Publication Year: - Title: Visit to Chow Tai Fook Diamond Cutting Factory in Foshan, China Abstract: Chow Tai Fook is a vertically integrated manufacturing-to-retail jewelry company. Their value chain includes state-of-the-art diamond cutting. Photo by Pedro Padua, © GIA, courtesy of Chow Tai Fook, Yueshun Fook Jewellery and Diamond Co.

                      Chow Tai Fook Jewellery Group Limited is widely considered to be China’s largest jewelry retailer. It’s part of Chow Tai Fook Enterprises Ltd., a diversified Hong Kong based company that’s also engaged in property development, hotels and casinos, and transportation, port, and telecommunication businesses.

Chow Tai Fook Jewellery Group Limited had retail sales of $7.4 billion US in 2012, with a profit of $730 million. The company has been listed on the Main Board of The Stock Exchange of Hong Kong since December 2011 and it’s the world’s largest jeweler based on its market capitalization. Chow Tai Fook is a member company of the Hang Seng China 50 Index and Hang Seng Mainland 100 Index.

	Chow Tai Fook Jewellery Group Limited is one of the best-known jewelry companies in Asia. The company is known globally for its success.
Along with its extensive retail network, the company covers the entire value chain, including raw material procurement, design, diamond cutting, jewelry manufacturing, marketing, and sales. Its principal products are mass-market and high-end luxury jewelry, including gem-set, gold, and platinum styles, and watches.

	Company Milestones
Chow Tai Fook had its start in the jewelry industry in 1929. In 1938 and 1939, respectively, they opened their first retail stores in Macau and Hong Kong. They introduced a line of 999.9 fine gold jewelry in 1956. This purity guarantee was highly successful at creating customer trust and building a loyal clientele.

Foshan Yushunfu Jewellery and Diamond Company Limited, a then-related part of the company, opened its first diamond processing and jewelry manufacturing factory in Shunde in 1988, thereby strengthening the vertical integration of the Group's business model. Foshan Yushunfu became a full subsidiary in 2011.  Zlotowski’s Diamond Cutting Works (Proprietary) Ltd., located in Johannesburg, South Africa, also became a subsidiary in 2011.

Chow Tai Fook has secured multiple sources of rough diamonds to supply their cutting factories and retail stores. In 1993, the company qualified as a Diamond Trading Company (DTC) sightholder, which gave them the right to source rough diamonds directly from the DTC. The addition of Zlotowski’s, already a DTC sightholder at the time, strengthened that position. In 2009, Chow Tai Fook became a Select Diamantaire of Rio Tinto Diamonds. In 2012, they entered into a strategic two-year agreement with Alrosa of Russia for procuring supplies of its rough diamonds.

Rio Tinto has also partnered with Chow Tai Fook to promote its Argyle mine diamonds in their stores. Rio Tinto’s new underground mining operation at Argyle has the potential to produce substantial quantities of small diamonds for the jewelry needs of the Chinese middle class.

	Like all diamond manufacturers, Chow Tai Fook needed to secure a constant supply of rough for their manufacturing needs in a tight global market. Photo by Eric Welch, © GIA, courtesy of Chow Tai Fook, Yueshun Fook Jewellery and Diamond Co.
In 1998, Chow Tai Fook opened the company’s first retail store in mainland China, located in Beijing. In 2003 they centralized their mainland operations with headquarters in Shenzhen. By 2010 they had 1,000 retail outlets in mainland China (including franchisees and their own outlets). Chow Tai Fook’s retail network now includes over 1,800 outlets in more than 400 cities in Greater China, Singapore, and Malaysia. It also has a growing e-commerce presence. Chow Tai Fook has plans to open 2,000 chain stores in mainland China by the year 2020.

In June of 2013, during an extensive trip through China, GIA representatives visited the Chow Tai Fook diamond-cutting factory in Foshan. The team was given a highly informative guided tour of the factory, with detailed explanations of each manufacturing area and process.

	At the Chow Tai Fook factory, the GIA team extensively documented the operation of each department involved in the company’s diamond manufacturing business. Photo by Eric Welch, © GIA, courtesy of Chow Tai Fook, Yueshun Fook Jewellery and Diamond Co.

	Sorting, Planning, and Marking
The tour began in the sorting, planning, and marking room. All incoming rough diamonds come to this room to be sorted by shape, size, clarity, and color. After sorting, the rough diamonds’ cuts are planned and the rough is marked. The process makes use of instrumentation that includes the Helium M Box, Sarin Galaxy 1000, and other Sarin optical measuring and marking instruments, as well as traditional hand marking.

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	Today, optical instruments play a critical role in planning a diamond’s cut.
The instruments can mark the rough with more precision than is possible by hand, and the line is typically straighter and more accurately placed. Even a difference of one degree, causing a weight difference of one percent, can make a substantial difference in value. This is highly important considering the tight profit margins of diamonds today and the large volumes of diamonds coming through a modern factory.

Rough that requires a lot of care in the planning stages due to inclusions often goes into the Helium M Box so the planner can use a microscope to closely examine the inclusions’ nature. Included rough can also be efficiently analyzed with the Sarin Galaxy 1000, which can plan the placement of the cut stone within the rough and eliminate many of the inclusions.

The Sarin DiaMark-Z is the factory’s most commonly used optical planning and marking instrument and is used for “normal goods,” meaning stones with SI1 to IF clarity and standard sawable shapes.

The GIA team watched a planner use the DiaMark-Z to analyze and mark diamond rough for sawing. The first step was for the planner to decide what diamond shape would result in the best yield and value, based on the shape of the rough. If the rough is long, the shape of the cut stone would most likely be something like a pear or marquise.

After the cut stone’s shape is selected, the best combination of cut stone sizes is determined. For most octahedral rough, the stone is sawn off-center so one cut stone will be larger than the other. The best shape and cutting style from octahedral rough is usually the round brilliant. Some rough that is more rounded in shape might best be sawn to produce two equal-size diamonds.

The Sarin DiaMark-Z quickly displays all the potential combinations for two round brilliant cut stones, and value calculations are built into the software. A simple instrument called a polariscope uses polarized light to determine if the rough crystal contains potentially damaging strain.

	In a simple instrument called a polariscope, these diamonds are being checked for strain that could cause breakage. Photo by Eric Welch, © GIA, courtesy of Chow Tai Fook, Yueshun Fook Jewellery and Diamond Co.
The Sarin Galaxy 1000 is an accurate, automated system for mapping out inclusions in more challenging, highly included stones. This machine scans a rough diamond’s exterior and records its dimensions. Mapping of inclusions takes place inside the machine, in some cases making it difficult to see them clearly. This is especially true with the edges of very fine feathers. However, the Galaxy 1000 is much faster than the Helium M Box, which is often used for larger stones.

	The Sarin Galaxy 1000 is a fast and efficient system for mapping a rough diamond’s inclusions. Photo by Eric Welch, © GIA, courtesy of Chow Tai Fook, Yueshun Fook Jewellery and Diamond Co.
The GIA team watched the planning of a challenging piece of rough using the Sarin Galaxy 1000 System. The instrument plotted all the inclusions and showed where round brilliants could be cut from the stone, eliminating most of the inclusions and producing higher-clarity, higher-value diamonds. The instrument identified three stones that could be cut from the rough while eliminating I1 to I3 clarity-grade inclusions. The instrument identified all the inclusions in the rough and then brought up a computer model for planning.

	This complicated piece of rough was analyzed by the Sarin Galaxy 1000. Results showed that it could yield three diamonds while avoiding inclusions that would substantially lower value. Photo by Pedro Padua, © GIA, courtesy of Chow Tai Fook, Yueshun Fook Jewellery and Diamond Co.
Inside the Galaxy 1000, the rough diamond is immersed in a liquid, making it more transparent and allowing more accurate identification and mapping of inclusions. The rough diamond appears white and the inclusions stand out as dark, making their locations and shapes easy to see. After the scanning is complete, the files are transferred to the computer for plotting of all the inclusions onto a 3D model. The model is saved into the company’s server so the diamond markers can open the file and plan the diamond cut.

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	The Sarin Galaxy 1000 helps prepare rough by mapping its inclusions.
The Helium M Box works along with a scanner and a microscope. First, the scanner performs normal mapping of the rough’s outline. Next, the rough is put under the microscope and the inclusions are plotted and input through the computer. At that point, the system can plan the cut, taking into consideration the inclusions and the potential clarity grades of the cut stones.

The microscope’s magnification level can reach to over 150X. The process is time consuming—one stone takes two to three hours—but the advantage is that the powerful microscope makes it very accurate, allowing for more options and the ability to improve the clarity, and ultimately the value, of the cut stones. The team watched this instrument map out a five-carat round brilliant and a four-carat round brilliant from a piece of rough, allowing for removal of a feather to improve the clarity grade of one of the cut stones.

	The Helium M Box uses a powerful microscope along with a scanner to locate and map inclusions. Photo by Eric Welch, © GIA, courtesy of Chow Tai Fook, Yueshun Fook Jewellery and Diamond Co.
The Helium M Box utilizes its very powerful microscope to map out the rough’s inclusions in great detail. This makes even difficult to map inclusions like fine feathers and pinpoints easier to detect. The Helium M Box is often used for analyzing larger stones. The Galaxy 1000 and the Helium M Box often work as a team. Important stones are placed in the Galaxy 1000 for initial mapping. The final mapping is done with the microscope and the Helium M Box.

	The technician used the Helium M Box and the microscope to plot a rough diamond’s surface-reaching feather, which is marked in green. Photo by Pedro Padua, © GIA, courtesy of Chow Tai Fook, Yueshun Fook Jewellery and Diamond Co.
At the end of the tour of the planning and marking area, the group’s expert guide, Simon, reviewed the machines being utilized: the Sarin DiaMark-Z, the Sarin Galaxy 1000, and the Helium M Box system. The Sarin DiaMark-Z is fast, easy to use, and accurate. It’s generally used for rough in SI1 and higher clarity grades. This instrument is not as capable as the other instruments at handling more-included rough, mapping out inclusions, or determining the cutting options for challenging rough.

After sorting, planning, and marking, the information for the rough is input into Chow Tai Fook’s proprietary software system, which tracks the rough and all decisions made throughout the manufacturing process. The first information recorded is the weight of the rough and the planned weight of the cut stones. The papers holding the rough are barcoded for scanning, and have areas where all the information can be recorded as it travels through the manufacturing process. After the information is input, the rough is ready to move on to the next stage—sawing.

	After planning and marking, it is critical to input data for tracking purposes. Photo by Pedro Padua, © GIA, courtesy of Chow Tai Fook, Yueshun Fook Jewellery and Diamond Co.
Chow Tai Fook’s software system can also track worker productivity and quality control. At every production stage, each worker’s production capacity—how many stones they can do in a day and in a week—is recorded. This information is then compiled into a graph. If any worker is not able to meet production standards, a management team works with them to determine how to raise their productivity. The tracking system is linked to the Sarin system. Salaries are linked directly to productivity.

	Sawing the Rough
Next, the GIA team witnessed the rough diamond sawing process. The first sawing system the team observed was the LMJ Laser Water Microjet. This advanced laser sawing process incorporates a continuous flow of water that keeps the rough diamond surface cool, helping to prevent breakage from heat. The laser beam is focused and guided into a hair-thin, low-pressure water jet to precisely target the material being sawn. The laser actually goes through the water to the diamond. This is considered an important advantage over more traditional dry lasers.

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	The factory uses laser technology for sawing and bruting.
Most lasers saw diamonds in a “V” shaped laser pattern. The Laser Water Microjet system uses an “I” shaped pattern with a 40-micron opening. This results in less weight loss than with the “V” shaped pattern: less than 1% for diamond rough over 1.5 carats. Simon estimated the speed of the LMJ laser to be twice that of older green-laser models, with 50% less weight loss. The “I” shaped laser pattern results in a uniform opening from the top of the cut to the bottom. The hot carbon vapor typically associated with laser diamond cutting is evacuated with the flow of water, resulting in a cleaner and smoother surface

Chow Tai Fook also makes use of green lasers for sawing diamonds. The green lasers are probably the most common lasers for sawing diamonds. They’re respected for low weight loss, minimal breakage, and production of smooth sawn surfaces. The green laser sawing machines are programmed during the day to saw multiple diamonds held in cassettes, operating all night without any employees present.

To set up the process, the technician aligns cross hairs on the sawing marks for all the diamonds in the cassette via a screen. Then the diamonds’ dimensions are programmed into the instrument’s computer, which can then saw the diamonds automatically.

Diamond sawing with both systems occurs during the normal 6-to-6 work shift. Then the green lasers are programmed to saw multiple diamonds through the night and into the next morning, when technicians pair up the sawn-off pieces and place them in the proper parcel papers.

Chow Tai Fook also uses lasers to cut the outlines of most of their fancy-shape diamonds. This process is much faster and more efficient for fancy shapes than traditional bruting methods.

	Bruting and Coning
Next stop on the tour was the bruting department, where round stone shapes are created after sawing. In the bruting machine, the diamond is rotated at high speed while it’s being rubbed against a flat-surfaced wheel charged with diamond grit and water. The water keeps the heat from the friction down and lessens the chance of damage to the diamond. A one-carat stone takes about ten minutes to form, with its girdle bruted and polished. The process takes about 6 to 7 minutes for a 0.50-carat diamond and 12 to 13 minutes for a two-carat diamond.

	Round brilliant diamonds are bruted against spinning wheels coated with diamond grit and flowing water. Photo by Eric Welch, © GIA, courtesy of Chow Tai Fook, Yueshun Fook Jewellery and Diamond Co.
While lasers are efficient for forming fancy shapes, Chow Tai Fook does not use them for bruting round-brilliant cut diamonds. The speed is about the same for laser bruting as for bruting with diamond grit, but with laser bruting there’s more risk of stone damage.

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	Bruting and coning form the basic shapes of the girdle and pavilion.
After bruting forms the round shape, the next stop is the so-called coning department, where a similar process is used to create the pavilion. This process is much faster than traditional blocking.

The desired pavilion angle is drawn with a red line. During the bruting of the pavilion, diamond rough is polished away until the red line is reached. This method shapes the pavilion in about 15 minutes compared to 3 hours for traditional blocking. The time needed to shape the pavilion is highly dependent upon the shape of the rough. Pavilions of fancy shapes are still blocked with a polishing wheel.

	Pre-polishing Quality Control
Next, the team visited the quality control department, where the diamonds are inspected after each manufacturing stage to make sure there are no errors before continuing. This is especially important before the labor-intensive last polishing step.

The different colors of the parcel papers are used to identify the suppliers, such as blue for DTC or purple for Alrosa, and also to create a visual management system. Here, the GIA team witnessed a diamond with an already-polished pavilion being checked for polish and symmetry while still in the dop.

	Parcel papers are color-coded to identify the supplier. Photo by Pedro Padua, © GIA, courtesy of Chow Tai Fook, Yueshun Fook Jewellery and Diamond Co.

	The quality of the pavilion’s polish and symmetry is carefully checked at this stage. Photo by Eric Welch, © GIA, courtesy of Chow Tai Fook, Yueshun Fook Jewellery and Diamond Co.

	Polishing
In the diamond-polishing area of the factory, the team could not help but notice the polishers’ intense concentration levels. Visits to diamond-cutting factories around the world have never revealed a higher degree and intensity of focus among polishers.

Demonstrating a high degree of skill and precision, the polishers constantly checked the polish and facet placement with a loupe. Throughout the polishing process, they repeatedly touched the diamond to the scaife and then quickly lifted it to check it with the loupe. For polishing the pavilion, the tang has clicks related to the pavilion facets. Each time one facet’s polish is complete, the polisher clicks to another pavilion facet. A knob on the tang allows for fine tuning of the angle. The polisher adjusts this knob constantly while checking the polish and facet placement.

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	The final polishing stage is a long, careful process.
The polishing speed depends on several factors, including the shape of the rough, the presence of surface graining, clarity considerations, and the shape of the finished stone. For typical octahedral, sawable rough with no complications, it takes about two hours of total polishing time—about one hour for the pavilion and about one hour for the crown—to produce a one-carat round brilliant.

	Final Quality Control
After polishing, all the diamonds go to the grading department for the final quality-control step. Cut is the first quality factor to be graded. Stones 30 points and above are all graded with the microscope. Stones of this size are sent to a gemological laboratory for grading reports, so it is imperative that the polish and symmetry be checked carefully before they leave the factory. Chow Tai Fook wants to make sure the cut grades they receive on reports are up to their standards and their customers’ requirements.

	Diamonds 30 points and above are cut-graded with a microscope. For stones under 30 points, graders use a loupe. Photo by Eric Welch, © GIA, courtesy of Chow Tai Fook, Yueshun Fook Jewellery and Diamond Co.
For smaller stones, grading is done with a loupe. The grader uses a typical overhead daylight-equivalent fluorescent light and a white pad. They separate diamonds into piles based on their quality or to indicate specific re-works such as scratches on the table, polish lines, etc.

After cut grading, the diamonds are color graded. Graders use daylight equivalent fluorescent overhead light, a white folded card, and masterstones. Chow Tai Fook prefers the accuracy of their graders’ eyes over any color-grading machines. By far, most of the graders are women. Chow Tai Fook has found that women tend to be more patient, focused, detail oriented, and accurate when it comes to grading.

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	After polishing, all diamonds go to the grading department.
The final grading step is for clarity. Like cut grading, stones 30 points and above are clarity graded with a microscope. Smaller stones are graded with a loupe. For stones under 30 points, the clarity-grading classifications are broader and not as fine. They grade these diamonds into VVS, VS, SI, and I grades without further classifying them as VVS1 or VVS2, etc. Clarity grading is very fast for these stones, with the grader grabbing a stone in the tweezers girdle to girdle for a quick look through the crown facets and then the pavilion.

	Conclusion
The Panyu, China, area, which includes Foshan, is known around the world as a gem cutting and jewelry manufacturing center, and with good reason. Several factors contribute to the success of the area’s industry. China markets the high quality of the country’s cutting factories in a campaign called China Cut.

While labor costs are lower than in areas like Antwerp and Belgium, Chow Tai Fook reports that their polishers earn 45 percent more than those in Surat, India, and that their labor costs increase about 15 percent a year. Chow Tai Fook maintains high standards of cut quality and markets top-quality cuts globally.

With such a careful process and so many dedicated and skilled workers, it’s no wonder Chow Tai Fook is well known globally for its diamond-cutting expertise. @chapter:27


Publication Year: 2022 Title: Volcano-Shaped Internal Feature in Trapiche-Like Sapphire Abstract: Figure 1. Each of these trapiche-like sapphires from Changle, Shandong Province, has a brown-black hexagonal core in the center and six white radiating arms. Three of the four sample slices weigh ~3.1 ct with a thickness of ~2.1 mm; the sample slice on the bottom right weighs ~0.7 ct with a thickness of ~1 mm. Photos by Suqin Xia.
Trapiche-like sapphires with hexagonal color zoning have been found in the Changle area of Shandong Province, China. Samples examined by the authors possessed a brown-black hexagonal core and a distinct six-rayed pattern (figure 1). The six rays or fibrous arms were oriented perpendicular to the sides of the core and the hexagonal growth structure. Graphite was randomly distributed in the dark core region in this sapphire, identified by Raman spectroscopy.

Figure 2. Inclusions along the white arms of trapiche-like sapphire. A: Thin-film inclusions display colorful interference colors under reflected light. B: Triangle-shaped fissures, which are perpendicular to the crystallographic c-axis, resemble overlapping hills, including a volcano just right of center. These fissures show spectral interference colors under reflected light. C: In transmitted light, the pattern of inclusions resembles a Chinese landscape painting with a volcano in it. Photomicrographs by Xiaojing Lai; fields of view 0.30 mm (A) and 0.15 mm (B and C).
Through further microscopic observation, we found that these fibrous arms were composed of thin-film fluid inclusions and fine fissures generally parallel to their elongation direction (figure 2). Many of these inclusions were two-phase, containing both gas and liquid, and a few were gas-liquid-solid three-phase. Interestingly, the fissures were triangular, scalloped, striped, or irregular in shape and about 10 to 40 μm in size, with spectral interference colors (figure 2A). With overhead lighting, the internal features presented a dramatic scene reminiscent of a post-eruption volcano surrounded by overlapping hills and rivers (figure 2B). In transmitted light, however, the same features resembled a Chinese landscape painting, and the previous “rivers” looked more like clouds surrounding the volcano and hills (figure 2C). The internal features found in this sapphire are interesting to gemologists both scientifically and artistically. @chapter:19


Publication Year: 2017 Title: Filled Pearl with Surface Features Abstract: Figure 1. This 20.60 ct specimen was purchased by the client as a “natural white pearl.” Photo by Lai Tai-An Gem Lab.

Pearl cultivation has been carried out for more than a century, with newer techniques supplying the trade with larger and more consistently round freshwater and saltwater pearls. While natural pearls are seldom perfectly round, their rarity makes them desirable nevertheless. The Lai Tai-An Gem Lab recently had the chance to examine a specimen that was purchased by the client as a “natural white pearl” (figure 1) while traveling in the Philippines.

The white baroque pearl measured 20.0 × 19.0 × 13.3 mm and weighed 20.60 ct, with a specific gravity of 2.60. It exhibited pink overtone. Long-wave UV produced a strong chalky blue reaction. Magnification revealed the typical overlapping platelet structure expected for nacreous pearls, but two abnormal surface features were also observed. These two areas displayed a coarse appearance and lower luster that differed from the rest of the pearl (figure 2).

Figure 2. Two fillings displayed a coarse appearance and lower luster that differed from the rest of the pearl. Photomicrographs by Lai Tai-An Gem Lab; fields of view 11.5 mm (left) and 8.6 mm (right).

Figure 3. The two filled portions of the pearl, shown in visible light (left images) and the DiamondView (right images). The DiamondView reaction showed a noticeable difference between the nacreous areas and the filled portions of the pearl.
We further analyzed the abnormal surface features to gather more data for future reference. DiamondView imaging showed a noticeable difference between the nacreous areas and the filled portions (figure 3). Raman analysis of the surface features revealed epoxy peaks at 635, 1108, and 1604 cm–1 and aragonite peaks at 1084 and 701 cm–1 (figure 4). These were consistent with results from FTIR reflectance spectrometry that showed calcium carbonate in the form of aragonite, with peaks at approximately 878 and 1484 cm–1.

Figure 4. Raman analysis of the pearl revealed epoxy peaks at 635, 1108, and 1604 cm–1 and aragonite peaks at 701 and 1084 cm–1.

Figure 5. X-radiography proved this was a bead-cultured pearl. The filling was very shallow due to the presence of mother-of-pearl (not visible). Image by Lai Tai-An Gem Lab.
X-radiography (figure 5) proved this was a bead-cultured pearl with a pre-drilled nucleus typically used in freshwater pearl cultivation. The filling was very shallow due to the presence of mother-of-pearl (not visible). Energy-dispersive X-ray fluorescence (EDXRF) analysis detected higher levels of manganese, confirming the pearl’s freshwater origin. The result came as a surprise to the client, who was expecting confirmation of a natural pearl. Such coatings and fillings, which we have seen before, show the importance of obtaining a reliable laboratory report when purchasing such a large pearl. @chapter:14


Publication Year: 2005 Title: Bismuthinite Inclusions in Rose Quartz from Madagascar Abstract: Figure 12. These faceted samples of rose quartz (5.74 and 12.55 ct) from the Itongafeno pegmatite in central Madagascar contain conspicuous inclusions of bismuthinite. Photo by J. Hyrsl.

              Eye-visible inclusions are common in almost all quartz varieties except rose quartz. Although massive rose quartz is colored by submicroscopic inclusions (see J. S. Goreva et al., “Fibrous nanoinclusions in massive rose quartz: The origin of rose coloration,” American Mineralogist, Vol. 86, No. 4, 2001, pp. 466–472), only very rarely does this material contain macroscopic inclusions (see, e.g., Summer 2003 Gem News International, pp. 159–162). At the 2005 Tucson gem shows, one of these contributors (FD) had some unusual rose quartz from Madagascar that displayed abundant, conspicuous inclusions with a metallic luster (figure 12).

The material was recovered from the Itongafeno pegmatite (also known as Tsaramanga), located 23 km west of Antsirabe near the village of Mahaiza. This deposit is part of the Analalava pegmatite district and has been worked for asteriated rose quartz and dark blue aquamarine for almost 100 years. In addition to common pegmatite minerals, it has produced rare examples of emerald and native bismuth. Several vertically disposed zones of mineralization have been identified in the pegmatite, including rose quartz, smoky quartz adjacent to a thin Nb-Ta oxide and biotite layer, and rose quartz with metallic inclusions. About 60 kg of the included rose quartz was extracted between September 2003 and June 2004, although only a small percentage was suitable for cutting.

The inclusions in 10 faceted stones were examined, and with magnification they appeared metallic gray to black and had peculiar shapes (figure 13). They occurred in parallel rows of strongly elongated, sometimes striated crystals about 0.5 mm thick. Powder X-ray diffraction (XRD) analysis of an extracted crystal and chemical analyses of several surface-reaching inclusions in one sample with a Jeol 5800LV scanning electron microscope equipped with a Princeton Gamma-Tech energy-dispersive IMIX detector identified the inclusions as bismuthinite (Bi2S3). These were sometimes accompanied by smaller, more equant, yellow-to-black chalcopyrite grains. XRD also suggested the possible presence of a Cu-Bi-sulfosalt close to gladite in composition, which probably was present as thin metallic needles seen in some samples.

	Figure 13. The bismuthinite inclusions in the rose quartz from Madagascar appeared metallic gray to black, and showed a variety of irregular forms. A network of needle-like inclusions, possibly rutile, was responsible for the asterism in this rose quartz. Photomicrograph by J. Hyrsl; the field of view is approximately 3 mm.
In addition to the inclusions described above, the rose quartz also contained abundant tiny colorless needles possibly rutile; again, see figure 13) oriented in three directions at angles of 120°. These needles are apparently the cause of asterism in samples that are cut as spheres or cabochons.

To our knowledge, this is the first confirmed report of bismuthinite in faceted quartz from a pegmatite. Previously, bismuthinite was identified in quartz from tintungsten deposits and from Alpine-type fissures (see J. Hyrsl and G. Niedermayr, Magic World: Inclusions in Quartz, Bode Verlag, Haltern, Germany, 2003, p. 48). @chapter:5


Publication Year: 2021 Title: GSA Meeting – GIA Session Abstract: Figure 1. Speaking at the GSA annual meeting, Shiyun Jin of GIA presents his research on the rapid diffusion of copper in Oregon sunstones. Photo by Robert Weldon.
A session of presentations on gemological research topics, organized by GIA, took place during the recent annual meeting of the Geological Society of America (GSA) in Portland, Oregon (October 10–13, 2021). Aaron Celestian of the Natural History Museum of Los Angeles began the oral presentations with a description of a famous piece of furniture—the Borghese-Windsor Cabinet—created in Italy around 1620. The large, multi-drawer wooden cabinet was decorated with semi-precious gems, including agate and lapis lazuli. A study of the geographic origin of the agates indicated that most were from the Idar-Oberstein area of Germany, with the remainder from another source. The early construction date of the cabinet makes Brazil an unlikely source for the agate; another possibility would have been India.
Cisil Badur of the Department of Geosciences of Auburn University in Alabama reported on plagioclase sunstones from the Columbia River basalts in Oregon that exhibit a schiller effect due to oriented copper inclusions. Argon-argon geochronological data indicate that the sunstones are younger in age than the host basalt. The author suggests this age discrepancy might be due to argon loss over geological time from the feldspar crystals, or it could be explained by the host basalt having been formed during a younger period of regional volcanism. A second talk on copper in Oregon sunstones was given by Shiyun Jin of GIA (figure 1). Rapid diffusion of copper in labradorite feldspars can induce red or green colors and aventurescence depending on the size of the exsolved copper particles. These tiny particles produce a red color by selective absorption of incident light or, in larger specimens, a green color by scattering red and orange light.
Rhiana Henry of the Department of Earth, Ocean and Atmospheric Sciences of the University of British Columbia investigated the sodium and water contents of the main varieties of beryl to develop a method to calculate water contents in beryl based on the more easily measured sodium contents. Rachelle Turnier of the Geoscience Department of the University of Wisconsin in Madison investigated oxygen isotope contents of sapphire from a variety of primary and secondary sources in Montana. She found a wide range of δ18O values in the corundum samples. This large range suggests that the Montana sapphire deposits originated from corundum formation in a variety of protolith source rocks. Aaron Palke of GIA studied what was initially thought might represent a rare new group of sapphire from the Rock Creek deposit in Montana. Although displaying a crystal shape and inclusions typical of sapphires from this area, these new sapphires exhibited low iron and gallium compositions. Dr. Palke emphasized the need for caution in using trace-element contents to decipher the geological origins of gem corundum and reported that these pale or yellow-colored sapphires do not represent a new group of material. Rather, they are typical Rock Creek sapphires that exhibit very low iron and gallium contents.
Zinc-enriched, fracture-filled, and fibrous overgrowths on classic Paraíba tourmaline crystals from Brazil were described by Darrell Henry from the Department of Geology and Geophysics at Louisiana State University in Baton Rouge. Such features are not observed in cuprian tourmalines from Nigeria or Mozambique, and thus they may be diagnostic of the original Paraíba material. Yicen Liu of the Gems and Technological Material Laboratory of Tongji University in Shanghai detailed the color mechanism and effects of heat treatment on spectral features and color for pink spinel from the famous Kuh-i-Lal deposit in Tajikistan. Che Shen of the Munsell Color Science Laboratory at the Rochester Institute of Technology described a method to calculate the color appearance of optically uniaxial colored gemstones.
Gabriela Farfan of the Department of Mineral Sciences of the Smithsonian Institution in Washington, DC discussed the effect of environmental factors on freshwater pearl mineralogy and chemistry. In a study of a lake in Kentucky, the pearl samples recorded oxygen isotope ratios and crystallographic signatures that could be correlated with seasonal variations in lake temperature, dissolved oxygen, and light levels at a one-meter depth. Chunhui Zhou of GIA reported the discovery of disordered dolomite crystals in the central internal structure of a natural pearl from a Cassius species mollusk.
Matthew Hardman of GIA discussed the use of multidimensional statistical analysis of the peak intensities of certain visible and near-infrared spectral features of irradiated green diamonds with and without green radiation stains. This type of spectral analysis offers a new approach to understanding the lattice defects in diamonds that result from natural and artificial radiation exposure. Roy Bassoo of GIA reported on a study of deuterium-hydrogen ratios in the low water content of nominally anhydrous minerals (such as olivine, enstatite, and garnet) found as inclusions in diamonds from the Guiana Shield in South America. This isotopic information could provide evidence for the geological conditions of diamond formation and growth in the upper mantle. Ira Litvak-Kochavi of the Department of Chemical Sciences at Ariel University in Israel discussed the results of a study of the influence on paramagnetic defect centers in diamond at the high temperatures (900°C or higher) that occur during facet polishing.

Figure 2. A poster illustrating the spectroscopic characteristics of blue spinel before and after heat treatment. Photo by Cathy Jonathan.

Figure 3. Dona Dirlam (left) and Barbara Dutrow (right) pose in front of a map highlighting colored stone and pearl sources utilized in seventeenth-century Indian jewelry. Photo by Robert Weldon.
In addition to the talks, GIA staff members prepared several poster presentations for the session. Jennifer Stone-Sundberg reviewed a quantitative description of the causes of color in corundum in terms of six major chromophore elements. Stephanie Persaud described five diamonds that exhibited a temporary color change from gray to yellow or blue when subjected to extremely low, liquid-nitrogen temperatures. Wasura Soonthorntantikul discussed the spectroscopic characteristics of both unheated and heat-treated blue spinels (figure 2). Heating tended to produce a less desirable grayish blue color. Paul Johnson reported on several light blue to purple type Ia diamonds that owe their color to a lattice defect associated with artificial irradiation. Dona Mary Dirlam presented a map that showed localities in Central Asia, Southeast Asia, Africa, and Sri Lanka (as well as Europe and the Americas) that were the sources of colored stones and pearls used for jewelry purposes in India during the seventeenth century (figure 3). Troy Ardon reviewed the different spectral features found in type I and type II pink diamonds. Evan Smith discussed the discovery of metallic inclusions with a heavy iron isotopic composition in high-quality type IIa colorless diamonds. This composition is attributed to the subduction of iron minerals formed by serpentinization of oceanic peridotite. Yusuke Katsurada described a study of iron and copper absorptions in the spectrum of blue/green Paraíba tourmalines and a method to determine whether a particular elbaite would correctly be classified as a cuprian tourmaline.

Figure 4. Robert Weldon talks with visitors at the GIA booth. Photo by Cathy Jonathan.

Figure 5. Nathan Renfro (left) and James Shigley (center) chat with conference attendees. Photo by Cathy Jonathan.
Overall, the 2021 GSA annual meeting saw strong attendance and notable interest in the gemology sessions and exhibits (figures 4 and 5). The 2022 event is scheduled for October 9–12 in Denver. @chapter:0


Publication Year: 1998 Title: Characterizing Natural-Color Type IIB Blue Diamonds Abstract: Although rarely encountered, blue diamonds are among the most famous, and most distinctive, of fine gemstones. To better understand these unique gems, more than 400 were studied at the GIA Gem Trade Laboratory over several years to reveal additional information about the relationships between their color, clarity, and other gemological properties. The overwhelming majority of natural-color blue diamonds are type IIb. The color appearance varies widely from light to dark, but there is a limited range of color saturation. As a result, color appearance between neighboring GIA GTL color grades can be subtle. Of the blue diamonds examined at GIA GTL, few had any solid inclusions. Nevertheless, internal features such as graining and color zoning can make the processing of these diamonds a challenge. @chapter:31


Publication Year: - Title: Revealing “The Angel in the Stone”: The Largest Known Square Cushion-Cut Tsavorite Abstract: Figure 1. The 283.74 ct rough tsavorite was mined in Merelani, Tanzania, by Bridges Tsavorite. Photo by Robert Weldon/GIA, courtesy of Bruce Bridges.

More than 50 years after Campbell Bridges discovered the green grossularite garnet later named tsavorite, the company that bears his name carries on his legacy of ethical sourcing and mine-to-market transparency. At the 2019 AGTA Tucson gem show, Bridges Tsavorite unveiled the largest known square cushion-cut tsavorite, weighing 116.76 ct. In March 2018, a GIA team traveled to Bridges Tsavorite’s Tucson office for a look at world-renowned gem cutter Victor Tuzlukov’s approach to cutting this rare gem.
The 283.74 ct rough stone (figure 1) was mined by Bridges Tsavorite in Merelani, Tanzania, in September 2017. Bruce Bridges, the company’s CEO and son of the late Campbell Bridges, told us that the rough was extremely clean for its size. It had several very well-terminated euhedral faces, unusual for tsavorite, which typically has more fragmented face formation.
The company had already received many inquiries from around the world about purchasing the stone post-cutting. Bridges said the buyer would likely be a knowledgeable collector or a jewelry connoisseur; retail jewelers rarely purchase stones of this value except on request from a high-end client.
Bridges Tsavorite sorts and cuts all of its production in-house. Bridges said they have always prided themselves on having a transparent mine-to-market supply chain. “The public nowadays really wants to know more about a gemstone: Where did it come from? How did it get from raw to cut?” he said. “I’m really happy about documenting the entire process, from rough to finished product.”

	Bruce Bridges shows the rough tsavorite and talks about the importance of ethical sourcing.

Along with the rough stone, Bridges showed us two cut tsavorites (figure 2): a 31.57 ct square cushion cut and a 58.52 cushion cut. Tuzlukov had just finished cutting the 31.57 ct tsavorite (figures 3 and 4). Planning the cutting process took six weeks; he then spent five days cutting the stone, working from 9 to 11 hours each day. Bridges said that along with the rough, these were the three finest tsavorites he had ever seen in their respective sizes. For Tuzlukov, cutting the 31.57 ct stone was a timely preparation for cutting the larger square cushion cut.

Figure 2. This 58.52 ct cushion cut and 31.57 ct square cushion cut, along with the 283.74 ct rough, were the three finest tsavorites in their respective sizes that Bruce Bridges had ever seen. Photo by Duncan Pay.

Figure 3. The 31.57 ct square cushion-cut tsavorite and schematic diagrams offer a glimpse into the cut planning process for the large rough tsavorite. Photo by Duncan Pay.

Figure 4. Victor Tuzlukov examines the 31.57 ct square-cushion-cut tsavorite. Photo by Duncan Pay.

	Bridges tells us about the 31.57 ct square cushion-cut and 58.52 ct cushion-cut tsavorites.

“Somebody said ‘I saw an angel in the stone and cut until I let him be free,’” Tuzlukov said. “I also try to see something inside the stone.”
Bridges and Tuzlukov began discussing the approach to cutting the 283.74 ct rough in early February 2018. Tuzlukov showed us on the rough tsavorite where he envisioned the table, the crown, and the pavilion. He said sometimes he knows immediately upon looking at a rough stone what the cut stone will look like (figure 5). Other times he thinks about it “for months or longer.” His approach to cutting gemstones is undeniably metaphysical. “I try to join my consciousness with the stone,” he said. “I try to explain to him that we go to perfection together. Sometimes when I get full contact with the stone, the stone begins to help me. Not by words—just by feeling. I feel when I have to stop when cutting.”

Figure 5. Left: Tuzlukov examines the rough tsavorite. Right: Another view of the rough, with the 58.52 ct cushion cut and 31.57 ct square cushion cut. Photos by Duncan Pay.
Originally from Russia, Tuzlukov lives in Bangkok, where he facets top-quality gemstones, creates original designs, and teaches faceting at the Gem and Jewelry Institute of Thailand. He worked as a marine navigator and an economist before being introduced to gemstone cutting by a friend of a friend. He obtained his G.G. from GIA in Moscow and began faceting gemstones in 1998. In 2006 he participated in the United States Faceters Guild Competition for the first time, and in 2010 he won the International Individual Faceting Championship in Australia (with a world record of 299.17 out of 300 points). Later that year he founded the Russian Faceters Guild and the faceting competition the Russian Open.
Tuzlukov said he tells his students “in the worst case you should be just two, you and the stone. In the best case, you should be one.” Sometimes he starts cutting, and then stops and comes back after some time—perhaps weeks—because he has not achieved what he calls “full contact” with the stone.

	Tuzlukov tells us about his approach to cutting.

Tuzlukov used the 3D model of the rough tsavorite to cut a test stone from yttrium aluminum garnet (YAG), a synthetic material. Angles and indices were calculated following the shape of the rough to save as much weight as possible, and were adjusted to account for YAG’s refractive index, which is higher than tsavorite’s. After the YAG stone was cut, the real work began.
Tuzlukov began to cut the tsavorite during our visit (figure 6). The remainder of the cutting was accomplished over the course of about a month.
“The material is amazing,” Tuzlukov said. “It’s not only a pleasure but an honor for me to cut this.”

Figure 6. Tuzlukov touches the rough tsavorite to the lapidary wheel for the first time. Photo by Duncan Pay.

	Tuzlukov begins to preform the rough tsavorite.

At the AGTA show, Bridges said the tsavorite (figure 7) could be a once-in-a-lifetime stone. Despite seeing most of the finest tsavorites in the world above 20 carats, he had never seen one comparable to this size in a square cushion cut. The square cushion and round cuts are the rarest shapes for tsavorite because the rough typically lends itself better to other shapes. Square cuts in particular result in the greatest loss of weight in cutting, he said. The tsavorite also has the distinction of being the largest tsavorite, and the largest gemstone of any kind, cut in the United States.

Figure 7. Victor Tuzlukov’s cutting process yielded a 116.76 ct square cushion cut, one of the rarest cuts for tsavorite. Photo by Robert Weldon/GIA, courtesy of Bruce Bridges. @chapter:1


Publication Year: - Title: Carnegie Research: Every Diamond Tells a Story Abstract: The work of Carnegie scientist, Dr. Steven Shirey and his co-workers has pushed the age of some diamonds back as far as 3.5 billion years. Duncan Pay © GIA, courtesy Carnegie Institution of Washington

                      To Dr. Steven Shirey, a senior scientist at the Carnegie Institution of Washington, every diamond tells a compelling story.

One of Shirey’s objectives, as a research scientist, is to get word out about his work into the nature of diamond and its fascinating origins deep beneath our planet’s surface. Diamonds, for Shirey and his co-workers, are unique containers that preserve minerals from deep within the earth. These tiny samples—forged under almost unimaginable pressures and temperatures— make it possible for scientists to peer hundreds of kilometers deep into the earth’s mantle.

At GIA, we also want to tell the geologic story of diamond because it underscores the unique value of the gem as a “special stone.” Shirey’s objectives are complimentary to ours: he knows his research into the age of diamond—and what it tells us about earth history—provides powerful tools for savvy jewelry salespeople to pique a customer’s interest in the gem.

Objectives

We really wanted to set up an ongoing relationship between GIA and the Carnegie Institution so this fascinating topic would be updated in our courses and website to benefit students and the public. The plus for Shirey, and his colleagues at Carnegie, is that we can expose their work to a different, more gem-focused audience.

We approached Shirey to write an article for Gems & Gemology on the knowledge available about diamond’s origin that we published in the Winter 2013 issue. As part of this initiative, a GIA team traveled to Shirey’s home institution, the Department of Terrestrial Magnetism in mid-2013.

We also wanted to document his work on inclusion dating of diamond, which has pushed the age of some diamonds from Canada back as far as 3.5 billion years. The concept that a tiny inclusion captured in a diamond crystal might provide an age of this magnitude—three quarters the earth’s age—is mindboggling.

The implication is that these minerals—passengers in the fabric of the diamond—have lain undisturbed for up to 3.5 billion years and might represent conditions when the earth’s geological processes were very different from today’s.

	These tiny diamond crystals contain sulfide mineral inclusions, which Shirey and his coworkers can use to determine their ages. Pedro Padua © GIA, courtesy Carnegie Institute of Washington
“I want to go back in earth’s history to see if the pattern of diamond growth tells us anything unique about the evolution of earth as a planet,” Shirey says.

His research involves selecting suitable inclusion-bearing diamonds from working mines, slicing them into sections to examine their growth history, and finally, breaking out the inclusions within them for age-dating studies.

“It would probably drive everybody in the gem business crazy to understand that we take a beautiful rough diamond and slice the center out of it,” says Shirey with a chuckle.

Other Diamond-related Research at Carnegie

We also wanted to provide a snapshot of Carnegie’s other diamond-related research. Two of the Carnegie Institution’s six research departments are based at the same Washington campus: the Department of Terrestrial Magnetism (DTM) and the Geophysical Laboratory.

The DTM was founded in 1904 to map the earth’s geomagnetic field as part of an emphasis on understanding the earth and our planet’s place in the universe. Today, it houses an interdisciplinary team of planetary scientists: astronomers, astrophysicists, geophysicists, and geochemists. They’re discovering planets outside our solar system, determining the age and structure of the universe, and studying the causes of earthquakes and volcanoes. Shirey’s diamond work is a subset of this research, one that illuminates our planet’s depths.

Shirey’s colleague, Dr. Jianhua Wang—a senior research scientist in the same department—investigates the growth structures of diamonds and the sources of the carbon and nitrogen within them. His work—using the Institution’s sophisticated ion microprobe—is able to separate diamonds that crystallized from carbon originally at the earth’s surface, from those that formed from ‘primordial’ carbon that originated deep in the mantle.

“This technique can show you where the carbon in a diamond came from,” Wang  says. “Whether it’s from the top—the surface of the earth—or it’s of deep mantle origin.”

	Dr. Wang explains the growth structure of a diamond using this cathodoluminescence (CL) image, which reveals its many layers. Dr. Wang’s work on carbon and nitrogen isotopes reveals much about how, and from which carbon sources diamonds grow. Duncan Pay © GIA, courtesy Carnegie Institution of Washington
Just next door, the Geophysical Laboratory—founded a year later, in 1905—examines the physics and chemistry of Earth’s interior. The lab is a world leader in petrology and high-pressure/ high-temperature (HPHT) physics, including the growth of chemical vapor deposition (CVD) synthetic diamond.

Valerie Hillgren, a research scientist there, uses HPHT presses not to grow diamonds, but to mimic, on a small scale, the formation of planets. She’s most interested in the separation of a planet’s core from its mantle, and is studying Mercury. “What we’re looking at is how the chemistry of different elements is partitioned between the mantle and the core of a planet, and how that happens under higher pressure,” she says.

	Videographer Pedro Padua records the closure of a high-pressure press at the Carbegie Institution's Geophysical Laboratory. Duncan Pay © GIA, courtesy Carngie Institution of Washington
Between them, these two departments have been responsible for a wide range of important discoveries, including mapping the earth’s magnetic field, the first fission of the uranium atom, the concept of “dark matter,” and in the early 1950s, the determination of the age of the earth to within about 2 million years. Before then, the earth’s age was ‘in ambiguo’—Latin for ‘in doubt’—and the margin of error was up to 2 billion years. Carnegie researchers put the age of the earth  on a sound footing. Today’s research encompasses all aspects of formation of the earth and solar system by looking at meteorites and radioactive decay systems for dating rocks and minerals.

Our aim at GIA is to stay in touch with Carnegie’s diamond-related research and publish regular updates and contributions on the GIA website and in Gems & Gemology. @chapter:29


Publication Year: 1998 Title: Cultured Abalone Blister Pearls from New Zealand Abstract: The successful culturing of abalone pearls has been known since French scientist Louis Boutan’s experimentation in the late 1890s, but commercial production has been achieved only in recent decades. The use of New Zealand’s Haliotis iris, with its colorful and iridescent nacre, has had the strongest recent impact on this industry. Empress Abalone Ltd. is producing large, attractive cultured blister pearls in H. iris. The first commercial harvest in 1997 yielded approximately 6,000 jewelry-quality cultured blister pearls, 9–20
mm in diameter, with vibrant blue, green, purple, and pink hues. Examination of 22 samples of this material by standard gemological and advanced testing methods revealed that the presence and thicknesses of the conchiolin layers had a significant impact on face-up appearance. Empress Abalone Ltd. is also experimenting with producing whole free-formed cultured pearls in this gastropod mollusk. @chapter:14


Publication Year: 1986 Title: Pink Topaz from Pakistan Abstract: In addition to the relatively recent discovery of significant amounts of emerald, aquamarine, and ruby, Pakistan has also begun to produce fine gem-quality pink topaz. In a small hillock of recrystallized limestone north of Katlang, narrow calcite veins encase pink topaz crystals up to 3 cm long accompanied by larger amounts of reddish brown, tan, and colorless topaz crystals. More than 70,000 ct of gem-quality pink topaz has been reported to date. The refractive indices, optic axial angle, unit-cell dimensions, and density of the topaz are influenced by a partial replacement of fluorine by hydroxyl ions. The color is due to trace elements—principally chromium (Cr3+). Treatment experiments revealed that the color of the brown, tan, and colorless topaz from this source may be improved by irradiation and heat. @chapter:2


Publication Year: 2014 Title: Lead-Glass-Filled Burmese Rubies Abstract: Figure 1. The Burmese ruby beads in this multi-strand necklace were filled with lead glass. Photo by C.D. Mengason.

              Rubies filled with a high-lead-content glass as a clarity enhancement were first reported by the Gemmological Association of All Japan (GAAJ) laboratory in 2004. Since then, many of these stones have been examined by gemological laboratories around the world. They are identified by their numerous large, low-relief fractures and their blue or orange flashes easily seen at different angles, as well as their flattened gas bubbles and voids that are obvious under magnification (S.F. McClure et al., “Identification and durability of lead glass–filled rubies," Spring 2006 G&G, pp. 22–34).

Figure 2. These wide fractures, filled with glass of relatively low lead content, showed a slightly lower luster than the host ruby. Photo by Nathan Renfro; field of view 2.96 mm.
The Carlsbad laboratory recently had the opportunity to examine a multi-strand necklace of graduated round ruby beads (figure 1), measuring 2.72 to 6.13 mm in diameter. Standard gemological testing showed properties consistent with natural ruby. Microscopic observations revealed typical inclusions for ruby: rutile silk, banded particulate clouds, twinning planes, red parallel planar zoning, and roiled graining. The appearance and chemical composition of the beads suggested that their geographic origin was Mogok, Myanmar. Their wide, low-relief fractures (figure 2) and cavities were filled with a foreign substance whose luster was slightly lower than that of the rubies. These observations suggested a lead-glass filler, although the lower luster was contrary to previous documentation and the filler did not display any flash effect. In some beads, the filler also showed a crazed appearance (figure 3) not typically observed in other rubies filled with high-lead glass.

Figure 3. In some beads, the filler also showed a crazed appearance not typically observed in other rubies filled with lead glass. Field of view 2.96 mm.
This strange observation prompted us to carry out a chemical analysis of the glass filler. We tested two spots using laser ablation–inductively coupled plasma–mass spectrometry (LA-ICP-MS) on a relatively large glass-filled cavity. The results after normalization showed that the filler contained approximately 43 wt.% PbO, which was much lower than the lead content reported by McClure et al. in 2006 (71–76 wt.%). The diminished lead content would lower the refractive index of the glass and explain the lack of flash effect and the lower luster observed in this filler.

These beads were the first examples of this lower-lead-content glass filling in Burmese rubies examined at the Carlsbad laboratory. On a GIA report, most of these beads would be identified as “rubies with significant clarity enhancement with lead glass filler.” Yet some of the beads were so highly fractured and filled that they would be considered “manufactured products consisting of lead glass and ruby” (figure 4).

Figure 4. Some beads were so highly fractured and filled that they would be called “manufactured products consisting of lead glass and ruby.” This material would easily disintegrate if the lead glass were removed. Photo by Nathan Renfro; field of view 2.96 mm. @chapter:8


Publication Year: 1995 Title: “Ti-Sapphire”: Czochralski-Pulled Synthetic Pink Sapphire from Union Carbide Abstract: One of the most interesting of the commercially available Czochralski pulled synthetic corundums is pink “Ti-sapphire.” This material owes its pleasant, somewhat orangy pink color to trivalent titanium, a common trace element in natural sapphires and rubies that occurs here in an unusual oxidation state. Although most of the gemological features are typical of Czochralski-pulled corundum (gas bubbles or small "pinpoint” inclusions, color zoning), these synthetic sapphires have distinctive fluorescence and optical spectra. These properties are also due to the chromophore Ti3+. @chapter:12


Publication Year: 1985 Title: Summer 1985 G&G Lab Notes Abstract: Amber, with Unusual Inclusions
Amethyst, with Confusing Inclusions
Diamond Damaged in Cutting
Fancy Blue Diamond
Fluorite Carving, Damaged by Sulfuric Acid
Hexagonite, Cat's-Eye
Unusual Gilson Synthetic Opal
Yellow-Green Opal
Freshwater Cultured Pearls from China
Imitation Pearls
Quartz, Very Dark Reddish Gray Cat's-Eye
Star Sapphire, Diffusion-treated
Scapolite, Dark Cat's-Eye
Topaz Imitation
Zircon, Cat's-Eye @chapter:17


Publication Year: 2015 Title: A Natural Pearl with an Intriguing Internal Structure Abstract: Figure 1. The 0.95 ct pearl measuring 5.22 × 5.04 mm is shown with a GIA triplet loupe for scale. Photo by Lhapsin Nillapat.

	Aspects of natural pearl formation remain a mystery in many cases; however, one generally accepted principle is that an intruder finds its way into the mantle or gill areas of a mollusk and instigates the pearl formation process. Gemologists are never sure what they will find when natural pearls are examined using microradiography. Substantial real-time X-ray microradiography (RTX) work by GIA staff in various locations has shown evidence of formation cause in only a few pearls.

	Early in 2015, a cream semi-baroque button pearl measuring 5.22 × 5.04 mm and weighing 0.95 ct (figure 1) was submitted to GIA’s Bangkok laboratory with nine other pearls. Externally the pearl appeared similar to many other previously examined natural pearls, but the microradiography uncovered something that was far from normal.

	After initial RTX examination, the apparent initiator of this specimen’s formation was found to be very different from anything encountered, to our knowledge, in a natural pearl. RTX revealed an attractive radiating structure within a central conchiolin-rich boundary and associated external arcs within the surrounding nacreous overgrowth (figure 2). The radial object displayed clear solid arms extending from the central core of the structure. Given the nature of the core, further investigation was performed in order to identify the radial feature and see whether the pearl was natural or formed via human intervention using an organic nucleus as a “bead.”

Figure 2. The RTX images of the pearl’s structure (left and right viewed from the side; center viewed from the top) revealed an intricate feature that might be an example of a foraminifera. The central feature measures approximately 1.95 × 1.93 mm, as determined by RTX and μ-CT.

	Computed microtomography (μ-CT) analysis was used to perform a 3-D examination of the radial feature. The μ-CT results revealed a magnificent structure with a snowflake-like intricacy to its form (figure 3). The structure created some doubts about the natural formation of the pearl. The dark organic/conchiolin-rich growth structure, with some gaps between the nucleus and the surrounding nacre, has been noted in other unusual natural pearls of known origin. This differs from the so-called “atypical bead-cultured pearls” that almost always display a tight structure (lacking growth arcs) around the inserted nucleus. Almost all of the whole shell nuclei experimentally inserted into Pinctada maxima hosts have shown the boundary of the shell/nacre interface to merge tightly with one another, with very little in the way of organic arcs within the surrounding nacre. This curious structure led to further investigations into published claims of natural organic nuclei within natural pearls.

Figure 3. The μ-CT images reveal the structure in even more detail. Here, the nature of the organic-looking natural core is shown in three different μ-CT slices in the three different directions examined.

	Similar but not identical structures have been documented in RTX and μ-CT work carried out on two pearls recovered from natural P. maxima shells by GIA staff (“An expert’s journey into the world of Australian pearling,” 2014). Pearls with unique structures have also been reported by others (K. Scarratt et al., “Natural pearls from Australian Pinctada maxima,” Winter 2012 G&G, pp. 236–261). The exact origin of the pearls studied in Scarratt et al. is unclear, although they are more likely to be natural in at least two of the examples cited. For instance, the whole shell of one sample mentioned by Scarratt et al. showed characteristics similar to the specimen described here, with visible arcs within the nacre surrounding a shell nucleus that has a notable void/organic interface between the shell and nacre. The very small drill hole present in the shell, as opposed to the larger drill holes commonly found in cultured pearls, also strongly suggests a natural origin.

	The nucleus of the 0.95 ct pearl under discussion appeared to be an organism such as coral. In order to find a match, coral samples were analyzed by RTX and μ-CT methods to compare their structures. Results indicated that the feature within the pearl may well be coral, but no exact match was noted. During the recent International Gemmological Conference (IGC) in Vilnius, Lithuania, it was suggested that the similar internal feature of a different pearl (N. Sturman et. al, “X-ray computed microtomography (μ-CT) structures of known natural and non-bead cultured Pinctada maxima pearls,” Proceedings of 34th International Gemmological Conference, 2015, pp. 121–124) could well be a remarkably preserved foraminifera, a marine micro-skeleton member of a phylum of amoeboid protists. They are usually less than 1 mm in size; their structures vary, and many live on the sea floor. Given the environment, size, and features evident in the form within the pearl under discussion, it may well be that the internal structure is a type of foraminifera sphere with a porous structure for passive filtration (see figure 6 at www.mdpi.com/1660-3397/12/5/2877/html). The μ-CT results revealed the interconnecting channels and radial structure characteristic of these spherical foraminifera.

	Whatever the true nature of the central form, the author considers the structure of this pearl to be natural based on the characteristics noted. It is also interesting to see that this pearl was small and not of particularly fine quality, other characteristics of natural pearl samples collected from the field. GIA’s own experiments with small pieces of shell and coral using P. maxima hosts have produced larger pearls with different external appearances and generally finer quality than the specimen studied here. Further research into the differences between unusual structures in natural and atypical bead-cultured pearls will continue. @chapter:14


Publication Year: - Title: Carnegie Scientists Use Diamond Presses to Study Planet Formation Abstract: The Carnegie Institution’s Geophysical Lab uses high-pressure, high-temperature (HPHT) presses for a variety of purposes, including geological research into the earth and other planets, as well as exotic new materials for technological applications. Here, scientists Steve Shirey and Stevce Stefanoski prepare to load an experiment into of one of the lab’s multi-anvil presses. Duncan Pay © GIA, courtesy Carnegie Institution of Washington.

                      To gemologists, the high-pressure, high-temperature (HPHT) press speaks of synthetic diamond growth or newfangled methods of diamond color treatment.

For Valerie Hillgren, a research scientist at the Carnegie Institution of Washington’s Geophysical Laboratory, the presses that create these conditions are a means to another end: studying how the terrestrial planets of our solar system might have formed.

We’re standing in a large machine room Geophysical Laboratory with Hillgren and her colleague, Dr. Steven Shirey, from the Carnegie’s Department of Terrestrial Magnetism.

The air rings with the hum of heavy equipment and the rhythmic tick of incremental pressure building in a myriad of pipes. The smell of oil is strong, and dials line the walls. Around us are four enormous multi-anvil presses—each the size of a small Volkswagen—that researchers use to simulate conditions deep inside the earth or other planets. Each apparatus can bring to bear pressures equal to that at the core of the planet Mercury.

The interiors of these machines can accommodate pressures measured in gigapascals (GPa). They’re capable of 25 GPa, the equivalent of 700 km (435 miles) beneath the earth’s surface. Pressures of this magnitude allow scientists to study rock-forming systems in the earth’s mantle.

Although this sounds impressive, it’s only a fraction of the depth of the earth’s layers: the center of the earth’s core is 6,378 km (3,963 miles) below the surface.

“When you want to start looking at things that happen in the deep earth, well, 25 GPa only gets you to the top of the lower mantle,” says Hillgren.

Just for comparison, the pressure inside the earth’s core is 360 GPa or 3.64 million bar. The pressure at the earth’s surface, about 1 bar, equals 0.0001 GPa.

	HPHT Research

	Valerie Hillgren was able to combine the two subjects she loved, astronomy and geology, into a dream job: studying planetary geology at Carnegie using the Geophysical Lab’s HPHT presses. Pedro Padua © GIA, courtesy Carnegie Institution of Washington.
Hillgren’s work focuses on separation of a planet’s mantle and core, specifically when they start to differentiate into metal-rich and silicate-rich portions. “What we’re looking at is how the chemistry of different elements is partitioned between the mantle and the core of a planet, and how that happens under higher pressure,” she says.

Hillgren tells us that the experiments can run anywhere from a few minutes to a day or two, depending on the objectives. “We usually start out with mixtures of oxides and metals in proportions that we think are reasonable for the compositions of the planets,” she explains, “and we put them inside the capsule and heat it up.”

After sufficient heat and pressure, she notes, “It separates into a metal portion and a silicate portion, and then we recover that and study the chemistry.”

View Gallery

	In this sequence of photos, you’ll take a glimpse at the inner workings of the Geophysical Lab’s multi-anvil presses.
Hillgren adds, “We look at what our results tell us about the materials that must have formed the planets, what sort of conditions must have existed, when the cores segregated, and perhaps also what has happened after the segregation of the core.”

“One of the things we can look at to understand that process is the chemistry of the mantle, which leaves a signature behind from when the metal segregates,” she continues. “So we just try to recreate that by using these presses, here, looking at the conditions in the deep interiors of the planets.”

Currently Hillgren is studying the solar system’s innermost planet: Mercury. “Mercury is a very unusual planet with proportionately a very large metal core compared to other similar terrestrial planets in the solar system—Mars, Earth, and Venus.

“It’s a mystery—why does Mercury have such a large core? Is it the innate chemistry of the planet, or is it some process that happened after the planet formed?”

Hillgren and her colleagues consider the compositions of the various meteorites as potential starting materials for planetary formation: “We have lots of different meteorite classes, and we’re looking to see if any of those make sense to be the starting materials that Mercury was made out of.”

	The Chergach meteorite, of which this is a part, fell in Mali in 2007. It’s representative of a class of meteorites called chondrites. These stony (non-metallic) meteorites have not been modified by melting and are considered pretty close to the starting material for many of the planets. Valerie Power © GIA, courtesy H. Obodda Precious Gems and Minerals.
She explains that they’ll experiment with different pressure and temperature conditions. “If we apply different conditions to materials, do we end up with different compositions of mantles and cores? We look at not just the earth, but other planets.”

We ask Hillgren which presses she uses. With a laugh she tells us she uses them all. “Depends on what pressure I want to go to! Right here is a piston cylinder, which can go to 2–3 GPa—which would be very shallow. The other presses are multi-anvils, where we can go up to 25 GPa if you want to go deeper.

Hillgren says the interesting thing about Mercury is its core-mantle boundary. “So if you want to look at the segregation of the core,” she explains, “it’s only 7 GPa, which makes it a very easy and accessible planet to study using these presses with very routine methods.”

Finally, we ask Hillgren how she became interested in this field. She feels very fortunate things turned out the way they did: “When I was young, I was always interested in astronomy, and once I got into college, I became very interested in geology…In my last year in undergraduate school, they had a course on planetary geology, and for me it was just combining two things that I really loved…outer space and geology.”

To see more on high-pressure research at the Carnegie Institution of Washington’s Geophysical Lab, visit: https://www.gl.ciw.edu/research/high_pressure_research

	Other High-Pressure Research at Carnegie
According to Dr. Steven Shirey, the Carnegie Institution’s Geophysical Lab has long been a leader in high-pressure research. It started with experiments in the early 1900s at much shallower pressure and higher temperature to look at rock-forming mineral systems in the earth. Scientists were looking to gain a basic understanding of their thermodynamics to work out how rocks and magmas form in the deep earth.

Shirey tells us there hasn’t been a lot of work on natural diamonds at the Geophysical Lab, but that there’s likely to be more in the future. Much of the lab’s work has been focused on synthetic diamonds—especially CVD-grown—and experiments into exotic new materials for use as semiconductors and other technological applications.

	Early Research Using the Piston Cylinder
Research in the 1960s used the piston cylinder, a simpler type of high-pressure device. As Shirey describes it, “You have a cylinder, that’s the confining jacket, and there’s an inner ring and then a subsidiary ring and then another ring. These confinement rings are assembled at pressure, so that they can handle the potential expansion as you push the piston.”

	Piston Cylinder

	Dr. Steven Shirey explains the Geophysical Lab’s early forays into the realm of high-pressure, high-temperature research, beginning with the earth’s rock-forming systems.
“The sample goes in a cylinder of various materials with a central region,” he says. “It’s usually some sort of capsule made out of a noble metal—could be gold or platinum, or it could be graphite. And then there’s a bunch of compressible components—could be salt or pyrophyllite—and then a jacket around that.”

Pyrophyllite is a phyllosilicate mineral composed of aluminum silicate hydroxide—Al2Si4O10(OH2)—that’s widely used in high-pressure experiments, both as a gasket material and as a pressure-transmitting medium.

Shirey explains that a resistance heating system goes in through the holes in the cylinder: “When you compress the whole thing, you get the pressure from compression and you get the heating from the application of a voltage across this resistance.”

These devices can get into the 50 kilobar (5 GPa) range or thereabouts, which would be about 150 km (93 miles) inside the earth, he says: “That’s about the top end of a piston cylinder.”

That’s miniscule compared to a multi-anvil press, Shirey says, gesturing at the larger apparatus behind him: “Nonetheless, the early problems attacked with the piston cylinder were basic things—the melting relations of the mantle, the kinds of melts that were formed, and this would simulate a lot of the experimental work you’d see in mantle xenoliths that are brought up in kimberlites.”

	Multi-Anvil Presses
Any work done on natural diamond formation would require use of the multi-anvil presses, which can hold larger volumes of experimental materials, Shirey says. Just like the piston cylinder, scientists can apply a voltage across a resistance to heat the ample to high temperatures to replicate those inside the earth or another planet.

	Multi-Anvil Presses

	In this video, Dr. Shirey shows us the Carnegie lab’s multi-anvil presses and explains their advantages over earlier devices like the piston cylinder.
But multi-anvil presses work in a different way, he says: “Here we have these opposed, cubic pieces that float in a larger containment, and then inside them are boron nitride cubes that then have a cutout in the corner and the sample goes in the corner of the cubes.”

Shirey holds the octahedral sample holder—made from a compound of magnesium and chromium oxides (MgO and Cr2O3)—between his thumb and forefinger. It nests at the center of the eight cubes that might be composed of either boron nitride or tungsten carbide. It’s rather tiny, given the bulk of the press. A diagonal hole pierces the sample holder, and that’s where the actual experiment occurs. Shirey tells, without a hint of irony, that this is a “larger-volume apparatus.”

“The virtue of these guys is that they can go to much higher pressures with a volume that’s big enough to put into an electron microprobe to do a pretty good analysis.” @chapter:29


Publication Year: 2000 Title: Purple to Purplish Red Chromium-Bearing Taaffeites Abstract: Gemological, microscopic, chemical, and spectroscopic properties are given for eight purple to purplish red chromium (Cr)- and iron (Fe)-bearing taaffeites and, for comparison, two grayish violet Fe-bearing but Cr-free samples. The eight purple to purplish red stones represent the largest sample of this extremely rare (i.e., Cr-bearing) variety of taaffeite that has been included in a single study; these taaffeites contain up to 0.33 wt.% Cr2O3, 2.59 wt.% FeO, and 2.24 wt.% ZnO. The purple to purplish red color is a function of the relative amounts of Fe and Cr present. Apatite and zircon crystals are common inclusions in taaffeite. Also present were healed fractures that consisted of negative crystals with multiphase fillings that contain magnesite. @chapter:4


Publication Year: - Title: Seattle Gemologists Import Pearls, Build Family Legacy Abstract: The Oba family – from left, Avery, Jessica, Yoshizumi and Amadea – is building its legacy in pearls. Courtesy Oba Family

                      Countless finished pieces traded hands at this year’s Tucson gem and mineral shows; among them were a handful of pearl and gemstone bead necklaces fashioned by an up-and-coming designer from Seattle: 6-year-old Amadea Oba.

Oba was arguably the youngest entrepreneur at the shows, but her 3-year-old brother, Avery, is hot on her heels. He’s already learning to shake pearls through sieves to sort them by millimeter size, say the pair’s parents, Yoshizumi “Yoshi” and Jessica Oba.

The elder Obas, owners of pearl importer Y.K. Trading, both graduated from GIA’s Santa Monica campus with Graduate Gemologist diplomas in November 1995.

Though the pair was originally scheduled to have different start dates, timelines changed and they ended up in the same classroom. Jessica Oba recalls meeting a polite young Japanese man her first day; her now-husband jokes that he knew right away they would be a good fit.

“Jessica was the best student in the class and I was the worst, so I knew I had to grab her,” Oba says. “I wasn’t really planning to meet my future wife at GIA – it must have been fate.”

Yoshi Oba grew up surrounded by the pearl industry in his hometown of Kobe, Japan. His father owned a pearl company, and Oba remembers hearing his father’s colleagues talk about GIA. Even as a young man, he says he noticed the respect a Graduate Gemologist diploma commanded among those in the industry.

Oba decided as a teenager that he would one day move to the United States and open his own business. He knew pearls, but wanted to learn more about other gemstones and other aspects of the jewelry industry. His first order of business was to learn English, so in 1990, Oba left Japan for his “adopted hometown” of Seattle, Washington.

Jessica Oba – lacking any family connection to the jewelry industry – had a lifelong interest in gems. Her first job, as a high school student in Oxnard, California, was working at a gift boutique that specialized in sterling silver and gemstone jewelry. Her curiosity was further piqued by the experience, and when an attentive manager handed her a GIA brochure, she enrolled in the Institute’s distance education courses.

Jessica Oba used her earnings from her high school retail job to continue coursework through her first post-graduation job with a fine jewelry store in nearby Camarillo, California.

“The correspondence work was satisfying and rewarding,” she says, “but I really longed to have the on-campus experience.”

So she moved to Santa Monica in May 1995 – where she met her future husband and business partner.

The couple moved to Seattle immediately after graduation in 1996. Yoshi Oba founded Y.K. Trading, and Jessica Oba accepted a job offer with a colored stone wholesaler. They married two years later, and Jessica Oba came on board to help build the family business.

Today, Y.K. Trading imports from Japan, China and Tahiti, and carries several types of pearls, including Japanese Akoya, Chinese freshwater, Tahitian and South Sea. Their primary customers are other small businesses, such as independent jewelry stores, designers and wholesale repair shops. They sometimes do specialty contract work – Jessica Oba strings pearls for other dealers, while Yoshi Oba drills and sorts large lots for other companies.

Their business works with a true international community, so Jessica Oba says their GIA experience comes into play regularly.

“The skills you learn at GIA are invaluable,” she says. “It provides a bit of shorthand when meeting other graduates – you instantly know there is this shared well of knowledge, and that increases your confidence when dealing with colleagues and clients.”

If their children’s early interest in the family business is any indication, the Obas may soon be using that gemological “shorthand” at home.

	Yoshi and Jessica Oba use their GG skills to help them in their pearl importing
	business, Y.K. Trading. Photo by Siegfried Markwart, courtesy Y.K. Trading @chapter:34


Publication Year: - Title: Long-Term Durability of CVD Synthetic Film on Natural Diamond Abstract: Figure 1. This 0.27 ct diamond with a boron-doped CVD synthetic diamond film on the pavilion received a color grade of Fancy Dark brownish yellowish gray. The distinct color zoning seen in this photo makes it apparent that the diamond has been treated in some way and is not a natural stone. Photo by Robison McMurtry.

                      In 2005, a thin film (10 µm) of synthetic diamond grown by chemical vapor deposition was deposited on the pavilion of a 0.27 ct natural diamond. The CVD layer was deliberately doped with boron to create a bluish color. No subsequent polishing was performed. Rather than blue, the resulting color was a less desirable gray. This natural diamond with CVD overgrowth was then reset in a ring and worn daily by the author for the next eight years. Recently, this hybrid diamond was removed from its setting for gemological and spectroscopic characterization and to assess the current state of the CVD film.

Well-controlled durability studies have examined non-diamond coatings on diamond (e.g., A.H. Shen et al., “Serenity coated colored diamonds: Detection and durability,” Spring 2007 G&G, pp. 16–34) and nanocrystalline diamond coatings on non-diamond materials (J.E. Shigley et al., “Characterization of colorless coated cubic zirconia [Diamantine],” Spring 2012 G&G, pp. 18–30). To our knowledge, however, none have been performed on CVD diamond films grown on natural diamond. The assessment of this one sample, given the exposure a ring is usually subjected to, can indicate the long-term stability of such coatings on diamond. The expectation was that such films would remain stable, as there is no lattice mismatch in the crystal structure between the CVD synthetic film and the natural diamond. Lattice mismatch and the resulting low cohesion at the diamond/non-diamond interface typically result in moderate to very poor durability.

It was difficult to find evidence of the CVD layer using spectroscopic techniques. FTIR absorption (which generally provides data from the bulk of the diamond) revealed no CVD-specific features, only that the underlying diamond was type Ia. Using PL spectroscopy, which collects data from a limited area, it was difficult to find spectroscopic evidence of the CVD film, even when the PL data were collected in confocal mode. No CVD-related 3123 cm–1 peak was detected in IR absorption, and the silicon peak at 737 nm was not observed in PL. The best evidence of the CVD layer’s continued existence on the diamond was from its unusual appearance in visual observation (figure 1) and microscopic analysis (figure 2). The pavilion also showed electrical conductivity, which provides another indication of the boron doping.

Figure 2. This differential interference contrast image shows the irregular texture of the CVD overgrowth film on the pavilion facets of the 0.27 ct natural diamond. Each facet is a different color, and the boundaries between colors are facet junctions. Image by Nathan Renfro.
By examining the pavilion of the diamond at high magnification, we could assess the condition of the CVD layer after eight years of daily wear. The film was still largely intact, covering the entire pavilion and containing only a few sporadic pinholes. There was no noticeable degradation at the facet junctions. The obvious color zoning in figure 1 that appears to divide the diamond into quadrants is likely due to differences in deposition and boron incorporation rates on the various facets. Recently, the diamond was annealed twice, at 600°C and 700°C for one hour each in a reducing atmosphere, in an effort to make it appear bluer. This treatment changed the color from Fancy Dark brownish yellowish gray to Fancy Dark gray.

As treatments become more sophisticated and move from the laboratory into the trade, the need for accurate detection only intensifies. Nevertheless, such semipermanent films are identifiable and reiterate the need to use both spectroscopic and traditional methods for gemological characterization. @chapter:15


Publication Year: - Title: Peridot History and Lore Abstract: This 146.10-carat peridot is in the collection of the Natural History Museum in London

                      Peridot has always been associated with light. In fact, the Egyptians called it the “gem of the sun.” Some believed that it protected its owner from “terrors of the night,” especially when it was set in gold. Others strung the gems on donkey hair and tied them around their left arms to ward off evil spirits.

The word peridot comes from the Arabic “faridat,” which means “gem.” Most peridot formed deep inside the earth and was delivered to the surface by volcanoes. Some also came to earth in meteorites, but this extraterrestrial peridot is extremely rare, and not likely to be seen in a retail jewelry store.

Early records indicate that the ancient Egyptians mined a beautiful green gem on an island in the Red Sea called Topazios, now known as St. John’s Island or Zabargad. Legend has it that the island was infested with snakes, making mining unpleasant until an enterprising pharaoh drove them into the sea. From the earliest times, people confused this stone—now known to be peridot—with other gems. It was one of many labeled as “topaz.”

Some historians believe that Cleopatra’s famous emerald collection might actually have been peridot. People in medieval times continued to confuse peridot with emerald. For centuries, people believed the fabulous 200-ct. gems adorning the shrine of the Three Holy Kings in Germany’s Cologne Cathedral were emeralds. They are, in fact, peridots. @chapter:25


Publication Year: - Title: Charles “Chuck” Fryer(1928–2003) Abstract: Like many of his contemporaries and successors at GIA, Chuck Fryer’s achievements came from a passion for gemology and a drive for excellence. His childhood hobby of cutting gemstones eventually led to a successful tenure as the head of the Institute’s West Coast Gem Trade Laboratory.

Prior to his military service, which included a tour of duty in the Korean War, Fryer worked as glazier, a tradesperson who cuts and installs glass in window frames. Using GI Bill benefits, he enrolled in GIA correspondence courses while continuing to work in construction, finally earning both his GG and FGA diplomas in 1963. A charter member and president of the San Diego Gemological Society, he joined the Institute in 1966 as an instructor, a position he held briefly before he became supervisor of the Gem Trade Laboratory in 1967. In 1987, he was named director of gem identification services, a position he held until his retirement in 1993.

GIA’s lab services thrived under Fryer, whose research led to his reputation as one of the world’s premier gemologists. Using X-ray diffraction, he identified very rare minerals such as pink benitoite, the second known painite crystal, and the first cut jeremejevite. He also identified the mineral components of maw-sit-sit, a jade-like gem material. Whereas previous X-ray diffraction tests required grinding samples into powder, Fryer developed a scraping technique that was virtually undetectable but could still analyze surface-reaching inclusions. Outside his duties at GIA, he was frequently called upon as an expert witness in legal cases pertaining to gem identification.

Fryer’s articles on gem identification appeared in Gems & Gemology, Journal of Gemology, and Jewelers’ Circular-Keystone. Of particular note was his Fall 1986 G&G study on the separation of natural and synthetic amethyst. Fryer further contributed to G&G as editor of the Lab Notes section from 1981 to 1997; he continued to serve on the journal’s editorial review board until his death in 2003. His influential lab findings advanced GIA’s standing as the world’s authority on gemstone identification. @chapter:20


Publication Year: 2015 Title: Artificially Irradiated Color-Change Diamonds Abstract: Figure 1. These two chameleon diamonds (0.35 and 0.27 ct) were color-treated with
artificial irradiation. Photo by Jian Xin (Jae) Liao.

Diamonds that exhibit a temporary color change, commonly referred to as “chameleon” diamonds, are rare in nature. Their color changes with gentle heating, or when they are left in darkness for a period of time. The change from a dark greenish to a lighter yellow hue upon gentle heating is due to the thermochromic properties of these diamonds (D.J. Content, Ed., A Green Diamond: A Study of Chameleonism, W.S. Maney & Son, Leeds, England, 1995, 42 pp.).

Recently the New York laboratory examined two chameleon diamonds, a 0.35 ct Fancy Deep yellow-green marquise and a 0.27 ct Fancy Deep grayish yellowish green marquise (figure 1). Spectroscopic analysis and gemological observations confirmed that these were typical chameleon diamonds. After excitation with short-wave UV light, both exhibited a strong blue to yellow phosphorescence often seen in natural chameleon diamonds. Their UV-Vis absorption spectra showed a broad band at about 480 nm, as expected for this type of diamond. But the spectra also displayed a peak at 741 nm (figure 2), known as GR1 (general radiation damage), that can contribute to a green color in diamonds. Because this radiation-related feature is not found in untreated natural chameleon diamonds, we concluded that both stones had been artificially irradiated.

Figure 2. The UV-Vis spectra for the two chameleon diamonds show a broad absorption peak around 480 nm and an atypical GR1 feature at 741 nm.
A chameleon diamond is an unlikely candidate for artificial irradiation treatment to enhance the stone’s green or blue bodycolor. It is likely that this property was not known or understood before the irradiation process. A permanent color change may occur if these treated chameleon stones are heated for a prolonged period, so it is important to exercise caution during testing. Because the diamonds’ original colors are unknown, they were issued reports stating that they had been artificially irradiated to enhance their color. @chapter:11


Publication Year: 1999 Title: Diopside Needles as Inclusions in Demantoid Garnet from Russia: A Raman Microspectrometric Study Abstract: Straight, acicular, colorless solid inclusions in demantoid garnet from the Ural Mountains of Russia were investigated by laser Raman microspectrometry. These “needles,” which occur in association with “horsetail” inclusions (curved, fibrous chrysotile), were identified as diopside. This study also demonstrated that Raman analysis is a highly sensitive method for distinguishing even between isomorphous mineral inclusions in gems, that is, minerals with similar crystal structures but different chemical compositions @chapter:13


Publication Year: 2023 Title: Chinese KOLs Boost Online Jewelry Sales Abstract: The Xindou platform, which collects various data from Douyin (TikTok) in China for search, ranking, live streaming, brand gathering, and downloading operations, disclosed a report on the top Key Opinion Leaders (KOLs) on Douyin in July 2023. It revealed that the highest sales in July 2023 came from the top three KOLs in the jewelry category. The first place was held by KOL Xin Jiang He Tian Yu Lao Zheng, and the second place by KOL Xiao Bei Zhu Bao Yan Xuan. Both achieved sales exceeding 5 billion RMB (25,000 million THB), while the third place went to KOL Yun Shang Zhu Bao and the fourth to Dong Fang Zhen Xuan. Dong Fang Zhen Xuan stopped live streaming for five days, causing a drop in popularity to fourth place in July. In contrast, Xin Jiang He Tian Yu Lao Zheng began ranking in the top 10 in February 2023 and climbed to first place, despite having only 1.01 million fans, compared to Dong Fang Zhen Xuan's 30.59 million fans, a difference of 30 times (exchange rate: 1 RMB equals 5 THB).
Currently, China's jewelry market is valued at up to 7 trillion RMB (3.5 trillion THB), with online trading increasing annually. This aligns with statistics from the Gems & Jewelry Trade Association of China, which revealed that in 2022, online jewelry sales reached 2.35 trillion RMB (1.18 trillion THB), expanding by 27% YoY, accounting for 33.33% of total jewelry sales.
The popularity of the jewelry industry on Douyin is supported by both platform promotion and trader initiatives. Interesting content stimulates consumer demand further. Live streaming by KOLs boosts purchasing decisions. Direct-to-Consumer (DTC) live streaming enables immediate pricing and broad consumer access.
Douyin's Chinese platform, which has over 600 million daily users, is beginning to slow down. Therefore, maintaining this user base requires diverse live streaming activities and selecting product categories that enhance platform memorability and stability. Previously, Taobao and Tmall focused on apparel and fashion products, JD.com on digital products, and Pinduoduo on agricultural products. Therefore, Douyin selected other product categories, such as jewelry. Even though jewelry has a high unit price, selling it successfully online can promote the brand and attract more consumers to Douyin. This helps expand consumption to other product categories.
Regarding jewelry consumers, the primary group has relatively high age. However, Douyin users are increasingly middle-aged and older, which is crucial for jewelry businesses. According to QuestMobile, in 2021, Douyin users aged 41 and over accounted for 36.3%, and those aged 51 and over accounted for 18.4%. These consumer groups have strong consumption capabilities and are decisive, making them essential for jewelry businesses on Douyin in China. Recent data up to June 2022 shows that e-commerce jewelry businesses on Douyin in China are valued at up to 1 trillion RMB (5 trillion THB), with an expected online jewelry sales increase of 54% YoY.
Regarding the sales strategy of jewelry via KOL live streaming, factors contributing to the popularity and saleability of high-priced jewelry include the KOL's credibility and communication skills with viewers during live streams. Moreover, setting up the live streaming environment, lighting, and showcasing the product's beauty and quality through the camera are crucial. The number one KOL, Xin Jiang He Tian Yu Lao Zheng, uses a straightforward visual approach, emphasizing continuous close-ups and product-highlighting lighting to explain product strengths. Marketing strategies like urging customers with phrases like "Lowest Price Reduction, Now Only 39.9 RMB, Buy It Now!" attract consumers to make immediate purchase decisions.
Economic impacts on Thailand and adjustments by the government, private sector, and Thai entrepreneurs
In the past, jewelry and gems were considered luxury goods, and they were only sold in specific places, making it difficult for ordinary consumers to access. However, with the growth of the economy, increased income, improved quality of life, and advanced internet development, consumers now have the purchasing power and easy access to consume luxury goods. Combined with the trend of increasing online jewelry sales in China each year, the sale of jewelry is not limited to offline channels as it was in the past. This makes the jewelry market a promising area for Thai jewelry businesses and exporters to expand into China by collaborating with local partners and using social media to build brand awareness for Thai jewelry. Thai entrepreneurs can also apply Chinese KOL live streaming sales formats to online jewelry sales in Thailand by targeting specific consumer groups, marketing, setting appropriate prices, creating live streaming room environments, and interacting honestly with consumers to sustainably capture consumers' hearts in China and Thailand. @chapter:27