Title: New Technologies and Techniques Abstract: Figure 1. Single-crystal CVD diamond. Courtesy of Element Six.

Synthetic CVD Diamond—30 Years On
Daniel J. Twitchen
Element Six, Global Innovation Centre, Harwell, Oxford, United Kingdom
Element Six first started its chemical vapor deposition (CVD) synthetic diamond program in 1988. Thirty years on, this talk will review notable high and low points, flagging some lessons learned.
Volume synthesis of diamond by CVD (figure 1) has not only contributed to reducing the cost of the material but also enabled the superlative properties of diamond to be more fully utilized. It has long been recognized that, aside from its extreme hardness, diamond is a remarkable material with many properties—optical, thermal, electrochemical, chemical, and electronic—that outclass competing materials. When combined, these properties offer the designer an engineering material with tremendous potential to create solutions that can shift performance to new levels or enable completely new approaches to challenging problems.
Components routinely fabricated using CVD synthetic diamond now span tweeters for loudspeakers, radiation detectors and sensors, optical components for lasers, windows for radio frequency and microwave transmission, blades and cutting tools, and electrodes for electrochemical sensing, ozone generation, and direct oxidation of organic matter.
Lightbox, a new De Beers company, has recently announced jewelry using white, blue, and pink lab-grown CVD diamonds. As crystal growers and materials scientists know, intrinsic undoped diamond is colorless in the visible range, but its absorption properties can be modified by defects, often referred to as “color centers,” formed either during the CVD growth process or through post-growth treatments such as irradiation and annealing. This presentation briefly summarizes some of the tools used to engineer CVD diamond. For example, controlling the nitrogen level (yellow CVD) to obtain particular thermal and optical properties, doping with boron (blue) to make electrically conducting diamond used to produce ozone for sanitization and for thermal management in telecommunications, and growing in nitrogen-vacancy centers (pink) to make magnetic sensors.
The diverse applications of diamond that harness its exceptional properties and the impact of color centers touch our lives in unexpected ways: Diamond is used to create the high-quality mirror finish on your smartphone and to produce the 170 miles of copper wiring in the aircraft that takes you on vacation, and it is also enables new higher-power lasers used in welding our cars together. It is even used in the quality control of food and in pharmaceutical manufacturing.
In summary, there has been considerable progress in the fabrication and commercialization of CVD-grown diamond over the last 10 years by a number of producers. This progress, coupled with the broad range of applications, shows that perhaps a new age of industrial diamond has truly begun—the age of CVD synthetic diamond.
Beyond Gemstones: The Medical, Industrial, Scientific, and Computational Applications of Lab Diamonds
Jason Payne
Ada Diamonds, San Francisco
Many gemologists know that there are important technological applications for laboratory-grown diamonds; however, it is less understood how broad the nongemological uses really are or why diamond is the ideal material for each use. This presentation will review modern industrial applications of laboratory-grown diamonds, including surgical tools, tumor detection, orthopedic implants, water purification, industrial tooling, compound refractive energy focusing, Fresnel lenses, high-pressure anvils (figure 1), sound reproduction, deep space communication, high-power electronics, quantum computing, long-term data storage, AC/DC conversion, and electrical vehicle efficiency.

Figure 1. Laboratory-grown diamond anvils, capable of generating 1 terapascal of pressure, enable high-pressure experiments for physics, chemistry, materials science, and industry. Photo courtesy of New Diamond Technology.
These applications are rooted in the less frequently discussed gemological properties of diamonds that make it a “supermaterial.” The biological, thermal, mechanical, optical, acoustic, and electrochemical properties of diamond will be introduced. Specific properties discussed will include thermal conductivity, Young’s modulus, breakdown field, band gap, and saturated electron drift velocity. Furthermore, the utility of diamond defects such as nitrogen vacancies and boron will be explored.
In addition to discussions about functional monocrystal diamonds, two unnatural forms of functional diamond will be discussed: polycrystalline diamond (PCD) and diamond-like carbon (DLC). Many of the functional diamonds discussed, including PCD and DLC, will be available for hands-on examination as part of the presentation.
Big-Data Analysis and Insights in the Online Gem and Jewelry Trade
Menahem Sevdermish and Guy Borenstein
Gemewizard, Ramat Gan, Israel
Big-data analytics is the process of collecting, organizing, and analyzing large volumes of data to reveal hidden patterns and unfamiliar correlations, identify market trends, and extract other useful information that might otherwise be invisible—even for the data manager.
Big-data analytics is seldom used within the gem and jewelry trade. The gem and jewelry sector is kept with general fixed inquiries that block the category from characterizing its inventory and users, and by that, identifying new opportunities.
Another challenge is that in most online marketplaces, the “What You See Is What You Get” experience is hindered by two main factors: improper disclosure and misrepresentation of images (e.g., digitally enhanced photos).
The research and development team of Gemewizard has devised and digitized a fully automatic big-data analysis system for large-scale gem and jewelry marketplaces, based on color and contextual search engine and image analysis (figure 1). This system generates unique market analytics and a fraud detection and prevention service.

Figure 1. The system algorithm crawls the HTML pages of gem websites for big data. For each gem, it condenses the item page to its attribute components and records useful data. The collected data is then compared against the entire database to identify insights and peculiarities.
Since 2016, the Gemewizard team has had the opportunity to examine the validity of the system using vast amounts of data from a world-leading online retail marketplace. The information gathered from this survey, together with additional volumes of information collected from the Internet, provided some important insights regarding the online gem and jewelry trade. Some of these insights, which we consider fruitful and eye-opening for any marketplace or e-tailer, will be revealed.
The gem-related information contains insights regarding common fraudulent activities and practices for 128 varieties, species, and series of merchandisable gems. The gathered data includes anomalies in attributes such as:

Gem type: Mineralogical, gemological, and trade names, as well as misnomers. Analysis includes accepted word combinations (e.g., “ruby” and “zoisite”) versus problematic ones (e.g., “diamond” and “moissanite”).
Color (e.g., “yellow emerald”)
Synthetic wording and nicknames (e.g., “heating with light elements”)
Treatment wording, ranked and analyzed according to severity (e.g., “heating” versus “diffusion” in ruby)

The trade-related information provides powerful forecasting tools for the marketplace administrator. These include sales and trends history, defined by attributes such as type, color, geography, seasonality, and price, and the ability to identify tendencies (e.g., “Prices of untreated ruby gems between 2 and 3 carats are on the rise in Europe…”) and pricing opportunities (e.g., “Currently, there is a high demand for pale-colored Paraíba tourmaline gems in Far East markets”).
Diamond Impression: The Key to Sustainable Competitiveness
Sergey Sivovolenko1, Roman Serov2, and Janak Mistry3 (presenter)
1OctoNus Finland Oy, Tampere, Finland
2OctoNus Software, Moscow
3Lexus SoftMac, Surat, India
People are impressed with the uniqueness of diamond, which incorporates factors such as brilliance and fire. When the trade commoditized the category through the Four Cs, it was partly due to the technical inability to promote diamond’s impressive optical effects, including optical illusions. This common trade practice inhibited diamond’s competitiveness against other goods in the luxury sector. But from now on, emerging technology will allow demonstration of diamond’s magic on a large scale with fine details.
Modern algorithmic craftsmanship creates the category of high-vibrancy diamonds, referred to here as Hi-Vi: exceptional diamonds with superior consumer benefits such as brilliance, fire, table color, symmetry, and spread, compared to others of the same shape, size, and pavilion color. The triple excellent round, which took centuries for the industry to craft, was the first Hi-Vi diamond.
Diamond vibrancy is a combination of optical effects and illusions. For example, brilliance, fire, scintillation, and spread depend on both objective parameters such as cut design and stone size, as well as subjective aspects of human vision, such as space-temporal sensitivity and stereo perception. Figure 1A demonstrates the scintillating grid illusion: The intersections seem to flicker white and black, generating additional brightness and contrast when the observer’s glance wanders. Distortion of pattern ruins this effect (figure 1B). Certain patterns produce higher perceived brightness. This example is a 2D effect; more astonishing optical illusions result from human stereo vision.

Figure 1. A scintillation grid (A), a scintillation grid with a wavy pattern (B), and squares covered by round brilliant-cut diamonds in different sizes (C).
The phenomenon of diamond brilliance has a similar origin—human vision peculiarity—as the scintillating grid illusion described above. The impact of optical illusions on both Hi-Vi diamond patterns and jewelry designs (e.g., melee) are to be considered, so Hi-Vi optimization is made for not just single diamond cuts, but also for each diamond jewelry piece as a whole.
Figure 1C shows squares with round brilliant-cut (RBC) patterns that differ only in size. The integral colored and colorless areas are exactly the same, while the perceptions of fire and brilliance in each image are quite different. It is impossible to maximize two performance parameters (both fire and brilliance, for example) simultaneously. The consumer’s final choice should be based on subjective preferences and rely on performance benchmarks.
Hi-Vi diamonds should be demonstrated with an optical performance digital “loupe,” which allows even inexperienced buyers to easily appreciate the performance difference at the highest levels of brilliance, fire, and scintillation. The “loupe” is critically important for mass marketing of relatively small diamonds. For sustainable market development, diamond impressiveness and vibrancy born of masterly designed optical illusions and visual effects is the selling proposition to craft, demonstrate, and explain. Source: GIA @topic:4


Title: Books: The Cheapside Hoard: London's Lost Jewels Abstract: By Hazel Forsyth, 272 pp., paperback, illus., publ. by Philip Wilson Publishers, London, 2013. £19.95.

                      Written to accompany the Museum of London's exhibition of the Cheapside Hoard jewels (October 11, 2013 to April 27, 2014), this book gives the reader a unique glimpse into the world of the Elizabethan jewelry trade. Author Hazel Forsyth, the museum's senior curator of medieval and post-medieval collections, says this book is not a catalog but instead provides the reader with some context of the gem and jewelry trade in late 16th- and early 17th-century London. It also explores and illustrates some of the most beautiful jewels of this era, jewels that were found in what is known as the Cheapside Hoard.

The book begins with the 1912 discovery of the hoard during the renovation of a building in the Cheapside area of London. The story itself is like a detective novel, involving shady characters and intrigue. Forsyth has done exhaustive research to bring it to light. The book is illustrated with period documents, drawings, and paintings. The thorough research into both the 1912 discovery and London’s 16th- and 17th-century jewelry trade will delight historians. The beautiful photos of the pieces highlight both the wonderful gems in the hoard and the unique settings created by Elizabethan and Jacobean jewelers. This book is a great resource not only for jewelry historians but also for anyone who has an interest in gems from this period.

The Cheapside Hoard, a treasury of nearly 500 pieces, is the most important collection of jewelry from this era. Forsyth takes the reader on a journey to the days when these jewels were created, exploring the gem trade in London and around the world. Exotic locations from which the gems originated, such as Persia, India, and Colombia, are interwoven in stories of the secretive and sometime dangerous gem trade. Also discussed are the guilds and the leading characters in the industry at the time. The reader is introduced to politics and disputes that took place within the trade through the court and guild documents cited by the author. The craftsmen’s workshops and tools are also described in detail.

Not only are the jewels beautifully illustrated, but the period paintings throughout the book show how they were worn. It is said a picture is worth a thousand words. To learn that a bodkin is a hair ornament is informative, but to see it worn in a 1617 portrait of Anne of Denmark illustrates the point even better. Earrings, rings, necklaces, cameos, and more are seen in period portraits throughout the book. The photos of the gems and jewels show the exquisite craftsmanship of the pieces in this collection. The enamel work, gold work, and imaginative settings of these pieces capture the reader's imagination.  They are of the highest quality from this period.

The most impressive piece in the Cheapside Hoard is the watch encased in a large hexagonal-cut Colombian emerald. The dial, with gold roman numerals, is made of green enamel to match the emerald’s color. The lid of the watch case is also solid emerald and is translucent enough to see the face and tell the time even when it is closed. It is truly a masterpiece of watchmaking and stone-cutting design.

The Cheapside Hoard: London's Lost Jewels is recommended to anyone who enjoys historical jewelry, the history of European trade, or beautiful gems. It is a chance to see precious artifacts with mysterious and intriguing stories, artifacts that give a glimpse into a bygone era. Source: GIA @topic:6


Title: Plume Agate from Iran Abstract: Figure 1. Iranian plume agate (22.45–82.03 ct) from the Ferdows agate field comes in two main varieties. The material on the left with white, green, and orange inclusions is known as “spring agate.” The stones on the right with red, yellow, and green inclusions are called “autumn agate.” Photo by Diego Sanchez.
Iran has long had a reputation as a source of quality agate, principally derived from extensive volcanic deposits throughout the country. Archaeological research on ancient tombs and finds in early human settlement sites there show that agate, chalcedony, and jasper were used not only for arrowheads and other stony instruments but also for ornamental beads and pendants.

Figure 2. Iranian “spring agate” showcases inclusions that are typically green, white, and orange. Photomicrograph by Nathan Renfro; field of view 3.78 mm.

Figure 3. A display of orangy red, green, and yellow inclusions seen in “autumn agate” from Iran. Photomicrograph by Nathan Renfro; field of view 6.00 mm.
Today, Iranian agates are primarily traded in the city of Mashhad, the largest holy city of Iran and the capital of the northwest province of Khorasan. Several varieties can be found in the market, but plume agates are the most colorful and most sought after. The samples of Iranian agate examined by the authors contained numerous plume structures in a variety of colors including green, yellow, red, white, and orange (figure 1). These plume structures are characterized by elongate billowy inclusions that can resemble clouds of smoke or feathers. The material with predominantly green, white, and orange inclusions is sold as “Bahary” (spring) agate (figure 2). The material that is principally green, yellow, and red is sold as “Paaeasy” (autumn) agate (figure 3).

Figure 4. An agate sample collected at the Aysak area in the Ferdows agate field in the southern region of Iran’s Khorasan Province. Photo by Hamid Mir-Blukey.
The samples examined were acquired in Iran by author MMS from Dr. Hamid Mir-Blukey, who has a private mining claim in the Ferdows agate field in the southern region of Khorasan (figure 4). Mining there is done mainly with primitive hand tools at or near the surface, where veins of agate are exposed as they weather out of their volcanic host rock.
While most material from this region is locally traded, the area could become an important global source for plume agate. Source: GIA @topic:11


Title: Large Namibian Demantoid Garnet Abstract: Figure 1. This selection of andradite garnet from Namibia’s Green Dragon mine includes an 11.63 ct demantoid round brilliant, an unusually large stone for this source. Photo by Robert Weldon/GIA, courtesy of Green Dragon mine.

              At the GJX show, Stefan Reif (Tsuen Wan, N.T., Hong Kong), showed us an 11.63 ct round brilliant demantoid garnet. It was an exceptional stone of intense vibrant green with a touch of blue. According to Reif, the original rough weighed approximately 46 ct—about 9 grams—making the yield a little over 25%. This is an exceptionally large gem for Namibia’s Green Dragon mine, where the bulk of production is suitable for small calibrated gems.

Namibian demantoid was first discovered in the 1990s (Fall 1997 GNI, pp. 222–223). The current production came from an open-pit, hard rock mine with an annual production between 5,000 and 10,000 carats. According to Reif, the local geology includes marble, pegmatite, and rhyolite. The distribution of demantoid pockets within these rocks is irregular and difficult to predict. Beside the geological challenges, water is scarce, and temperature extremes range from freezing at night to baking desert heat in the daytime.

The Green Dragon mine is renowned for its production of well-proportioned rough. This material is suitable for cutting smaller gems into 2–3 mm sizes in a range of colors from slightly bluish green through “lemongrass” green to greenish yellows and reddish browns. These are used for precision-cut calibrated and melee-sized goods placed as accent stones in high-end jewelry. Most of the cutting is done in Thailand, and the yield is approximately 10% due to the desire for well-proportioned cut gems. Besides precision-cut demantoid and andradite garnet in calibrated sizes, Reif also cuts to higher tolerances for the watch industry, producing 3 × 2 mm tapered baguettes for watch bezels.

Even in these small sizes, well-cut gems display high luster and very distinct fire, making them an excellent visual alternative to diamond. Rough suitable for gems of 6.0 mm (about 1 ct) is much rarer, but material for larger gems does come up once in a while. Source: GIA @topic:2


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

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

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

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

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

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

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

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

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

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

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

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

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

Figure 1. A freshwater tissue-nucleated cultured pearl, shown in visible light (left), in an X-radiograph (center), and an optical coherence tomography image (right).
Traditionally, the internal structure of pearls has been examined by radiography. This imaging method uses X-rays (figure 1, center), which are at the higher-energy end of the electromagnetic spectrum. This technique generates two- and three-dimensional images. To get a clearer picture of the internal structure, 3D images are generated by computed tomography (CT), where multiple 2D images from different angles undergo computer processing. The time to generate an image with good resolution can vary from seconds to several minutes. While passing through the pearl, a certain amount of X-ray radiation is absorbed (dependent on the pearl’s density and structural composition) as well as scattered. Although the radiation is not harmful, there may be a slight degree of ionization occurring when the X-rays are absorbed by the pearl. In addition, the operator must take safety measures while working with ionizing radiation.
Here we present an alternate form of imaging that uses the lower-energy end of the electromagnetic spectrum, namely the near-infrared region. Optical coherence tomography (OCT; figure 1, right) is a noninvasive, micron-resolution cross-sectional scanning of visually translucent to opaque structures. It allows live 3D imaging of sample morphology without sample preparation or exposure to ionizing radiation. OCT fills the imaging gap between ultrasound and MRI (deeper coverage and lower spatial resolution) on one end, and confocal microscopy (shallower coverage, higher spatial resolution) on the other. It can be likened to sonar or medical ultrasound, but using light waves instead of sound waves. OCT has proved very successful in ophthalmology and cardiology applications.
In this technique, a beam of light (typically in the near-infrared spectrum) is used to scan the sample. Coherence refers to the fact that an interferometric, low-coherence technique is used for depth discrimination. Tomography means cross-sectional imaging. To further explain the basic optical setup, the light is split between two arms, one for the sample and one for the reference mirror. The reflected beam from the sample and the reflected beam from the reference mirror interfere with each other. That interference represents the intensity of the reflection from a specific depth in the sample. In classic time-domain OCT, scanning the position of the reference mirror in the interferometer allows the interference signals from different depths to be acquired and processed, thus forming an axial line representing the intensity of reflections from each depth in the sample. In swept-source OCT, a laser source produces a rapid sweep of wavelengths (colors). For each wavelength, an interference pattern is formed. This interference pattern can be processed with exquisite sensitivity, leading to exceptional rejection of signals from depths outside the detection window.
In the case of the 3D data presented here, a pair of galvanometer scanners were used to scan the light in two directions perpendicular to each other and both perpendicular to the depth direction (see the table for the scanning systems’ specifications). Although there have been attempts in the past 20 years to apply OCT technology for pearl examination, none have garnered sufficient interest. Part of this has to do with the cost-effectiveness of this technology for commercial use. In addition, the resulting imaging was still not suitable for pearls, since the penetration depth and sensitivity from available systems was insufficient. Our studies have demonstrated the exceptional performance of a compact and cost-effective advanced swept-source OCT system in delivering high-quality noninvasive 3D images of pearls in real time. Source: GIA @topic:4


Title: GSA 2017 Annual Meeting Abstract: Figure 1. Presenters, session advocates, and senior executives from GIA at GSA’s annual meeting in Seattle. Photo by Tao Hsu.

The Geological Society of America (GSA) held its annual meeting October 22–25 in Seattle. For the fifth year, GIA hosted technical sessions on gemological research in the 21st century. More than 30 researchers, students, and gem experts from multiple institutions shared their most recent research results (figure 1).

Invited speaker Evan Smith (GIA, New York) presented the diamond inclusion suite study he carried out over the past two years. Following his paper published in Science on type IIa Cullinan-like, large, inclusion-poor, pure, irregular, resorbed (CLIPPIR) diamonds, Dr. Smith investigated in situ mineral phases in more than 20 extremely rare type IIb diamonds selected from GIA’s day-to-day grading operations. The identified inclusions indicated that type IIb diamonds can originate from the lower mantle, at depths beyond 660 km. This surprising result refuted the well-accepted view that almost all superdeep diamonds are small and not of gem quality. Nancy McMillan (New Mexico State University) talked about the diamond provenance study she performed with Catherine McManus (Materialytics, Killeen, Texas). To ease consumer concerns about conflict diamonds, they conducted multivariate analysis of laser-induced breakdown spectroscopy (LIBS) on diamonds from various origins as well as synthetic diamonds. The information provided by LIBS on trace element composition and the electronic structure of atoms in diamonds aided in provenance determination. Through infrared (IR) mapping, Sally Eaton-Magaña (GIA, Carlsbad) and her colleague Troy Ardon documented the spatial changes of the optical defect center B0 (uncompensated boron) in two type IIb diamond samples: One specimen was irradiated along an edge and then annealed, while the other was only annealed. The irradiated diamond showed an obvious gradient in B0 across the specimen itself and larger gradient changes during annealing compared to the other sample. These were caused by changes in compensating defects, which were then plotted by photoluminescence (PL) mapping.

The following three presenters from the University of Alberta shared their intriguing diamond formation research. Mandy Krebs offered trace element data of fluids trapped in gem-quality diamonds and compared them to those in fibrous diamonds that have been extensively studied. The results showed clear similarities in trace element patterns in both categories, which indicates that fibrous diamonds and gem diamonds may share a common origin. Rebecca Stone reported on diamond growth in saline fluid. She and her colleagues carefully documented diamond growth features under different salinities using a mixed KCl-NaCl brine system within the diamond stability field. Their series of experiments showed that Na-rich brine is a better medium for diamond growth than K-rich or Na+K mixed brines. Robert Luth discussed the partial melting mechanism facilitating diamond formation. He noted that the amount of diamond formed during this process depends on the lithology being melted and the composition of the fluid. The origin of the C-bearing fluid was also explored.

Following the diamond research presentations, invited speaker Darrell Henry (Louisiana State University) started the colored stone session with a talk on gem tourmaline. He pointed out that tourmaline is a very sensitive mineral that can incorporate and retain chemical and textural fingerprints from its environment. Paraíba, Paraíba-like, liddicoatite, and “chrome” tourmaline were used to illustrate this mineral’s incredible scientific value. Aaron Palke (GIA, Carlsbad) discussed his recent findings on demantoid garnet’s coloration mechanism. The existing theory attributes the brown coloration of this gem to intervalence charge transfer between Fe2+ and Ti4+ or Fe3+. Dr. Palke challenged this interpretation based on recent spectroscopic results showing insufficient Fe2+ in demantoid to justify this mechanism. Philippe Belley (University of British Columbia) addressed the challenges of modeling spinel deposits. His potential solutions are based on detailed petrographic and geochemical studies on 14 samples from exceptionally well-exposed in situ spinel occurrences on Baffin Island in Nunavut, Canada. Donald Lake (University of British Columbia) compared two beryl occurrences in northern Canada with Colombian emerald deposits. He pointed out that in terms of formation environment, these potential emerald deposits are the first “Colombian-type” sources outside Colombia. Rachelle Turnier (University of Wisconsin–Madison) presented her study on oxygen isotope fractionation factors in corundum. Oxygen isotope ratios are important to understanding corundum genesis and origin determination. This study empirically calibrated the calcite-corundum oxygen isotope fractionation factor from the metamorphosed karst-bauxite deposits at Naxos, Greece. GIA’s Jennifer Stone-Sundberg closed this portion of the session with a presentation on matrix-matched corundum standards development. She explained the importance of these newly developed standards in accurately determining trace element concentration and elaborated on the advantages of these standards over other commonly used products.

Figure 2. The GSA annual meeting’s gemological research poster session featured 18 presenters from all over the world. Photo by Cathy Jonathan.
This year’s poster session attracted 18 presenters, triple the number from last year (figure 2). Daniel Howell (University of Padua) presented new applications of DiaMap software in automated and semi-automated mapping of single substitutional defects (N and B) and micro-inclusion-bearing diamonds. Paul Johnson (GIA, New York) reported the first observation of nickel as the cause of the green color of an HPHT synthetic diamond. Nickel is commonly used in the metal flux that produces HPHT synthetic diamond, but it rarely contributes to diamond coloration. Tyler Sundell (Missouri State University) evaluated the viability of in situ 13C measurement in diamonds using time-of-flight secondary ion mass spectrometry (ToF-SIMS). Tingting Gu (GIA, New York) shared her study on micro- and nano-inclusions containing both N and Fe in type IaB diamonds. Kyaw Soe Moe (GIA, New York) presented the identification features of irradiated and annealed pink diamonds using IR spectroscopy and DiamondView imaging. Elizabeth Levy (Louisiana State University) explained how to directly measure Fe2+ and Fe3+ concentration in tourmaline crystals using synchrotron-based X-ray absorption near-edge spectroscopy (XANES). Cole Mount (New Mexico State University) found that using multivariate analysis of LIBS spectra of tourmaline can remove the negative influence of chemical zoning on host lithology determination. Ulrika D’Haenens-Johansson (GIA, New York) gave her insights on the 812 ct Constellation and two other large rough diamonds. FTIR and morphology observations indicate that the three could possibly be pieces from the same rough. Christopher M. Breeding (GIA, Carlsbad) described the first ever co-occurrence of magnesite, olivine, graphite, and silicon-vacancy defects in natural diamonds and explored the unusual conditions under which these diamonds formed. Karen Smit (GIA, New York) discussed the formation of peridotitic diamonds through isochemical cooling and eclogitic diamonds through redox buffering. George Harlow (American Museum of Natural History, New York) and Rachelle Turnier discovered that syenite-hosted sapphires from six different sources show a wide range of δ18O values, which indicates scavenging of sapphire from multiple reservoirs. Troy Ardon (GIA, Carlsbad) used IR mapping, cathodoluminescence (CL) imaging, and hyperspectral mapping to correlate various optical and infrared point defects in diamonds with strong brown coloration. Susanne Schmidt (University of Geneva) outlined U-Pb geochronology work done on zircon inclusions in Sri Lankan sapphires. This study was performed by her former graduate student Emilie Elmaleh. Ziyin Sun (GIA, Carlsbad) investigated the role of chromophore vanadium in coloration of pyrope-spessartine garnet, using samples without a color-change phenomenon. Eric Brinza (University of Wisconsin–Eau Claire) described an IR spectroscopic study on hydrothermal quartz crystal. Different hydroxyl species concentrations vary both vertically and horizontally through the crystal. Kyle Tollefson, also of the University of Wisconsin–Eau Claire, presented IR and visible spectroscopic study on coloration of watermelon tourmaline. The results showed that the chromophore was incorporated during crystal growth and could reflect changes in the growth environment. Dona Dirlam and her coauthors from GIA’s Richard T. Liddicoat Gemological Library and Information Center (Carlsbad, California) chronicled the legendary John Sinkankas, whose collection of books and other publications was acquired by GIA in 1988 to form the basis of its world-renowned gemological library. Source: GIA @topic:7


Title: New Designs from Paula Crevoshay Abstract: Figure 1. Paula Crevoshay’s “Penguin” pendant features 120 white moonstones, 10.09 carats total. It also contains 152 black diamonds with a total weight of 4.22 carats, 14 yellow diamonds (0.43 carats total), and eight orange opals (0.27 carats total), set in 18K gold. Photo by Robert Weldon/GIA.

	New designs from Paula Crevoshay

Paula Crevoshay continues to delight with whimsical designs and masterful control of color and light. At the AGTA show, she introduced several new pieces in her collection of threatened and extinct species, such as the charming penguin shown in figure 1. Crevoshay currently has a one-woman exhibition at the Natural History Museum of Los Angeles County entitled Art of the Jewel: The Crevoshay Collection, which explores her exhaustive process for creating jewels depicting nature all the way back to the uncut gem materials. A collaboration with lapidary intarsia master Nicolai Medvedev yielded the breathtaking “Garden of Delight” mystery box (figure 2), replete with a blue columbine on top, gold insects on each corner, mating hummingbirds that arise when the box is opened, and a delicate string of ladybugs making their way up the hinge. Another piece that demonstrates Crevoshay’s artistry is the “Anemone” pendant/brooch, which mixes greens and blues from a variety of gems, including sphene, opal, zircon, sapphire, garnet, and apatite (figure 3).

Figure 2. The “Garden of Delight” mystery box (165 × 188 mm) contains lapis lazuli, opal, sugilite, malachite, turquoise, azurite-malachite, rhodochrosite stalactites, and maw-sit-sit. The hummingbirds and branch inside the box feature amethyst, spinel, sapphire, tsavorite, opal, and black diamond. The removable columbine brooch on the lid is set with 13.89 carats of Yogo sapphire along with yellow sapphire and diamond in 18K yellow and white gold. Photos by Robert Weldon/GIA.

Figure 3. Crevoshay’s “Anemone” features a 10.86 ct center sphene surrounded by 16 opals with a total weight of 5.37 carats: four pears, four marquise cuts, and eight rounds. The outer layer contains blue zircon, sapphire, tsavorite, and apatite. Photo by Robert Weldon/GIA. Source: GIA @topic:10


Title: Gemstone Lore Abstract: Gemstones have long been believed to carry healing, protective and even magical properties. Today, gemstones are enjoyed for their beauty in jewelry and if, by chance, they carry some mysterious qualities that repel insects, heal illnesses, protect travelers or attract love...why not accept a bit of chance good fortune?

DIAMOND
Diamonds have the longest endurance of any substance known to man. On average they are 3.4 billion years of age.  The word “diamond” comes from the Greek word adamas, meaning “unconquerable and indestructible.” Diamonds were worn in ancient times to promote strength, invincibility and courage. Diamond is also the gemstone of love: when carried or worn, diamond is said to advance positive relations with the opposite sex, to conquer infertility and to ensure fidelity. The earliest record of a man giving a diamond to a woman for her hand in marriage was in 1477, when the Archduke of Austria gave one to Mary of Burgundy. Now, more than 500 years later, diamonds are still the most popular gemstones in engagement rings.

EMERALD
The word “emerald” comes from the Greek word smaragdos, meaning “green.” A member of the beryl mineral species, it contains chromium, which gives emerald its green color. In ancient Egypt, this tranquil green gem was highly prized by the wealthy and by priests. It is said that Isis wore a green emerald in her headband and that those who looked upon it would be able to conceive. Emeralds in ancient Rome were highly prized and valued for their calming and soothing effects. Nero watched the Roman games in the Colosseum through a set of highly prized emerald glasses. Emeralds, like almost all green gemstones, are also thought to be advantageous for business/money ventures.

RUBY
Ruby is made of aluminum oxide (corundum). The red in rubies is caused by trace amounts of chromium—the redder the gem, the more chromium. Rubies are found primarily in Myanmar, Thailand and Sri Lanka. The ruby represents the sun power in Hindu ancient writings, and is said to have been given as an offering to Buddha in China and Krishna in India. An ancient belief about rubies was that dreaming of them meant the coming of success in money matters and love.

SAPPHIRE
Sapphire is also made of aluminum oxide and is considered the sister stone to the ruby. It comes in all colors except red, which has been designated as “ruby.” Blue sapphires have enjoyed increased popularity in recent years, which fashion mavens credit to the sapphire engagement ring given to Princess Diana. The Buddhists believe that the sapphire favors devotion and spiritual enlightenment. The ancient Greeks linked sapphire with Apollo, and wore it as an aid to prophecy when consulting oracles. Source: GIA @topic:1


Title: Bringing Gemology to a Bigger Stage: The 2015 GSA Annual Meeting Abstract: The 2015 Geological Society of America (GSA) annual meeting was held Nov. 1–4 in Baltimore. GIA hosted two gemology technical sessions in the conference. Photo by Tao Hsu/GIA.

	Deeply rooted in mineralogy, modern gemology has become increasingly multidisciplinary with the incorporation of theories and techniques from many other scientific branches, especially those in the geoscience realm.

Kate Donovan from the GIA Alumni Association and Dr. James Shigley discuss gemological research and education with visitors to the GIA booth. Photo by Tao Hsu/GIA.

	The annual Geological Society of America (GSA) meeting attracts more than 6,000 geoscientists from all over the world and is one of the best platforms for presenting recent research and finding inspiration for future work. Since 2013, GIA researchers have participated in the GSA annual meeting. At the 2015 conference, held in Baltimore Nov. 1–4, GIA hosted two technical sessions, one oral and one poster, with 26 presentations altogether. At the same time, GIA hosted a booth at the exhibition hall in the Baltimore Convention Center, where representatives from the institute were on hand to answer questions.

	GEMOLOGY ORAL TECHNICAL SESSION

	GIA’s Dr. James E. Shigley and Dr. Wuyi Wang co-hosted the oral session. Dr. George Harlow led with a talk on how gem material studies provide insights on the whole geological system of the Earth. Dr. Wang presented the discovery and distribution of [Si-V]– defects in HPHT synthetic diamonds. This study by a team from GIA’s New York lab challenged the widely accepted theory that [Si-V]– defects only occur in CVD synthetic diamonds, while also showcasing photoluminescence mapping as a powerful research technique.

Dr. James Shigley stands next to the schedule for the gemology oral technical session. Dr. Shigley and Dona Dirlam, director of the GIA library, established the gemology technical sessions at the GSA annual meeting in 2013. Photo by Tao Hsu/GIA.

	Taking a truly multidisciplinary approach, Dr. Laurent E. Cartier from the Swiss Gemmological Institute SSEF worked with a biologist to apply DNA analysis to the origin determination of organic gems. The current study is focused on pearls. For the first time, gemologists can conclusively identify the mollusk species of a pearl. Dr. Cartier and his colleagues are working to perfect this technique and exploring the possibilities with other organic gems such as coral and ivory.

	Dona Dirlam is the director of GIA’s Richard Liddicoat Research Library and Information
	Center. Dona is one of the founders of gemology technical sessions in GSA. Photo by
	Cathy Jonathan/GIA.

	Dr. Karen Smit, a postdoctoral researcher from GIA’s New York lab, studied the Re-Os isotope of sulfide inclusions in type Ib diamond from West Africa. The isotopic study was used to explain the assembly of the Gondwana supercontinent. Next, Dr. Steven Shirey from the Carnegie Institution of Washington presented his Re-Os geochronology study on a sulfide inclusion in superdeep diamond from Brazil. The age of this inclusion indicated crystal recycling facilitated by mental convection beneath. Both studies demonstrate the important role gem materials can play in earth science research.

GSA attendees wait for the gemology oral session to start. Photo by Tao Hsu/GIA.

	Gemological studies of famous stones and historical jewelry pieces are also of great interest. Alan Hart from the Natural History Museum in London explored the creation of the Mogul cut. Using the famous Koh-i-Noor (”Mountain of Light”) diamond from the British Crown Jewels as a case study, Mr. Hart found that differential hardness was the key factor that brought about the Mogul cut with the primitive cutting tools available at the time.  Dr. Raquel Alonso-Perez from Harvard University studied the tourmalines mounted in the Hamlin Necklace, a piece of 19th-century North American jewelry, using both spectroscopic and trace-element analysis.

Dr. Shigley introduces the technical session, co-hosted by Dr. Wuyi Wang. Photo by Tao Hsu/GIA.

	Inclusion study is one of the pillars of modern gemology. GIA’s leading inclusion researcher, John Koivula, pointed out the possibility of misidentifying synthetic corundum as natural heat-treated material. Experimental studies proved that heat-fused cracks generated in both pulled and flame-fusion synthetic corundum look virtually identical to the features associated with so-called flux-healed natural stones. Dr. Aaron Palke, a postdoctoral researcher from GIA’s Carlsbad lab, found some unusual glassy melt inclusions in sapphires from southwestern Montana. Dr. Palke and colleagues hypothesized that these sapphires crystallized as peritectic minerals during high-grade metamorphism that generated silica-rich melt and an alumina-rich restite. Future research on this topic may shed light on the source and transportation of Montana sapphires.

	Dr. Steven Shirey answers questions from the audience after his presentation. Photo by
	Tao Hsu/GIA.

	Phenomenal gems are especially interesting materials for scientific study. Dr. Keal Byrne and colleagues from the Smithsonian Institution investigated the luminesce of “chameleon” diamonds, which show an intriguing color-change response to temperature and/or light. Xiayang Lin from Pennsylvania State University discovered the microscopic surface feature that causes iridescence in natural quartz crystals from India.

Dr. Aaron Palke presents his research on unusual glassy inclusions found in Montana sapphires. Photo by Tao Hsu/GIA.

	Researchers also presented studies on American gem deposits. Dr. Michael Wise from the Smithsonian Institution presented his work on the hydrothermal emerald and hiddenite mined in the Hiddenite area of North Carolina. Yury I. Klyukin from Virginia Tech investigated the fluid evolution of the deposit at North American Emerald Minenear Hiddenite. Dr. William B. Simmons from Maine Mineral and Gem Museum shared the recent discovery of gem-quality pollucite in Mt. Mica pegmatite.

Presenters from the gemology oral session. Photo by Tao Hsu/GIA.

	GEMOLOGY POSTER SESSION

	The gemology poster session on Nov. 4 featured twelve posters. Although it was held on the final day of the conference, the session was very well attended. The flexibility of presentation time and format allowed for dynamic discussion between exhibitors and viewers.

The gemology poster session attracted considerable attention on the last day of the GSA conference. Photo by Tao Hsu/GIA.

	The posters covered a wide range of topics. GIA researchers displayed their studies on micro-diamonds, diamond defect formation, and low–pressure, high-temperature (LPHT) treatment of type Ia diamonds. Sarah Ostrye presented the GIA library’s rare book digitization project. Catherine McManus of Materialytics introduced her project on diamond origin determination using multivariate analysis of LIBS spectra. Gary S. Michelfelder from Missouri State University and coauthors presented their study on the origin of alluvial diamonds in the Coromandel area of Brazil.

	Sarah Ostrye from the GIA library presented the rare book digitization project. Photo by
	Cathy Jonathan/GIA.

	It was also impressive to see Chinese gemology students present their research on newly discovered gem corundum deposit in northeastern China and a color study on tanzanite. Topics and abstracts from the poster session can be found at https://gsa.confex.com/gsa/2015AM/web
	program/Session38771.html.

Dr. Rodney Ewing received the Mineralogical Society of America’s Roebling Award for his distinguished contributions to mineralogical research. Photo by Tao Hsu/GIA.

	In another highlight from the GSA meeting, Dr. Rodney C. Ewing, a professor of geological and environmental sciences at Stanford University, received the Mineralogical Society of America’s Roebling Medal. Dr. Ewing has served on GIA’s board of governors for nine years, providing insightful guidance on research activities and nurturing the institute’s postdoctoral program.

The 2016 GSA conference will be held in Denver and will once again communicate high-quality gemological research to the geoscience world. Photo by Tao Hsu/GIA.

	Since their inception at the 2013 GSA meeting, the gemology technical sessions have provided a broader stage to share important research findings with other scientists. The 2016 GSA annual meeting will be held in Denver, and the gemology session organizers will start work on it soon. Source: GIA @topic:7


Title: Yellow Sapphire Filled with Lead Glass Abstract: Figure 1. This 4.27 ct sapphire was filled with orangy yellow lead glass throughout the stone. Photo by Gagan Choudhary; courtesy of Dheeraj Gupta.

              This contributor has previously reported glass-filled, color-changing red and blue corundum (Spring 2008 GNI, pp. 88–89). After recent reports of green sapphire filled with lead glass (Fall 2013 Lab Notes, p. 176) and sapphires with cobalt-colored lead glass (e.g., T. Leelawatanasuk et al., “Cobalt-doped glass-filled sapphire; an update,” Australian Gemmologist, Vol. 25, No. 1, 2013, pp. 14–20), an orangy yellow sapphire filled with lead glass was presented to us by Dheeraj Gupta (Gem & Jewellery Sales Promotion Council, New Delhi).

The 4.27 ct sapphire (figure 1) was hazy throughout, with a roiled effect reminiscent of hessonite, but standard gemological properties and microscopic analysis identified the specimen as natural corundum. It gave an RI of 1.762–1.770; a hydrostatic SG of 4.03; an absorption band at around 450 nm, along with fine lines in the red end under the desk-model spectroscope; and reddish orange fluorescence in long- and short-wave UV. The sapphire showed stronger fluorescence under long-wave UV. Microscopic examination revealed numerous low-relief cracks throughout the stone with a distinct flash effect. Also visible were trapped, flattened gas bubbles, as seen in figure 2, and whitish cloudy patches; these are typically associated with filled stones. Also present were milky zones consisting of fine discs (usually rutile) and negative crystals associated with liquid films. Under diffused lighting, the glass-filled fractures appeared orangy yellow against the pale yellow bodycolor of the stone (again, see figure 2). As a result, the face-up color also appeared orangy yellow. The color of the filler glass was similar to that observed in glass-filled rubies. The lead content of the glass was further confirmed by EDXRF analysis, while the presence of iron (the cause of the sapphire’s yellow color) was confirmed by an Fe-related 450 nm band in the UV-visible spectrum.

	Figure 2. The color of glass-filled fractures appeared orangy yellow against the sapphire’s pale yellow bodycolor; thus, the face-up color also appeared orangy yellow. Note the spherical bubbles trapped within the fractures. Also present were flattened bubbles and a typical flash effect (not shown here). Photomicrograph by Gagan Choudhary, magnified 32×.
Since this was first example of lead-glass-filled yellow sapphire examined by this contributor, its market penetration is still unknown. With its transparency and color, this material qualifies as an inexpensive substitute for yellow sapphire, provided there is complete disclosure. Source: GIA @topic:3


Title: Tucson, Centurion Upbeat, But Caution Remains Abstract: Diamond manufacturers are making profits again after more than two years of struggling with high-priced rough and depressed polished prices. SAFDICO in South Africa specializes is larger diamonds, which were less affected by the rough-polished price squeeze. Photo by Russell Shor/GIA

	Business at the February Centurion show in Scottsdale, Arizona, geared mainly to higher end independent retailers, was generally good according to attendee reports. The exceptions were retailers from states where the economies depend on the oil business. Demand for gemstones at Tucson reportedly was decent and in line with expectations, so the mood was generally good, according to exhibitors.

	The outlook remains cautious, however, as major jewelry retailers are forecasting little to no sales growth for 2016 in the U.S. and a slight decline in other major consumer centers.

	U.S. retail jewelry sales were up about 2% from 2015, according to the U.S. Bureau of Economic Analysis. Sales of retail jewelry at specialty stores, i.e. retail jewelers, were up 3.6% year-on-year, probably reflecting stronger business at the higher end. In addition, year-on-year revenue comparisons are compromised by the fact that diamonds and gold were significantly lower in price in 2015 than the previous year.

	The e-commerce diamond retailer Blue Nile, for example, reported its worst year ever: sales down 5% from the holiday season, mainly because its core engagement ring business was down 8%. The company did note, however, that unit prices were lower and profit margins actually rose slightly on the year. The company also reported fewer sales over $25,000, which may reflect the difficulties of oil-dependent regions or a trend back to brick-and-mortar for high-ticket pieces.

	The decent sell-through in the U.S. market absorbed a lot of excess inventory and helped revitalize diamond manufacturing, which nearly came to a halt at the end of 2015. Bankers and diamond analysts have cautioned that manufacturers may be resuming the speculative buying that caused a bubble several years ago, however, bank credit remains extremely tight, which will restrict such buying on a long-term basis.

	Diamond manufacturers have apparently found De Beers’ price reduction sufficient to make a profit. Prices came down an average of 7% at the January sight and the side deals made at the same time, but many categories of goods were discounted 12% to 15%. The sight was about $450 million, with side deals adding about $90 million to the total.

	What was extraordinary about this sight was that, for the first time in its history, the company announced its monthly sales volume. This is apparently the first step in what De Beers claims will be a “major restructuring of its global sightholder system” for the sight term that will begin next year.

	De Beers' second sight of the year is this week.

	The company’s rough sales fell 40% to 20.6 million carats in 2015, while production fell 12% to 28.7 million carats. The deepest production cuts, 16%, were in Botswana’s operations, which supplies about two-thirds of the company’s output.

	Alrosa, the Russian diamond producer, reportedly doubled the quantities of rough diamonds from its December sales to match De Beers’ total. Alrosa apparently did not lower prices in January like De Beers, but the company had been selling comparable goods for a few percentage points less at its offerings over the past two years. Alrosa has continued to mine diamonds at the same rate, but has stockpiled some $3 billion worth with the central government stockpile, Gokhran.

	Although De Beers and Alrosa gave clients the right to defer their purchases (up to 50% for De Beers and 70% for Alrosa), indications are that few clients did so.

	Globally, LVMH, the luxury group that operates the De Beers stores and Bulgari, as well as the prestige watch brands Hublot and TAG Heuer, reported that its watch and jewelry sales rose 19% in 2015, led by Bulgari and TAG Heuer. Source: GIA @topic:8


Title: Laminated Tortoiseshell Scepter Abstract: Figure 1. This tortoiseshell scepter is from the Palais Royal collection. Photo by Tony Leung.

	“Tortoiseshell” generally refers to a material produced from the shell of the hawksbill sea turtle (T. Hainschwang and L. Leggio, “The characterization of tortoise shell and its imitations,” Spring 2006 G&G, pp. 36–52). Because of its attractive appearance, durability, and thermoplasticity, it had been widely used for jewelry, personal items, and ornamental objects since ancient times, until the international trade of new tortoiseshell was banned in the 1970s under the Convention on International Trade in Endangered Species (www.cites.org). Today, this material is seldom submitted to gemological laboratories.

	Recently, a mottled brownish orange scepter measuring 203.00 × 41.45 × 42.52 mm was submitted to GIA’s Hong Kong laboratory (figure 1). The object was adorned with white metal and numerous stones of various shapes and colors.

	Standard gemological testing revealed an RI of 1.56. In addition to the orange bodycolor with distinctive brown patches and resinous luster, the strong odor of burned protein given in hot point testing ruled out most inorganic and organic materials except the keratinous materials tortoiseshell and horn. Under magnification, the piece showed a layered structure and mottled color patches made up of numerous brownish dots of pigment (figure 2), both typical of tortoiseshell. The only remaining question was the thickness of the piece, which at 42.52 mm far exceeded tortoiseshell’s maximum thickness of 9–12 mm (Hainschwang and Leggio, 2006). The orange part of the scepter exhibited a strong blue reaction to long-wave UV radiation, with a wavy layered structure and distinct boundaries (figure 3, left), and a weaker reaction to short-wave UV. The brown patches were inert to both long-wave and short-wave UV. Taking into account the piece’s exceptional thickness and the unusual structural discontinuities observed under UV source, we concluded this material was laminated tortoiseshell.

	Figure 2. The brown patches in the tortoiseshell scepter were made up of numerous brownish spots. Photo by Xiaodan Jia; field of view 1.88 mm.

	Figure 3. Left: Under long-wave UV, the scepter showed disordered wavy layers of various thickness and boundary layers marked by structural discontinuities. Right: A natural tortoiseshell tablet displays a parallel layered structure in side view. Field of view 19.27 mm. Photos by Johnny Leung (left) and Jonathan Muyal (right).

	Further analysis by FTIR on powdered samples collected at different layers showed a keratin spectrum with predominant amide peaks at 1637, 1516, and 1236 cm–1 (figure 4), which confirmed the material was tortoiseshell (Hainschwang and Leggio, 2006). High levels of S and Cl detected by EDXRF were also consistent with known tortoiseshell samples.

	Figure 4. FTIR spectra of the tortoiseshell displayed amide peaks at 1637, 1516, and 1236 cm–1. The spectrum on the right is a closer view of the region in the red box on the left. Source: GIA @topic:12


Title: Exhibition Review: Unique by Design at the Metropolitan Museum of Art Abstract: American artist Myra Mimlitsch-Gray’s Brass Knuckles, a ring composed of 24K gold over brass with brass charms, is one of the pieces exhibited in Unique by Design: Contemporary Jewelry in the Donna Schneier Collection.  Photo courtesy of the Metropolitan Museum of Art, Gift of Donna Schneier, 2007 (2007.384.38).

                      The Metropolitan Museum of Art’s exhibit of contemporary jewelry from the Donna Schneier Collection features an eclectic assembly of works from 88 designers in 19 countries that bridges the gap between art and jewelry. The exhibit, curated by Jane Adlin, includes over 130 pieces of contemporary jewelry. Located in the Lila Acheson Wallace Wing for Modern and Contemporary Art Design and Architecture, the show runs through Aug. 31, 2014.

Schneier’s collection documents the evolution of the studio art movement at a time of intense and diverse experimentation. The exhibition comprises many seminal art jewelry pieces, dating from the 1960s through the present, some of which are prominent in contemporary jewelry art books and well deserving of such display at the Met. The following are particularly worthy of mention: a silver, yellow gold, enamel, mother-of-pearl, ebony, and semi-precious gemstone necklace by Earl Pardon; a paper cord and canvas bib necklace and bracelet suite by Eugene and Hiroko Pijanowski; a diamond and PVC-laminated photograph brooch by Gijs Bakker; and a yellow gold, bezel-set emerald, chrysoprase, sapphire, lapis, and enamel square brooch by Hermann Junger.

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	Images from Unique by Design: Contemporary Jewelry in the Donna Schneier Collection
The exhibit’s museography is simple. The show is hosted in a square room, with the work of three artists highlighted on the back wall: David Watkins's minimalistic silver, steel, and acrylic geometric pieces; William Harper's gold, gemstone, and cloisonné enamel virtuosic numbers; and Thomas Gentille’s oversized eggshell, wood, and lacquer creations. The rest of the exhibit is split between seven themed vitrines, each allowing the visitor to observe objects from the front and the back.

The first window is dedicated to the Eugene and Hiroko Pijanowski suite. The second window presents a few selected “Gold” pieces. One of the most notable is the Mary Lee Hu Choker # 70, a magnificent woven necklace which assembles 20 kite-shaped motifs. With these magnificent gold pieces, the exhibition starts with strong, prominent jewelry. The third window's theme, revolving around “Minimalism,” includes the aforementioned diamond brooch by Gijs Bakker and a delicate translucent acrylic cuff bracelet by Emily Van Lersum. Of utmost interest for the gemologist is a silver and mica chain by Joan Parcher. This chain, made of pierced circular mica links, remains a lapidary enigma: How to carve mica, one of the most fragile gem materials? This fascinating display revisits the perception of value by using non-precious material, demonstrating that craftsmanship and design may be more important than the value of the material used.

The fourth group challenges the usual notion of scale displays “Maximal” pieces. One of the most impressive examples featured is an oversized silver, yellow gold, and garnet heart brooch by Lola Brooks. The fifth vitrine assembles jewels with a “Narrative” quality. The most striking, a breastplate by Kiff Slemmons made of silver, No. 2 pencils, stone, horsehair, coins, and leather, is reminiscent of a Native American trophy neckpiece. The sixth column is filled with “Found and Parodied Objects.” One of the most illustrative items in this ensemble is a gold-plated silver, plastic polymer, and found-objects necklace by Helen Britton. The last vitrine presents “Sculptural” jewelry. This extremely diverse group, comprised mainly of brooches, clearly highlights a parallel between sculpture, architecture, and jewelry. Georg Dobler's steel wire and black chrome geometric lattice brooch provides an emblematic example.

For jewelry enthusiasts, students, and modern art amateurs, the Schneier collection is a must-see exhibition that displays the endless variety of art studio jewelry. The impressive collection would certainly have benefited from a more detailed and didactic museography to help the visitor appreciate the originality and quality of the items displayed. Who better than the Met could draw enlightening parallels between the antique, Viennese School, and Art Deco inspirations? One could only lament that jewelry exhibitions in general provide little explanation on how these works of art are inspired and produced. The magnificence and significance of this ensemble may not be fully appreciated, as the visitor leaves the Met with no documentation related to the show. Jewelry collections, even contemporary ones, require more historical and cultural background materials to convert art amateurs into avid jewelry collectors. Source: GIA @topic:6


Title: De Beers Eases Prices Slightly, But Retailers Stand Firm Abstract: De Beers headquarters is located at 17 Charterhouse St., London. Photo by Russell Shor/GIA.

	De Beers’ June 10-14 sight totaled about $585 million – nearly the same as May – with slightly lower prices by 2-3% on some categories of rough, mainly those that would polish out in the range of a quarter carat to 10 points. A number of sightholders refused these goods last month because they are more expensive than the resulting polished stone would realize in the market. The small price decrease did not enable manufacturers to turn a profit, so several clients again refused to take these goods.

	De Beers’ clients, both manufacturers and rough dealers, bristled at the May price increase, which averaged just over 5%, because polished prices had been softening for several months, squeezing profitability. Dealers reportedly took a 3% or 4% loss on sight goods in May. They estimate this sight may break-even.

	Polished prices have remained stable under extreme pressure because retailers in the U.S. and around the world have pushed hard against any attempt to raise them.

Las Vegas: After slow business at the Hong Kong and Basel fairs, Las Vegas offered some relief to diamond dealers and jewelry manufacturers, but prices remained static. A combination of a reviving economy in the U.S., a sharp decline in the price of gold and the low inventories of many U.S. retailers contributed to a better than expected show for many exhibitors.

	Exhibitors at the high end Couture and Luxury shows reported strong business, but business was less consistently good in the main part of the show, particularly in the competitive area of the diamond pavilion and AGTA Gem Show.

	Diamond people generally reported good demand, though many deals fell apart over price. Exhibitors who raised prices before the show met with strong resistance from buyers and intense competition from those who kept prices steady. Retailers are not willing to pay higher prices, especially when many of them, especially in the U.S., fill a portion of their diamond needs from second-hand sources at much lower prices. In addition, diamond companies have to bear the cost of holding higher inventories because the banks have been aggressively cracking down on memo deals and long payment terms that, at their peak, accounted for as much as 70% of U.S. diamond wholesale business.

	The India diamond industry is dealing with profit drains because of the deterioration of the rupee exchange rate against the dollar, effectively raising rough prices (which are traded in dollars). The rupee hit a record low of 59 ($1) on June 12, a loss of about 10% in the past six weeks.

	Colored gemstone demand in Las Vegas was quite strong with many dealers showing high-end pieces they had previously reserved for Basel or Hong Kong.

	Exhibitors at the American Gem Trade Association pavilion noted that jewelry designers were looking for stones that would complement this year’s colorful fashion looks. Emeralds were particularly strong as was fancy color sapphire, untreated or only heat treated.

	On the main floor, designers were creating bolder colored looks from large pieces of malachite, lapis and other inexpensive, opaque material. Amethyst and citrine were also popular for the same reason.

	Exhibitors were also showing much more reconditioned second hand pieces, noting that they have become popular and are not items easily found on the Internet. Source: GIA @topic:8


Title: Radioactive Irradiated Spodumene Abstract: During routine testing, a parcel of spodumene imported from Brazil was found to be radioactive. Detailed analysis showed that individual stones had levels of gamma ray emission far above those acceptable for jewelry purposes. Gamma ray spectroscopy revealed that they had been irradiated with neutrons. The colors of these stones are similar to those observed in citrine and have no counterpart in untreated spodumene. They range from brownish orange through orange to orange-yellow and greenish yellow. Source: GIA @topic:3


Title: The Young Generation: Tom + Jutta Munsteiner Abstract: With this remarkable bilingual volume, Wilhem Lindemann presents the works of husband and wife Tom and Jutta Munsteiner, master gem cutters and jewelers. Second-generation gem cutter Tom Munsteiner followed in his father’s footsteps. Beginning in the 1960s and continuing through the mid-1990s, Bernd Munsteiner reinvented gemstone cutting with his unique edged, multifaceted gem carvings. Working near Idar-Oberstein, the mecca of the German lapidary and colored stone trades, he cut an abundance of “rediscovered” gemstones from Brazil’s pegmatites, particularly tourmalines, aquamarines, amethysts, quartzes, and topazes.
Tom and Jutta Munsteiner were classically trained as apprentices after showing early artistic promise. Today, they exhibit at venues such as the Tucson, Las Vegas, and Basel shows. Visiting the couple’s booth, one can only be struck by the strength and originality of their creations. Whether gem carving or sculpture, each work exhibits a fine combination of jewelry and art.
In the first part of the book, Lindemann retraces the evolution of lapidary art, from late third millennium bc cylinder seals to contemporary art movements such as Bauhaus. Tom Munsteiner’s influences, dating as far back as the Romantic era, have inspired him to envision the entire crystal as a landscape, with its inclusions and flaws. He rejects traditional gem cuts such as the round brilliant, which focuses on the reflecting quality of a diamond and is far too complex for human sight. For this reason he adopted a cutting style that is asymmetrical, inviting the viewer’s attention inside the crystal rather than on its reflective qualities.
The next section takes the reader on an inspirational journey through the work of Tom Munsteiner, whose most memorable creations include “Magic Eye,” “Ritmo,” and “Spirit of Nature.” The “Magic Eye” pieces have a sphere carved into the back of the gems at the interface of their axes to produce reflections on the face. “Ritmo” features geometric notches on the reverse side that re-create random asymmetrical imaginary structures. Of particular interest to gemologists is the “Spirit of Nature” series of gem carvings, which accentuates the inclusions in a wide range of materials. Some of the most striking pieces are an oligoclase with red hematite platelets, an elongated aquamarine prism with a helicoidal inclusion running through the length of the gemstone, and rock crystal carvings displaying phantom crystals. This section is one of the book’s strongest.
The third part focuses on Jutta’s jewelry designs, which feature her husband’s gem carvings. Her inspiration features sinuous curves, as evidenced by the “Personalities” neckpiece series. The imposing “Jeanne d’Arc” necklace shows a ridged, elongated rutilated quartz mounted on a custom-made snake chain.
The fourth part illustrates Tom and Jutta’s collaboration through images of their classic jewelry, such as the “Twins” series of rings, each featuring an original gemstone carving paired with a diamond. They incorporated a proprietary round cut called “Spirit,” as well as the square “Context,” which resembles a modern French cut.
The photos exhibit a precision that complements the Munsteiners’ cutting style. The rendering of color has not been artificially enhanced, which is often a treacherous temptation. Captions generally mention the carat weight of the gemstones, which is important since neither scale nor dimension are indicated. Given the impressive size of certain objects, this information helps the reader appreciate the quality and craftsmanship involved. Numerous illustrations show the variation of cutting, within each series and from one series to another. The many photos serve to distinguish the couple’s respective pieces: Tom’s unique gem carvings and Jutta’s minimalist jewelry designed with a sharp, powerful style.
The text speaks to the Munsteiners’ inspiration, but also describes how the gems were cut—a helpful feature since some of the gems were cut from the back to create a sense of volume and depth. Without those details, such techniques would be difficult to comprehend.
This magnificent opus would have benefited from the Munsteiners’ original sketches, which would have made the volume livelier and more personal. Some basic technical explanation of cut and lapidary work, being the couple’s craft and expertise, would have also provided some foundation. But these criticisms are minor considering the quality of gemstones and illustrations presented.
The illuminating text and the striking originality and craftsmanship of the Munsteiners’ work make this volume a real treat for students, gemologists, gem cutters, and jewelry enthusiasts. It offers an incomparable insight into Europe’s contemporary and cutting-edge creations.
Reviewed by Delphine A. LeBlanc
Hoboken, New Jersey Source: GIA @topic:10


Title: Italian Precious Coral Abstract: Mediterranean coral from different regions. Left: Dark red fine coral from the northern coast of Sardinia. Center two pieces: “Classic” coral from the southern coast of Sardinia. Right: Orangy coral, termed “Sciacca,” from the coast of southern Sicily. Photo by Lisa Kennedy; courtesy of Fulvio Di Gennaro Srl.
Coral from the Mediterranean Sea has been harvested and used for adornments for thousands of years. More than 7,000 species are categorized as precious, common, or reef coral. Precious coral is defined by the World Jewellery Confederation (CIBJO) Coral Commission as “those that are used in jewelry and decoration, specifically red, pink, and white varieties with porcelain-like luster after polishing.” Italian coral harvested from the Corallium rubrum species is considered precious.
At the GJX show, the authors spoke with Sergio Di Gennaro of Fulvio Di Gennaro Srl. (Torre del Greco, Naples) about the Italian coral market. The Mediterranean has been precious coral’s major source since it was first collected for ornamentation over 3,000 years ago, followed by Taiwan and Japan with smaller quantities. Beginning in the late 1970s, Mediterranean coral was threatened by overharvesting. Di Gennaro explained that many strict regulations for harvesting coral are in place today. Harvesting is limited to coral with trunks having a basal diameter of at least 7 mm recovered from 50 meters or deeper by licensed scuba divers.
Precious coral is the exoskeleton of very tiny marine invertebrates, known as coral polyps. When a colony of polyps arrives in a particular area, they start to create the exoskeletons on rocks, growing upward in a branch-like or fan formation. Di Gennaro mentioned that divers do not harvest coral with active colonies as these will continue to grow and the future, larger coral will be more valuable. Divers therefore tend to harvest the coral where the colony has already left. Unlike other types of corals, such as common and reef, these Mediterranean “deep sea” precious corals are not a natural habitat for other marine species. Reef coral species, which are a natural environment to many different marine species, are in many cases endangered and must be preserved.
Di Gennaro explained that the quality of the coral depends on the locality. He showed us a piece of dark red coral (see above, left), which is the typical color of coral harvested from northern Sardinia. It is a darker red due to cooler water temperatures from strong currents in the area. Coral from the southern portion of Sardinia (see above, center) tends to be lighter in color. Di Gennaro described this as a more “classic” color of Mediterranean coral. He also showed us a piece of reddish orange coral called “Sciacca,” named for a town in southern Sicily where the coral is harvested (see above, right). Di Gennaro said that volcanic activity below the surface results in warmer water temperatures, which in turn causes a more orangy color.
Di Gennaro emphasized the importance of sustainability in the coral industry, noting the heritage of the city of Torre del Greco, which was built on the art of processing coral. While current restrictions have reduced the amount of coral being harvested compared to decades past, sustainable production will guarantee that we continue to see stunning Mediterranean precious coral for decades to come. Source: GIA @topic:5


Title: Emerald and Gold Treasures of the Spanish Galleon Nuestra Señora de Atocha Abstract: During the 1970s and 1980s, treasure hunters discovered the centuries-old remains of the sunken Spanish galleons Nuestra Señora de Atocha and Santa Margarita. Not only did they find massive amounts of silver and gold in coins, bars, and chains, but they also uncovered a number of rough emeralds and several pieces of emerald-set jewelry. Recently, some of the treasures recovered from the Atocha were examined at the Santa Monica office of the GIA Gem Trade Laboratory. Gemological testing of the emeralds revealed inclusions typical of stones mined in Colombia as well as possible evidence of extended submersion in seawater. Study of the jewelry revealed a high-karat gold content and fine workmanship that represented methods typical of the era. Source: GIA @topic:1