# Publication Year: 2014
# Title: Natural Pearls Reportedly from a Spondylus Species (“Thorny” Oyster)
# Abstract: Figure 1. Four non-nacreous pearls, weighing 12.40, 11.55, 8.22, and 5.72 ct (left to right), were submitted for identification. Photo by Sood Oil (Judy) Chia.

              Non-nacreous conch, clam, Melo melo, Cassis, and scallop pearls are often submitted to GIA for identification. Four non-nacreous pearls, weighing 5.72 to 12.40 ct and measuring from 9.55 × 8.60 mm to 16.35 × 9.36 mm, were recently submitted to GIA’s New York laboratory for identification. These examples caught our attention because of their unusual appearance (figure 1).

Their bodycolors and shapes varied. Each exhibited some degree of pink and orange hues, and either elongated or button shapes. The porcelaneous surfaces also exhibited areas with clear flame structures. Under fiber-optic light, fine flame structures resembling those seen in other porcelaneous pearls such as Tridacna gigas and Strombus gigas (conch) pearls were observed. While the typical whitish flame structure was readily apparent, the more notable observation was that some of the flames had a distinct blue coloration (figure 2). Other types of pearls usually do not show blue flames. Microradiography was of little diagnostic assistance, as only tight structures were observed; this is not unusual for porcelaneous pearls. Raman spectroscopy detected both aragonite and calcite separately on different parts of the samples. In the authors’ experience, this differs from conch or clam pearls, which are usually composed of aragonite only.

Figure 2. The porcelaneous surface appearances of two of the pearls, weighing 12.40 ct (left, magnified 20×) and 8.22 ct (right, magnified 10×) show their characteristic blue flames, indicated by the arrows. Photos by Joyce WingYan Ho.
Due to their unique shapes, colors, surface, and flame structures, we suspected these pearls were from one of the many Spondylus species (figure 3), commonly called “thorny” or “spiny” oysters. Although rarely encountered in GIA laboratories, Spondylus pearls have been documented in the past (Winter 1987 Lab Notes, p. 235; E. Strack, Pearls, Ruhle-Diebener-Verlag GmbH & Co., Stuttgart, 2006, p. 255), and some samples have been collected by the Qatar Museums Authority (H. Bari and D. Lam, Pearls, Skira Editore S.p.A, 2009, pp. 88–89). Our client later informed us that these specimens were found by a fisherman in shells of Spondylus princeps off the coast of Baja California, Mexico.

Figure 3. These shells are from various Spondylus species. Courtesy of GIA’s Bangkok laboratory. Photo by Nuttapol Kitdee.
This was a rare opportunity to see natural pearls from a known Spondylus species, and to document their unique gemological characteristics as references for mollusk identification in the future. @chapter:11 @chapter:4 @chapter:11


# Publication Year: 2015
# Title: CVD Synthetic Diamond with Unstable Color Centers
# Abstract: Figure 1. Left: These growth planes were observed in a CVD synthetic diamond; fine pinpoints were found along the growth planes. Photomicrograph by Meenakshi Chauhan; magnified 30×. Right: Pinpoints along the growth plane were also visible from the table. Photomicrograph by Meenakshi Chauhan; magnified 10×.

The Indian Gemological Institute – Gem Testing Laboratory, New Delhi recently examined a 1.42 ct (7.06–7.08 × 4.49 mm) round brilliant. Viewed perpendicular to the pavilion facets with its table down, the sample displayed a grayish yellow color, but a slight rotation changed the color to pinkish. On viewing the specimen parallel to the direction of the growth planes, the sample appeared grayish yellow; viewing perpendicular to these same planes, the sample appeared pinkish.

Infrared spectroscopy showed features typical for type IIa diamond. Magnification revealed no internal features except for a feather on the girdle and the two growth planes, which appeared textured. There are very fine pinpoint-like inclusions lying just along the planes (figure 1, left). These planes of pinpoints were also visible from the table (figure 1, right). Examined in the DiamondView (using less than 225 nm short-wave UV radiation) to reveal its growth patterns, the round brilliant showed parallel striations indicative of CVD growth (figure 2). It also exhibited moderate phosphorescence under the UV lamp for approximately 20–25 seconds. (figure 2, inset), confirming synthesis by a CVD process.

Figure 2. In the DiamondView, the 1.42 ct round showed striations typical of CVD growth. Notice the two parallel planes fluorescing stronger than the bulk of the crystal. The sample also showed moderate phosphorescence (inset), another indication of CVD growth. Images by Meenakshi Chauhan.
Upon removal from the DiamondView after approximately two minutes of exposure time, it showed a distinct grayish blue color. After exposure to a 100-watt halogen bulb for about three minutes, the synthetic diamond regained its initial color (figure 3).

Figure 3. The CVD synthetic diamond before (left) and after exposure (right) to the
short-wave UV radiation of the DiamondView. Photos by Meenakshi Chauhan.
This process was repeated, and the sample turned a grayish blue color after a single minute of exposure to the short-wave UV radiation of the DiamondView and regained its initial color in approximately one minute under the halogen light.

UV exposure produced unstable color centers in this CVD synthetic diamond, which gave it a grayish blue color. Heat removed the color centers, restoring the CVD synthetic diamond to its initial grayish yellow color. @chapter:9 @chapter:1 @chapter:9


# Publication Year: 2016
# Title: Turquoise with Simulated Matrix
# Abstract: Figure 1. A 78.60 ct greenish blue turquoise oval bead with
artificial metallic pyrite. The turquoise was filled with a mixture of crushed pyrite and polymer. Photo by C.D. Mengason.

	The Carlsbad laboratory recently examined a 78.60 ct greenish blue oval bead with patches that contained fragments of a metallic material in dark matrix (figure 1). Standard gemological testing of the greenish blue areas showed properties consistent with turquoise, including a refractive index of 1.60. Microscopic observations revealed the typical visual characteristics of turquoise: blue and white mottling, a granular texture, and a waxy luster with no evidence of dye. Raman analysis confirmed the metallic material was pyrite, and infrared spectroscopy indicated the greenish blue material was turquoise.

	Upon closer investigation using a standard gemological microscope, it became clear that the pyrite was composed of irregular and angular broken fragments suspended in a fine-grained black matrix. In addition, each dark patch displayed well-defined boundaries with hemispherical voids, presumably gas bubbles that had been cut through during polishing. Interestingly, one patch showed a discontinuity between two different shades of color and textures of the pyrite in black matrix (figure 2). Based on our observations, we believe these patches were formed by filling the cavities of the turquoise with a mixture of crushed pyrite crystals and a type of polymer resin. The treatment might have involved one or more filling episodes, which could explain the discontinuity seen in one of the patches. The filled turquoise was later polished into the finished product we observed.

	Figure 2. Closer magnification revealed crushed pyrite crystals, voids left behind from gas bubbles, and a discontinuity between two episodes of filling. Photo by Rebecca Tsang and Nathan Renfro; field of view 4.02 mm.

	In the past, we have seen a variety of treatments for turquoise, but this was the first example of an artificial pyrite-containing matrix examined at the Carlsbad laboratory. @chapter:24 @chapter:0 @chapter:24


# Publication Year: -
# Title: Leaf Motifs: Timeless Beauty for All Seasons of Jewelry
# Abstract: Combine emeralds and gold with the sophisticated design of Cartier and voilà − earrings of timeless beauty. Courtesy of a private collector. Photo by Tino Hammid/Copyright GIA and Tino Hammid

	Infused with inspiration, the commonplace becomes extraordinary. The humble leaf, for example – from the simple shapes of some to the complex web of veins in others – has captivated artists, including jewelry designers, for centuries. The simple leaf has transformed into enduring beauty throughout the periods of jewelry history.

	Leaves hold symbolism in many cultures, but in general, they symbolize fertility and growth. The green leaves of spring and summer depict hope, renewal and revival. Blazing yellow, orange and red leaves of fall represent the change of season. Ultimately, fallen leaves complete the circle of life with the final stages: decline and death.

	In the Chinese tradition, leaves represent all of the beings in the universe; they collectively allude to people because of their vast number.

	In heraldic coat of arms, leaves represent different virtues or qualities. For example, oak leaves represent strength, heroism and victory. Grape leaves represent plenty, freedom and rebirth. Holly or mistletoe represents truth, foresight and defense.

	The olive branch, a symbol of peace and goodwill in Western culture, originated in Ancient Greece, where it was used to form a crown as the prize for the winner at the Olympic games. Laurel leaves were also woven into a wreath to honor heroes, scholars and poets. The symbolic importance of laurel has been passed down to modern times in a number of ways. It is the source of the words baccalaureate, poet laureate and Nobel laureate, derived directly from the practice of bestowing a laurel garland for a notable achievement.

	The creativity in the jewelry seen here shows no indication of the designer or jeweler "resting on their laurels.”

View Gallery

	Leaves are seen as both accent and focal points in Victorian, Art Nouveau and 20th century jewelry. The Renaissance inspired the early Victorian era with flowers, branches, leaves, grapes and berries dominating the design motifs. The Art Nouveau period saw a resurgence of enameling, a metal technique that lends itself to the free-flowing lines of flowers and leaves.

	The leaf motif flourishes in the 20th century designs of Tiffany & Co., Cartier, Schlumberger and René Boivin − and is sure to remain a favorite on its perennial journey through history. @chapter:25 @chapter:2 @chapter:25


# Publication Year: 2015
# Title: Visible Absorption Spectra of Colored Diamonds
# Abstract: ABSTRACT
Diamond color is usually the result of selective absorption of incident white light. The unabsorbed portion of this light is transmitted through the diamond and is interpreted by the human vision system as the perceived color. The spectroscope allows a gemologist to observe some of the more intense and narrower absorptions in the visible spectrum of diamond as dark bands at specific wavelengths. Yet the broader regions of absorption, which can be difficult to observe with the spectroscope, often have a greater influence on a diamond’s color. A chart has been prepared to illustrate the visible spectra of various colored diamonds as recorded at low (liquid-nitrogen) temperatures with a spectrophotometer. The chart shows how similar diamond colors can result from different light absorption patterns. In 2013, the authors published a simple chart listing the major optical defects that can occur at the atomic lattice level in diamond (Shigley and Breeding, 2013). The chart presented some basic information on those defects, including the ones responsible for the colors and ultraviolet fluorescence reactions of most diamonds. The brief article that accompanied the chart discussed the ongoing challenge presented by the identification of natural, treated, and synthetic diamonds. It also discussed how spectroscopy techniques, used to detect absorption and/or emission bands caused by those optical defects, play a leading role in making this important determination. GIA’s laboratory staff, which has the opportunity to examine a large number of colored diamonds, faces this identification challenge on a daily basis.
A theoretically pure and defect-free diamond would be completely colorless, and a unique attribute would be its transparency (or lack of light absorption) across a wide portion of the electromagnetic spectrum from the ultraviolet through the visible and into the infrared regions. There are, however, intrinsic absorption features in the spectra of all actual diamonds. As discussed in our 2013 article, most diamonds also contain lattice defects which, in sufficient concentrations, can produce selective absorption of incident light. (In these instances, the lattice defects are often referred to as optical defects.) When white light strikes a polished diamond, some of the light is reflected, while the rest enters the diamond where it is refracted and dispersed based on wavelength. Some of the light energies (i.e., wavelengths) are absorbed by the defects, while the unabsorbed wavelengths are transmitted. When they exit the diamond, these transmitted wavelengths in combination can create the sensation of color in the human vision system (figure 1). Visible absorption spectroscopy is the analytical tool for understanding most causes of diamond coloration.

Figure 1. In most cases, transparent gemstones owe their color to selective absorption of light. In the case of a yellow diamond, the blue portions of the incident white light are absorbed by the diamond, while the remaining portions in combination are transmitted to the eye and interpreted by our vision system as a yellow color. In the spectroscope, this selective absorption is seen as a darkening toward the blue end of the spectrum (below 425 nm). Recording the spectrum with a spectrophotometer produces a graph of wavelength (horizontal scale) versus absorption (vertical scale). Greater absorption is represented by the higher portions of the spectrum trace, and greater transmission by the lower portions. Below 425 nm, the height of the spectrum trace increases. In the case of this yellow diamond, superimposed on this increasing absorption are several sharp absorption bands or peaks on the spectrum trace between 415 and 478 nm due to the N3 optical center. Gemologists often refer to this set of dark bands as the “Cape” absorption lines characteristic of type Ia yellow diamonds.
At GIA’s laboratory, visible spectra of diamonds are recorded with a spectrophotometer. Since diamond is optically isotropic, the same spectrum can be recorded in any direction through the sample. The faceted stone can be positioned in any orientation as long as the light transmitted through it is sufficient to reach the instrument’s detector. The gem’s shape and facet arrangement can make this a challenge, though. The best positions are those where the light travels directly from the table facet to the culet, or across the diamond through the opposing girdle facets. The diamond is held in a cryogenic unit and cooled to low temperatures with liquid nitrogen. Removing heat from the sample produces a less noisy spectrum. Under these conditions, absorption features that result from certain optical defects are stronger and sharper. Data collection conditions are selected to produce a spectrum that extends from about 350 to 800 nanometers (nm).

Because of a polished diamond’s high refractive index, light can be internally refracted a number of times within it, so the total distance traveled cannot be directly measured or calculated. This uncertainty makes it difficult to relate the strength of the light absorption (as recorded by the spectrophotometer) to the path length of light traveled within the gemstone. Yet this relationship can be estimated by comparing absorption peak height to the heights of some intrinsic absorption features. This relationship also provides an indirect way of comparing the visible spectra of diamonds of different sizes and faceting styles. Because of internal reflection and longer path lengths within the polished diamond, the face-up saturation of the color may appear stronger than the intensity of the absorption features (i.e., height of the absorption bands) in the visible spectrum would suggest.

Natural diamonds occur in all colors of the spectrum. A few colors, such as yellow and brown, are very common, but most are very rare. Nitrogen is the most widespread and abundant impurity element in diamond. It can be present in several optical defects, all of which produce absorption toward the blue end of the spectrum. These factors help explain the prevalence of yellow diamonds in nature. While the face-up appearance of colored diamonds is also influenced by their size and the choice of faceting style, visible absorption spectra provide a tool to understand most causes of diamond coloration.

The accompanying chart representative visible spectra and photos of the major color categories of diamond. The spectra are shown over the 400–750 nm wavelength range. Relative absorption is shown on the vertical scale of each graph, with light absorption increasing higher on the scale (and, conversely, light transmission increasing lower on the scale). Thus, the lower portion of each graph represents the transmitted portion of the spectrum that creates the material’s color sensation. The chart summarizes the major categories of colored diamonds; it is not intended as a detailed discussion of diamond coloration. The graphs are grouped in columns and ranked in descending order of frequency. The colored diamonds included in the chart were selected because their spectra (and color) are principally the result of one main lattice defect. As discussed in our 2013 article, the cause of some defects is well understood, while others are not. We occasionally encounter unusual colors in diamonds whose visible spectra do not correspond to any of the categories shown on the chart.

Download a Larger Version of this Visible Absorption Spectra Chart
The information presented on the chart suggests several observations:

In most cases, diamond colors result from different absorption spectrum patterns, with each pattern originating from one or more optical defects. This can be seen for the different yellow diamonds shown in the first column.
Broad and intense spectral absorption features are more important in producing various colors than sharp or weak bands. Conversely, sharp absorption bands (such as the N3 observed at 415 nm, H4 at 496 nm, and H3 at 503 nm) that can be seen using the spectroscope are helpful in gem identification. We used a spectrophotometer to record the visible spectra, as it can better capture broad absorption bands that are difficult or impossible to see with the eye through a spectroscope.
Similar diamond colors can result from different absorption spectra patterns. In other words, since perceived color is a combination of the wavelengths transmitted to the eye, different absorption patterns can produce similar colors. For example, type Ia and type Ib diamonds, which have different visible spectra patterns, can both exhibit a yellow color (although the color is usually more intense for the latter).
Some diamond colors are the result of just one optical defect, while others result from more than one defect. For example, the chart indicates that the GR1 defect can create a blue or a green color. The defect alone produces a blue color, but when there is also absorption toward the blue end of the spectrum due to nitrogen impurities, the resulting color is green.
Some diamond colors are simply the result of selective light absorption, while others stem from a combination of light absorption and light emission (or luminescence). For example, certain greenish yellow diamonds are yellow due to absorption, while the green component is due to luminescence.
Variations in the types of optical defects, and in their relative concentrations, produce slight color variations among similar diamonds.
Where a diamond photo is shown without an accompanying visible spectrum, the color is due to physical causes other than light absorption—most often the presence of mineral inclusions (e.g., numerous graphite inclusions causing black color in natural diamonds).

This chart is intended as a simple reference for those interested in understanding diamond coloration. While the visible spectra of diamonds are often presented in the gemological literature, compilations of spectra are rarely encountered. @chapter:22 @chapter:1 @chapter:22


# Publication Year: -
# Title: New Tool for Diamond Appearance Research
# Abstract: The L-Box™ can be used to compare the appearance of two or more diamonds, or fitted with a camera to capture a series of photos while the objects are moving. The images can be combined to build a high-resolution or 3D movie. Download PDF to view. @chapter:41 @chapter:1 @chapter:41


# Publication Year: -
# Title: Winter 2010 G&G Book Reviews
# Abstract: “Blood on the Stone: Greed, Corruption, and War in the Global Diamond Trade”
By Ian Smillie, 252 pp., publ. by Anthem Press [www.anthempress.com], London, 2010. US$29.95

“Jewellery in the Age of Queen Victoria: A Mirror to the World”
By Charlotte Gere and Judy Rudoe, 552 pp., illus., publ. by The British Museum Press [www.britishmuseumshoponline.org], London, 2010. £50.00

“Amethyst Uruguay”
By Reinhard Balzer, 304 pp., illus., publ. by Christian Weise Verlag [www.lapis.de], Munich, 2009. US$65

“The Fancy Color Diamond Book: Facts & Secrets of Trading in Rarities”
By Eden Rachminov, 231 pp., illus., publ. by Diamond Odyssey [www.diamondodyssey.org], Tel Aviv, 2009. US$215.00

“Agates and Jaspers”
By Ron Gibbs, 239 pp., illus., publ. by theimage.com [www.theimagebooks.com], Wedington, NC, 2009, US$40.00

“Minerals & Precious Stones of Brazil”
By Carlos Cornejo and Andrea Bartorelli, 704 pp., illus., publ. by Solaris [www.solariseditora.com.br], São Paulo, Brazil, 2010, R$148.00

To view the full section, download the PDF above. @chapter:38 @chapter:2 @chapter:38


# Publication Year: 2022
# Title: Old Techniques Reimagined: Maki-e Pearls
# Abstract: Figure 1. An inrō dating back to eighteenth-century Japan with gold maki-e and mother-of-pearl inlay. Courtesy of Getty Images.
At the AGTA show, Eliko Pearl (New York) exhibited a series of unusual cultured pearls, many of which were worked after culturing to create unique pieces of art. Among these, maki-e pearls caught the authors’ attention.
Maki-e is an ancient Japanese lacquer technique that translates to “sprinkled picture” and is said to have originated more than 1,200 years ago. A fine brush is used to paint a design with lacquer, which is then sprinkled with gold powder before the lacquer dries. More lacquer may then be painted again over the design and polished. For centuries, the meticulous technique has been used to decorate screens, inrō (a type of small case worn in traditional Japanese culture; figure 1), Japanese letter boxes, and other vessels, and it has now been adapted for use on pearls.
A representative from Eliko Pearl explained that each pearl is decorated by hand using a combination of urushi lacquer and 24K gold powder overlay, with abalone shell inlay (figure 2). The natural lacquer is derived from the sap of the urushi tree, which is native to Japan, China, Vietnam, and Southeast Asia. Sap can be harvested from a single tree for 14 to 15 years, during which the tree only yields about 200 grams of material. The sap also goes through a lengthy treatment process before it can be used as a lacquer. After application, the urushi lacquer must cure in a high-humidity environment (70–90%) in a series of thin layers. The time-consuming and laborious process of harvesting, processing, and applying the lacquer on pearls makes urushi lacquer a costly material, but the finished maki-e pearl is a treasured piece of art.

Figure 2. A pair of Tahitian pearls decorated with 24K gold maki-e and abalone shell inlay (left). A single near-round Tahitian pearl, decorated by the same technique in a flower motif (right). Photos by Emily Lane; courtesy of Eliko Pearl.
The décor adorns Tahitian pearls predominantly and can be found on matching pairs as well as single pieces. Prices vary from piece to piece based on the detail of the design and the size and shape of the pearl, with the most expensive shape being round (figure 3).

Figure 3. Trays of Tahitian maki-e pearls offered by Eliko Pearl at the 2022 AGTA show in Tucson. Available in a range of sizes in matching pairs and single pieces. Photo by Lisa Kennedy; courtesy of Eliko Pearl. @chapter:56 @chapter:4 @chapter:56


# Publication Year: 1989
# Title: Summer 1989 Gem News International
# Abstract: Diamonds
            Companies Vie for Angola Diamond Rights
            Australian Diamonds
            Diamonds from China
            Deep Space Diamonds
Colored Stones
            Visual Representation of Amethyst to Citrine Alteration
            Aquamarine Found in Wyoming
            Colored Stone Update from China
            Tunnels Used to Mine Emeralds at Muzo
            Hackmanite: A Remarkable Variety of Sodalite
            Australia's Opal Industry Crippled
            A Significant Find of Mexican Quartz
            Rose Quartz from Connecticut
            Blue Sapphires from Kenya
            Sapphire in Ontario
            An Interesting Zoned Australian Sapphire
            "Padparadscha" Sapphire
            Large Tourmaline Pocket Discovered at the Himalaya mine
Pearls
            Two Remarkable Natural Freshwater Pink Pearls from Texas
Synthetics and Simulants
            "Bull's-Eye" Optic Figure in Synthetic Berlinite
            An Unusual Ceramic Cameo
            A Clever Imitation Emerald Crystal
            Chatham Expands
            Union Carbide Growing Large Synthetic Sapphires
Announcements
            New Museum Opens in Brazil
            Gemmological Association of Israel is Formed
            Zambian Trade Association
            Jewelry Manufacturing Symposium
            KOSIMA ’89 in Greece
            FIT Symposium Announced
            Mineralogical Society of Southern California

To view the full section, download the PDF above. @chapter:21 @chapter:0 @chapter:21


# Publication Year: 2017
# Title: Oiled Ruby: A Remarkable Visual
# Abstract: The red color of the oil within the cavity of a ruby displays a remarkable contrast with the bodycolor of the gem. Unlike the flattened bubbles regularly encountered, a rounded bubble attests to the size of the cavity containing the oil. Photo micrograph by E. Billie Hughes; field of view approximately 2.5 mm.

As laboratory gemologists working in Bangkok, we often encounter gems that have been treated with oil to minimize the appearance of fissures. Most of these  stones come from Myanmar, where many vendors consider oiling an accepted standard procedure to enhance their goods, particularly ruby and spinel (http://www.lotusgemology.com/index.
php/library/articles/315-lotus- gemology-lab-alertfor-oiled-gems). Furthermore, red oil is commonly used not only to improve clarity, but also to enhance the color of the stone (in Chanthaburi, Thailand, it is sold under the brand name “King Ruby Red Oil”). Often this treatment can be identified by flattened gas bubbles in the fissures or by droplets of oil seeping out of the fissures on the surface when the stone is gently warmed by microscope light or hot point.

The image above shows a small surface-reaching cavity filled with oil in an unheated 1.75 ct ruby from Myanmar. Unlike other examples we have seen, this remarkable gem contained enough of the filler to easily photograph the striking red color of the oil itself within the cavity. With oblique fiber-optic lighting, a stunning image of this enhancement in situ was made possible, turning even an otherwise commonplace forensic determination into an aesthetic exploration of the micro-world. @chapter:16 @chapter:0 @chapter:16


# Publication Year: 2014
# Title: Diamond Laser
# Abstract: R. P. Mildren, A. McKay, R. J. Williams, and O. Kitzler, “Diamond Raman Lasers,” Optics & Photonics News, Vol. 25, No. 9, 2014, pp. 42–49. Photo by Robert Weldon/GIA.

              Diamond’s extreme properties will fill voids in the laser industry as well as many other optical, mechanical, and electronics technical areas, as advances in chemical vapor deposition (CVD) growth processes erase the scarcity issue of high-purity, high-quality single-crystal diamond. Today, these synthetic diamonds are readily available in sizes greater than 1 cm.

Ideal laser materials can lase at multiple wavelengths, with excellent beam quality and extremely stable power—a combination of characteristics that require durability, transmission through many wavelength ranges, high heat conductivity, low thermal expansion, and efficient conversion of various input powers into desired wavelengths. Diamond, a material first demonstrated as a laser only five years ago, happens to have all of these characteristics to a far greater extent than other bulk crystals. It is also the only known material capable of producing continuous wave (CW), Q-switched, ultrafast lasing ranging from the deep ultraviolet (UV) to the mid-infrared. Diamond is the material that has the potential to bring Raman lasing into the commercial realm.

While diamond’s compact lattice keeps it from functioning as a traditional solid-state laser—large fluorescing dopant cations would disrupt the lattice—it is highly suited as a Raman laser material. Raman lasers rely on efficiently stimulated Raman scattering (an inelastic light-scattering process) rather than stimulated emission from excited dopant ions. This difference opens up access to many wavelengths not accessible from traditional solid-state lasers. In effect, the laser wavelengths achievable are limited by pump wavelength and medium transparency.

Low efficiencies, poor heat management, and limited transparency ranges have plagued the Raman laser materials explored to date, so here is where diamond can really shine. Silicon, a material with the same structure as diamond, was demonstrated as a Raman laser in 2005. There was much excitement over this for the possibility of Si acting as a gain element in on-chip optical processors. But it has less than a tenth of diamond’s thermal conductivity, much lower transparency, less than half of diamond’s Raman shift, and multiple absorption issues throughout much of the wavelength ranges it has been considered for.

Diamond, meanwhile, has unmatched thermal conductivity, transmission range, and hardness, and an intrinsically large cross-section for Raman scattering with a gain coefficient of 10 cm/GW—the top end for all Raman materials. Not only do you get enhanced power and wavelength range with diamond, you get it with lower pump thresholds, using shorter crystals. Diamond has already demonstrated the highest-output CW power for Raman crystals by an order of magnitude, and it approaches the highest power of any Raman laser (in the form of fiber lasers) at 300 W. To surpass this limit and approach the theoretical limit, conversion efficiency by reducing low absorption losses in the near infrared (NIR) will have to be enhanced by improving crystal quality. Therefore, the pressure is still on to produce larger crystals of even higher purity and structural perfection. @chapter:9 @chapter:1 @chapter:9


# Publication Year: -
# Title: Making the Cut: The Art and Science of Fantasy Carving
# Abstract: Waterfall Suite, a group of three aquamarine sculptures on onyx bases by Sherris Cottier Shank, won an AGTA Cutting Edge Award in 1994, in part because of its fluid appearance. Courtesy of Gemscapes. Photo by Robert Weldon/GIA

Some gem cutters are “gem whisperers” who claim their rough “tells” them what it wants to become. For them, carving becomes a process of communication with the material, closely observing and taking note as the rough’s inner structure and features guide the design. Others take a mathematical approach to cutting the rough and achieve stunning, precision faceting.
No matter the method, these incredibly gifted artists create breathtaking jewels.
About the Science
Flat facets are the traditional two-dimensional facets we see in diamonds and colored gemstones. They are shaped by the adjoining facets and the angles at which they intersect. Concave facets, on the other hand, literally add another dimension to faceting. They not only possess length and width, but also depth. Their potential to create sculptural works of art is endless.

This 140 ct Brazilian amethyst is faceted by Victor Tuzlukov. Courtesy of Victor Tuzlukov. Photo by Robert Weldon/GIA
Many people feel that concave facets increase the stone’s brilliance and scintillation, giving it more life and beauty. A wide reflection of bright light from a flat facet washes out color. A concave facet acts as an internal convex mirror to produce reflected rays from more directions within a gemstone. The light from above reflects to the overhead observer as a narrow bright line of light at the top of the curved surface, and each side of the line will be darker, setting up strong contrast.

Master gem cutter Alexander Kreis created a fantasy cut sunstone carving that makes dramatic use of the gem’s color zoning. Courtesy of KREIS Jewellery. Photo by Robert Weldon/GIA
“Strong contrast makes a gemstone appear brighter and more appealing ... Scintillation is more dynamic when there is strong contrast between adjacent virtual facets,” according to Al Gilbertson, a research associate at GIA, in a 2013 Gems & Gemology article.
The internal reflections of light tend to hide inclusions and also eliminate windowing. Gems with light to medium tones show the greatest improvement in appearance. Dark stones may look darker. Multi-color ametrine, tourmaline and sunstone make especially attractive carvings and rutile inclusions in quartz add special interest.

This fantasy cut faceted colorless quartz is fashioned by Dalan Hargrave. Angular facets placed on the culet of the gem create a fascinating pattern when viewed through the gem’s table. Photo by Robert Weldon/GIA, courtesy of Dalan Hargrave.
“This brilliance [from scintillation] can give the impression that the stone has a higher refractive index (RI), making quartz look like beryl, beryl like topaz, topaz like corundum, and corundum like zirconium,” according to Eddy Vleeschdrager in “Cutting Technique Flat, Concave, or Convex?” a 2002 article in Le Bijoutier International.
Craftsmen in the Idar-Oberstein area have produced stones with concave cut facets on the pavilion since the early 1900s. These stones became fashionable around 1920, and again in the 1950s and ‘60s.

This 18 ct ametrine is cut by Michael Dyber featuring Dyber optic dishes. Courtesy of Orasa Weldon. Photo by Emily Lane/GIA
About the Artists
Sherris Cottier-Shanks tells us the material talks to her. She senses its energy and gets a picture in her mind that she translates into the beauty of its new form. Using a simple carving arbor, she holds the gem by hand as it is being carved, resulting in curved form with a very soft, liquid appearance. She gained inspiration from Henry Hunt and indigenous Canadian Inuit art.

This 216 ct ametrine from Bolivia features the Dyber optic dish. Courtesy of Michael M. Dyber, gem designer. Photo by Robert Weldon/GIA
Michael Dyber became the first American to ever win first prize in competitive gem design at the annual German Award for Jewelry and Precious Stones in Idar-Oberstein, 1994. He is known for his signature, trademarked “Dyber Optic Dishes” and “Luminaires.” Both techniques create optical illusions using a form of concave faceting. The “Luminaires” constitute a hollow channel form of faceting within the gem.

“Dreamscape” citrine is one of several trademark cuts by John Dyer. This is a unique matched pair of fantasy cuts. Courtesy of John Dyer & Co. Photo by Lydia Dyer
John Dyer began a meteoric gem cutting career in 1996 when his trial and error methods began to yield beautiful, sparkling gemstones. He won his first AGTA Cutting Edge Award in 2002 and in 2005 was the first person to sweep an entire category in the AGTA Cutting Edge Awards. He creates collections of trademarked cuts that live up to their names: “Dreamscape,” “Starbrite,” “Sunburst,” “Regal Radiant,” “Light Weaver” and “Sculptural.”

This 320 ct Bolivian ametrine was fashioned on specially designed faceting machinery built by the artist, Mark Gronlund. The sculpture makes excellent use of the unique color zoning seen in ametrine. Courtesy of Mark Gronlund. Photo by Robert Weldon/GIA
Mark Gronlund, an award-winning cutter himself, met with Richard Homer early in his career, and became intrigued by the concave and convex facets created by the OMF (optically magnified facet) cutting machine. His fascination with curved lines led him to create a niche in non-traditional spiral and scallop cuts. He creates gemstone suites of bold colors and shapes for designer jewelry.

This fantasy cut ametrine, 67.50 ct is cut by Dalan Hargrave. Courtesy of Minerales y Metales del Oriente, Bolivia, SA. Photo by Robert Weldon/GIA
Dalan Hargrave’s focus is in developing new gemstone cuts as works of art. He teaches classes in the lapidary arts as a way of passing on his knowledge to the next generation of artisans. He enjoys customizing specialized faceting equipment for his innovative styles.

This stunning pink tourmaline, 29.56 ct was cut by Richard Homer, a pioneer in concave faceting. Courtesy of Columbia Gem House, Inc. Photo by Robert Weldon/GIA
Richard Homer is known for the exceptional brilliance of his cut gems. He masterfully curves the facets along the table, pavilion and girdle that return an explosion of light and color, and is often credited with designing the innovative “concave facet.” His dramatic designs sometimes employ new cutting techniques and curved outlines for which he custom tools specialized equipment.

This “Chanting of the Stars” rutilated quartz carving was created by Alexander Kreis of Idar-Oberstein. Courtesy of KREIS Jewellery. Photo by Robert Weldon/GIA
Alexander Kreis, of KREIS Jewellery, hails from a long line of lapidaries based in Idar-Oberstein. He challenges himself to create gem sculptures that tell a story. He creates innovative techniques and tools when necessary for the design and concept.

Metamorphosis III is a sculpture in rock crystal quartz with rutile inclusions carved by Bernd Munsteiner, 1995. Photo by Robert Weldon/GIA
Bernd Munsteiner is often credited with inventing the fantasy cut, which employs the art of sharp, angular cutting or faceting to reflect and refract light in transparent gems. He began his work in agate relief before moving on to transparent materials in the late 1960s and early ‘70s, removing large areas of the material for the sake of his art, defying the conventional practice of cutting to retain weight. The results are dynamic sculptural pieces that create movement of light comparable to animation. He is known for bold notches or slashes, producing a striking geometric form.

“Visions in Crystal” carved by Tom Munsteiner consists of 264 rock crystals, citrines, and smoky quartz, each weighing approximately 200 cts, free standing in a lattice structure consisting of similarly sized rectangles which are supported by two columns of aluminum with a height of 210 cm. The cut and polished crystals reflecting towards the front have almost the same color tone. The rock crystals are completely transparent, the citrines translucent yellow, only the smoky quartz progress from dark to light. Photo by Robert Weldon/GIA
Tom Munsteiner carries on his father's legacy as a master of gem sculpture. His work reflects the influence of architectural elements in his designs, such as his “Visions in Crystal” sculpture, which stands at more than 6 feet tall and is comprised of 264 tiles of rock crystal quartz, citrine and smoky quartz each cut with various angular facets. He created the piece as an example of how gemstones can be seen as fine art.
Further Reading
Morgan, A. D. (October 2002) Development of concave faceting of gemstones, The Journal of Gemmology, October 2002.

Munsteiner, Bernd, Reflections in Stone, Wilhelm Lindemann, editor. 2004, Arnoldsche.

Oriel, Andy, (November 1997) Learning Curve, Lapidary Journal.

Weldon, Robert, (April 2005) Mathematical Brilliance, Professional Jeweler. @chapter:33 @chapter:2 @chapter:33


# Publication Year: 2022
# Title: Natural Near-Colorless Type IIb Diamond
# Abstract: Figure 1. FTIR spectrum of the sample showing a band (2802 cm–1) characteristic of type IIb diamond.
While colorless to near-colorless HPHT laboratory-grown diamonds usually contain detectable boron impurities (classified as type IIb; see S. Eaton-Magaña et al., “Observations on HPHT-grown synthetic diamonds: A review,” Fall 2017 G&G, pp. 262–284), it is uncommon to encounter a boron-bearing diamond of natural origin due to its rarity (0.02% of natural gem diamonds; E.M. Smith et al., “Blue boron-bearing diamonds from Earth’s lower mantle,” Nature, Vol. 560, No. 7716, 2018, pp. 84–87). The boron concentrations in natural diamonds are generally low (typically <1 ppm), but boron is such an efficient coloring agent that it imparts a blue color to most type IIb diamonds. However, exceptions still exist. For example, when boron absorption is accompanied by absorptions from plastic deformation, the combined effects may give rise to other colors (e.g., yellowish green; Spring 2012 Lab Notes, pp. 47–48; see also Summer 2009 Lab Notes, p. 136). Occasionally, some type IIb diamonds are near-colorless because their boron concentrations are too low to cause a blue color (e.g., E. Fritsch and K. Scarratt, “Natural-color nonconductive gray-to-blue diamonds,” Spring 1992 G&G, pp. 35–42), but they are far from common. Therefore, any near-colorless type IIb diamond submitted to a gem laboratory should be given particular attention to determine its possible lab-grown origin.

Figure 2. DiamondView imaging of the 0.24 ct diamond revealed blue fluorescence (left) and moderate blue-green phosphorescence (right). Subtle dislocation networks on the table (red arrow) that resulted from plastic deformation, typically observed in type IIa and IIb diamond, are consistent with a sublithospheric origin. Images by Wenqing Huang.
Recently, we had the opportunity to examine such an example. This 0.24 ct round brilliant cut had an I color grade due to its grayish component, usually seen in natural type IIb diamond. Fourier-transform infrared (FTIR) absorption spectroscopy detected a weak band at 2802 cm–1 (figure 1), characteristic of uncompensated boron, and identified the sample as type IIb. The diamond was inert to both long- and short-wave ultraviolet radiation. When observed with the DiamondView, it exhibited blue fluorescence and moderate blue-green phosphorescence (figure 2). The dislocation networks observed on the table (figure 2, left), typically seen in some natural type IIa and IIb diamonds but not previously described for lab-grown diamonds, suggest a natural origin. Further evidence of natural origin came from photoluminescence (PL) spectroscopy and inclusion analysis.

Figure 3. Photoluminescence spectra from the type IIb diamond under 473 nm and 532 nm laser excitations. Nitrogen-related defects such as H4 (top) and NV0 (bottom) were observed, along with GR1 (bottom).
Multiple laser excitations (473, 532, and 633 nm) were used to characterize its photoluminescence features at liquid nitrogen temperatures. The PL spectrum measured with a 473 nm excitation revealed the presence of nitrogen-related defect H4 (496.0 nm) (figure 3, top). PL spectroscopy using a 532 nm laser (figure 3, bottom) revealed the occurrence of GR1, NV0, and a sharp peak at 648.2 nm that is probably related to interstitial boron, all of which have been documented previously in type IIb diamonds (S. Eaton-Magaña et al., “Natural-color blue, gray, and violet diamonds: Allure of the deep,” Summer 2018 G&G, pp. 112–131). Nickel defect-related peaks (883/884 nm), a common feature in HPHT laboratory-grown diamonds of various colors, were not detected with any of these excitations.

Figure 4. Inclusions (outlined in red circles) observed in the type IIb diamond tended to show a satellite-like appearance. Fields of view are 2.5 mm (left) and 2 mm (right), respectively. Photomicrographs by Wenqing Huang.

Figure 5. Raman spectra of mineral inclusions in the type IIb diamond. Left: Baseline-corrected Raman spectra of a mineral inclusion (blue line) match the CaTiO3 perovskite reference spectrum (light gray line) from Nestola et al. (2018). The included mineral could be perovskite or CaSiO3 perovskite, since their Raman spectra are almost indistinguishable. Right: Baseline-uncorrected Raman spectrum of a coesite inclusion inverted from the presumed stishovite, showing main bands at approximately 530, 272, and 195 cm–1. Reference spectrum is from RRUFF-X050094.
Magnification indicated several solid inclusions (figure 4), mostly in the crown, that resulted in its SI1 clarity grade. The inclusion scenes were consistent with those described in natural type IIb blue diamonds (Smith et al., 2018). Namely, they tended to show a tiny satellite-like appearance composed of the main inclusion and accompanying decompression cracks. Raman spectra using a 532 nm laser revealed that two of these inclusions were coesite (figure 5). This feature confirmed the diamond’s natural origin. Coesite is a relatively common inclusion in lithospheric diamonds that formed at depths of ~150–200 km. However, recent studies show that type IIb diamonds have a sublithospheric origin and are formed in the upper part of the lower mantle (Smith et al., 2018). For type IIb diamond formed at such depths, the coesite inclusion has not been considered to be in its original pristine form, but rather the back-transformation product from stishovite. Another inclusion showed bands matching roughly with perovskite (CaTiO3) (figure 5), but its precise mineralogy was difficult to determine. This is because the Raman spectra of perovskite and CaSiO3 perovskite, both of which have been described in sublithospheric diamonds, are very similar (F. Nestola et al., “CaSiO3 perovskite in diamond indicates the recycling of oceanic crust into the lower mantle,” Nature, Vol. 555, No. 7695, 2018, pp. 237–241). No matter what exact mineral this inclusion corresponds to, its occurrence implies a sublithospheric origin for the host diamond. Other mineral inclusions could not be identified, probably because of their depth within the diamond.
Due to the scarcity of natural type IIb diamonds, any near-colorless diamond that contains boron detectable by FTIR spectroscopy should be given close attention to determine its origin. The near-colorless type IIb diamond examined here, though rarely encountered, was identified as natural on the basis of its gemological and spectroscopic characteristics. @chapter:22 @chapter:1 @chapter:22


# Publication Year: 2017
# Title: Book Review: Cartier Magician: High Jewelry and Precious Objects
# Abstract: By François Chaille, hardcover, 264 pp., illus., publ. by Flammarion, Paris, 2016, US$125.00.

Art historian François Chaille’s beautifully illustrated book focuses on the Magician Collection of high jewelry and precious objects by the House of Cartier. The book is divided into chapters such as “The Magical Art,” “The Magic of Light,” “The Magic of Design,” and “The Magic of Reality.” Each one is illustrated with pieces from the collection, as well as colorful artwork. The author takes the reader to a magical past when diamonds were illuminated by candlelight, then later thrown into a modern world of electric light, and explains how that changed jewelry setting. He explores the innovative designs of Cartier through the last century, and how this new collection is a continuation of the brand’s mystique.

The book begins with the historical belief that some stones hold supernatural properties, that nature is full of miracles and magical virtues. Chaille quotes French writer and diplomat Paul Claudel, a friend of the Cartier family. In 1937, inspired by a visit to the Cartier shop on Rue de la Paix, Claudel wrote of a child who dreamed of taking in his hand a “drop of dew that sparkles in the May dawn like a star.” He continues: “The child knows that this wonder, once on his index finger… would give magical powers.” Then he closed by saying, “But all this is no dream, it is real.”

The concept of Cartier as magician came from the poet Jean Cocteau, a loyal client. In his 1910 poem “The Frivolous Prince,” he called Cartier “that subtle magician who captures fragments of the moon on a thread of sun.” Chaille refers to the company’s workshops as a place where “Merlin the Magician and other conjurers are in attendance,” imparting life to gems. A Mystery clock from 2015 is shown as an example of the magical designs conjured by the House of Cartier. Its hands are suspended in crystal with no apparent connection to a mechanism, yet they still move.

The reader then walks through the history of light and its use in art, from the Hall of Mirrors at Versailles and paintings by Caravaggio to works by Van Gogh, Rothko, and Picasso and light sculptures by James Turrell and Robert Irwin. The author discusses the magic of light in art, and how we react to it as viewers. The importance of light and how it plays on gemstones cannot be emphasized enough; it is vital to the life of the stone and to jewelry. Louis Cartier started to use platinum in the late 19th century to show diamonds at their best, especially in the newly discovered electric light. The age of platinum jewelry had come into its own, and Cartier was at the forefront of this evolution. Platinum and diamond bracelets, tiaras, necklaces, and rings with names such as Clairvoyant, Luminance, Psyché, Oracle, and Incarnation fill these pages, adding to the mysticism of the Magician Collection.

The Illumination bracelet is made to create light through a combination of colorless diamonds and rock crystal. At the center of the bracelet is an impressive 31.16 ct D-IF emerald-cut diamond flanked by rectangular diamond-set platinum frames containing etched rock crystal panels. These panels lie on top of one another. Light reflects off the diamond through the crystal panels, which act like mirrors to reflect the light back. It is a wondrously imaginative design. Cartier creations use each of the major diamond cuts to enhance the shine, sparkle, and luster of their high jewelry. Since the 1920s they have used them in various combinations to bring a kaleidoscope of light effects to their jewelry. This is illustrated in a 1929 platinum and diamond bracelet that contains brilliant-cut, baguette-cut, single-cut, and bullet-shaped cut diamonds. Also illustrated is the Luminance necklace, which continues this tradition today by combining 11 modified triangular-shaped rose-cut diamonds totaling 19.15 carats with round brilliant-cuts to create scintillation and luster.

The chapter titled “The Magic of Design” gives a background on 1950s and ’60s kinetic art, which focuses on motion, and Op Art, a style that uses optical illusions. Alexander Calder, Victor Vasarely, and Yaacov Agam are a few of the artists whose work illustrates these styles. The chapter features Cartier pieces that transform from one thing to another or have a magical sense of movement. One page has six vintage cigarette cases from 1912 through the ’20s and ’30s. These cases have elaborate Art Deco designs that pre-date the Op Art movement by decades, yet look very contemporary with their kinetic optical illusions and use of positive and negative space.

The sense of movement and transformation is echoed in pieces from the Magician Collection. The Incantation necklace is made of platinum set with round and baguette-cut diamonds on a petal-like fringe. Hanging from this fringe is a 22.84 ct cushion-shaped Ceylon sapphire. The sapphire can be removed and worn as a ring, and the curve of the necklace can be inverted to make a completely different design. The Ubiquité set is a pair of platinum and diamond-set rings that can be worn as one ring or easily converted into two: one set with a 15.06 ct cushion-cut Kashmir sapphire, the other a 10 ct D-IF cushion-cut diamond. When locked together they create the Cartier Toi et Moi (You and Me) or Crossover ring. A piece that captures the sense of movement is a black jade bypass bracelet in the Apparition suite. The terminals of each bypass have a platinum, diamond, and onyx cap set with a cushion-cut Colombian emerald. These “caps” can be removed and transformed into earrings with a total emerald weight of 15.1 carats.

This final chapter, “The Magic of Reality,” focuses on the pieces inspired by nature and the world around us. Under the direction of head designer Jeanne Toussaint, Cartier began to create naturalistic depictions of flowers and three-dimensional animals. The iconic Cartier panther collection became very popular in the early 1920s. Designer Peter Lemarchand, like Toussaint, loved animals and birds, and together they designed some of the most iconic Cartier creations. In this final chapter, the focus on three-dimensional animals and flowers continues throughout the century and into the Magician collection. Elephants with raised trunks made of platinum and diamonds support an 85.25 ct oval emerald in a design for the Ganesh bracelet. On the opposite page is a design for Ganesh earrings that have pear-shaped sapphires, totaling 14.65 carats, suspended from pavé platinum elephant heads. The Jouesue ring has the famous Cartier platinum panther, paved in diamonds with black onyx spots, wrestling with a python coiled around a cabochon-cut 30.64 ct East African ruby. Another stunning piece is the Panthère Hypnotique necklace, where the panther stands upon a 52.53 ct black opal. The Crocodiles necklace, from 1975, is a bold pair of three-dimensional yellow gold crocodiles, one pavé set with yellow diamonds and the other with emeralds. One of the most whimsical pieces is the Adwaita ring, in which a turtle crawls over the top of the white gold mounting of pavé diamonds and cuddles up to a heart-shaped 29.37 ct spinel. Its shell is made of a cabochon gray-blue star sapphire.

Flowers are another inspiration in the Cartier workshops. Photos of a wide variety of floral pieces are included in this last chapter. A brooch from 2013 captures the virtuosity of the master jewelers. It is a flower set with a 46.12 ct cushion-cut pink tourmaline surrounded by pavé diamonds, and plique-à-jour enamel creating delicate petals. The Illyrie necklace combines carved morganite flowers with briolette-cut morganite drops and pear-shaped spinels to create a cascade of pastel flowers from a pink gold color of pavé diamonds. Carving of stones into three-dimensional flowers is an art form. Cartier has created many of these in brooches such as the Iridacée brooch, a purple iris carved from a piece of amethyst and set with a pear-shape yellow diamond along with accents of pavé white diamonds. The Gardenia brooches are carved in pink or blue chalcedony set in pink or white gold.

In the 1920s Cartier, influenced by the maharajahs, created what has come to be known as their Tutti-Frutti jewelry. It combines carved rubies, sapphires, and emeralds with diamonds to create an Indian look. The carved colored stones are combinations of pumpkin-cut and leaf-shape stone, some engraved with floral designs. It was quite popular in the ’20s and ’30s, and Indian motifs were revived in the 1960s. Recently this Indian-style jewelry has been brought back by Cartier. One of the most impressive pieces in this book is the Rajasthan set of necklaces that can be worn together or separately. The first necklace is a row of graduated pumpkin-cut emeralds with a pendant that contains a 136.99 ct carved emerald suspended from a pear-shaped carved ruby. This can be worn with another necklace—a bib of carved emeralds, sapphires, and rubies suspended from pavé diamond branches—to make a major statement piece. The large emerald can be transformed into a brooch, and the suite comes with earrings, ring, and bracelet to complete the set.

François Chaille’s knowledge of art, combined with his love of fine jewelry, creates a fascinating read for those who have a passion for both. He uses archival and modern jewels to weave history and art history to tell the story of the Cartier Magician Collection.

This book is sumptuously illustrated with high-resolution photos and archival preliminary sketches, as well as important art works. It is a scholarly work but easy to read, as informative as it is enjoyable. @chapter:25 @chapter:2 @chapter:25


# Publication Year: 2015
# Title: Book Review: Collector’s Guide to Herkimer Diamonds
# Abstract: By Michael R. Walter, softcover, 96 pp., illus., publ. by Schiffer Publishing, Ltd. Atglen, PA, 2014, US$19.99.

	Quartz, chemically the simplest form of the silicates, is abundant in the earth’s crust. Herkimer diamonds are a unique form of quartz crystal found in the state of New York. Most of the brilliant, water-clear crystals show the classic 18-sided, doubly terminated hexagonal form.

	Author Michael Walter gives us an in-depth look at every aspect of Herkimer diamonds. Mineralogical properties such as crystal shapes, sizes, surface growth features, and crystal combinations are fully described. Calcite, dolomite, iron sulfides, and hydrocarbons are associated minerals. Inclusions that provide clues to the origins of the Herkimer diamonds are solids, liquids (salt water or petroleum), gases (most often carbon dioxide), two- and three-phase inclusions, and negative crystals. Anthraxolite, formed by polymerization of petroleum over geological time periods, is the most common solid inclusion.

	The geological history of Herkimer diamonds is an intriguing one that begins at the bottom of a shallow sea about 495 million years ago. The material that would later form the crystals was deposited as a waxy organic material along with quartz sand and masses of pyrite. All of this was encased in a rock made up of two carbonate minerals: dolomite and calcite. Sediments slowly buried the rock and its temperature rose. As a result, molecules that had been holding quartz dissolved from the sand in solution were broken apart by thermal splitting. This caused the quartz to come out of solution very slowly and resulted in the growth of quartz crystals of exceptional clarity.

	The book’s main purpose is about where to go for treasure hunting and how to work the rock based on firsthand experience. No single aspect of field collecting goes undiscussed. Collecting is only possible during the favorable weather of summer. The rock is hard, and the author gives invaluable information on equipment and tools and how to use them. Specific methods used to effectively extract Herkimer diamonds are described.

	A full chapter is dedicated to the preparation of specimens: cleaning, trimming and preservation. Some of the mines are operated as fee locations and open to the general public. These and some closed mines and locations outside the traditional Herkimer diamond region are documented. A handy appendix section contains maps and GPS coordinates of Herkimer diamond localities, including Ace of Diamonds, Herkimer Diamond Mines, Crystal Grove Mine, Diamond Acres, and Hickory Hill.

	Good rock and mineral collecting field guides are hard to find. This guide offers 210 vivid color images and a well-written, easy-to-read text. This book is a must have if you are thinking of prospecting for Herkimer diamonds. @chapter:44 @chapter:1 @chapter:44


# Publication Year: -
# Title: Recycled Diamonds: ‘Mining’ the World’s Largest Diamond Resource
# Abstract: At a recent auction of recycled polished diamonds in Hong Kong, White Pine offered more than 200 lots of mainly smaller diamonds, ranging from 20 carats total weight to nearly 1,200 carats. This lot contains 1,160.68 carats of approximately 0.01 ct. stones of mixed qualities. Photo by Russell Shor/GIA

                      Diamond mining companies continue to explore promising sources in Africa and Canada, but perhaps the world’s largest diamond resource is well above ground in the U.S.: Jewelry owners.

During the second half of the last century, according to De Beers’ market surveys, American jewelry buyers accounted for between two-third and three-quarters of all diamond jewelry sold at retail. And in the past five years they have been sending several million carats – numbers approaching a large diamond mine – back into the market each year.

One of the largest buyers of pre-owned diamonds is White Pine Trading of New York, which handled more than 500,000 carats of stones in 2015. This will make it, by its own account, the world’s largest buyer of pre-owned diamonds.

The company was created in 2010 as the world economy struggled to right itself from the financial crisis that began at the end of 2008. At the time, gold was climbing strongly in price toward $1,900 per ounce, and a flood of sellers were eager to convert their jewelry pieces – many of which often contained small diamonds − to cash.

A 2010 GIA survey of the U.S. “secondary market” by this author estimated that 1.4 to 1.8 million diamonds larger than 0.30 carats (cts.) – or a total of 500,000 to 700,000 carats − were channeled from consumers back to retail jewelers, pawnbrokers and gold buying firms. The number of smaller diamonds totaled an estimated 3 million carats.

There are immense numbers of diamonds in consumers’ hands. De Beers’ annual surveys conducted between 1976 and 1999 found that U.S. consumers bought a total of nearly 400 million pieces of diamond jewelry, representing 1.3 billion diamonds. Within that total there were more than 37 million engagement rings averaging about one-third of a carat. De Beers stopped publicizing its surveys after 2000, but later surveys from other sources indicate that acquisition rates have continued.

Last year, industry analyst Chaim Even-Zohar estimated the “recycled diamond market” at $450 million, which represents a significant decline from the peak of 2010-12 when economic necessity, combined with extremely high gold prices and rising diamond prices, probably resulted in more than $1 billion worth of diamonds returning to the market.

	The majority of buyers at White Pine’s Hong Kong auctions were the jewelers who line
	Nathan Road, one of the main shopping streets in the city. Photo by Russell Shor/GIA
White Pine said its 2015 sales will total $100 million. “We believe that’s it’s extraordinary to carve such a huge niche in a market that is basically contracting,” said Myles Schakler, vice president of Diamond Melee Sales and Auctions.

The company grew by networking, he said. First, it recruited agents to buy melee from gold dealers, retailers and pawnshops around the U.S. These small diamonds were mostly by-products of their gold buying activities and the company offered them a ready outlet for tiny stones for which they had no viable use. White Pine parlayed this business into buying larger diamonds – quarters-, thirds- and even some one-caraters.

White Pine has expanded its buying activities to Japan and several European nations and has about 20 buying agents. It has expanded acquisition beyond pawnshops and gold buying operations to cover store closeouts, bank and estate liquidations. This expansion was necessary, Schakler said, because consumers are selling back much less gold jewelry than they did when the price of the metal hovered at $1,900 an ounce.

The company sells melee goods back into the trade through regularly scheduled auctions in various venues around the world. Schakler notes that the melee is sold in mixed quality lots, from .01 ct. to 0.1 ct., because it is not economical to sort them further. The lots range from a total of 20 carats to 1,100 carats.

He acknowledges there will be a certain number of rejection goods in the parcels. “The experienced buyers know how to factor them into their offers,” he said.

Buyers leave sealed bids, and lots that don’t sell are opened to new offers after the sale. “We usually have a good idea of what the parcels will bring,” Schakler said. “But if we do not have offers that meet the reserve, we generally will sell within reason.”

The company sends diamonds larger than 0.20 cts. to GIA for grading, then lists them on trading sites like RapNet. Some of these goods, particularly older stones, have to be recut before they are sold. “In fact, it is surprising how poorly cut some goods are,” Schakler said.

The exception, Schakler said, is very low quality diamonds, which go into the melee auctions.

The 2010 GIA survey found that the majority of melee and diamonds under 0.30 cts. were purchased at steep discounts from the prevailing wholesale price and were then brokered back into the trade. Retailers who purchased larger goods from consumers or estates often paid well below wholesale, had them recut if needed, and added them to their own inventories. @chapter:37 @chapter:3 @chapter:37


# Publication Year: 2013
# Title: Wittichenite from the Cattle Grid Pit, Mount Gunson Mine, South Australia
# Abstract: In 1981, large, attractive wittichenite crystals found at the Cattle Grid Pit in South Australia were mistaken for chalcocite. Then in 2008, they were correctly identified by the Smithsonian Institution. Electron microprobe analysis of this species shows Cu, Bi, and S (weight percentages of 38.67%, 41.70%, and 19.90%, respectively).

					The Cattle Grid wittichenite is brittle, with strongly conchoidal fractures and a relatively low hardness. The colors vary from highly lustrous silvery white to bronze to a deep purple-black. The crystals are predominantly tabular-prismatic in habit, but some show myriad crystal faces and deeply striated prisms. The Miller indices for these crystal forms, and their intricate and complicated crystal morphology, are discussed in depth.

					The article contains 16 large photos of wittichenite, some crystals weighing more than 75 grams, as well as the mine site and the copper localization stratigraphy. The number of wittichenite crystals larger than 2 cm in maximum dimension is estimated to be about 30, and these are held in only three collections (two institutional and one private). Unfortunately, the entire production of copper sulfide concentrate from the Cattle Grid Pit is now owned by a private smelter, where the bismuth-containing wittichenite is considered an undesirable impurity.

Abstracted by Edward R. Blomgren @chapter:0 @chapter:0 @chapter:0


# Publication Year: 2015
# Title: Treated Pink Diamond with HPHT Synthetic Growth Structure
# Abstract: Figure 1. This multi-step treated 1.62 ct Fancy pink natural diamond shows what appears to be HPHT synthetic growth structure. Photo by Sood Oil (Judy) Chia.

	HPHT synthetic diamonds are grown using high pressure and high temperature but with a much higher growth rate than natural diamond. Consequently, their growth structures are different. GIA’s New York lab recently examined a multi-step treated diamond with a growth structure similar to that of HPHT synthetics. The 1.62 ct Fancy pink type IIa round brilliant seen in figure 1 showed spectral characteristics suggestive of HPHT treatment, irradiation, and annealing. This diamond was internally clean, except for the presence of strong, colorless internal graining (figure 2). Tatami and banded strains with strong interference colors could be seen under cross-polarized light (again, see figure 2). Based on these microscopic features, we concluded that this was a natural diamond.

Figure 2. Tatami strain (left, field of view 3.20 mm), banded strain (middle, field of view 3.20 mm), and heavy internal graining (right, field of view 2.45 mm) are evidence of a natural diamond.  Photo by Kyaw Soe Moe.

	DiamondView imaging of the stone showed cuboctahedral growth with dark sectors and pink coloration (figure 3). This crystal habit is usually observed in HPHT-grown synthetic diamonds. As seen in figure 3 (left), the cubic {100} sector can be located in the pavilion, along with octahedral {111} sectors. In order to understand more about this growth, we compared it with a type IIa 0.27 ct HPHT synthetic, which was treated post-growth to induce a Fancy Intense orangy pink color (figure 3, right). Both specimens showed similar fluorescence patterns; however, the natural diamond’s greenish blue phosphorescence was evenly distributed, as seen in the middle image of figure 3. This is unlike the dark images yielded from type IIa pink HPHT synthetics, which are not phosphorescent.

Figure 3. DiamondView fluorescence images of the treated 1.62 ct pink natural (left) and the post-growth treated 0.27 ct pink HPHT synthetic (right) showed similar growth patterns, containing cubic {100} sector and octahedral {111} sectors. The middle image of phosphorescence of the 1.62 ct pink natural diamond showed even color distribution without growth sectors. Type IIa pink HPHT synthetic diamonds are usually not phosphorescent. Images by Kyaw Soe Moe.

	Although most natural diamonds show octahedral growth structure in DiamondView images, some natural gem-quality colorless and yellow diamonds may show cuboctahedral growth (Winter 2010 Lab Notes, pp. 298–299; Winter 2011 Lab Notes, p. 310; Spring 2013 Lab Notes  pp. 45–46). Some non-gem-quality diamonds possess cuboctahedral form (D.G. Pearson et al., “Orogenic ultramafic rocks of UHP (diamond facies) origin,” in R.G. Coleman and X. Wang, Eds., Ultrahigh Pressure Metamorphism, Cambridge University Press, 1995, pp. 456–510). Growth rate, pressure, and temperature of geological environment control the habit of a diamond crystal. A slow growth rate causes octahedral crystal growth, but a high growth rate can facilitate cubic {100} and octahedral {111} sectors developing simultaneously. As a result, cuboctahedral habit can be formed naturally.

	While the DiamondView is very reliable at revealing the growth structure of natural vs. synthetic diamond, it is important to correctly interpret all identifying characteristics. When cuboctahedral growth structure is observed, one should look for other features to support the origin. Microscopic features and spectral characteristics are useful for this purpose. @chapter:9 @chapter:1 @chapter:9


# Publication Year: 2022
# Title: In Memoriam: Peter Keller
# Abstract: Dr. Peter Keller during his time as director of education at GIA. Photo by GIA.
Gems & Gemology mourns the passing of Dr. Peter Keller (see above) on November 8, 2022. Keller dedicated 50 years of his life to the gemological community and made countless contributions to GIA and G&G.
Born in 1947 in Allentown, Pennsylvania, Keller became interested in rocks and minerals at an early age. After obtaining his undergraduate degree in geology from George Washington University, Keller earned a master’s degree and a PhD in geology and earth science from the University of Texas. Keller began his career as curator of the Gem and Mineral Hall at the Natural History Museum of Los Angeles County before joining GIA as director of education in 1980.
For more than a decade, Keller was instrumental to G&G as an author and as associate editor. In the first half of the 1980s, he wrote several landmark articles documenting his visits to gem deposits worldwide. “Emeralds of Colombia” (Summer 1981) received third place in G&G’s annual Most Valuable Article awards. He was a key contributor to G&G’s Spring 1986 special issue on China, reporting on the emerging gem resources in various Chinese provinces.
In addition to writing for G&G, Keller wrote and published two influential books, Gemstones and Their Origins (1990) and Gemstones of East Africa (1992). He even ventured into filmmaking earlier in his career, serving as associate producer on a documentary film titled Gems of the Americas, which was coproduced by the Natural History Museum of Los Angeles County and GIA.
Keller spent much of his career as president and CEO of the Bowers Museum in Santa Ana, California. He is survived by his wife, children, stepchildren, and grandchildren. We extend our deepest condolences to his family, friends, and colleagues. @chapter:34 @chapter:0 @chapter:34


# Publication Year: -
# Title: Searching for Emeralds in Afghanistan
# Abstract: Afghanistan's Panjshir Valley, home to world-class emeralds. Photo © Andy Lucas

                      GIA field gemologists are a different breed. When Andy Lucas, GIA manager of Field Gemology in Carlsbad, decided to take some vacation time, he didn’t make for the usual destinations. No beaches, ski resorts, or cosmopolitan cities. Lucas instead headed off to Afghanistan, lured by deposits of fine emeralds.

	Emerald Adventuresin Afghanistan

Lucas’ destination was the remote emerald mines of Panjshir Valley. It’s a place where few dealers go, as it’s a difficult trek with its share of hazards. So before setting out, Lucas and his traveling companion, Arthur Groom of Eternity Emerald (who arranged the trip), met with Abdullah Abdullah, a prominent politician. With Abdullah's support, the two set out on their emerald adventure to the Panjshir Valley located on the Panjshir Province.

	Gem trading happens on Chicken Street, which formerly was an antique and poultry market. Photo © Andy Lucas

	Arthur Groom (right) sits across from a gemstone dealer at Kabul’s Chicken Street – the gem trading center of the country. Groom is dividing a parcel of emerald rough by the quality of the gemstones. Photo © Andy Lucas
Rugged beauty and breathtaking vistas were the welcome to Panjshir Valley. The valley’s name means “five lions,” a tribute to five spiritual brothers who once lived there.

“Come as a foe and leave defeated. Come as a friend, and you will find some of the most hospitable and friendly people on the planet,” reflects Lucas about their trip to the Panjshir Valley. “The miners and dealers I traveled with, in fact, were constantly concerned about my welfare,” Lucas recounted with obvious affection.

	The way to travel the rugged, mountainous terrain is by horse. Photo © Andy Lucas
Upon their arrival at the town of Pawat, Lucas started climbing the steep mountain trails in hopes of reaching the emerald mines before dark. After a four-hour hike to the mining area, he arrived at sunset.

	Mountainside homes of the miners. Photo © Andy Lucas
Lucas paints the scene: “A few hundred miners were working at the camp. Most were winding down for the day, but another shift, which worked through the night, was starting. I had a most unusual serenade that evening – the wind whistling through the mountains, punctuated by dynamite blasts from the mines.”

Dinner at the mining camp was a meal of fresh lamb, rice, and Nan-e Afghani, the national bread, baked as it has been for centuries. The next day’s breakfast, says Lucas, was just as tasty: fresh goat milk and more Nan-e Afghani.

	A miner cooking in an open-air kitchen bakes bread for his comrades. Photo © Andy Lucas
Lucas then visited the mining tunnels to watch the mining and ore processing operations. The mining was typical for hard rock deposits – a diesel-powered drill was used to make holes in rock. Charges were placed in them to remove the overburden rock but not to destroy the emeralds – a tricky task!

Once the explosives were detonated, miners returned, removed the rocks, and searched for emerald. Promising rocks were sent to a processing area, where they were broken apart by hand tools and washed using screens.

Lucas noted that emerald mining benefits many: “Like many colored gemstone mines, business people provide the capital to purchase food, equipment, and whatever else is needed to run the operation. Profits are divided between the owners and miners. Many of the owners once were miners.”

	"Pencil" emeralds – named for their shape – mined in the Panjshir Valley. Photo © Andy Lucas
Lucas is now home, incorporating his findings into GIA educational materials. Insights include updated content on the type of gem material coming out of Afghanistan, mining practices, and the nature of the trade. If you’re planning to take the Colored Stones and Gem Identification courses, expect to benefit from Lucas’ travels.

	A Primer on Emeralds from Afghanistan

		Emeralds from Afghanistan can have excellent color – so much so that they “rival any source,” according to Lucas.

		The shape of Afghanistan emeralds can make for a good retention rate, meaning that less stone is lost when they are cut.

		Even small crystals mined in Afghanistan still tend to have rich colors.

		Longer pieces of rough (called pencils because they have a similar shape to one) are often cut into melee and used in fine watches. @chapter:23 @chapter:2 @chapter:23


# Publication Year: -
# Title: Industry Experts Share Encouraging Advice with Job Seekers
# Abstract: Students plan their day before the start of “Job Success in Today's Market,” which kicked off the event. Photo by Eric Welch/GIA

                      Act with integrity. Adapt to change. Know what your next job will be. Don’t be afraid to fail.

These are just some of the words of advice offered to job seekers at GIA’s 20th annual Jewelry Career Fair on Oct. 22. The event, held at the Institute’s world headquarters in Carlsbad, is a free, one-day-only opportunity for attendees to connect with companies through panel discussions, one-on-one career coaching sessions and networking. It also included three panel sessions: “Job Success in Today’s Market,” “From Design to Finish” and “Creative Careers.”

Here is some of their best advice:

Alan Bell, managing director of The Bell Group, Inc., shared principles he learned from his father: “It’s not enough to conduct yourself with integrity in the jewelry industry. You must conduct yourself in a manner that leaves no doubt about your integrity. You must always do what you agree to do.”

Douglas Kazanjian, CEO of Kazanjian Bros. Inc., on how to get into the estate jewelry business: “(Look for) the company that has the most turnover of goods. You really want to go in looking for the experience first. Salary and compensation should be the last things you think about – it takes a long time to become valuable (because of your knowledge) in the estate business.”

David Pomije, chairman and CEO of Top Hat, Inc.: “People don’t care how much you know until they know how much you care.”

Mark Smelzer, publisher of JCK magazine: “Take advantage of the slower economy to rethink, replan, reimagine. Think about what your core strengths are, do your homework, think about how you present yourself.”

Jewelry designer Erica Courtney: “You can’t get lucky if you don’t get out there. You can’t get lucky if you’re sitting at home waiting for someone to discover what a genius you are. You have to make them know you’re a genius.”

Steven A. Mindel, managing partner of Feinberg, Mindel, Brandt & Klein, LLP: “There are a million different opportunities for people coming into the jewelry industry. You’ve got to keep your eyes really open because there may be a strange path to get in.”

Steve Shonebarger, executive vice president and chief operating officer of Montres Corum USA, always had his next job in line: “I always had aspirations to work for the next big company, but you don’t want to have a resume that shows you’ve changed jobs every year or two. You want to have at least 4 to 5 years with every company.”

Debra Dolphin, director of fulfillment for Blue Nile: “Give yourself a break if you fail once in a while. You’re going to learn from it, pick yourself up and be better next time.”

George Blodwell, celebrity stylist: “We’re already successful just being human beings. We are gems; we are so special and priceless. Remember that when you’re waking up in the morning. Be happy, be yourself – people respond to that authenticity. Don’t try to be something you’re not, don’t try to be impressive. Just be a real person and say what comes from your heart.” @chapter:45 @chapter:3 @chapter:45


# Publication Year: 1986
# Title: Some Unusual Sillimanite Cat's-Eyes
# Abstract: Brown-black sillimanite cat's-eyes from Sri Lanka present an unusually sharp band, which would make them extraordinary gems were it not for the rather unattractive body color of the stones. A study of six of these stones found that they contain 0.5 wt. % iron oxide. The principal inclusion mineral is ilmenite, which occurs in elongated, submicroscopically thin lamellae. Complex thicker lamellae consist of hercynite spinel grown together with a member of the pyroxene group. These thicker inclusions were not found in all of the specimens investigated. @chapter:8 @chapter:0 @chapter:8


# Publication Year: -
# Title: Boron Carbide: A New Imitation Black Diamond
# Abstract: Figure 1. This 1.04 ct black submetallic round brilliant, initially represented as diamond, was identified as boron carbide. Photo by G. Choudhary.

                      As black diamond has gained popularity in the past few years, so have aggregates of black synthetic moissanite and crystalline silicon (Spring 2011 Lab Notes, pp. 54–55). One specimen received by the Gem Testing Laboratory in Jaipur, a 1.04 ct black submetallic round brilliant (figure 1), appeared to be synthetic black moissanite but proved otherwise. The specimen was presented to the owner as a diamond.

Due to the prevalence of black synthetic moissanite in the marketplace and laboratories, we immediately checked for the typical aggregate structure under the microscope. Although a granular pattern was distinctly visible in reflected light (figure 2), it was much denser and finer than the kind usually seen in black synthetic moissanite. This raised uncertainty, so additional gemological tests were performed. The specimen had an over-the-limit RI, an SG of 2.43, and a hardness above 9 on the Mohs scale. The low SG value ruled out the possibility of synthetic moissanite (3.22), but otherwise offered no clues as to the specimen’s identity.

	Figure 2. Under reflected light, the boron carbide specimen displayed a dense fine granular structure typically associated with aggregates such as ceramics. Photomicrograph by G. Choudhary; magnified 48x.
Qualitative EDXRF analysis revealed Fe with traces of Si and K. Raman spectra taken from several points using 532 nm laser excitation showed major peaks at approximately 260, 320, 480, 532, 720, and 1088 cm-1, with smaller peaks at about 800,824, 874, 967, and 998 cm-1. This combination of features did not match anything in our database, but an extensive literature search revealed an exact match with the Raman spectra of boron carbide (V. Domnich et al., “Boron carbide: Structure, properties, and stability under stress,” Journal of the American Ceramic Society, Vol. 94, No. 11, 2011, pp. 3605–3628).

Boron carbide is an advanced ceramic material with high hardness, low density, thermal stability, and extreme abrasive resistance, making it suitable for nuclear, military, and aerospace applications. The material is typically produced by reacting and fusing carbon with boric oxide (B2O3) in an electric arc furnace, followed by a sintering process of hot pressing in graphite dies under a vacuum or argon atmosphere at temperatures of 1900–2200oC and pressures of 0.02–0.04 GPa for 15–45 minutes (Singhal and Singh, “Sintering of boron carbide under high pressures and temperatures,” Indian Journal of Engineering and Materials Sciences, Vol. 13, April 2006, pp. 129–134).

Although boron carbide is common in engineering and materials science—uses such as scratch-resistant coating and plating in tank armor, bulletproof vests, and padlocks—this was our first encounter with it as a diamond simulant. Research also did not reveal any gemological uses of this ceramic product. Distinguishing boron carbide from black diamond or synthetic moissanite was straightforward based on SG, but Raman spectra and reference data were needed for identification. The possibility of market penetration cannot be ruled out.

Acknowledgment: Mr. Sandeep Vijay, staff gemologist at the Gem Testing Laboratory, for conducting a thorough literature search. @chapter:43 @chapter:1 @chapter:43


# Publication Year: 2021
# Title: Rare Faceted Hexagonite
# Abstract: Figure 1. This 3.27 ct pinkish purple hexagonite is the largest example examined by the authors. Photo by Robert Weldon; courtesy of Vance Gems.

A saturated pinkish purple hexagonite (figure 1) was recently examined at the Carlsbad laboratory. Standard gemological testing revealed a refractive index of 1.599–1.629 and a specific gravity of 2.97 obtained hydrostatically. Microscopic examination showed needle-like inclusions and iridescent cleavage cracks (figure 2).

Figure 2. Iridescent cleavage cracks and needle-like structures were present in the faceted hexagonite. Photomicrograph by Nathan Renfro; field of view 3.50 mm.
When observed with a dichroscope, pleochroic colors of pink, orangy pink, and violet were observed. These results were consistent with the mineral tremolite. The pinkish purple variety of tremolite is recognized as hexagonite, which owes its color to manganese. Hexagonite was once thought to be a hexagonal form of tremolite, which is how its name was derived, but was later confirmed to be monoclinic (Summer 1985 Gem News International, p. 110).

This particular stone was faceted by Bill Vance of Vance Gems, who sourced the rough that was reportedly from the original type locality, the Balmat-Edwards zinc mining district in St. Lawrence County, New York. Hexagonite is also found at the town of Fowler in St. Lawrence County. The saturated pinkish purple color and large size make this rare stone an exceptional example of this material. While very few faceted hexagonite gems have been tested at GIA, this 3.27 ct stone is the largest one examined by the authors. @chapter:3 @chapter:0 @chapter:3


# Publication Year: 1991
# Title: Summer 1991 Gem News International
# Abstract: Diamonds
            DeBeers Unveils Centenary Diamond
            Large "Chameleon" Diamond
            Soviet Production Estimates Updated
            Australian Marine Search for Stones
            World-Record Auction Price for a Diamond
            Update on Diamond Mining in Brazil
            Jewelry-Quality Diamond Crystals
            Bluish Gray Synthetic Diamond thin Films Grown on Faceted Diamonds
Colored Stones
            African Gem Update
            Amethyst from Afghanistan
            Unusual Corundum/Mica Carving Material
            Joint Venture for Russian Emeralds
            Large Carved Labradorite
            Fine Greenish Blue Opal
            Another Phenomenal Organic Gem Material
            Cultured Pearls Auction
            Green Zoisite
Enhancements
            Faceted Aqua Aura Update
            Plastic-Treated Jadeite
            Dyed Quartzite Imitation of Dyed Jadeite
Synthetics and Simulants
            Chatham Signs Agreement with Japanese Crystal Grower
            Chatham Issues Warning on Trademark Infringements
            Novel Fiber-Optic Glass
            New Glass Imitation of Lapis Lazuli
            "Encapsulated" Mexican Opal
            Plastic Imitation Opal from Thailand
            Update on Soviet Synthetics
Instrumentation
            Loupe with True Darkfield Illumination
            New Cutting Machines Developed
Announcements
            Canadian Gemmological Assn. to hold Conference in October

To view the full section, download the PDF above. @chapter:27 @chapter:1 @chapter:27


# Publication Year: -
# Title: Chow Tai Fook Expands Blockchain Initiative with GIA
# Abstract: Chow Tai Fook plans to expand the offering of blockchain-secured, digital diamond grading reports for its T MARK diamonds to additional stores in Hong Kong and mainland China. The addition of GIA’s secure digital reports documents the diamond journey and grading information in one place.

One year after Chow Tai Fook Jewellery Group and GIA announced a pilot program to give customers who purchase the Chow Tai Fook’s T MARK diamonds blockchain-secured, digital diamond grading reports, the company announced that it will expand the program to additional stores in Hong Kong and mainland China.
“Launching our T MARK diamond brand represented a significant breakthrough as we were the first retailer to share the life journey of a diamond,” said Kent Wong, managing director of Chow Tai Fook Jewellery Group, a Hong Kong-based jewelry retailer that has more than 3,000 outlets globally.
According to Wong, the addition of GIA’s secure digital reports makes the T MARK program truly complete because it documents the diamond journey and grading information in one place.
The pilot program was launched in September 2018 and reached 10 Chow Tai Fook stores in Hong Kong by March 2019. Customers who buy T MARK diamonds can choose to receive a digital GIA grading report through the dedicated T MARK app on their phones instead of the usual printed document. All of the GIA grading report data is secured through blockchain technology using the IBM Blockchain Platform.
“It made perfect sense to add GIA’s secure digital blockchain reports into our T MARK program to add another layer of trust for our customers,” said Chow Tai Fook executive director Bobby Liu.
Chow Tai Fook executives say the blockchain initiative has gone down well with its customers, particularly the younger generation, who are excited about blockchain technology because it aligns with their pursuit of authenticity, higher security and a paperless lifestyle. The company also said customers liked the idea of storing the digital GIA reports in the T MARK app because the diamond grading information is just a few taps away and can be retrieved anytime.
“Ensuring consumers’ trust in their diamond jewelry purchases is fundamental to GIA and Chow Tai Fook,” said Tom Moses, GIA executive vice president and chief laboratory and research officer. “This innovative collaboration enhances that all-important consumer trust and helps meet expectations around transparency, trust and sustainability.”

A GIA blockchain diamond grading report on the T MARK app. The featured icon on the top of this report and in GIA Report Check indicates a blockchain-enabled report number. The blockchain diamond grading report includes the key GIA grading data – Color, Clarity, Cut, Carat Weight, Shape and Cutting Style – and GIA’s Statement of Authenticity.
Secure, Easy-to-Access Info on Diamond’s Journey
Of course, there is also a great deal of curiosity about the T MARK app because many customers are not familiar with the concept of blockchain. According to Chow Tai Fook, a well-prepared sales staff is the key to making the T MARK program work. Their sales staff are well-trained to explain the benefits of this technology:

Greater data security – the grading report is digital and secured in the blockchain database. Importantly, this digital record of the diamond’s grading information is linked to the customer when they purchase a diamond and register on the T MARK app - a first for grading reports.
A more streamlined experience – instead of a separate printed grading report, the digital report is incorporated into the T MARK app, so all of the diamond’s information is available in one place, anytime and anywhere, easily accessible with the tap on the screen. This eliminates the risk of losing, and the inconvenience of handling physical reports.
Enhanced assurance – consumers are receiving the same independent, accurate and unbiased analysis that GIA has been providing since 1931, integrated into the T MARK app, which provides full transparency about their diamond’s journey. Customers know everything about their diamond - its source, its journey and its 4Cs grading information from two trusted sources: Chow Tai Fook and GIA.

Chow Tai Fook sales staff stress to customers that blockchain technology is already used to protect high-value assets such as in fine wines, works of art and other luxury products, and critical data in other industries. Chow Tai Fook and GIA are the first to offer this technology to diamond purchasers. Chow Tai Fook also notes that once a record is added to the blockchain database, it is permanent and cannot be changed, ensuring the security of the data.
Most importantly, though, the retailer tells all of its customers that blockchain technology is simply a tool that helps to enhance what they have already come to expect from Chow Tai Fook and GIA.
“Using blockchain technology to link a customer to their diamond’s grading report and history is an important milestone for the diamond industry,” said Pritesh Patel, GIA senior vice president and chief operating officer. “Together, Chow Tai Fook and GIA brought blockchain security to gem and jewelry consumers.”
Education is Key to Explaining the Benefits of Digital Diamond Information
Chow Tai Fook acknowledges that not every T MARK customer is ready to go without the printed reports. There is a period of transition, and as with any new product or service, its executives said, education is a key factor during this time.
Indeed, just as when companies like Apple or Nike introduced digital receipts and warranties, there were some customers who were early adopters and some who preferred paper. In the initial stages of the project, the company plans to give customers both options.
The company will make a continuous effort to adopt digital reports as the norm, especially after it expands the offering to Chinese consumers in mainland China in the coming months.
As Chow Tai Fook expands beyond its pilot blockchain program, it believes there is ample room for growth, especially as it adds more stores, trains more front-line staff and works with GIA to closely monitor the program. @chapter:37 @chapter:3 @chapter:37


# Publication Year: 1990
# Title: Spring 1990 G&G Lab Notes
# Abstract: Simulated Amethyst
Cat's-Eye Andalusite
Diamond Cutting Risks
Diamond with a Rare Inclusion
Emerald with Filled Fractures
Unusual Natural Opals
Gray Cultured Pearls
Rock Crystal Quartz with Lazulite Inclusions

To view the full section, download the PDF above. @chapter:18 @chapter:1 @chapter:18


# Publication Year: 1982
# Title: Summer 1982 G&G Lab Notes
# Abstract: Alexandrite
Diamond
Emerald Fakes
Grossularite Garnet
Dangers of Heating Jadeite during Jewelry Repair
Kornerupine with Apatite Inclusions
Flow Structure in Opal
Oolitic Opal
Opal Doublet
Mysterious Pearls in Shells
Unusual Natural Pearl
Synthetic Star Ruby
Dangers of Heating Sapphires during Jewelry Repair
Natural Sapphire with Heat-Induced Star
Treated Synthetic Sapphire
Inclusions in Spinel
Cat's-Eye Tourmaline

To view the full section, download the PDF above. @chapter:18 @chapter:1 @chapter:18


# Publication Year: 1984
# Title: Inclusions in Taaffeites from Sri Lanka
# Abstract: This article reports on a gemological and mineralogical study of inclusions in taaffeites from Sri
Lanka, with photomicrographs of some of the most characteristic occurrences. The presence of minerals such as apatite, phlogopite, spinel, and muscovite is noted and their significance in the genesis of taaffeite is discussed. @chapter:14 @chapter:0 @chapter:14


# Publication Year: -
# Title: Gems for Pantone Colors Spring/Summer 2015
# Abstract: When Pantone announces its colors for the year and season, the fashion world takes notice. So does the jewelry industry.

We looked for interesting gems that matched Pantone’s Color of the Year (Marsala) and the other gemstones in the Spring/Summer family. We also went a step further and followed Pantone’s lead by identifying gems that “pair well with” the primary colors of choice.

We’ve done the research. Now get ready to use our finds in your gemological work and jewelry creations.

	Marsala
Leatrice Eiseman, executive director, Pantone Color Institute described it as “hearty yet stylish tone,” and that it “embodies the satisfying richness of a fulfilling meal while its grounding red-brown roots emanate a sophisticated, natural earthiness.” Gem connoisseur can rejoice. There is a wealth of gems that mirror Marsala.

View Gallery

	Scuba Blue
One of Pantone’s Spring/Summer 2015 colors is Scuba Blue – which “offers a feeling of escape that is reminiscent of a tropical ocean.” It is a soothing hue that conjures lazy days spent on secluded beaches. We dove into gemological waters to find matching gemstones.

View Gallery

	Lucite Green
Fresh…cool….clarifying – that’s how Pantone describes Lucite Green. It’s a paler shade of green that’s soothing to the spirit. Chrysoprase, tourmaline, and tsavorite are some gemstones that capture this gentler hue.

View Gallery

	Classic Blue
Called the “anchor of the Spring/Summer 2015 palette,” Classic Blue is said by Pantone to create calmness and to evoke the sea. A number of gemstones mirror the colors of the ocean. Sapphire is a familiar one; benitoite and apatite are two less-familiar ones.

View Gallery

	Tangerine
Pantone says Tangerine is “spontaneous,” “energizing” and “friendly.” The gem world is filled with beautiful options that fit the description. These stunning stones make for colorful center stones in statement pieces.

View Gallery

Now that you know some of the gems that match up with the Pantone 2015 Spring and Summer colors, you can create and sell matching jewelry with greater confidence. As the days shorten, look for GIA to provide suggestions to Pantone’s Fall and Winter colors. @chapter:40 @chapter:0 @chapter:40


# Publication Year: 1984
# Title: Spring 1984 G&G Lab Notes
# Abstract: Beryl, with Iridescent Coating
Coral, Dyed Blue with Plastic Coating
Diamond with Unusually Large Laser Holes
A Successful Laser Experiment with Diamond
Oiled Emerald,
Magnetic Hematite
Dyed Jadeite
Dyed Nephrite
Hollow Natural Pearl
Ruby, "Manufactured" Mineral Specimen
Scapolite, a New Cat's-Eye from Kenya

To view the full section, download the PDF above. @chapter:18 @chapter:0 @chapter:18