levels has subsidized the farmers who have suffered from demolition, though most are still reported to have suffered serious losses because of culturing bans.
At the same time, the new environmentally friendly and standardized aquaculture models will usher in a new era for Chinese freshwater cultured pearls. The Chinese Academy of Agricultural Sciences and various enterprises have developed many new culturing methods. For example, fish-clam mixed cultivation has been shown to improve water quality and increase output value, and the three-part aquaculture model of fish, clam, and poultry can balance ecological concerns and generate considerable income. Environmentally friendly aquaculture will become the new standard for freshwater cultured pearls, and it will take about 5 to 10 years to adopt automated aquaculture technology across mainland China.
To summarize, wholesale and retail prices of Chinese freshwater pearls will fluctuate significantly in the next two to five years based on the freshwater pearl culturing cycle. China’s freshwater cultured pearl industry has formed a complete and relatively mature supply chain over the past decade. It is still facing new challenges, new development opportunities, and critical decisions for a sustainable industry under the government’s new policy and the promotion of new aquaculture technologies. At the same time, the increasing demand for high-quality freshwater cultured pearls in China and around the world is prompting the upgrade and transformation of the product.
REFERENCES
Akamatsu S., Li T.Z., Moses T.M., Scarratt K. (2001) The current status of Chinese freshwater cultured pearls. G&G, Vol. 37, No. 2, pp. 96–113, http://dx.doi.org/10.5741/GEMS.37.2.96

New York Water Quality Standards (2016) https://www.epa.gov/sites/pro-duction/files/2014-12/documents/nywqs-section1.pdf
Comparison of Laser Ablation and Solution ICP-MS Analyses of Emeralds
Ruan Hattingh1, Raquel Alonso-Perez2, Aaron C. Palke3, Lee Groat4, and James M.D. Day1 (presenter)
1Scripps Institution of Oceanography, La Jolla, California
2Harvard University, Cambridge, Massachusetts
3GIA, Carlsbad, California
4University of British Columbia, Vancouver, Canada
Geochemical studies of emeralds can confirm their provenance and improve our understanding of deposit origin. LA-ICP-MS is a minimally destructive and relatively high-throughput technique that allows determination of more than 30 major, minor, and trace elements simultaneously using small spot sizes (20–100 μm). A reliable and consistent LA-ICP-MS protocol requires good standardization, including the use of matrix-matched standard reference materials. Here we provide a robust assessment of the quality of LA-ICP-MS analysis of emeralds, utilizing a set of natural and synthetic gem-quality emeralds housed within the Mineralogical & Geological Museum at Harvard University. Our goals were to identify large emeralds as potential standard reference materials and to examine the robustness of certain trace elements in emeralds for provenance and for petrogenetic models of their origin.

Figure 1. Comparison of selected trace-element abundances in emeralds measured using both solution- and laser-ablation ICP-MS.
In this study, we have analyzed more than 45 emeralds using both LA-ICP-MS and solution ICP-MS techniques. For solution ICP-MS, between 5 and 10 mg of individual emeralds was digested in HF-HNO3 prior to analysis of Be by standard addition and all other elements by comparisons with standard reference materials spanning a range of major-, minor-, and trace-element compositions (see also the oral presentation by R. Alonso-Perez from this conference). Some emeralds that we analyzed contained small inclusions, but the majority were inclusion-free. For comparison, portions of the same emeralds were also measured by LA-ICP-MS using 100 μm spot sizes on a New Wave Research UP213 (213 nm) laser ablation (LA) system coupled to a ThermoScientific iCAPq ICP-MS. In general, we found excellent agreement for major-, minor-, and trace-element data between the solution ICP-MS and LA-ICP-MS techniques (figure 1), finding reliable results by LA-ICP-MS for Li, Be, Na, Mg, Al, Si, K, Sc, Ti, V, Cr, Fe, Ni, Zn, Ga, Rb, Cs, and Pb. Less reliable results were generated for Sr and the rare earth elements, due to the generally low abundances of these elements in emeralds. During this study, we identified natural emeralds as potential standard reference materials for future inter-laboratory LA-ICP-MS comparison, as well as a synthetic emerald (Harvard ID 109678) that is enriched in the key elements outlined above and in Mo.
Fluid Effervescence: A New Process for Natural Color Variation In Gems
Dan Marshall
Simon Fraser University, Burnaby, British Columbia, Canada
The emeralds from the Emmaville-Torrington deposit in Australia are commonly zoned (figure 1) and display alternating bands of emerald green and colorless growth zones within individual crystals at the millimeter scale. The zoning is seen optically but can be observed via imaging techniques such as backscattered electron and cathodoluminescence, and detected chemically via electron microprobe analyses. Additionally, there is a correlation between the presence of a population of primary vapor-rich fluid inclusions within the clear growth zones (figure 2) and a second population of highly saline three-phase (liquid + vapor + halite) fluid inclusions in the darker or colored growth zones.

Figure 1. Internal features of a zoned emerald crystal from the Emmaville-Torrington deposit. Photomicrograph by Dan Marshall.

Figure 2. Enlarged area of the photomicrograph of the primary fluid inclusions from figure 1 showing alternating colored and clear areas in the zoned emerald crystal. The clear zones correspond to growth zones dominated by primary vapor-rich fluid inclusions. The field of view is approximately 650 microns. Photomicrograph by Dan Marshall.
The two fluid inclusion populations appear to represent conjugate sets of a boiling or effervescent system, with the three-phase fluid inclusions having an average salinity of approximately 33 wt.% NaCl equivalent. This population undergoes total homogenization into the liquid and probably represents fluids trapped in the liquid system of a two-phase (effervescent) system. The vapor-rich population of fluid inclusions (again, see figure 2) have an average salinity of approximately 6 wt.% NaCl equivalent and homogenize into the vapor phase at higher temperatures.
The correlation of color versus clear growth zones—corresponding to high-salinity liquid-dominant and vapor-dominant low-salinity primary fluid inclusions, respectively—indicates that the color banding within the Emmaville-Torrington emerald is related to emerald precipitation in the liquid or vapor portion of an effervescing fluid system. Other emerald deposits worldwide display similar growth banding, as do some other deposits of gem topaz and gem varieties of quartz.
The Heat Treatment of Basalt-Related Blue Sapphires
Wasura Soonthorntantikul, Ungkhana Atikarnsakul, Charuwan Khowpong, and Sudarat Saeseaw
GIA, Bangkok
Heat treatment is the most common method used to improve the color and/or clarity of corundum. Basalt-related blue sapphires typically have an unattractive dark blue color due to their high iron content, and low-temperature heat treatment can be applied to lighten this material (Nassau, 1981; Hughes et al., 2017). The main factors that influence the changes in corundum are the temperatures employed, the conditions in which they are heated, and the duration of the treatment process. However, it is difficult to distinguish between naturally heated and heat-treated blue sapphires from basalt-related deposits using only standard gemological testing and microscopic examination. In this study, basalt-related blue sapphires from various locations (Thailand, Cambodia, Australia, and Nigeria) were heat treated at low temperatures, ranging from 700 to 1050°C, for durations of 1.75, 7, and 28 hours in air (oxidizing atmosphere). The changes in color appearance, UV fluorescence, internal features, and spectroscopic properties were investigated.

Figure 1. Color-calibrated photos of basalt-related blue sapphires before (top) and after heating at 1050°C for 28 hours (bottom). Photos by Sasithorn Engniwat.
The results indicated a negligible change or a slight lightening of the blue color after treatment at 700°C, while an obvious lightening of the blue color resulted from heating at 900°C and 1050°C (figure 1). Some solid inclusions, iron stains, and partially healed fractures showed signs of alteration during the heating experiments, while needles and minute particles did not show any signs of change. Unheated samples were inert to short-wave ultraviolet (UV) radiation. After heating, most basalt-related blue sapphires remained inert under short-wave UV, but a few samples exhibited a very weak chalky green fluorescence. Fourier-transform infrared (FTIR) spectra obtained from the samples varied considerably, with differences between the peak intensities recorded before each heat treatment process and also after each unique temperature and time treatment combination. In most cases, unheated blue sapphires from basalt-related deposits revealed the characteristic 3309 cm–1 series of peaks in the FTIR spectrum (the intensity of 3232 cm–1 being much lower than that of 3309 cm–1). After heating at 700°C and 900°C, the intensity of the 3309 cm–1 peak decreased and the 3232 cm–1 peak increased, respectively. However, some samples that initially showed a relatively intense 3232 cm–1 peak in the series before treatment exhibited a more intense 3309 cm–1 peak and a less intense 3232 cm–1 peak post-treatment. After heating at 1050°C for 1.75 hours, we recorded a decrease in the intensity of the 3309 cm–1 peak and an increase in the 3232 cm–1 peak, to the point where they were of almost comparable intensity. When subsequently heated for 7 and 28 hours, the intensity of 3309 cm–1 peak increased and that of the 3232 cm–1 peak decreased (figure 2). The ultraviolet/visible/near-infrared (UV-Vis-NIR) spectra obtained from the samples heated at 900°C and 1050°C for 1.75, 7, and 28 hours showed a reduction in the height/intensity of the broad band centered at 580 nm related to an Fe2+-Ti4+ intervalence charge transfer. This reduction is the root cause of the lighter color after heat treatment.

Figure 2. FTIR spectra of the sample before and after heating at 1050°C for up to 28 hours.
The results of this study show that even with advanced data, it is very challenging to separate basalt-related stones that have been heated from those that have not undergone any post-mining heat treatment, owing to the variable results associated with the experimental temperatures and durations used. Inclusion studies may provide sufficient evidence in some cases, but even when comparing the inclusions scene before and after treatment, separation often remains challenging.
REFERENCES
Hughes R.W., Manorotkul W., Hughes E.B. (2017) Ruby & Sapphire: A Gemologist’s Guide. RWH Publishing/Lotus Publishing, Bangkok, pp. 146–148, 200–201.

Nassau K. (1981) Heat treating ruby and sapphire: Technical aspects. G&G, Vol. 17, No. 3, pp. 121–131, http://dx.doi.org/10.5741/GEMS.17.3.121
“Low-Temperature” Heat Treatment of Mozambican Ruby
Sudarat Saeseaw, Charuwan Khowpong, and Ungkhana Atikarnsakul
GIA, Bangkok
Mozambique is one of the most important sources of ruby today, with the Montepuez mine producing material ranging from light to dark purplish red. To improve their color, Montepuez rubies are heated at low temperatures to remove the purplish component—caused by blue color zoning—and create a more attractive and desirable red color. For this study, 47 samples were selected for heat treatment in air (oxidizing environment) at different temperatures and varying durations. The samples were heated to 600, 700, 800, and 900°C for 2 hours and 40 minutes, 8 hours, or 24 hours. The results showed no significant change to the blue color zoning when heated to 600 or 700°C over any of the time frames chosen; however, the blue component was reduced when heated to a minimum of 800°C for 2 hours and 40 minutes (figure 1).

Figure 1. Color-calibrated photos of a Montepuez ruby before (left) and after (right) heat treatment at 800°C for 8 hours. The stone’s blue color component clearly decreased after heating. Photos by Sasithorn Engniwat.
Observing any changes to inclusions can be challenging when examining material subjected to lower-temperature heating, since there is less chance inclusions will be affected (Pardieu, 2015). Inclusions in Mozambican rubies are limited to needles, platelets, and other fine particles. When any alteration takes place, the evidence is very subtle. During treatment, spots can form on these platelets (figure 2), although this is not always the case. When crystalline inclusions are present, it is easier to identify heat treatment because fractures often develop around them, especially in larger crystals. Some gems contain fractures with associated iron staining or fingerprints, and their appearance may change drastically during treatment (Sripoonjan, 2016). Inclusion studies are not always conclusive, however, and advanced techniques such as FTIR spectroscopy are needed to assist in detecting low-temperature heat treatment. The presence of the 3309, 3232, and/or 3185 cm–1 peak(s) appears related to heat treatment, since they were only observed in heated stones.

Figure 2. Mozambican ruby with spotted platelets that indicate heat treatment. Brightfield and fiber-optic illumination. Photo by Charuwan Khowpong; field of view 1.0 mm.
REFERENCES
Pardieu V., Saeseaw S., Detroyat S., Raynaud V., Sangsawong S., Bhusrisom T., Engniwat S., Muyal J. (2015) GIA lab reports on low-temperature heat treatment of Mozambique ruby. GIA Research News, Apr. 28, https://www.gia.edu/gia-news-research-low-temperature-heat-treatment-mozambique-ruby

Sripoonjan T., Wanthanachaisaeng B., Leelawatanasuk T. (2016) Phase transformation of epigenetic iron staining: indication of low-temperature heat treatment in Mozambique ruby. Journal of Gemmology, Vol. 35, No. 2, pp. 156–161.
Pearl Classification: GIA’s Approach
Joyce Wing Yan Ho and Sally Chan Shih
GIA, New York
Pearls form in a wide variety of sizes, shapes, and colors. As a result, they are among the most popular materials in the jewelry industry. Their unique appearance and the affordability of many types of cultured pearls on the market have allowed them to gain a greater audience. Throughout the ages, pearls have been associated with class, grace, and beauty by many cultures. Such a diverse range of pearl types has meant that a way of grading or classifying them was required, and as a consequence, a number of different grading systems have been developed. The differences make the comparison of grades between systems difficult to align, and agreeing on a universal grading system has remained one of the many challenges facing the pearl industry.

Figure 1. Color is one of GIA’s 7 Pearl Value Factors. This hue circle depicts generalized color distribution by pearl type.
GIA created the “7 Pearl Value Factors” (figure 1) for the same reason it developed the 4Cs of diamond quality: to establish a standard terminology for describing quality using language everyone can understand. Each value factor is important in determining a pearl’s overall quality. This poster reviews each value factor, starting with size and then looking at shape, color, luster, surface, nacre quality, and matching. GIA has developed a modernized color scale for all types of pearls (saltwater and freshwater) and physical master sets to ensure a pearl is graded with a degree of consistency. Every GIA laboratory worldwide uses the same grading system to produce consistent results. Adopting GIA’s standard pearl classification terminology throughout the gem and jewelry industry would foster improved communication within the trade and, by default, bridge the communication gap between buyers and sellers through easily understandable terminology.
A Pearl Identification Challenge
Nicholas Sturman1, Laura M. Otter2,4, Artitaya Homkrajae3, Areeya Manustrong1, Nanthaporn Nilpetploy1, Kwanreun Lawanwong1, Promlikit Kessrapong1, Klaus Peter Jochum4, Brigitte Stoll4, Herman Götz5, and Dorrit E. Jacob2
1GIA, Bangkok
2Macquarie University Department of Earth and Planetary Sciences, Sydney
3GIA, Carlsbad, California
4Max Planck Institute for Chemistry, Mainz, Germany
5Johannes Gutenberg University, Mainz, Germany
Pearl testing in laboratory conditions usually follows a set routine. The pearls are examined to obtain a preliminary idea of their type and identification, and then a series of steps (e.g., trace-element geochemical analysis, optical X-ray luminescence, microradiography, and X-ray computed microtomography) are undertaken to confirm the initial examination. With experienced gemologists it is possible, in many cases, to reach the same conclusion that was arrived at after the initial examination. However, all experienced gemologists have encountered situations—whether handling pearls or other gems—where the final result does not match the initial opinion.
This poster illustrates the trace-element characteristics of pearls in general, but focuses on two nacreous pearl samples in particular that revealed “atypical” properties not encountered in any pearls tested previously by GIA gemologists. On initial examination, the pearls did not show clear indications of being either freshwater or saltwater. Nor was it clear whether they were likely to be natural or cultured. In most cases, these two questions would be resolved very quickly after some of the initial examination procedures were completed. This was not the case with these two examples, however, since the energy-dispersive X-ray fluorescence (EDXRF) results conflicted with the optical X-ray luminescence observations. This led to additional LA-ICP-MS analysis, a procedure not often required in routine pearl testing. The situation appeared even more perplexing after RTX work revealed inconclusive structures, which led to additional analysis using μ-CT. The pearls were so unusual in a number of ways, especially with regard to their trace-element chemistry, that we decided to seek a second opinion on this aspect in particular. Hence, the pearls were sent to the Max Planck Institute for Chemistry (MPIC) in Mainz, Germany.
The results of the work by GIA and MPIC showed that the pearls consisted of layer-like zones with distinct trace-element signatures associated with both saltwater and freshwater environments, as confirmed by the spot analysis undertaken by three different LA-ICP-MS units in three different locations operated by three different groups of scientists. While the pearls were in Germany, the opportunity was also taken to perform μ-CT analysis on both samples. The results were in keeping with those obtained by GIA, though the interpretation of the structures was not straightforward and together with the trace-element chemistry led to various questions about the producing mollusk and the origin/type.
In summary, the pearls were found to be a mixture of saltwater and freshwater layers. While the pearls are likely non-bead cultured, their true identity remains a puzzle owing to their complex chemistry and questions raised concerning the producing mollusks. To our knowledge, these pearls with mixed trace-element patterns are the first of their type recorded in the literature.
The Study of Tanzanite’s Gemological and Color Characteristics
Jinding Yu and Ren Lu
Gemmological Institute, China University of Geosciences, Wuhan
Tanzanite was discovered in the Merelani Hills in the Arusha region of northeastern Tanzania during the 1960s. It first became popular with a promotional campaign by Tiffany & Co. in the late 1960s. The fact that there is only one deposit in the world further raised its value. Never before had a newly discovered gemstone gained so much success within such a short time.
Natural, unheated blue tanzanite is rare and known for its trichroic colors: bluish violet, violetish blue, and yellow-green. To best realize the hidden beauty, natural tanzanite, often showing a brown hue, is heated to achieve a predominantly blue coloration before reaching the market. It has been previously reported that heated tanzanite will convert from trichroic to dichroic, but there have been few details and virtually no quantitative UV-Vis absorption coefficient data to support that claim.
Tanzanite exhibits metachromatism, a color change, when illuminated by cold and warm light sources. In addition, tanzanite also exhibits the Usambara effect. The only form of zoisite to have its Usambara effect studied until now was epidote. If these two color phenomena are also recognized, it will raise tanzanite’s status and value.
For this study we chose several brown zoisites, a violet tanzanite, a pink zoisite and a green zoisite from Merelani, and a green zoisite from Afghanistan. We conducted a systematic and quantitative analysis of the tanzanite sample using XRF and LA-ICP-MS, as well as FTIR, Raman, and UV-Vis spectroscopy. We attempted to quantitatively analyze the tanzanite’s color before and after heating.
The results showed that tanzanite changed from trichroic to nearly—but not completely—dichroic after heating. The difference between these two types of blue was eye visible but also indicated by the spectrum and the photos. The study revealed tanzanite’s color-change quantitative data and the method for taking photos of its color-change effect. We also found that the brown zoisite displayed the Usambara effect. Lastly, we concluded that the tanzanite’s blue level is probably related to vanadium.

Figure 1. Colorimetric parameters for three axes of an unheated and a heated tanzanite sample are shown in CIELAB color space under standard A illuminant (left) and standard D65 illuminant (right). See Liu et al. (1999), Schmetzer et al. (2009), and Sun et al. (2015).
REFERENCES
Liu Y., Shigley J.E., Halvorsen A. (1999) Colour hue change of a gem tourmaline from the Umba Valley, Tanzania. Journal of Gemmology, Vol. 26, No. 6, pp. 386–396.

Schmetzer K., Bernhardt H.-J., Bosshart G., Hainschwang T. (2009) Colour-change garnets from Madagascar: Variation of chemical, spectroscopic and colorimetric properties. Journal of Gemmology, Vol. 31, No. 5-8, pp. 235–282.

Sun Z., Palke A.C., Renfro N. (2015) Vanadium- and chromium-bearing pink pyrope garnet: Characterization and quantitative colorimetric analysis. G&G, Vol. 51, No. 4, pp. 348–369, http://dx.doi.org/10.5741/GEMS.51.4.348 @chapter:14


Publication Year: - Title: Spring 2012 Gem News International Abstract: Tucson 2012
Colored Stones and Organic Materials
            Aquamarine from Mavuco, Mozambique
            Azurite in Granitic Rock from Pakistan
            Cat's-Eye Emerald from the Belmont Mine, Brazil
            New Production of Purple Common Opal from Mexico
            Rare Stones Used in Jewelry: Smithsonite, Cobaltite, Pyrrhotite, Nickeline, Nuummite
            Rosalinda: A New Ornamental Scapolite Rock from Peru
            Vlasovite from Quebec
Synthetics and Simulants
            "Sterling Opal" Debuts
            Bicolored Tourmaline Imitation
Conference Reports
            U.S. Faceters Guild Seminars
Miscellaneous
            Meteorite Watches
GNI Regular Features
Diamonds
            Diamond Mining to Resume at Birim River, Ghana
Colored Stones and Organic Materials
            Iris Agate from Montana
            Black Cassiterite
            Diopside from Kenya
            Emerald Mining in Mingora, Pakistan
            Dark Yellowish Green Enstatite from Kenya
            New Gem Discoveries in Ethiopia
            Burmese Spessartine
Synthetics and Simulants
            Enameled Jewels in the Chinese Market
            Geikielite from Sri Lanka with Fake Star Effect
Treatments
            A Dyed Blue Opal with Play-of-Color
Conference Reports
            Mines to Market Conference
            Gem-A Conference 2011
Miscellaneous
            Gem News from Myanmar

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


Publication Year: 2016 Title: Quartz Windows in Chalcedony Abstract: Figure 1. Measuring 52.56 × 36.71 × 2.88 mm, this half-moon-shaped chalcedony plate contains more than a dozen hexagonal quartz windows. Photo by Kevin Schumacher.

	We recently examined a 55.08 ct polished half-moon-shaped plate of white and brownish yellow chalcedony from Madagascar that was fashioned by Falk Burger (Hard Works, Tucson, Arizona). As can be seen in figure 1, more than a dozen hexagonal windows of transparent colorless quartz accentuated by thin frames of brownish yellow chalcedony are randomly scattered throughout the host. In this specimen the quartz crystals would be considered protogenetic inclusions since the chalcedony formed around the preexisting crystals. The quartz crystals are all twinned on the Brazil law, and the c-axes of the quartz windows are all aligned in parallel fashion. As a result, when the chalcedony plate is examined between crossed polarizing filters, the transparent windows all display their twinning through the presence of colorful stellate patterns (figure 2) that vary in appearance as the plate is rotated or moved about in the polarized light field (see video at http://www.gia.edu/gems-gemology/quartz-window-chalcedony).

	Figure 2. When viewed between crossed polars, Brazil-law twinning in the quartz windows is revealed as stellate patterns (left). As the analyzer is rotated, different colors are revealed along the twinning (right). Photomicrographs by Nathan Renfro; field of view 19.01 mm. @chapter:10


Publication Year: 2014 Title: Shell Pearl as a Pearl Imitation Abstract: Figure 1. These shell pearls range from 10 to 12 mm and display black, white, and golden colors. Photo by Jian Xin (Jae) Liao.

              Imitation pearls made of shell, or “shell pearls,” have a long history in the jewelry market and have been reported in previous Lab Notes columns (Fall 1984, p. 170; Winter 1986, p. 239; Summer 2001, pp. 135–136; Summer 2004, p. 178). The shell beads are often coated with artificial materials to simulate a wide variety of natural and cultured pearls in the market. Recent submissions of such imitations to GIA prompted researchers in the lab to obtain several samples from a commercial website. Labeled as shell pearls (figure 1), they resembled Tahitian black, white, and yellow/golden South Sea cultured pearls.

Although the samples were similar in appearance and heft to cultured pearls, routine gemological tests revealed unnatural surface characteristics. The black shell pearl necklace also exhibited multicolored but rather oily orient. Magnification showed numerous minute particles with a glittering effect (figure 2, left), as well as a lack of the obvious overlapping nacre platelets commonly found in nacreous pearls. These features suggested that an artificial coating had been applied to the bead. Inspection near the drill holes of some samples revealed chipping and peeling of this very thin coating, exposing white bead-like shell material underneath (figure 2, right).

	Figure 2. Left: The surface of the imitation pearls contained a glittery coating rather than overlapping nacre platelet structures (magnified 112.5×). Right: White bead-like shell material was exposed at a damaged area near the drill hole (magnified 10×). Photos by Chunhui Zhou (top) and Jessie Yixin Zhou (bottom).
X-radiography showed only the inner bead, with occasional parallel banding and cracks—similar to the banding and trematode “tunnels” common in some saltwater shell beads—while the outer coating remained transparent (figure 3). EDXRF analysis detected a high concentration of bismuth, which usually does not occur in pearls but had been reported previously in coated natural and cultured pearls (Fall 2005 Gem News International, pp. 272–273; Winter 2011 Lab Notes, pp. 313–314). Finally, Raman spectroscopic analysis of the exposed white bead identified it as aragonite. These results, coupled with the bead’s inert reaction under X-ray fluorescence, confirmed it was made of saltwater shell.

	Figure 3. X-radiography revealed banding and cracks in the inner shell beads.
We have noted the use of the terms shell pearl or just pearl for such imitations in product descriptions on numerous commercial websites. Such inappropriate nomenclature could be misleading to inexperienced buyers. According to the CIBJO Blue Book on pearls, “Imitations or simulants of natural pearls and cultured pearls . . . shall be immediately preceded by the word ‘imitation’ or ‘simulated’, with equal emphasis and prominence . . . as those of the name itself.” Imitation pearl would be the proper name of this material, and consumers need to be aware of its true identity. @chapter:14


Publication Year: 2003 Title: Gem-Quality Synthetic Diamonds Grown by a Chemical Vapor Deposition (CVD) Method Abstract: Brown-to-gray and near-colorless single-crystal type IIa synthetic diamonds grown using a chemical vapor deposition (CVD) technique by Apollo Diamond Inc. have gemological properties that are distinct from those of both natural diamonds and HPHT-grown synthetic gem diamonds. The tabular crystals typically range up to 1 ct or more and a few millimeters thick, and consist of an overgrowth on a natural or synthetic diamond substrate. Faceted CVD synthetic diamond usually cannot be separated from natural diamond with standard gemological techniques; although when portions of the substrate are still present, an experienced gemologist may be able to recognize differences in luminescence or color between the overgrowth and substrate. In all cases, however, the CVD synthetic diamonds examined to date could be identified in a gemological laboratory by the combination of a strong orangy red fluorescence seen with the De Beers DiamondView deep-ultraviolet imaging system, a characteristic anomalous birefringence (strain) pattern, and distinctive features in their infrared absorption spectra (e.g., at 3123 cm-1) and photoluminescence spectra (strong 575 and 637 nm emissions, a doublet at 596 and 597 nm, and a line at 737 nm). @chapter:11


Publication Year: 1997 Title: Gem Rhodochrosite from the Sweet Home Mine, Colorado Abstract: Massive banded rhodochrosite has long been used for carvings and other ornamental objects. Although intense red transparent rhodochrosite crystals of remarkable size have been known in Colorado since 1895, not until recently were mining techniques developed to recover them economically. These new mining techniques have combined state-of-the-art equipment and technology to detect and extract large, fine-quality rhodochrosite specimens and gem rough. Although rhodochrosite is a soft mineral, faceted rhodochrosite can be set into jewelry provided it receives special handling and consideration with respect to wear. Faceted rhodochrosite can be readily separated from possible imitations on the basis of standard gemological testing. @chapter:0


Publication Year: 2022 Title: Diamonds from Guyana, Ekanite from Sri Lanka, a New Amber Source in Vietnam, and More... Abstract: Welcome to the Summer 2022 issue of Gems & Gemology! This installment is packed with interesting new content, including five feature articles ranging from reports on new and lesser-known gem sources to a study of the emeralds once embedded in the crown of Napoleon III.
“…an overview of diamond production and mining practices in Guyana, along with findings on color…”
In our lead article, Roy Bassoo and Kenneth Befus explore diamonds and diamond mining in Guyana. Drawing on their own observations of diamonds from various alluvial deposits, coupled with government reports, datasets, and historical accounts, the authors provide an overview of diamond production and mining practices in Guyana, along with findings on color, morphology, nitrogen content, and luminescence.
Our second article investigates the uneven shapes and surface features of ekanite from Sri Lanka. Lutz Nasdala and his team analyze ekanite fragments and ekanite-containing specimens of rock discovered near Ampegama, comparing the samples to those from other Sri Lankan sources to identify the processes that led to the distinctive shape and surface features.
As part of an ongoing effort to research gemstones of historical significance, Stefanos Karampelas and coauthors present their analysis of 45 “emeralds” formerly set in the coronation crown of Napoleon III. Using nondestructive mobile spectroscopic and gemological means at Mines Paris - PSL, they verified that 41 of these 45 gems were emeralds, likely of Colombian provenance, while the remaining four were glass containing iron and/or copper.
Next, a team led by Le Ngoc Nang examines the gemological properties and commercial potential of a newly discovered amber source on Phu Quoc island in Vietnam. They conclude that based on the high quality of the amber and the wide distribution of the host rock on the island, Vietnam’s only known amber locality may have a promising future in the market.
In our final article, Dariusz Malczewski and colleagues present their study on natural radioactivity in nephrite. After examining 11 serpentinite-related nephrite samples from Poland, Russia, Canada, and New Zealand, the authors determined that there is no radiological risk to handling nephrite and that the levels of the radioactive isotopes studied are very low.
Our regular columns deliver interesting finds from around the world. Highlights from the Lab Notes, section include a very rare large bright orange benitoite, the famed De Beers Cullinan Blue diamond, and pearls embedded with RFID devices. In Micro-World, the inner beauty of gems comes alive with an impressive blue apatite inclusion in garnet, eye-visible etch channels in a natural diamond, and a rock fragment exhibiting a very realistic eye pattern. Gem News International keeps you up to date with the latest developments, including unusual chatoyancy in omphacite fei cui jade, a company with a mission to support women in the gem trade, testing of color instability in yellow sapphire, and a museum exhibit celebrating a major tourmaline discovery in Maine. Colored Stones Unearthed returns to cover inclusions in gems, explaining how they form, how they are studied, and what they mean for gemologists and geoscientists.
Finally, we invite you to join the Gems & Gemology Facebook group at www.facebook.com/groups/giagemsgemology. Since its launch in February 2020, our growing community has surpassed 25,000 members. Thank you for your continued support and interest in G&G! @chapter:1


Publication Year: - Title: Unveiling a Chinese Luxury Jadeite Brand: A Visit to Zhaoyi Cuiwu in Beijing Abstract: This “Dancing Bird with Jade Feathers” jadeite necklace was made by Zhaoyi Cuiwu. The necklace’s evocative name comes from an impressionistic resemblance to a bird rather than a literal representation. The pendant portion of the necklace suggests the slender neck of a bird, and the portion above the flower clip suggests its wings. The green jadeite cabochons symbolize glistening bird feathers. The piece epitomizes a key difference between Chinese and Western jewelry design, in that the Chinese tend to focus on the symbolic, rather than naturalistic, representation of natural subjects. The necklace won the Media Attention Award in the China Jewelry Design and Manufacturing Contest. Photo courtesy of Zhaoyi Xintiandi Co. Ltd.

                      Zhaoyi has been the leading fine jadeite jewelry brand since its debut in 2003. In 2012, it was honored by the American luxury lifestyle magazine The Robb Report as one of China’s top ten emerging luxury brands. In 2013, a GIA field gemology team visited Zhaoyi Cuiwu, one of the three production lines that operate under Zhaoyi Xintiandi Co. Ltd. This eye-opening experience allowed the authors and Western jewelry industry experts to re-envision the traditional Chinese gold-jade culture as an inexhaustible source of luxury innovations.

	Zhaoyi Cuiwu jewelry

	Sales professionals describe high-end jadeite jewelry made by Zhaoyi Cuiwu.

	Brand Profile
The brand name “Zhaoyi” originated from the ancient Chinese Palace of the Han Dynasty (206 BC to 9 AD). It was one of the high official titles assigned by the emperors to women who served in the palace. In Chinese, “Zhao” means “illuminating” or “being bright,” while “Yi” means “etiquette.” These concepts are also the core of the Chinese gold-jade culture.

Zhaoyi Xintiandi Jewelry Co., Ltd. was formed in Beijing in 2003. From day one, this company has established its image as the leader of Chinese high-end jewelry trends and the inheritor of traditional Chinese jewelry manufacturing craftsmanship. The company integrates jadeite rough purchasing, jewelry design, haute couture design, jewelry manufacturing, jewelry retailing, and brand promotion.

In 2004, Zhaoyi opened its first retail store in Beijing. In 2007, Zhaoyi opened its first flagship store in the Beijing Kunlun Hotel. In that same year, movie star Wenli Jiang walked the red carpet of the international film festival in Rome wearing a Zhaoyi suite consisting of a colorless transparent jadeite necklace and ring. For the first time, fine jadeite jewelry designed and made by Zhaoyi stood out on an international stage.

The store visited by the GIA team in the Grand Hyatt Beijing opened in September 2008. Well-known film stars attended the opening ceremony. In 2012, a new Zhaoyi Cuiwu store image was unveiled at the Shanghai Top Marques private luxury exhibition. International movie star Kar-ling Lau modeled top-quality jadeite jewelry at the show. Since the company’s formation, Zhaoyi has collaborated with many movie stars, and many of them became collectors of Zhaoyi’s fine jadeite jewelry.

Movie star Pace Wu wore Zhaoyi’s imperial jadeite jewelry suite. As a well-known fashion icon, Wu demonstrated to the public, especially the young generation, that green jadeite can be very fashionable. Photo courtesy Zhaoyi Xintiandi Co. Ltd.
Great leadership and industry expertise are always important to the development and prosperity of a business. Zhaoyi’s president and CEO, Ms. Yunhe Wang, has very sharp insights and a clear sense of her company's direction. She selected filigree inlay designer Master Yingyi Bai and Canadian-Chinese jewelry designer Grace Lee as the chief designers. This turned out to be one of the most successful moves in Zhaoyi’s history.

Ms. Yunhe Wang, President and CEO of Zhaoyi Xintiandi Co. Ltd., treasures the industry experts she has recruited for Zhaoyi. From left to right: Chief filigree inlay designer Master Jingyi Bai, Yunhe Wang, and famous movie star Kai-ling Lau. Photo courtesy Zhaoyi Xintiandi Co. Ltd.
Currently, Zhaoyi has a total of 13 boutique stores in nine cities. While not a large number, every store is like an art gallery. The Beijing store even houses a private filigree museum. Aside from major cities in mainland China, Zhaoyi also has locations in Hong Kong and is planning to open franchised shops in Paris, New York, and other metropolitan areas all over the world. Their goal is to bring the Chinese gold-jade culture to the international market.

	Creative Jewelry Design
Targeting the high-end jadeite jewelry market in China, Zhaoyi creates jadeite masterpieces with particular appeal to art collectors. In order to successfully inherit and carry on the gold-jade culture and its thousands of years of history, designers apply groundbreaking Western design concepts to jadeite jewelry. These creative designs attract the attention of the younger generation and the Western world.

View Gallery

	Creative Designs
Colorless transparent jadeite jewelry is one of Zhaoyi’s special products. Previously, colorless jadeite was not favored by jadeite professionals in China. However, it can actually display outstanding transparency and extremely fine texture. Industry experts in Zhaoyi sensed the potential of this material and created the classic transparent colorless jadeite cabochon. Now, transparent jadeite cabochons more or less symbolize the Zhaoyi Cuiwu brand. This is significant, especially because of the shortage of high-quality green jadeite rough. At the same time, for balance, designers bravely use diamonds and colored stones as accents for these cabochons. This has never before been popular in China’s history.

View Gallery

	The Beauty of Colorless Transparent Jadeite
Besides colorless transparent jadeite and the traditionally popular imperial jadeite, jadeite in other colors is also beautifully designed and manufactured by Zhaoyi.

View Gallery

	More than Green

	Company Treasures
When a great designer works with extremely rare top-quality material, masterpieces are expected. Zhaoyi claims both elements as company treasures.

Grace Lee, the chief designer of Zhaoyi Cuiwu, was once a broadcaster. Her design innovations resulted in jewelry pieces featuring colorless transparent jadeite. Photo courtesy Zhaoyi Xintiandi Co. Ltd.
Grace Lee, a Canadian originally from Hong Kong, is the chief designer of Zhaoyi Cuiwu. Once a broadcaster at ATV World in Hong Kong, Grace stepped into the gem and jewelry industry with a jewelry design degree from Hong Kong Baptist University and a GIA Graduate Gemologist diploma. Since she became a jewelry designer, her works have become very popular in auction houses such as Sotheby’s and Christie’s. As Zhaoyi’s chief designer, two of her product lines, “Jade for You” and “Jade That She Wants,” are very well favored by clients. Both have been extended into high-end custom jewelry lines.

“Jade that She Wants” is one of two Zhaoyi high-end custom jewelry lines designed by Grace Lee. These jewelry pieces feature large, top-quality, colorless transparent jadeite cabochons and complementary colored stones. Photo courtesy Zhaoyi Xintiandi Co. Ltd.
One of Grace’s jadeite masterpieces is also the company’s symbol. It’s called “The star of Zhaoyi.” It was released in 2012 and won the Robb Report's Best Chinese Selected Jewelry Award. The center stone of the The star of Zhaoyi is a top-quality lavender jadeite cabochon that weighs 9,499 carats. The cabochon is mounted in precious metal with numerous diamonds and colored stones. The piece resembles a blossoming peony, which is considered the national flower of China. Ten matched rings were made to surround the larger piece. Each ring has a top-quality colorless transparent jadeite as the center stone. All ten rings have the same design as the star of Zhaoyi.

The star of Zhaoyi is the company’s symbol. This piece features a center stone that weighs 9499 carats. Top-quality lavender jadeite of this size is extremely rare. Ten matching rings were also made. The suite looks like a blossoming peony surrounded by ten small flowers. Photo courtesy Zhaoyi Xintiandi Co. Ltd.

	Contribution to the Jade Industry
In addition to promoting and managing the brand, Zhaoyi also played an important role in the formation of the National Jadeite Grading Standard. Because Zhaoyi has access to a huge amount of jadeite of different qualities, it became the sponsor of the research into the grading system. Zhaoyi provided standard samples, and some experts from the company even participated in the research. In December, 2012, the Chinese Standardization Administration officially approved the “transparent jadeite (colorless) classification” standard. This standard was in practice at the end of 2013. @chapter:21


Publication Year: 2016 Title: Quarterly Crystal: Triplite in Topaz Abstract: Figure 1. A pinkish orange inclusion dominates the interior of this 20.58 ct unpolished topaz crystal from Pakistan. Photograph by Kevin Schumacher.

	The transparent colorless 20.58 ct topaz crystal in figure 1 clearly hosts a prominent translucent pinkish orange inclusion. The topaz, from Biensa in Braldu Valley, Gilgit-Baltistan, Pakistan, was acquired from Dudley Blauwet of Mountain Minerals International (Louisville, Colorado). The bodycolor of the inclusion suggested that it might be either of two equally rare pegmatitic phosphates, triplite or väyrynenite, that are known to occur in pegmatites in that part of the world (figure 2).

Figure 2. A combination of Raman and EDXRF analysis served to identify the inclusion as triplite. The inclusion is seen here using brightfield and fiberoptic illumination. Photomicrograph by Nathan Renfro; field of view 9.39 mm.

	Laser Raman microspectrometry was able to narrow the inclusion’s identity to these two suspected phosphates. Triplite and väyrynenite have very similar Raman peak patterns, and the topaz host masked some of the significant peaks needed to conclusively separate the two minerals. Since triplite contains iron and väyrynenite does not, focused energy-dispersive X-ray fluorescence (EDXRF) analysis was used to examine the inclusion’s chemical composition. Results indicated the presence of iron, identifying the inclusion as triplite. This marks the first time triplite has been reported as an inclusion in topaz. @chapter:13


Publication Year: 1999 Title: Spring 1999 Gem News International Abstract: TUCSON 1999
Diamonds
            Fashioned Diamonds from the Ekati Mine, Northwest Territories, Canada
            Synthetic Diamonds Widely Available
Colored Stones and Organic Materials
            Cat’s-Eye Andradite from San Benito County, California
            An “Enhydro” Emerald from Colombia
            Abundant Eudialyte
            New Cuts for Oregon Sunstone
            Near-Colorless Forsterite
            “Watermelon Garnet”
            New Deposits in India and Nepal
            Iolite and Other Gems from Canada
            Jasper “Planets”
            Opal in Matrix from Brazil
            White and Pastel Chinese Freshwater Cultured Pearls
            Drusy Quartz “Leaves”
            Twelve-Rayed Star Quartz from Sri Lanka
            New Finds of Spessartine in Brazil
Treatments
            “Blatant” Dyed Pearls
Synthetics and Simulants
            Fused Silica Glass, Sold as “Cultured Snow Quartz”
            Blue Slag Glass from Sweden, Resembling Opal
            Imitation “Chinese Freshwater” Cultured Pearls
            Synthetic Zincite Possibly Represented as Sphalerite
Miscellaneous
            Drill Holes as Design Elements: Michael M. Dyber and “Luminaires”
            Using Mineralogical Techniques to Solve Gemological Problems
            Part 1: Internal “Becke Lines” in Spinel
            Part 2: “Plato Lines” and Growth Structures In Synthetic Corundum

Announcements
Nature of Diamonds at the San Diego Natural History Museum
            New Exhibit at the Royal Ontario Museum
            International Colored Gemstone Association Congress
            International Gemological Symposium
            International Society of Appraisers Conference
            Gemstones in Upcoming Scientific Meetings

To view the full section, download the PDF above. @chapter:2


Publication Year: 1987 Title: Man-Made Jewelry Malachite Abstract: Jewelry-quality synthetic malachite is now being manufactured in the USSR. The texture, structure, and physical and physico-chemical properties of this synthetic malachite are reported. Three textural types have been identified: banded, silky, and budlike. The malachite is composed of closely adjacent spherulitic aggregates, the generation and growth of which are controlled by the crystallization conditions. In chemistry, color, density, hardness, optical properties, and X-ray diffraction, the synthetic malachite proved virtually identical to the natural material. Only in the thermograms were significant differences noted. Therefore, the manmade malachite holds much promise for use in stone cutting and the jewelry trade. @chapter:2


Publication Year: - Title: My Life as a Colored Gem Liquidator Abstract: Bryan PavlikICA Director

	Interview with Bryan Pavlik, ICA Director
Mr. Pavlik started out buying and selling cut gems, then added gem cutting to his skill set with a stint in the famed cutting center of Idar-Oberstein. Eventually, he turned to liquidation of others’ excess and unused gem materials. Now, he travels the world to seek gems that, for one reason or another, haven’t sold, and matches those “unwanted” products with the right buyer.

Mr. Pavlik states that knowledge is essential to a successful liquidation business. He uses his cutting knowledge to help him determine if a stone can benefit from recutting—making it smaller, but also making it more marketable by eliminating distracting inclusions.

Market knowledge is also important. He tells of buying a quantity of fashioned tanzanite that a seller in Eastern Europe had been unable to sell for ten years. Mr. Pavlik bought the stones at a bargain price, recut them to improve their appearance, and resold them in the United States—where tanzanite was in demand—for a profit.

Turning to talk of the market, Mr. Pavlik explains that, while the US was once the biggest gem market, China, India, and Russia are expanding rapidly. Also, American and European markets are highly saturated at this point, so everyone in those markets is looking for the next level of stones: spectacular specimens, especially untreated stones of any kind.

He says this is where knowledge and disclosure come in: When you can explain to a customer the price difference between a treated and untreated stone, and even among different levels of treatment, the customer will understand what he can afford, making him more likely to buy.

He also says that brand names and certification are extremely important to today’s gem buyers, especially in China. All these factors will lead to an increased need for trained gemologists. The next decade, he says, will be the decade of the gemologist, but only the best ones with the most up-to-date skills.

Mr. Pavlik tells the interviewer that he is starting to limit his participation in gem shows to concentrate on other areas of his business. The next stage will be investment in high-tech identification equipment. True to his personal pursuit of knowledge, he will also learn how to use it to enhance his own business. @chapter:38


Publication Year: 1999 Title: Winter 1999 G&G Book Reviews Abstract: “Rock Crystal Treasures From Antiquity to Today”
By Sylvie Raulet, 240 pp., illus., publ. by Vendome Press, New York, 1999. US$75.00

“Beyond Price—Pearls and Pearl Fishing: Origins to the Age of Discoveries”
By R.A. Donkin, 448 pp., illus., publ. by the American Philosophical Society, Philadelphia, PA, 1998. US$45.00

“Amber”
By Andrew Ross, 73 pp., illus., publ. by the Harvard University Press, Cambridge, MA, 1998. US$12.95

“Gem Minerals of Victoria”
By William D. Birch and Dermot A. Henry, 120 pp., illus., Special Publication No. 4 of the Mineralogical Society of Victoria, Melbourne, 1997. Aus$34.95

To view the full section, download the PDF above. @chapter:25


Publication Year: 2014 Title: Indian Ruby Mining Abstract: Figure 1. Top left: Rubies are mined in a mango orchard in Channapatna, India. Top right: This 15 kg rough ruby is from Subramaniam, in the Indian state of Karnataka. Photos by Pooja Shirole. Bottom left: This thin section of ruby is surrounded by an isotropic reaction rim. Bottom right: A corundum granulite showing ruby with blue and pink interference colors. Photomicrographs by Pooja Shirole; crossed polarizers, magnified 4×.

              The Karur-Kangayam and Hole-Narsipur belts, in the southern Indian states of Tamil Nadu and Karnataka, respectively, are famous throughout the subcontinent for their gemstones, including sapphire, moonstone, iolite, aquamarine, garnet, sunstone and corundum. The city of Karur itself is well known for rubies. Ruby is also found in Subramaniam (also known as Red Hills), near Madikeri in Karnataka. Channapatna (figure 1, top left), roughly 280 km (117 miles) from Madikeri, is famous for its star rubies. In all of these locations, mining is performed using primitive methods.

Good-quality transparent rubies come from the Karur region, though color varies along this gemstone belt. The mines situated in Karur are located on barren land along the roadside; the nearby towns of Kangayam and Paramatti also have ruby mines.

Madikeri is a remote hill station covered by lush green forests, located in the Western Ghats of India. The ruby found here is lighter, translucent to transparent, and of good quality. A ruby-bearing granulite, commonly called ruby rock, is used for making artifacts such as wands and crystal balls.

In the town of Subramaniam, close to Madikeri, large hexagonal pillars of ruby are mined; deposits are also located in the nearby villages. The stones are mainly hexagonal but come in many sizes and shapes. They have a maroon color, and some show 16 mm dot inclusions of hematite. These rubies range from 20 to 100 mm across the pinacoidal face, with the length across the prism faces varying from 10 to 50 mm. Their weight ranged from 10 g to 2 kg, though specimens are as large as 15 kg, as in the top right image in figure 1.

In the Bangalore district of Karnataka, opaque maroon star ruby is found in the village of Channapatna and other nearby villages. It is extracted from red and yellow soils in mango and coconut orchards, rather than from traditional mines.

Granulite, the host rock of the Karur rubies, is somewhat similar to the host rock of Mozambique rubies (see Winter 2012 GNI, pp. 309–311). Both contain hornblende, biotite, and plagioclase. In certain areas such as Sengal and Kiranur, rubies are found in association with gem-quality iolite (cordierite). The ruby in Pamakondampalayam is found with a reaction rim of spinel, sapphirine, and cordierite (figure 1, bottom left), while the Madikeri rubies are associated with plagioclase, augite, garnet, sillimanite, and sphene in corundum granulites (figure 1, bottom right). Madikeri ruby also occurs in corundum-fuchsite-mica schists, which have a mineral assemblage of fuchsite mica, quartz, corundum, and rutile.

In summary, good-quality transparent ruby comes from host rocks in Karur; tabular hexagonal crystals ranging from transparent to translucent are mined from corundum granulites in Madikeri; and opaque star-ruby is found in the mango and coconut orchard soils of Channapantna. @chapter:3


Publication Year: 2023 Title: Sapphire from Montana’s Secondary Deposits, Colombian Emerald Morphology, the 2023 Tucson Shows, and More… Abstract: Welcome to the Spring 2023 issue of Gems & Gemology! A new volume year kicks off with our recap of the Tucson gem shows, where buyers, sellers, and industry professionals from all over the globe converge. And with two major feature articles, our regular sections, and the annual G&G Challenge, this issue is sure to captivate readers.
“The article also details the fascinating history of sapphire mining in these three Montana mining districts, which still hold substantial resources.”
In our lead article, Dr. Aaron Palke and coauthors present their study of the gemological characteristics of sapphire from Montana’s secondary deposits. Using Rock Creek, Missouri River, and Dry Cottonwood Creek samples in a variety of colors, the authors provide typical inclusion scenes and trace element chemistry fingerprints. The article also details the fascinating history of sapphire mining in these three Montana mining districts, which still hold substantial resources.
Next, Dr. Karl Schmetzer and Gérard Martayan investigate the less common morphological and growth phenomena of Colombian emerald samples to understand their growth and post-growth history. Based on their observation of 15 isolated emerald crystals and seven specimens in matrix using optical methods, they offer insight into the different patterns, with a goal of expanding the database of morphological features in Colombian emerald.
Our regular features provide informative snapshots, beginning with Lab Notes. Highlights from the section include a rare example of the purple collector gem anhydrite, a heart-shaped golden South Sea cultured pearl displaying natural shape and color, and the largest sample of synthetic rutile examined at GIA to date. Explore the inner landscapes of gemstones in our Micro-World section, where you’ll see rare cloud inclusions resembling a starry night in diamond, a macroscopic mineral inclusion cluster in a Pakistani aquamarine crystal, a three-phase inclusion in alexandrite, and more. Diamond Reflections returns in this issue, this time exploring plastic deformation in diamond. Our Gem News International section begins with nearly 30 pages covering the 2023 Tucson gem shows, ranging from the latest trends and market updates to noteworthy designs, followed by an opulent photo gallery packed with finds from the shows. The GNI regular features include various pearl discoveries from around the world and a new source of ruby from Liberia.
Finally, test your gemological knowledge of our 2022 feature articles in the annual G&G Challenge, and find out which articles received the Dr. Edward J. Gübelin Most Valuable Article Award.
We hope you enjoy the latest issue of Gems & Gemology! @chapter:2


Publication Year: 2015 Title: An Unusual Filled Ruby Abstract: Figure 1. This 12.12 ct red stone showed features typically associated with a natural ruby. Photo by A. Droux/LFG.

A 12.12 ct corner-cut rectangular red stone (figure 1) was submitted to the Laboratoire Français de Gemmologie (LFG) for analysis. The sample’s refractive index, specific gravity, and Raman spectrum confirmed its identity as a ruby. It fluoresced a medium to strong red in long-wave UV radiation, and a weaker red in short-wave UV. Under magnification, it showed fairly dense accumulations of long needles, some of them rather flat and most of them iridescent (figure 2). Many parallel twin lamellae crossed the gem (figure 3). There was no indication of thermal enhancement. The inclusions and chemical composition were consistent with ruby from Myanmar.

Figure 2. Dense accumulations of iridescent needles were visible within the red stone.
Photomicrograph by A. Droux/LFG; magnified 50×.

Figure 3. Contrasted twin lamellae in this ruby are similar to those often observed in
material from Myanmar. Photomicrograph by A. Droux/LFG; magnified 60×.
Many fractures were apparent, with smaller ones following the twin lamellae. Examining the surface of the fissure, it became apparent that some material was present inside the fractures, and in some locations had left a whitish trace in the fracture close to the surface. Deeper within the fractures there were flat bubbles and networks of cracks similar to those seen in drying mud, with a somewhat dendritic aspect.

These same patterns were observed with the drying of oil in emerald (H. Hänni, “Gemmology, an oil well in your garden?” Schweizer Uhren & Schmuck Journal, No. 3, 1988, pp. 461–464; H. Hänni et al., “How to identify fillings in emeralds using Raman spectroscopy,” Jewellery News Asia, No. 145, 1996, pp. 154–156). Under the heat of the optical fiber used for observation, some droplets formed at the outcrop of the fissure, indicating that the material was either liquid or had a melting point just above room temperature, suggesting that the filler could be either oil or wax.

Exposure to the ultra-short UV wavelength of the DiamondView revealed the filling material inside the fractures (figure 4). Infrared absorption confirmed the presence of an organic material in the fractures (figure 5). “Oil” peaks at about 2852, 2925, and 2955 cm–1 were at positions nearly identical to those observed for oil-impregnated emerald (P. Zecchini and P. Maitrallet, “Que peut apporter la spectrographie infrarouge dans l’étude des émeraudes?” In D. Giard, Ed., L’émeraude: Connaissances Actuelles et Prospectives, Association Française de Gemmologie, Paris, 1998, pp. 81–96; M. Johnson et al., “On the identification of various emerald filling substances,” Summer 1999 G&G, 82–107). The peaks were accompanied by sharp features around 3600–3700 cm–1, attributed to kaolinite group minerals (A. Beran and G. Rossman, “OH in naturally occurring corundum,” European Journal of Mineralogy, Vol. 18, 2006, pp. 441–447). The band at 2463 cm–1 was produced by CO2.

Figure 4. DiamondView imaging of the ruby showed the filling of fractures. Image by A.
Droux/LFG.

Figure 5. Infrared spectrum of the ruby showing the same absorptions as for the filling of
some emeralds.
On the basis of microscopic observation and infrared spectroscopy, we concluded that the ruby showed moderate indications of clarity enhancement—with oil, in this case. Although glass-filled rubies are common on the market today, oiled corundum is much rarer. This oiled ruby was also unusual for its size and evidently Burmese origin. @chapter:10