Publication Year: 2017 Title: Tri-Color-Change Holmium-Doped Synthetic CZ Abstract: Figure 1. This 68 ct synthetic CZ shows three distinct hues in CIE standard illuminant F10 (left), CIE standard illuminant F9 (center), and CIE standard illuminant D65 (right). Photos by Robison McMurtry.
Colored yttria-stabilized synthetic cubic zirconia (CZ) has been an attractive diamond substitute since the late 1970s (R.T. Liddicoat and J.I. Koivula, “Synthetic cubic stabilized zirconia,” Summer 1978 G&G, pp. 58–60). The different colors seen in synthetic CZ are caused by the introduction of specific transition metal elements and rare earth elements (K. Nassau, “Cubic zirconia: an update,” Spring 1981 G&G, pp. 9–19). At this year’s Tucson Gem and Mineral Show, the authors obtained an interesting synthetic CZ rough that exhibited an unusual color-change behavior (figure 1). Unlike traditional color-change stones such as alexandrite, color-change corundum, and color-change garnet, this material did not exhibit different colors when illumination alternated between incandescent light and daylight conditions (approximated by CIE standard illuminants A and D65, respectively). Surprisingly, it showed three distinct hues in daylight/incandescent light (yellowish green), in fluorescent lighting corresponding to CIE standard illuminant F9 (green-blue), and in CIE standard illuminant F10 (purplish violet). One wafer with 3.32 mm thickness was polished and analyzed to understand this color-change phenomenon.

The wafer’s chemical composition was obtained using a Thermo Fisher iCAP Q ICP-MS coupled with a New Wave Research UP-213 laser ablation unit. Laser ablation–inductively coupled plasma–mass spectrometry (LA-ICP-MS) analyses were performed in the same spot where the spectroscopic data was collected. Based on its calculated chemical formula of Zr0.52Y0.45Ho0.02Hf0.01O1.79 (the formula is nonstoichiometric and calculated by forcing cations to 1 atom per formula), the wafer was a holmium-doped yttria-stabilized CZ (S. Gutzov et al., “High temperature optical spectroscopy of cubicholmium doped zirconia, Zr0.78Y0.21Ho0.01O1.90,” Physical Chemistry Chemical Physics, Vol. 9, No, 4, 2007, pp. 491–496). Holmium was the only detected chromophore, at a concentration of about 7780 ppma.

Visible spectra were collected with a Hitachi U-2910 spectrometer with a 1 nm spectral resolution at a scan speed of 400 nm/min. The wafer’s spectrum matched the holmium-doped CZ spectrum reported by Gutzov et al. (2007). The unusual color change under different illuminants can be qualitatively understood by examining figure 2. The violet and orange emission peaks of the F10 illuminant are not absorbed by Ho-doped CZ; however, there is significant absorption by holmium of the green emission peak for the F10 illuminant. This selective absorption of the F10 emissions creates a purplish violet color (figure 2, top). The F9 illuminant has more of a broadband emission, which is unaffected by the strong but narrow absorption by holmium of green light at 540 nm. This results in a blue-green color under F9 illumination (figure 2, middle). The D65 illuminant is essentially a broadband emission roughly corresponding to a black body irradiator at 6500 K. Under D65 illumination, a yellowish green color is produced because of the strong absorption of blue light by holmium (figure 2, bottom).

Figure 2. The UV-Vis-NIR absorption spectrum of holmium-doped
synthetic CZ is shown with the relative power distribution curves of
CIE illuminant F10 (top), CIE illuminant F9 (middle), and CIE
illuminant D65 (bottom).

Figure 3. In the CIELab 1976 color circle, the color of holmium-doped synthetic CZ with 10 mm light path length changes from yellowish green in CIE standard illuminant D65 to blue-green in CIE standard illuminant F9 to purplish violet in CIE standard illuminant F10. The hue angle differences are 148.61° between D65 and F10, 34.96° between D65 and F9, and 113.65° between F10 and F9. The chroma differences are 4.73 between D65 andF10, 15.52 between D65 and F9, and 10.79 between F10 and F9. In contrast, the hue angle difference and chroma difference between D65 and A are 3.37° and 5.79, respectively.
The wafer’s visible absorption spectrum was reflection corrected by subtracting the absorbance value at 850 nm, where no chromophoric absorption is expected, from values for every other data point along the rest of the spectrum. The reflection-loss-corrected visible spectrum can then be used to quantitatively calculate the color of this material at a wide range of path lengths and under different lighting conditions (Z. Sun et al., “Vanadium- and chromium- bearing pink pyrope garnet: Characterization and quantitative colorimetric analysis,” Winter 2015 G&G, pp. 348–369). There are large differences in the CIE L*, a*, b* color coordinates between D65, F10, and F9 (figure 3). One way to judge the quality of a color-change stone is to plot the color pair in the CIE 1976 color circle. Well-defined color-change pairings show a large hue angle difference, a small chroma difference, and high chroma values. The color coordinates of the material with a 10 mm light path length in D65, F9, and F10 were plotted in the CIE 1976 color circle shown in figure 3; calculated color panels for the illuminants were also placed alongside the faceted material (see below). The fact that the material shows three distinct hues in three different white lights makes it unique. @chapter:32


Publication Year: 2003 Title: Beryllium Diffusion of Ruby and Sapphire Abstract: Over the past two years, the heat treatment of corundum involving lattice diffusion of beryllium (Be) at temperatures over 1800°C has become a major issue in the gem trade. Although initially only orange to orangy pink (“padparadscha”-like) sapphires were seen, it is now known that a full range of corundum colors, including yellow and blue as well as ruby, have been produced or altered by this treatment. An extension of the current understanding of the causes of color in corundum is presented to help explain the color modifications induced by Be diffusion. Empirical support is provided by Be diffusion experiments conducted on corundum from various geographic sources. Examination of hundreds of rough and faceted Be-diffused sapphires revealed that standard gemological testing will identify many of these treated corundums, although in some instances costly chemical analysis by mass spectrometry is required. Potential new methods are being investigated to provide additional identification aids, as major laboratories develop special nomenclature for describing this treatment.

	DATA DEPOSITORY

Table 1: Samples Used for Gemological Characterization
Table 2: Trace-Element Compositions of Be-Diffused and Natural-Color Corundum Determined Using SIMS (ppma)
	Submitted by Wuyi Wang
	Prepared by Gems & Gemology staff
	July 30, 2003

Table 3: Durability and Stability of the Treatment in Be Lattice Diffusion–Treated Orange to Pinkish Orange Sapphires
	Submitted by Robert E. Kane
	Prepared by Gems & Gemology staff
	July 30, 2003

Supplementary Bibliography on Corundum Diffusion
	Prepared by Gems & Gemology staff
	July 30, 2003 @chapter:12


Publication Year: - Title: Classic, Funky Cufflinks Reflect 227 Years of Family Tradition Abstract: James Deakin designed these silver Tok Tokki beetle cuff links after a camping trip in Africa. They are called Tok Tokki beetle cuff links because of the noise they make tapping their bodies on the ground.

                      Family history runs deep at Deakin & Francis -- seven generations deep. That’s how long the workshops in Birmingham, England, founded by Charles Washington Shirley Deakin in 1786 have been designing and manufacturing some of the world’s finest cuff links.

Today, Charles’ descendants, James and Henry Deakin, brothers and GIA alumni, own and manage the business.

	Brothers Henry and James Deakin are at the helm of the business created by their ancestor in 1786. Photos by provided by Deakin & Francis
James, director of design and manufacturing, said he feels a sense of responsibility for carrying on the company’s long legacy. His favorite part of being in the family business is “creating products to the very best of our abilities so they will last and be treasured for generations.”

“My father’s parting words before retiring were, ‘Someone out there will always try to make it cheaper than you, but don’t let anyone make it better’,” he said.

Deakin & Francis designs are worn by business people, celebrities and members of royalty worldwide. Styles include gold and silver cuff links that incorporate vitreous enamel and fine gemstones and run the gamut from traditionally shaped (diamond, rectangle and square) to animal-, insect- and sport-themed cuff links, including King Rat, motorcycles and a skull and cross bones topped with a crown.

InStyle magazine featured the company’s “Knockout” cuff links in its December 2012 gift guide and GQ highlighted the bumblebee, pirate and dinosaur cuff links in its January 2013 issue.

“It’s great that our designs are becoming internationally recognized,” James said. “GQ and InStyle magazines are ideal publications for us to be featured in.”

Both brothers attended GIA to enhance their knowledge of design and gemstones: James earned his GIA Graduate Jeweler diploma in 1995 and GIA Graduate Gemologist (GG) diploma in 1996 in Santa Monica; Henry earned his GG and Jewelry Design certificate in Vicenza in 2001. Both worked for Aspreys in New York before returning to the family business.

James said attending GIA was a great way for him to get the bench experience he was seeking.

“All I was interested in at that time was designing and making,” he said. “I use the skills that I learned at GIA every single day. From design to gemology to manufacture, these three courses were tailored exactly to processes I go through every day either in the factory or in meeting with clients.”

Henry, director of sales, said GIA gave him all of the skills and confidence he needed to join the family business.

“I was very young when I started working and my GIA education was a great help in reinforcing confidence in my abilities, not only for myself but also for my customers,” he said. “When I am talking with them I am able to understand their needs and advise them on the best designs, materials and stones to fit their specifications.”

These days the brothers are focused on coming up with new ideas and designs to keep the family business competitive.

“We have found that continually redesigning the collection of products we offer and not worrying about what other companies are doing has kept us ahead,” Henry said.

That includes going with your gut inspiration and being prepared to be wrong -- and being happy to be different, James said.

“Some of my weirdest designs have become our best sellers,” he said. “I originally drew them for myself out of curiosity to see what they would look like. Some of these designs have made their way into the world’s best stores.” @chapter:16


Publication Year: - Title: The “Glet Filling”: The Filling of the Cracks in Precious Stones Under Scrutiny Abstract: This short article discusses several important aspects of crack-filling in colored stones and diamonds: the differences in market values between included and filled stones, especially in high quality goods; the impact of nondisclosure within the supply chain; a brief discussion of different methods of filling and their limitations; and, finally, methods of detection.

Several similar methods of filling cracks (“glets”) have been developed under such names as Yehuda and Koss (Israel) and Diascence, Genesis Enhanced, and Goldman Oved (New York). One of the filling methods discussed in more detail, the Koss system developed at least ten years ago, limits the rainbow or “flash” effect (the yellow-orange color flashing into electric blue under dark field microscopy) characteristic of many other filling methods, and useful for identifying the presence of a filler.

Regardless of method, the visual improvements achieved from filling cracks with oils or the more modern vitreous, high-RI materials is temporary; eventually the tears and cracks become visible after a few months or years. Fillers degrade with time and by environmental conditions. Some dry out to reveal noticeable residue; others deteriorate with exposures to ultrasound, ultraviolet, heat, acids, and chemical cleaners.

Several methods of detecting fillers are briefly mentioned. Gemologists commonly use magnification to observe bubbles, filler textures, the flash effect, and effects of deterioration. Advanced instruments such as the scanning electron microscope, X-ray fluorescence analysis, and Raman spectroscopy easily reveal the presence of filled glets.

Abstracted by Edward R. Blomgren @chapter:35


Publication Year: - Title: Summer 2023 G&G Available Now Abstract: The summer issue of G&G is packed with interesting new content! In our three feature articles, read about a newly discovered treatment in spinel, a find of augite in Vietnam, and the origin of mammoth ivory’s brown color. In addition to these articles and our regular quarterly sections, we see the return of Colored Stones Unearthed and finish the issue with a spotlight on fire obsidian.
COLOR MODIFICATION OF SPINEL BY NICKEL DIFFUSION: A NEW TREATMENT
Dr. Michael Jollands and GIA researchers share their study of a new color treatment for natural spinel, which turns lightly colored stones into deeper blue and green hues. Their analysis of a set of faceted spinel submitted as “cobalt diffused” revealed that the gems were actually diffused with nickel. With this treatment likely to become more common in the gem market, the team also suggests criteria for identifying nickel diffusion in blue and green spinel.
GEM-QUALITY AUGITE FROM DONG NAI, VIETNAM
A team led by Le Ngoc Nang reports on a variety of gem-quality augite from Dong Nai, Vietnam. Characterized by intense dark brown or dark green colors when viewed in transmitted light, the augite is classified as magnesium-rich and has potential for use in jewelry and in carvings.
ORIGINS OF COLOR IN BROWN MAMMOTH IVORY
Mammoth ivory is most commonly found with a brown surface color. Zhaoying Huang and coauthors investigate the origin of this brown color by studying mammoth ivory samples’ spectroscopic and mineralogical characteristics, surface morphology, and chemical composition. They determine that formation of iron oxides, manganese oxides, manganese hydroxides, and iron sulfides on the ivory underground resulted in the brown surface color.
LAB NOTES
GIA’s global laboratory staff present their latest findings in the Lab Notes section, including yellow zoning in unusual natural pink diamonds, invisible markings in CVD laboratory-grown diamonds, and an exceptionally large South Sea cultured pearl.
MICRO-WORLD
The Micro-World section, dedicated to the inner world of gemstones, highlights thread-like serpentine inclusions in brown peridot, a globular iron stain and curved lines in yellow sapphire, an interesting metal sulfide inclusion in garnet, and more.
COLORED STONES UNEARTHED
Colored Stones Unearthed returns to examine gem minerals that form in metamorphic environments, such as jade, corundum, tanzanite, and tsavorite garnet. Studying these gems offers gemologists insight into the evolution of tectonic activity that led to their formation.
GEM NEWS INTERNATIONAL
GNI contributors cover a wide variety of topics, ranging from reports on several pearl species to a new treatment used to create phantom structure in opal. The section also includes a roundup of the spring 2023 auction highlights and recaps of the 2023 Sinkankas Symposium and the sustainability panels at the JCK show in Las Vegas.
IN THE SPOTLIGHT
Lastly, we spotlight fire obsidian, a rare volcanic glass found only in the Glass Buttes region of Oregon. Lapidary artist Tom Dodge shares his work revealing a vibrant spectrum of iridescent colors. @chapter:3


Publication Year: 2016 Title: Ferropericlase Inclusion in Diamond Abstract: The changing iridescent colors of a ferropericlase inclusion are revealed through different facets of the host diamond. Photomicrographs by Evan M. Smith; field of view 1.99 mm.

	Most diamonds originate from the cratonic lithosphere, the basal portion of the thickest, oldest parts of continents. Rarely, diamonds are found with mineral inclusions that indicate a deeper origin, below the lithosphere, within the convecting mantle. Ferropericlase, (Mg,Fe)O, is one of the most common of such “superdeep” inclusion phases (T. Stachel et al., “Inclusions in sublithospheric diamonds: Glimpses of deep Earth,” Elements, Vol. 1, 2005, pp. 73–78). It often exhibits a vivid iridescence that serves as a helpful identifier. A 1.54 ct Fancy Light pink type IIa diamond with a spectacular ferropericlase inclusion was recently examined in GIA’s New York lab (see above). The exact cause of this iridescence is unknown, but it may arise at the inclusion-diamond interface due to thin-film interference from trapped fluid or structural coloration from ultra-fine exsolution of magnesioferrite. The iridescent colors of these ferropericlase inclusions change with viewing and lighting angles. The iridescence is not always uniform and can sometimes be absent, in which case the inclusion appears a transparent deep brown color.

	Strictly speaking, ferropericlase inclusions alone do not necessarily indicate a sublithospheric origin (T. Stachel et al., 2005). This is the case for the present diamond, so the assignment of sublithospheric origin is only tentative. It may be possible to create ferropericlase at shallower depths, in the lithosphere, if special conditions occur that lower the availability of silica. @chapter:35


Publication Year: - Title: Summer 2017 G&G: Russian Diamonds and PL Mapping of Synthetic Diamonds, Plus Sapphire Inclusions Chart Abstract: The Fall 2017 issue of Gems & Gemology covers topics across the gemological spectrum, from HPHT synthetic diamond identification criteria to natural saltwater pearls harvested during the Columbian era and the current state of Colombia’s emerald industry. Other highlights include a study of photoluminescence spectra in emerald as a method of determining geographic origin, a review of synthetic star corundum from mid-twentieth century Germany, and an examination of the material known in the industry as “dalmatian jasper.”
OBSERVATIONS ON HPHT-GROWN SYNTHETIC DIAMONDS: A REVIEW

While some HPHT synthetic inclusions appear transparent, most appear to be pieces of dark solidified metal flux. A variety of shapes are possible, including thin rods and irregular shapes, and some are associated with feathers. These metallic inclusions can create a magnetic attraction. Photo by Sally Eaton-Magaña.
While synthetic diamonds grown by the high-pressure, high-temperature (HPHT) method have been commercially available since the mid-1990s, the technology has made great strides in the last decade. In the issue’s lead article, GIA’s Sally Eaton-Magaña, James E. Shigley, and Christopher M. Breeding provide insight into the HPHT-grown material available on the market, including statistical data about the cut, color, and clarities available as well as identification criteria for gemologists.
SALTWATER PEARLS FROM THE PRE- TO EARLY COLUMBIAN ERA: A GEMOLOGICAL AND RADIOCARBON DATING STUDY

These natural pearls, reportedly from thepre- to early Columbian era, represent some of the 85samples examined in the study. They were discoveredalready drilled but were only recently strung as anecklace. The center blister pearl (31.41 × 16.86 ×10.25 mm) consists of multiple small pearls thatformed as an aggregate. Photo by Sood Oil (Judy)Chia.
Pearls were treasured by the indigenous people of the Americas and by the Spanish colonists. Oyster beds in the Caribbean were heavily exploited during the first half of the sixteenth century before oysters became scarce. A supplier came into possession of 85 pearls, reportedly from Central or South America and dating from the pre- or early Columbian era. A team from GIA and the Gübelin Gem Lab, led by Chunhui Zhou, analyzes the pearls through a variety of methods to validate these claims.
PHOTOLUMINESCENCE SPECTRA OF EMERALDS FROM COLOMBIA, AFGHANISTAN, AND ZAMBIA

Emerald crystals from Zambia (left), Colombia (top right), and Afghanistan (bottom right). Each emerald’s hexagonal prismatic crystal habit has been enhanced by polishing flat the two hexagonal end faces (perpendicular to the crystal’s c-axis) and two or more prism sides (parallel to the c-axis). Photo by D.B. Thompson.
Photoluminescence (PL) in emerald arises from trace chromium impurities. An emerald’s PL spectrum displays two features that can vary depending on the stone’s origin. Lead author David Brian Thompson and his team examine the PL spectra of 48 emeralds from Colombia, Afghanistan, and Zambia to provide evidence for or against possible geographic origins.
SYNTHETIC STAR SAPPHIRES AND RUBIES PRODUCED BY WIEDE’S CARBIDWERK, FREYUNG, GERMANY

Three synthetic blue star sapphire cabochons and one synthetic star ruby cabochon in direct sunlight. The ruby weighs 8.92 ct and measures 13.2 × 11.0 mm; the sapphire at the bottom left weighs 3.67 ct and measures 9.1 mm in diameter. Photos by K. Schmetzer.
During the 1950s, Wiede’s Carbidwerk patented a method of growing star synthetic corundum for the commercial market. The company sold these goods through the late 1970s, though the samples from the 1960s and beyond differ slightly from their earlier counterparts. Karl Schmetzer and his coauthors explore the variant of the Verneuil process that Wiede’s used to grow these synthetics.
TRUE COLORS OF “DALMATIAN JASPER”

Dalmatian stone samples examined in this study reveal a spotted appearance connected with the presenceof alkali amphiboles disseminated through feldspar-quartz matrices. Left: A rough block-shaped specimenmeasuring 1.5 × 1.5 × 1 cm. Right: A polished bracelet (1 cm bead diameter) alongside a pendant measuring 3 cmin length. Photos by Tomasz Powolny.
The decorative gemstone known in the trade as “dalmatian jasper” due to its black spots (identified as arfvedsonite) is not widely discussed in the published literature. Tomas Powolny and Magdalena Dumańska-Słowik investigate the stone’s mineralogical composition and properties. On the basis of the study, they suggest the use of “dalmatian stone,” as the material does not meet the gemological definition of jasper.
THE COLOMBIAN EMERALD INDUSTRY: WINDS OF CHANGE

Colombian emerald-producing areas such as Muzo have a long tradition of independent mining. The hope of finding the stone that will change their lives is a strong motivator for miners, but bringing them into a formal system is challenging. Photo by Andrew Lucas.
Emerald mining in Colombia dates back more than a thousand years. Yet its greatest opportunities may still lie ahead, as multinational companies invest in the industry as transparency and traceability come to the forefront. In this field report, an expedition led by Colombian gemologist Darwin Fortaleché documents the recent changes in the country’s mine-to-market emerald industry.
LAB NOTES

A Brazilian kimberlite yielded a 50.8 ct rough type Ia diamondwith a dodecahedral habit, the result of resorption. Right: This 20.1ct round brilliant with I color was cut from the Brazilian rough.
Updates from GIA’s labs include reports on a high-quality diamond from Brazilian kimberlite, synthetic overgrowth on a flux-heated ruby and a beryllium-diffused sapphire, and separation of synthetic melee from natural diamond using GIA’s iD100 screening device.
MICRO-WORLD

Reminiscentof a flower in a rainstorm,this inclusionscene has been dramaticallyenhanced usingmodified Rheinberg illuminationto accentuatea growth blockageand thin-film rosettewithin a sapphire fromElahera, Sri Lanka.Photomicrograph byJonathan Muyal; fieldof view 1.34 mm.
G&G’s photomicrography section features a flower-like inclusion in a Sri Lankan sapphire, silvery rutile inclusions in quartz, and fluorite hosting eye-visible barite inclusions.
GEM NEWS INTERNATIONAL

These sapphires (0.64–8.27 ct) are from Antangand Gombe, in northern Nigeria. Photo by ShunsukeNagai.
The Fall GNI section includes an update on Mozambique ruby mining, an analysis of blue-green pyrope-spessartine with high vanadium, and an examination of sapphires reportedly from new sources in northern Nigeria. @chapter:23


Publication Year: - Title: Synthetic Diamonds: How Many Are Out There? Abstract: GIA research scientist Sally Eaton Magana analyzes the image of a marquise diamond in the DiamondView to determine whether or not the stone is synthetic. Photo ©GIA.

Another report of a gemology lab spotting a parcel of undisclosed synthetics has prompted renewed questions about how many synthetics may have infiltrated the gem market – and there is considerable disagreement.

One estimate by Tacy Ltd. said that more than $700 million worth of synthetics – disclosed or not – entered the jewelry market last year. De Beers, on the other hand, while not providing a dollar amount, claims that only a fraction of that figure is in the market. De Beers said it bases its opinion on the costs involved in producing both Chemical Vapor Deposition (CVD) and High-Pressure, High-Temperature (HPHT) synthetics, both of which it manufactures through its Element Six division.

GIA has seen no appreciable upturn in the numbers of synthetics to its lab, disclosed or not, said Tom Moses, senior vice-president of Laboratory and Research.

The controversy over undisclosed synthetics is generally focused on smaller diamonds (under 0.30 carats) that are less likely to be submitted to GIA or other gemological labs. While there is ample evidence that Fancy yellow and yellowish brown melee-sized HPHT synthetics have been in the market for some time (Gems & Gemology, Fall 2008), small CVD colorless synthetics offer very little price advantage over natural diamonds because of high production costs, according to Stephen Lussier, Executive Vice President, Marketing, De Beers Group; CEO, Forevermark who was interviewed last Spring. He believes the majority of undisclosed small CVD synthetics are by-products of large pieces created for industrial uses and believes that those turning up in labs are still “isolated examples.” CVD-grown diamonds are type IIa, free of nitrogen that can add color, which makes them useful for optics and electronics.
The technology to create CVD synthetics, however, is improving, which means their numbers in the market may increase. Dr. James Shigley, GIA’s Distinguished Research Fellow, notes that recent samples he has examined show no signs of post-production treatment. Earlier CVD synthetics often came out gray colored and required costly heat treatments to improve their color. Eliminating post-treatment heat processing cuts costs considerably, but also lessens the risk of damage to the newly made stones.

De Beers, Lussier said, is preparing a defense against undisclosed synthetics in the form of a mass-screening device to fast-check melee for synthetics. The unit is in testing. Earlier this month, the company reported that it had tested numerous parcels of melee on behalf of its clients and found no synthetic diamonds.

One recent synthetics-sighting was in a group of 18 type IIa Fancy brown stones, ranging from 0.14 to 0.63 carats, that a dealer purchased in hopes of improving the color through HPHT treatment. The treatments were unsuccessful, however, prompting the dealer to send them to a lab for examination. The lab reported that 13 of the stones were CVD synthetics.

GIA researchers continually test synthetic samples with the De Beers’ DiamondSure, which can flag all synthetics, along with some types of treated diamonds, and also a small percentage of natural diamonds. Stones that are referred by the DiamondSure as possibly synthetic have spectra collected by advanced testing instrumentation and are typically screened by the larger DiamondView, which provides an extremely detailed fluorescence image that GIA researchers use to  identify whether the diamond is natural or synthetic.

GIA researchers perform a battery of additional tests on all “referred” diamonds to be absolutely certain of a diamond's origin.

The DiamondSure is the one of the first tests a diamond will receive after submission to GIA labs. If the diamond is Type II and shows certain characteristics, the DiamondSure will refer the stone to the DiamondView for further testing. Photo ©GIA.

The DiamondView enables lab staff to view tell-tale growth patterns for synthetic diamonds. The regular striations visible in the middle of this round diamond indicate it is a CVD-grown synthetic. Photo ©GIA. @chapter:31


Publication Year: 2016 Title: Application of the DiamondView in Separating Impregnated Jadeite Abstract: Figure 1. The two jadeite samples exhibited a mottled dark and light green bodycolor (left, 4.91 ct oval) and a uniform lighter green bodycolor (right, 0.32 ct pear). Photos by Lai Tai-An Gem Lab.
Infrared and Raman spectroscopy are frequently used to separate impregnated jadeite jade from untreated material. Recent trials show that the DiamondView instrument provides reliable results in detecting impregnated material, offering gemologists a new identification method.

The Lai Tai-An Gem Lab in Taipei analyzed two client-submitted jadeite samples (figure 1): a 4.91 ct oval measuring approximately 19.64 × 11.78 × 2.62 mm and a 0.32 ct pear-shaped drop measuring 7.77 × 5.91 × 0.95 mm. The oval possessed a mottled dark and light green bodycolor, while the pear shape exhibited a more uniform, lighter green bodycolor. Both pieces were translucent. Standard gemological testing showed spot RIs of 1.66 and SGs of 3.30 for the oval and 3.24 for the pear. A handheld spectroscope revealed lines at 630, 655, and 691 nm, indicative of naturally colored jadeite; both samples were inert to long-wave and short-wave UV fluorescence. Microscopic observation revealed fine surface-reaching networks of cracks and uncovered the “cobweb-like” features characteristic of bleached jadeite. However, DiamondView imaging produced striking blue reactions (figure 2), clearly indicating that both jadeites had been impregnated.

Figure 2. DiamondView imaging of the jadeite samples. Top: Both the oval (left) and the pear shape (right) displayed the “cobweb” feature under visible light. Bottom: The DiamondView’s UV light produced striking blue reactions in the cobweb structure, indicating impregnation in both jadeites. Images by Lai Tai-An Gem Lab.
We confirmed that the samples were impregnated jadeite using the advanced methods commonly applied in such cases. FTIR spectroscopy revealed absorptions at 3061, 3037, 2965, 2925, and 2874 cm−1 (figure 3), while Raman spectroscopy using a 532 nm laser showed peaks at 638, 1112, 1608, and 3066 cm−1. Both offered proof that an epoxy was used as the impregnation material.

Figure 3. Peaks in the jadeite sample’s FTIR spectrum at 3061, 3037, 2965, 2925, and
2874 cm–1 proved that an epoxy was used as the impregnation material.
Impregnated jadeite jade appears to be readily separated from untreated material by DiamondView imaging. While more samples need to be examined, this technique could be a simple and effective way to identify impregnation treatment. @chapter:37


Publication Year: 2019 Title: Book Review: Figures & Faces: The Art of Jewelry Abstract: By Patrick Mauriès and Évelyne Possémé, 127 pp., hardcover, illus., published by Thames & Hudson Ltd., London. US$24.95.

Patrick Mauriès and Évelyne Possémé have written a trilogy of books dedicated to decorative themes and the art of jewelry. Preceded by Flora and Fauna, Figures & Faces explores the human form as depicted in jewelry. The books exclusively feature items from the collection of the Musée des Arts Décoratifs in Paris.
The book opens with a preface by Olivier Gabet, director of the Musée des Arts Décoratifs, and a forward by Marie Vallanet and Nicolas Bas, the presidents of École des Arts Joailliers and Van Cleef & Arpels, respectively. Each sets up the reader for the beauty in the pages to come. Next come essays titled “Discreet Effigies,” and “The Bejeweled Body.” The first, written by Patrick Mauriès, explores the history of the human form in jewels of adornment. Here, Mauriès traces the evolution of jewelry as a means to depict religious and mythological figures to its use as talismans of great sentimentality and, ultimately, of love. The second esssay, written by Évelyne Possémé, discusses the societal attitudes of the use of the human body in jewelry.
The rest of the book consists of chapters on devotion, love, faces, portraits, fantasy and the Art of the Vanitas. “Mythological Figures” covers just that: this section shows lovely jewelry set with carvings of Medusa, Minerva, Achilles, and other Greco-Roman figures. The popularity of this subject matter has ebbed and flowed throughout history but the authors recall how the popularity of the female form in jewelry peaked during the Art Nouveau period. The photographs throughout this book are very well done and I was amazed, particularly in this chapter, with the minute details these photos could reveal in the carved pieces shown here. For example, even in rings, details such as nostrils, eyelids, and individual wisps of hair are carefully depicted.
The chapter “Figures of Devotion” highlights jewelry in religious motifs from the Byzantine era to present day. Of particular note here is the discussion on reverse painting, which was frequently used to show religious scenes that include full-bodied figures. Reverse painting is a technique involving painting a scene, in reverse, on a transparent material, usually glass or rock crystal quartz. The painting is then flipped over and set into all forms of jewelry so that the image is now sandwiched between the transparent material and a backing material, usually precious metal. The details of these tiny works of art can be staggering and very beautiful.
“Figures of Love” points out that jewelry “often conveys a message of love,” and fittingly, can often show Cupids, putti, clasped hands, and intertwined human forms. An interesting point made in this chapter is the fact that aluminum, when first discovered, was considered a precious metal and was treated appropriately. As a result, there are many pieces of art cast in or created from aluminum. A stunning nineteenth century bracelet of two putti, made of aluminum, gold, rubies, and diamonds is included in this chapter.
Next comes the chapter called, “Historical Faces.” The chapter features an impressive array of pieces showcasing images of various kings, queens, and other notable figures. In “Personal Portraits” we learn that during the eighteenth century it became acceptable to carry images of loved ones. Prior to that time, it was considered “unseemly” to wear items of such sentimentality. The chapter features jewelry set with painted and enamel portraits, as well as cameos. And “Figures of Fantasy” places an emphasis on feminine figures and provocative body parts—lips, hands—again using the style of the Art Nouveau era, executed in all manner of materials or sculpted in precious metal.
The final chapter, “The Art of the Vanitas” features jewelry that depicts skulls. “Vanitas” refers to works of art that contain symbols of death or depict symbolic reminders of the inevitability of death. These memento mori, or reminders that death will come for everyone, can be found in rosaries and all manner of jewelry. Notable in this chapter are an amazing enameled pomander shaped as a skull and an impressive skull-shaped watch case.
As a reader, I found the text engaging and to the point. It was not unduly heavy, making it enjoyable to read. As a jewelry lover myself, I greatly enjoyed the beautifully photographed, and painstakingly crafted pieces found at the Musée des Arts Décoratifs. Having never had the opportunity to visit that particular museum, I now hope for the chance one day.
I have admittedly not read the previous two texts in this set of three. I now plan to backtrack and read Flora and Fauna because of how extraordinary I found Figures & Faces to be. I would gladly recommend this book to anyone interested in the history of jewelry. @chapter:21


Publication Year: 2021 Title: Prominent Growth Planes Observed in HPHT-Processed CVD Laboratory-Grown Diamonds Abstract: Figure 1. Face-up images of four CVD laboratory-grown diamonds with an eye-visible growth plane. These four diamonds range from 1.81 to 2.51 ct. Photos by Johnny Leung and Tony Leung.
The laboratory-grown diamond industry is ever evolving and improving. With state-of-the-art growth and treatment technology, high-quality CVD diamonds, in terms of clarity and color, are now commonly seen on the consumer market. Laboratory-grown diamonds are occasionally submitted for natural diamond grading services, and recently GIA’s Hong Kong laboratory received a total of 43 undisclosed CVD-grown diamonds treated by high pressure and high temperature (HPHT), ranging from 0.70 to 2.63 ct in weight, from the same client. Laboratory-Grown Diamond Reports were issued for these synthetics, which received E–I color grades and VVS2–I2 clarity grades.
Four samples had a very eye-catching feature—a dark circle or ring at the center when viewed face-up without magnification. The ring appeared to be a thick grayish layer at the culet when viewed from the pavilion (figure 1). As the extraordinary feature looked shiny and resembled the separation plane often observed in assembled stones, questions about the true identity of these samples were raised.
Microscopic examination of these four samples revealed some interesting findings. There was a textured plane almost parallel to the table facet, each with a different appearance (figure 2): fine clouds all the way across; ripple-like waves with some “holes” (colorless areas); a mixture of both; and a ripple-like plane that was not visible all the way around.

Figure 2. Visible planes with different textures: fine clouds (top left, field of view 3.83 mm) and wave ripples (top right, field of view approximately 3 mm). Colorless “holes” observed in a ripple-like plane under the microscope (bottom left, field of view 3.83 mm) and in immersion (bottom right). The blue color in the top left photo is due to a different white balance to emphasize the texture. Images by Billie Pui Lai Law (top left, top right, and bottom left) and Johnny Leung (bottom right).
An additional 26 samples had visible grayish/brownish planes either at the pavilion, which were much less prominent, or at the pavilion viewing through the table. Eight of these additional samples had a plane at an angle to the table facet. The plane appeared as a line with no color difference when immersed in water and viewed in a parallel direction to the growth plane. All 43 samples generally showed a banded and cross-hatched strain pattern when viewed with crossed polarizers (figure 3).

Figure 3. A banded strain pattern seen across the visible plane. Photo by Billie Pui Lai Law; field of view 11.45 mm.
Spectroscopic analysis of the 43 samples yielded very similar results. They were either type IIa or type IIb and had a very strong silicon vacancy doublet peak (736.5 and 736.9 nm) in their photoluminescence spectra, typical of CVD-grown diamonds. PL spectra were also collected at the table and at the pavilion somewhere between the growth plane and the culet for the samples with a very prominent growth plane, but the data did not show any critical differences. The most diagnostic test was DiamondView imaging, as all 43 displayed very distinct growth layers (figure 4). It also revealed the HPHT treatment history that the CVD diamonds had experienced.

Figure 4. DiamondView imaging provided evidence of CVD growth. Images by Billie Pui Lai Law.
The uniformity of the growth layers observed in DiamondView imaging and under crossed polarizers, together with the immersion test, showed no evidence of assembly and therefore excluded the possibility of a doublet. The color making the growth plane visible is believed to come from the non-diamond carbon deposited between two growths. It could not be removed by the post-growth HPHT treatment. @chapter:15


Publication Year: - Title: Tucson Visit Spurs Geology Professor, Publisher to Head Back to School Abstract: Dr. Hobart King, GG, began prospecting for invertebrate fossils in his parents’ limestone driveway as a 6-year-old and tumbling rocks a few years later. He enjoyed a long, established career as a geology professor before purchasing the website Geology.com. “Always be learning,” he says. “Keep your eyes open for new skills, tools, and information that can advance your business.” Courtesy of Geology.com. Photo by Bradley Cole

Dr. Hobart King was already an accomplished geologist with more than 40 years of experience, 20 of those spent teaching at the university level. He’d moved on to a career in publishing, but a casual visit to GIA’s informational booth at the Tucson gem and mineral shows led him back to the classroom – this time, as a student.
King, who worked as a geologist at West Virginia University and the West Virginia Geological and Economic Survey from the mid-1970s through the early 1990s, taught at Pennsylvania State University and Mansfield University of Pennsylvania from the 1980s through 2008. He taught geology, hydrology, global positioning systems and web-based cartography, and served as the director of Mansfield’s Center for Effective Teaching and a content advisor for the Earth and Space Science Education program.
When King approached the GIA booth in 2010, he had already started to consider furthering his own education. He had also begun publishing informational articles on Geology.com, an Earth science news and information website he purchased in 2005 with the intent to help educate the general public and those interested in introductory geology.

“Tumbled stones are the least expensive way to start a gem collection,” says King, who sells a few tons of the stones each year to hobbyists and beginning lapidaries, and even sends them to GIA for identification. “When I took GIA’s Gem Identification course, I was happy to be asked to identify a number of tumbled stones.” Courtesy of Geology.com. Photo by Bradley Cole
“I’d always been interested in gems,” he says. “As I wrote articles about rocks and minerals for Geology.com, many were gem materials, and I’d sometimes include a photo of a cabochon or faceted stone. I noticed the gem photos led to a large increase in visitors, so I started adding more information about gems to those articles. The popularity of those articles increased in page views and how much time they’d spend on the page – my visitors wanted to know about gems! That compelled me to obtain a formal education in gemology so I could write more competently.”
King had been an early adopter of online education, helping Mansfield University of Pennsylvania develop what he believes was “one of the first interactive geology courses in the United States delivered completely online.” He was surprised and pleased to learn that GIA offered Distance Education classes, and enrolled immediately in Colored Stones Essentials, continuing with other GIA Distance Education courses over the next several years.
In 2016, King had a personal breakthrough that made it possible for him to delve even deeper into the world of gemology: new vision.
“Cataract surgery dramatically improved the clarity of my vision and perception of color,” he says. “That motivated me to enroll in GIA’s lab courses, so I decided to take the Colored Stone Grading lab class while visiting California, and returned later for Diamond Grading and Gem Identification.”

King’s team, which works in publishing and e-commerce for Geology.com and RockTumbler.com, includes (from left): Bradley Cole, Amber Cole, King’s sister Laura Rittenhouse, Hobart King, and his daughter Angela King. Courtesy of Geology.com. Photo by Bradley Cole
King, whose interest in geology began as a 6-year-old “prospecting” for invertebrate fossils in his parents’ limestone driveway, earned his Graduate Gemology diploma in 2017 – 42 years after earning his first degree in geology.
“I’m convinced that GIA’s Gem Identification course is one of the finest – if not the finest – distance education course available,” he says. “The entire GG program has to be among the best programs delivered online, and it’s been an important asset for me. It is extremely helpful in my content writing, and provides a credential that separates me from writers who are not writing from formal education and experience.”
The continuing education has helped equip King and his four employees, including his sister and daughter, who also run a lapidary and rock tumbling retail site RockTumbler.com, to better serve the million-plus visitors that Geology.com draws every month.
“A typical visitor might arrive looking for information about rocks, minerals, volcanoes or maps – then, they see an article about a gemstone and read that,” says King, who considers writing educational content for them to be his most important job. “In a way, our website has become an ambassador for gemology, an applied form of mineralogy, one of geology’s core disciplines.”

“As in gemstones, the inclusions of mineral debris in coal is undesirable,” says King, a former geology professor and a GIA GG. “Evaluating coal is similar to evaluating the clarity of gemstones, the difference is mainly a matter of scale.” His image of a “highly magnified view of coal in transmitted light” shows a spore (large yellow object), thin shreds of woody material (red bands), smaller spores and algal debris (orange and yellow particles), and charcoal or opaque mineral inclusions (black material.) Courtesy of Geology.com. Photo by Hobart King
He’s found that researching and preparing Geology.com’s daily news page, for which he aggregates relevant news stories from trade and consumer media, takes the bulk of his work time while also attracting significant engagement from visitors.
“The daily news page is the part most visited by professional geologists, and they engage with stories related to oil, gas and mining,” he says. “Oil and gas, earthquakes, volcanoes and mining stories are the most popular with our overall readers. Knowing what they engage with guides me, and I include a sprinkling of other topics for curious visitors.”
King is fascinated by the “connections and patterns” he finds between news stories.
“With natural gas, for example, when I see topics surrounding discoveries, pipeline projects announcements and liquefied natural gas over a period of months, it helps me make connections and understand the movement of prices and global production, consumption, investment and politics,” he says. “And I hope my readers will see these patterns, too.”
As King has advanced in his own studies of gemology, he’s making connections between gem and jewelry news on JCK daily blogs, for example, and stories in Gems & Gemology and Mining.com.
“Retail, research and mining have many intersections,” he says.
King is endlessly curious, and hopes the accessible, educational content and introductory lapidary supplies his companies provide will inspire others to also develop eager, open minds.
“We learn something new every day,” he says, “and we’ll continue to share as we learn.” @chapter:18


Publication Year: 2017 Title: Mysterious Iridescence in Aquamarine Abstract: Figure 1. This 40.27 ct aquamarine contains eye-visible parallel stringers that could be responsible for interference colors seen when the crystal is viewed along the c-axis with a fiber-optic light. Photo by Kevin Schumacher.

Iridescence is a common interference phenomenon seen in many minerals and gems. It occurs when light travels through a stone and interacts with a thin film that has a different refractive index (RI) than the host material, producing a rainbow effect. Iridescence caused by a layered structure occurs on or near the surface of many gems, including iris agate, “rainbow moonstone,” and the fossilized ammonite gem known as Ammolite. Iridescence can also indicate the presence of a fracture or cleavage (see Fall 2016 Micro-World, pp. 312–313).

An appealing 40.27 ct aquamarine crystal on calcite matrix owned by Lucas Fassari (Costa Mesa, California) featured eye-visible, cloud-like stringer inclusions that extended from the base of the crystal parallel to the c-axis (figure 1). Inexplicably, examining the stone down through the c-axis with oblique fiber-optic illumination revealed a concealed iridescent, slightly three-dimensional “shimmer” that shifted colors as the light source moved (figure 2). What was puzzling was that in the iridescent regions  there seemed to be no evidence of a break, thin film, liquid inclusion, or other discernible feature that would cause these interference colors. We hypothesize that the cloud-like stringers could be creating dislocations, producing a structure capable of generating interference colors in the localized region just above the stringers.

Figure 2. The surface of the aquamarine crystal contains a hidden iridescence that is only visible when the light source is at certain angles relative to the surface of the stone. The angle of the oblique fiber-optic illumination in the photo on the left does not make the iridescence visible. As this light is swept across the surface, changing the angle of illumination, colorful iridescent colors appear (center). The appearance of the phenomenon alters along with the angle of illumination (right). The large dark area in the right portion of each image is a reflective void. Photomicrographs by Nathan Renfro; field of view 4.8 mm.
This aquamarine crystal is one of the most interesting the authors have encountered because of its unusual and unexplained iridescence. @chapter:19


Publication Year: 2015 Title: Ginger Garnet, “Fancy” Tanzanite Abstract: Figure 1. Marketed as “ginger” garnet, these four garnets range from 8.33 to 35.54 ct. Photo by Robert Weldon/GIA; courtesy of Advanced Quality.

Kobi Sevdermish (Advanced Quality, Ramat Gan, Israel) showed us large fine “ginger” garnets and discussed the cutting of natural-color tanzanite crystals. The garnets are from a new find in Tanzania, discovered in late 2014. In large sizes, the stones have a pleasing “open” pinkish orange or orangy red hue (figure 1). By “open,” Sevdermish meant the tone is not too dark, remaining lively and relatively bright even in sizes above 30 ct. He noted that many red garnets cut in large sizes have a tendency to become very dark, and this material avoids that pitfall. If fashioned correctly, it “pops.” Along with the virtues of lighter tones and relatively large sizes, it possesses high clarity.

	Advanced Quality, Ltd. | “Ginger” garnets from Tanzania, more on “fancy” tanzanite

Kobi Sevdermish of Advanced Quality introduces us to new pinkish orange to orangy red “ginger” garnets that remain bright in larger sizes. He also outlines the trials and tribulations of sourcing and cutting the unique “fancy” tanzanite crystals his company specializes in.
Supply has been limited—Sevdermish had only seen a few parcels of larger rough suitable for cutting gems up to 40 ct—and some of this material was of lower clarity. Standard gemological testing revealed an RI of 1.74 and an SG in the range of “Malaya” garnet (3.78–3.85).

As in 2014, Sevdermish reported that “natural-color” tanzanite remained a very successful item for Advanced Quality. He showed us a selection of unheated gems in a range of subtle secondary colors (greens and pinks) behind the predominant “typical” blue to purple tanzanite colors (figure 2). Sales have been strong in Europe and particularly Asia. According to Sevdermish, this is because no two are exactly alike. To demonstrate, he showed us a large suite of mixed fancy colors (figure 3).

Figure 2. A selection of reportedly natural-color, unheated tanzanites ranging from 9.93 to 27.86 ct. Photo by Duncan Pay/GIA; courtesy of Advanced Quality.

Figure 3. Kobi Sevdermish of Advanced Color shows off natural-color tanzanite, including a remarkable multicolor necklace of almost 170 carats total. Photo by Duncan Pay/GIA.
He explained that rough of “odd” colors—unheated pinks and greens—did turn up over the years, but in the last year and a half, material from Block B of the tanzanite mining area has provided some “magnificent” natural colors: lavender, cognac or golden colors, and very rare pink and yellow and green.

Sevdermish noted that buying suitable tanzanite rough in these colors is a painstaking business, even though the company has cultivated connections in Africa that locate this material for them. Some purchases take time, he said, and require him to extend buying trips to obtain a few special, unique pieces. He added that it takes persistence to negotiate with miners and their representatives. And if no other buyers outbid you, you succeed. Sevdermish said that many of the stones at his booth were cut about a week and a half earlier.

Advanced Quality documents, through video recording and photography, each rough piece as it goes through the planning, sawing, and faceting process—in essence, the mine-to-market story of each significant gem. In this way, Sevdermish asserted the company can show—to the best of its knowledge—the unheated nature of its gems to clients. Many of the stones promoted as “unheated” in the market are actually the products of less-than-successful heating, he explained.

Just a couple of weeks earlier, he managed to obtain a few large pieces of rough with unique light yellow colors, one of which yielded a 27.59 ct antique cut (figure 4). The gem came out predominantly greenish yellow, but with flashes of lilac pink, which is what Sevdermish initially expected from the rough. The company debated whether to cut the original rough, as it was such a spectacular piece, but ultimately decided to fashion it because the crystal was not quite perfect enough to be a specimen.

Figure 4. This 27.59 ct unheated, natural-color zoisite or “fancy” tanzanite shows a subtle tint of lilac pink against a greenish yellow bodycolor. Photo by Robert Weldon/GIA; courtesy of Advanced Quality.
Sevdermish described buying and cutting rough as a lottery. Certain gems—some spinels or even regular tanzanite—are more or less predictable. But with others, especially the rough for this “fancy-color” tanzanite, the results are less foreseeable. The rough for the 27.59 ct gem promised a “kaleidoscope of colors” blending pink, yellow, and green, so Sevdermish expected to see an interplay of colors inside the fashioned gem. Instead, he was dismayed to find the gem was colorless. Fortunately, Sevdermish reported, the hoped-for greenish yellow color returned after the gem had “rested” for two days in its parcel paper. @chapter:5


Publication Year: 2022 Title: Dyed Fluorite Abstract: Figure 1. These two rough pieces weighing 454.27 and 358.03 ct were identified as dyed fluorite. Photo by Annie Haynes.
Two pieces of green rough weighing 358.03 and 454.27 ct (figure 1) were recently sent to the Carlsbad laboratory for an emerald identification and origin report. Standard gemological testing could not be performed due to the rough surfaces and size of the stones. Raman spectroscopy was used to aid in the identification (figure 2), and the Raman spectra were consistent with the mineral fluorite.

Figure 2. Overlay of the Raman spectra of one of the dyed fluorite samples
and a known emerald sample.
Internally and externally, both pieces showed typical massive habit fluorite features. Small octahedral crystals were scattered along the surfaces, and perfect cleavage in four directions was documented. Cleavage is not a gemological property of emerald, and octahedral cleavage is a key identifying feature for fluorite. Weak color banding could be seen with diffused lighting, but the most abnormal observation with both of these stones was the presence of obvious dye concentrations along their fractures (figure 3).

Figure 3. Obvious dye concentrations within surface-reaching fractures. Photomicrograph by Nicole Ahline; field of view 7.26 mm.
Fluorite naturally comes in a wide range of colors and can have multiple colors in a single crystal. These stones are a careful reminder to analyze every stone thoroughly for proper identification and to detect the most uncommon of treatments. @chapter:13


Publication Year: 2020 Title: Pink Sapphires from Madagascar, Rose-Cut Colored Stones from the Baroque Era, Separating Blue Amber Localities, and More… Abstract: Welcome to the Winter 2020 issue of Gems & Gemology! This issue brings an exciting conclusion to the volume year with a study on low-temperature heat treatment of pink sapphire, a characterization of rose cuts that adorn rare artifacts of a bygone era, and the means to separate the three principal localities for blue amber.
“A characterization of rose cuts that adorn rare artifacts of a bygone era…”
In the lead article, a team led by Sudarat Saeseaw examines the effects of low-temperature heat treatment on inclusions in pink sapphire from Ilakaka, Madagascar. The detailed characterization of these samples before and after heating will help laboratories develop treatment detection criteria. This study also presents a useful technique using Fourier-transform infrared (FTIR) spectroscopy to detect low-temperature heat treatment of this material.
In the second article, researcher Karl Schmetzer returns to the pages of G&G with an evaluation of seventeenth-century colored stones fashioned as rose cuts, which richly decorate rare artifacts once belonging to archbishops and prince-electors of Trier and Cologne. This article seeks to fill a gap in the historical record, as rose-cut colored stones have been mainly overlooked in favor of their diamond counterparts.
Next, Zhiqing Zhang and a team from the Gemmological Institute, China University of Geosciences in Wuhan use observation, UV-Vis-NIR spectroscopy, and excitation-emission mapping to separate blue amber mined from the Dominican Republic, Mexico, and Myanmar. This widely loved organic gemstone may be grouped according to very strong blue fluorescence and distinct emission and excitation wavelengths.
In the final article, Doan Thi Anh Vu from Vietnam National University heads an investigation of mineral inclusions in basaltic sapphire from southern Vietnam. The team analyzes inclusion chemistry using EPMA to understand the formation model of these sapphires in relation to the basaltic volcanism of this locality.
As always, our regular columns feature an array of interesting gemological findings. Highlights of from Lab Notes include a large “all-American” diamond from Arkansas and artificial glass prisms masquerading as Paraíba tourmaline. Micro-World enchants with the inner beauty of gems: lazurite and snowflakes in Burmese ruby from Mogok and Mong Hsu, respectively, and sapphires exhibiting elongated rutile. Stay up to date in the Gem News International section with a new emerald locality in Southern California and the use of rhodium plating on etched iron meteorites. Diamonds from the Deep returns with a unique perspective on how diamond ages can help us understand continent evolution spanning billions of years.
Finally, we include a reprint of the Spring 2020 article by Emily Dubinsky et al. (“A Quantitative Description of the Causes of Color in Corundum”) to correct the color of several photos and areal color density circles. We regret these errors and have used the opportunity to produce a new wall chart displaying the corundum chromophores from this article.
We hope you enjoy our Winter issue! @chapter:3


Publication Year: 2000 Title: Identification of HPHT-Treated Yellow to Green Diamonds Abstract: Examination of recently introduced greenish yellow to yellowish green HPHT-treated diamonds from three companies revealed several identifying characteristics. Gemological properties include a highly saturated body color, well-defined brown to yellow octahedral graining, moderate to strong green “transmission” luminescence to visible light (associated with the graining), and visual evidence of heating. Most of the treated diamonds, including some from each of the three sources, exhibit chalky greenish yellow to yellow-green fluorescence to UV radiation (long- and shortwave). Distinctive features seen with a handheld spectroscope include a 415 nm line, a strong band from about 480 to 500 nm, a strong line at 503 nm, and emission lines at 505 and 515 nm. IR spectra reveal that they are type Ia diamonds. Near-IR spectra show a peak at 985 nm, an indicator of high-temperature exposure. A small number of these HPHT-treated diamonds are yellow to brownish yellow; they do not show any green transmission, but other properties identify them as treated. @chapter:15


Publication Year: - Title: De Beers’ Sight: Recovery or Overload? Abstract: De Beers’ CEO Phillipe Mellier noted that demand for both rough  and polished diamonds has improved. The company released its largest sight in many months in April, citing the upturn. Photo by Robert Weldon/GIA

	De Beers reportedly raised rough diamond prices by an average of 2% at its April 4-8 sight cycle. The $660 million total announced by De Beers was larger than expected.

	The price increase caused some concern in the market from manufacturers who have just begun to return to profit after nearly two years of struggle. Since there have been no reports of clients refusing goods as they did last year, however, most were still on the profitable side and have accepted the deals.

	De Beers’ CEO Philippe Mellier said polished diamond demand has been reasonably positive at the wholesale level and that “rough demand is significantly stronger” than last year. He hinted that the May 16-20 cycle will be smaller because seasonal demand usually declines mid-year.

	Alrosa announced it was sitting on a 22 million carat (valued at $2.5 billion) stockpile of rough left from last year, when it cut back sales by nearly 25%. The company will reduce its mining output this year by 5% to 7%, but noted that it sold $780 million worth of rough in January and February, slightly less than De Beers by value.

	Some analysts worry that De Beers and Alrosa may be compromising the recovering market by selling more rough than world demand warrants.

	In addition, the credit situation in the diamond industry continues to tighten even as the trade recovers from the difficulties of last year. Bankers − and most diamond people − acknowledge that the recovery is fragile, based on a reduction of excess inventory and firming polished prices.

	This week, Standard Chartered Bank, which holds about $2 billion in loans to the industry (about 12% of the industry’s total outstanding credit), reportedly informed its clients that they would have to provide collateral for 100% of their outstanding loans or obtain payment insurance for their outstanding balances. The bank said it will not accept receivables as collateral as it (and other banks) had done in the past.

	Standard Chartered blamed its action on an increased regulatory and compliance environment, but the bank has been struggling with non-performing loans across the board, particularly in commodities – especially oil and gas – that have fallen sharply in price since the China bubble burst. Bloomberg reported that the bank is trying to shed or restructure about 40% of its $261 billion loan portfolio. The new CEO also replaced all of the bank’s senior managers.

	The presidents of the Israel Diamond Exchange and International Diamond Manufacturers Association both called for a concerted action to lobby industry lenders to ease credit restrictions at the upcoming World Diamond Congress in May.

	China’s largest jewelry retailer, Chow Tai Fook, reported continued declines in sales, both in Hong Kong and the Mainland. The company said same store sales were down 26% for the quarter that ended March 31, compared to the same period last year.

	COLORED STONES

	Gemfields reports that its April auction of quality emerald rough achieved near record prices: 469,000 carats sold for $33 million or about $70.68 per carat.

	CEO Ian Harebottle said the company was shifting its marketing strategy to get closer to retail markets. It did not renew the three-year contract with actress Mila Kunis, who it previously featured in its advertising. The company is putting that money into partnering with top retailers, such as Bergdorf Goodman in the U.S., to promote emerald and ruby jewelry, much of it under the Faberge brand it acquired two years ago.

	The company earned $12.3 million on revenues of $171.4 million in 2015, selling 30.1 million carats of emeralds from its Kagem mine and 8.4 million carats of ruby from its Montepuez mine. Harebottle said the company is committing 20% of its revenues to growing demand, 11% on advertising, and 9% on exploration, with projects in Colombia, Sri Lanka, Madagascar and Ethiopia.

	AUCTIONS

	This spring auctions will bring potentially record-breaking sales of fancy colored diamonds and a major ruby to market.

	On April 20 in New York, Christies will offer the 15.99 ct. Jubilee Ruby set by Verdura and a 10.07 ct. Fancy Intense purple pink diamond, graded by GIA. On May 18 in Geneva, Christie’s will auction the 14.62 ct. Fancy Vivid Blue Oppenheimer diamond, which is expected to bring $38 to $45 million.

	Sotheby’s Geneva auction on May 17 will offer the “Unique Pink” a 15.38 ct. GIA-graded Fancy Vivid pink diamond, which is expected to sell for $28 to $38 million. And, earlier this month, the 10.1 ct. De Beers Millennium 4 Fancy Vivid blue diamond brought $3.1 million per carat ($31.8 million total) at Sotheby’s Hong Kong sale. The same sale brought a $2.47 million price for a Fancy Vivid orange diamond and a similar price for an imperial jadeite ring with matching earrings. @chapter:30


Publication Year: 2017 Title: Multi-Elemental Diffused and Melt-Grown Synthetic Sapphire Abstract: Figure 1. Top left: Color concentration was seen along the pavilion facet junctions of the synthetic sapphire, and blue halos were shown on the table facet. Top right: A spherical gas bubble was observed. Bottom left: Numerous clouds were visible throughout the stone. Some formed fingerprint-like patterns. Bottom right: Under the DiamondView's short-wave UV radiation, blue fluorescence was absent where there were concentrations of the diffusion color in the stone. Photos by Jonathan Muyal (top and bottom left) and Nicole Ahline (bottom right). Fields of view: 9.61 mm (top left), 1.25 mm (top right), 2.9 mm (bottom left), and 8.58 mm (bottom right).
GIA’s Carlsbad laboratory examined a 4.21 ct faceted blue oval. Standard gemological testing determined that the stone was uniaxial negative and had a refractive index of nε = 1.759 and nω = 1.769, with a corresponding birefringence of 0.010. Hydrostatic specific gravity was measured as 4.00. The stone was inert to long-wave UV and showed medium chalky blue color to short-wave UV. These properties were consistent with heated sapphire, either natural or synthetic. Under magnification and diffused transmitted lighting, a blue color concentration was observed along the facet junctions on both the pavilion and crown facets, along with a few large blue halos on the table facet (figure 1, top left), which indicated that the stone had been titanium diffused (R.E. Kane et al., “The identification of blue diffusion-treated sapphire,” Summer 1990 G&G, pp. 115–133; Summer 2015 GNI, pp. 203–205). Under darkfield lighting, individual large spherical gas bubbles were present (figure 1, top right). Numerous clouds observed throughout much of the stone could have easily been mistaken for natural clouds. Some of them grouped to form natural-looking fingerprint-like inclusions (figure 1, bottom left). The stone’s internal characteristics indicated a melt-grown synthetic origin. However, when immersing in methylene iodide under crossed polarizers and viewing down the optic axis, no Plato lines were observed (see W. Plato, “Oriented lines in synthetic corundum,” Fall 1952 G&G, pp. 223–224). The absence of Plato lines does not rule out flame-fusion growth. The heat from diffusion treatment can reduce the visibility of Plato lines (S. Elen and E. Fritsch, “The separation of natural from synthetic colorless sapphire,” Spring 1999 G&G, pp. 30–41). More advanced testing is needed to reveal all the physical and chemical properties of this unique stone.

Under the short-wave radiation (a 20-nm-wide band centered at 225 nm) in a DiamondView device, the stone displayed a strong chalky blue fluorescence. Hughes and Emmett (2005) concluded that the chalky blue fluorescence was due to isolated Ti4+ ions, or Ti-Al vacancy pairs. The strength of the chalky fluorescence depends on the growth temperature and Ti4+ concentration relative to other impurities. In melt-grown corundum, the high growth temperature allows Ti4+ to pair with Al vacancies more easily than other charge compensating ions; this creates the chalky fluorescence. In contrast, Pairing of Ti4+ with other ions (usually Fe2+ or Mg2+) and the presence of Fe3+ ions prevent fluorescence. That could explain why the chalky fluorescence was not present where the blue diffusion color was concentrated (R. Hughes and J. Emmett, “Heat seeker: UV fluorescence as a gemological tool,” 2005, www.ruby-sapphire.com/heat_seeker_uv_fluorescence.htm).

Laser ablation–inductively coupled plasma–mass spectrometry (LA-ICP-MS) analysis was performed on the girdle of the stone. Three laser ablation spots were drilled six times down into the stone. The concentration vs. depth profile is shown in figure 2. From the surface of the stone to around 180 µm depth, the Be concentration decreased from 76.8 to 13.9 ppma, Mg from 7.8 to 0.8 ppma, Ti from 580 to 391 ppma, Fe from 390 to 83.4 ppma, and Ga from 6.12 to 1.36 ppma. The results confirmed diffusion treatment, not only by Ti and Fe but also by Be, Mg, and Ga. The presence of Mo provided some indication of synthetic origin. In a GIA identification report, the stone was described as titanium and beryllium diffused. It is the first time GIA has examined a multi-elemental diffused and melt-grown synthetic sapphire.

Figure 2. The synthetic sapphire’s concentration vs. depth profile revealed that
concentrations of Be, Mg, Ti, Fe, and Ga decreased significantly when the laser
ablation spots went deeper into the stone. @chapter:12


Publication Year: - Title: Cautious Outlook for Fall; Gemfields Accedes to Takeover Abstract: A worker sorting emeralds at Gemfields’ Kagem mine in Zambia. Photo by Russell Shor/GIA

With rough inventories on the increase and financing for diamond companies growing more elusive, De Beers and the other major diamond producers will be approaching the summer and early fall sales periods with caution.
De Beers and Alrosa both have cycle sales (sights) set later this month and most industry watchers believe there will be reductions from June’s allocations.
De Beers did not announce a price increase at its June sight, but its clients did find some types of goods slightly more expensive, based on stronger-than-expected demand at the JCK show in Las Vegas. The sight and side sales totaled $530 million for June, a bit more than the May totals, which were $522 million.
De Beers’ executives said demand for rough was good, “following positive feedback from the Las Vegas show and in line with other trends.”
Alrosa’s June rough diamond sales totaled $354.4 million, slightly down from the June 2016 total. The company announcement, which also gave six-month total rough sales of $2.44 billion, said the market is “stable, though there was a seasonal slowdown at the end of June.”
In the weeks since Las Vegas, however, retail sales, including jewelry, have remained slow in the U.S. New taxes on the trade in India and a tug-of-war between a bank and a major Antwerp diamond firm have undercut confidence.
The Indian government imposed a 0.25% tax on rough diamond imports in June, which took effect this month. The country’s diamond manufacturers denounced the tax, saying profits are already under extreme pressure and that this tax could cause some to start losing money and shedding workers.
FINANCES
In Antwerp, KBC Group Bank and diamond manufacturer Excelco are at odds over $29 million in outstanding loans, resulting in a see-saw battle over its assets. Excelco is a leading Antwerp manufacturer and former De Beers’ sightholder that supplies a number of U.S. retail chains.
Originally reported by Bloomberg News, KBC, which is winding down its diamond portfolio, obtained an order earlier this month to have the company’s assets seized from its Antwerp offices. This followed a seizure of company assets held by De Beers and ABN Amro bank. Exelco reportedly owed KBC $29 million.
On July 6, however, a Belgian court ordered KBC to return all of the company’s assets, claiming it was on-track to repay its loan by 2020, as contracted.
COLORED GEMS
The not-quite-friendly takeover of Gemfields by its largest shareholder, Pallinghurst, is not expected to have a significant impact on the gemstone mining company’s operations. As it reverts to a privately held company, however, the gemstone world could lose an important source of information.
In fiscal 2016, which ended in September of that year, Gemfields:

Ruby: 10.3 million carats of both high quality and commercial grade from its 75%-owned Montepuez mine in Mozambique. Sold for $73.1 million.
Emerald: 30.1 million carats of high and commercial grade from its 75%-owned Kagem mine in Zambia. Sold for $101 million. Gemfields claims Kagem accounts for 25% of the world emerald production by volume.
Amethyst: 964,548 kilograms from its 50% stake in the Kariba mine in Zambia. Sold for $660,000.

A Gemfields’ survey of the global colored gemstone market in 2016 reported that world sales of gemstones and cultured pearls totaled an estimated $8.4 billion; 69% of that amount were ruby, sapphire and emerald.
Gemfields’ executives had advised its shareholders to reject Pallinghurt’s offer because it “significantly undervalued Gemfields and its prospects as a leading player in the colored gem sector.”
The company also owns Fabergé, the luxury jewelry manufacturer (2016 sales were $11.8 million). @chapter:30


Publication Year: - Title: A Sunstone Odyssey, Part 1: The Ponderosa Abstract: John Woodmark, CEO of the Ponderosa mine, is a man in his element. Photo by Robert Weldon.

THE MINE'S LOCATION

View Gallery

	In this slideshow, you will explore the Ponderosa mine, learn about its gem recovery processes, and view the beautiful sunstones that originate in the rocks of southeastern Oregon.
With a sweep of his arm, John Woodmark invites us to take in the majestic vista below: “You can see the large meadow… it stretches for miles. That used to be an ancient lake…Native American people have been in here for 15,000 years, hunting around that lake.” He adds some more-recent history, telling us: “Into the 1900s, they were still camping in this area and using the dried-up lake bed as pasture for their horses.”

This connection to the native people extends to the present day. Woodmark partners with the local tribal outreach program to offer seasonal employment to Native American teens at the Ponderosa mine. This is something Woodmark is very proud of, and we’ll return to it a little later.

Right now, we’re standing on the steep slopes of Donnelly Butte, just above the Ponderosa mine’s pit. At our backs, magnificent stands of lofty ponderosa pines extend uphill. We are about a five-hour drive from Portland, Oregon, and the transition from that busy city to the silence and serenity of the Ponderosa is jarring.

Beneath us, entombed in an ancient lava flow, millions of carats of rough sunstone—Oregon’s state gemstone—await discovery. The Ponderosa mine is possibly the state’s most important source of the repeatable commercial sizes required by jewelry manufacturers.

	The red rocks of the Ponderosa mine’s pit complement the setting sun. Photo by Robert Weldon.
The beauty of the mine’s location isn’t lost on Woodmark: “It’s a pristine area, it’s beautiful…It’s wonderful just to come up here, let alone find a truly exotic gem like Oregon sunstone.” With this in mind, he strives to make his mining activities as low-impact as possible: “We’ve got over a million board feet of huge ponderosa, most of them in the 250 to 300 year old range, and we’re trying very hard not to disturb any of those trees and still get the same stones that we need to mine.”

Beyond the direct environmental impact, Woodmark and his crew also have to synchronize their mining to the regional climate. These are Oregon’s High Lava Plains, after all, and the winters can be brutal: “The mine is located at 5900 ft., so from October to June we’re covered with as much as ten feet of snow up here, so there’s absolutely no mining during those months.”

Despite these constraints, he knows the Ponderosa’s weathered reddish basalts are blessed with high concentrations of sunstone: “This mine is tremendously rich—the whole mine is 60 acres—and we get a kilo and a half of sunstone out of every cubic yard of dirt moved…so it’s arguably one of the richest gemstone mines in the world.”

Because of the richness of this deposit and the weathered nature of the basalt around the gems, they’re easier to recover than at some of Oregon’s other sunstone locations. Woodmark explains: “We do ten-day mining stints…sometimes four to five times throughout that four month period…It all depends on the demand for Oregon sunstones…the more demand, the more often we mine.”

	Introducing the Ponderosa

	John Woodmark, CEO of Desert Sun Mining & Gem, provides a brief history of the mine and its location, as well as explains how the Ponderosa’s location at 5,900 ft. affects the mining season.

BEAUTIFUL SUNSTONE
Woodmark is passionate about sunstone: “You never get tired of it…it isn’t like you’re mining amethyst, which is all purple. Ours is so many different colors, every stone is unique.” As he talks on, his enthusiasm and love of this unique gem is infectious: “You can get reds, with just a sprinkling of the copper platelets, which makes it look like you’re looking into a red sky with gold stars…It’s just gorgeous.”

	A rare 11.76-ct. bicolor sunstone gleams with an added bonus of glittering, reflective copper platelets. Photo by Robert Weldon.

	This group of red sunstones reflects recent production from the mine’s pit. Photo by Robert Weldon.
He draws our attention to sunstone’s unique hallmark—tiny particles of native copper metal that produce a glittering effect called schiller. “And then you have the intense schiller…When the sun hits it and it just pops out at you…you can’t even believe it!”

	Beautiful Gems, Pristine Location

	Owner John Woodmark introduces us to the Ponderosa Mine’s pristine location and explains how the gems from the mine mirror the natural beauty of the environment.

THE PONDEROSA MINING PROCESS
Woodmark is determined that we see all of the mine’s operations and witness the recovery of gem sunstone directly from the pit wall. We start right at the wall, which bears sets of deep, parallel gouges. He mentions this is the work of the “magic finger,” developed by a member of his crew as an attachment for their backhoe, and which makes mining much easier.

	Pickers scour their screens for the gleam of red sunstone. Photo by Robert Weldon.
He directs us to a rich red area of the pit wall. “In the rest of the mine, we only get about one-and-a-half to three percent red.” This patch, he asserts, is very different: “This area produces twenty percent red to the volume that we’re picking…so rich it’s incredible.”

Woodmark adds that the backhoe’s special attachment—basically a flattened metal spike—was the missing ingredient: “We haven’t monkeyed around with anything else since we got our ‘magic finger’ to break this stuff down. Before, it was too hard for our machines to work.”

Once enough of the pit wall is torn down by the backhoe, a small loader moves the ore onto an area of the pit floor. Next, the Ponderosa crew runs their massive forty-thousand pound loader over the material to crush it and loosen the stones.

The loader feeds the crushed rock through a dry trommel—a rotating screen that, with the harsh clatter of stone on metal, separates the dirt from the ore-bearing material. The next stage is a second trommel, this time using water. John tells us this piece of equipment takes the concentrate and “washes it, scrubs it, and knocks off a little bit of the volcanic crust that’s on the crystals.”

One load fills about twenty five-gallon buckets. The buckets quickly stack up behind each of the three screening stations set up at the time of our visit.

A picker stands behind each screen. Woodmark picks up a bucket of concentrate and pours the contents onto a screen to demonstrate for us: “We…throw all the big rocks off…spread it out fairly evenly…” He picks up a hose and directs a jet of water over the concentrate. “…then come back and spray it down.”

He pauses to pick up a choice piece of sunstone. “Nice red,” he observes. “And then we start…systematically going through the whole screen.” With a small trowel, he works methodically from one end of the screen to the other, telling us, “What we try and do is turn every stone…leave no stone unturned we tell the kids…so you start at one end and you just systematically turn every stone.”

	We recovered this nice specimen of zoned sunstone crystal in host basalt after it passed through the wet trommel. You can see that the crystal was originally considerably larger. Photo by Duncan Pay.
John’s diligence pays off with a small handful of rough sunstone, “You’ll get a handful like that off every screen…which probably weighs a few ounces.” He drops the red pieces into a plastic cup and tosses yellow or colorless rough into a bucket next to his feet. “They’ve got to go through a lot of screens to get a kilo…but like I say, they’ll pick about ten kilos on average per day.”

John emphasizes that speed is of the essence: It’s important to go through the screens quickly but accurately. “Don’t miss a thing, and get on to the next screen.” His rule of thumb is that the more screens you go through, the more you’re going to make: “I’ll do a screen every five-to-six minutes…it’s important not to jump around…because you’ll start to miss them.”

John’s eyes scan methodically from one end of the screen to the other, his trowel making quick movements to flip over the larger pieces: “A lot of our stones have a volcanic crust on them and even though they’ve gone through all the processes to get here, they’re very hard to find, so we go through it very methodically.”

“Don’t leave a stone unturned…” he admonishes us, “…because sure enough, there will be a red one hiding underneath there…and we don’t want to miss a red one.”

Once all the concentrate from a load is recovered, it’s washed for about an hour in a small cement mixer, which takes about 35 kilos at a time (60-70 pounds). “It’s almost like a rock tumbler…a giant rock tumbler,” Woodmark jokes.

When John tips out the mixer, there’s a crystalline glitter and tinkle as freshly washed rough cascades onto a small screen. “I’m looking for how many reds and how much schiller is in there…I’m looking for good stones that will bring money.”

He plucks out a limpid chunk of feldspar. “There’s a beautiful yellow…it’s a nice big size…see how clear and nice that stone is…that’ll make a terrific stone.” And then, a better prize: “Here’s a beautiful red…that’s going to make a tremendous faceted stone!”

The final step at the mine is to grade all this freshly cleaned concentrate. John leads us to a small table in front of the mine’s bunkhouse, where trays of sorted rough—reds, bicolors, schiller stones, yellows, and clears—rest in water-filled metal trays. The water cuts down reflections and helps with grading, he explains. There, in the shadow of tall ponderosa pines, John outlines the qualities a really fine gem might have: “The pinnacle is if it would be good enough to make a carving. A carving has to be something over 25 carats finished.”

He continues, “It has to have all the attributes…color…schiller…so it really is the pinnacle of an Oregon sunstone…We sell them for a lot of money…That’s just one in thousands of stones that we find.”

	Mining Sunstone at Ponderosa

	In this series, Ponderosa Mine owner John Woodmark explains how his crew goes about mining and processing, and grading rough sunstone.

NATIVE AMERICAN PICKERS
John is proud of his partnership with the local tribal outreach program, which started with five kids in 2006 and continues to the present. “We’ll pick for ten days at a stint,” John tells us. “After ten days, they’re burnt out picking stones and standing down there in the hot sun.”

	The Ponderosa partners with the local tribal outreach program to use Native American pickers. Photo by Jeff Jessing, Nature Revealed Photography, © 2009; courtesy of Desert Sun Mining Group
Unfortunately, at the time of our visit, there had been a robbery at the reservation and all the teens had left to assess the damage. However, each of us spent several hours working the screens, just as the pickers do. This gave us a very good concept of these kids’ “Ponderosa experience.”

	A lucky picker’s haul: A fine collection of “reds” decorate this screen. Photo by Robert Weldon
John outlines how his outfit houses, feeds, and pays the teen pickers: “For most of them it’s the most money they’ve ever had of their own…so the kids have all been absolutely great…they’re respectful, they’re glad to have a job, and all of us mentor them around the campfire.”

	A red crystalline glint in a scattering of red rock attracts this worker’s attention.
	Photo by Robert Weldon
To John, the amount of work he can provide hinges on the success of his business and, in turn, the popularity of sunstone with the jewelry-buying public. “The more sunstones we sell, the more people we can then hire,” he explains. “So if more people would get in behind Oregon sunstones, we’d have a lot more kids working here.”

	Employing Native American Teens

	The Ponderosa mine has an arrangement with the local tribal non-profit to provide work experience for Native American youth. The mine’s owner describes the benefits for both parties.

PROFIT
Woodmark is a savvy businessman, successful in many ventures before he acquired the Ponderosa mine. He applies the same financial acumen to sunstone as he would to any other commodity; “A kilo of red is worth twenty thousand dollars…we’ve got 25 of them in five days.”

	This choice piece of red sunstone rough will make a fabulous faceted gem. It’s just one piece in the 25 kilo haul the Ponderosa miners recovered during this trip. By Robert Weldon.
"We average 600 cut carats per kilo…an average price of 100 dollars per carat, I mean…is sixty thousand dollars…times 25…” He leaves us to do the math. “Yeah,” says Woodmark finally with a smile, “I think it’s pretty profitable!”

	Value of Rough Stones

	CEO John Woodmark explains the economics behind sunstone recovery at the Ponderosa mine.

THE GREAT ANDESINE CONTROVERSY
When we ask John about the andesine issue, there’s a hint of resignation in his answer. “Around 2004 or so, we started running into resistance because of a product out of China called andesine.” He explains that the jewelry channels jumped on it because every stone looked exactly alike, and as he puts it, “They could get them for nothing and sell them for a lot.”

Then for four years, while gemologists and geologists the world over tried to prove the authenticity or treated nature of this new gem, sales of Oregon sunstone were flat because people were afraid to invest. John is pragmatic on this topic: “We got hundreds of thousands of dollars’ worth of gemologists’ time and effort to prove that the andesine was a treated stone, but it also verified that Oregon sunstone was all natural.”

John contends that all the publicity over andesine was, in reality, a public relations blessing. “Nobody ever heard about Oregon sunstone before this andesine mess. Now everybody knows andesine was trying to be like an Oregon sunstone.”

In the three years since andesine’s treated nature was confirmed, John asserts his sales have increased year on year.

	Treated Andesine's Impact

	Recent issues with treated feldspar have impacted the market for natural Oregon sunstone. In this video, John Woodmark describes how his business was harmed, but also outlines some unexpected benefits from the affair.

SELLING SUNSTONE
Most consumers know about diamond, ruby, sapphire, and emerald, and might well favor those Big 4 gems. John understands it takes time and effort to open peoples’ eyes to sunstone’s unique attributes. “You have to sell an Oregon sunstone,” he says. “Most customers don’t know what it is.”

“The whole process of educating people and telling them about it,” he explains, “makes the stone personal.”

One of the qualities that make handling sunstone a challenge for commercial jewelry manufacturers—the uniqueness of individual gems might make them hard to match in jewelry—can play well with enlightened consumers looking for something different.

“We tell them about the uniqueness of having the copper particles in the stone, which makes their stone as unique as a snowflake,” John continues. Finally, he adds another set of strengths: “This is an American gemstone, picked by Native Americans…It’s only found in America, and it’s rare and exotic…so you know, it’s a terrific stone.”

	Educating Customers

	CEO John Woodmark explains his belief that the key to acceptance of sunstone as a mainstream gem lies in consumer education. @chapter:24


Publication Year: 1997 Title: Fall 1997 G&G Lab Notes Abstract: Cabochon Cut Diamond
Rare Fancy Vivid Orange Diamond
Diamond with Surface Droplets of Filling Material
A Faceted Cat’s-Eye Emerald
Impregnated Jadeite Jade with Exceptional Transparency
Resembling Nephrite Jade
Synthetic Green Periclase
Quartz Quench-Crackled and Dyed to Imitate Amethyst
Topaz Fashioned to Imitate Diamond Rough

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


Publication Year: 2002 Title: Liddicoatite Tourmaline from Anjanabonoina, Madagascar Abstract: Liddicoatite, a calcium-rich lithium tourmaline, was recognized as a separate mineral species in 1977, and named in honor of Richard T. Liddicoat. Most of the remarkable polychrome tourmalines with varied geometric patterns that are characteristic of this species were produced during the 20th century from the Anjanabonoina pegmatite deposit in central Madagascar. To best display its complex color zoning and patterns, the tourmaline is commonly sold as polished slices or carvings. Liddicoatite exhibits physical and optical properties that overlap those of elbaite, so quantitative chemical analysis is required to distinguish these species; both may occur in a single crystal. The most common internal features are color zoning, strain patterns, partially healed fractures, feathers, needle-like tubes, negative crystals, and albite inclusions.

	DATA DEPOSITORY

Table 1: Samples from Madagascar
Table 2: Samples from Localities Other Than Madagascar
	Submitted by Brendan Laurs
	May 17, 2002
	Notes: These tables provide all of the chemical data on liddicoatite-elbaite tourmaline that were obtained for this article. The references cited in the table are listed in the reference list of the original article. @chapter:5


Publication Year: 2013 Title: Silicon in Natural Type IIa and Type IaB Diamond Abstract: The presence of Si in diamond is typically revealed by detection of the 736.6/736.9 nm (“737 nm”) doublet zero-phonon line (ZPL), observed by either absorption or photoluminescence (PL) spectroscopy. This feature has been assigned to the negatively charged state of the silicon split-vacancy defect, SiV–, which is frequently incorporated into CVD synthetic diamonds due to the etching of silicon-containing growth chamber components. Conversely, reports of the 737 nm peak in natural or HPHT synthetic diamonds are notably rare (see C.M. Breeding and W. Wang, “Occurrence of the Si-V defect center in natural colorless gem diamonds,” Diamond and Related Materials, Vol. 17, 2008, pp. 1335–1344; Winter 2010 Lab Notes, p. 302; Winter 2012 Lab Notes, pp. 304–305). Consequently, this feature is considered an important tool for identifying CVD synthetic diamonds.

Recently, SiV– was detected in the PL spectra (liquid-nitrogen temperature with 633 nm laser excitation) of five diamonds submitted to GIA’s Mumbai laboratory. These 0.31–0.90 ct round brilliants were issued colorless grades of either D or E. Their clarity grades ranged from VVS1 to SI2, where the lower grades arose from the presence of trapped crystalline inclusions.

FTIR spectroscopy revealed that four of the samples were type Ia, with hydrogen-related peaks at 3107 and 1405 cm–1. The remaining sample was type IIa, with no discernible impurity-related IR features. Multi-laser, liquid-nitrogen-cooled PL spectra acquired for the fifth sample were similar to those reported in Breeding and Wang’s 2008 investigation of SiV– in natural diamonds. The latter also showed
luminescence at 737, 714.6, 589.8, 557.8/558.2, 554.2, and 550.3 nm, in addition to NV0/– (575 and 637 nm, respectively) and 3H (503.4 nm). This SI2 sample contained several inclusions with intact crystalline faces, identified by Raman spectroscopy as olivine, consistent with the former investigation (figure 1, top). Through gemological and spectroscopic observations, it was possible to distinguish this natural type IIa diamond from Si-containing type IIa CVD synthetics.

	Figure 1. Room-temperature Raman spectroscopy (830 nm laser excitation) identified the different inclusions in the type IIa, SI2 (top) and type IaB, SI1 (bottom) natural diamonds containing silicon. The former spectrum is consistent with olivine, while the latter is attributed to spessartine garnet.

The type Ia diamonds studied by Breeding and Wang all contained A-aggregates and varying concentrations of B-aggregates (type IaA±B). In the present group of type Ia diamonds, only B-aggregates were detected (pure type IaB). With the exception of the 737 nm feature, the type IaB diamonds’ PL spectra did not include any of the spectroscopic features characteristic of Si-containing type IaA±B diamonds. An emission line at 664.3 nm was detected in all the type IaB specimens, however. These samples also showed emissions from NV0/– (575 and 637 nm, respectively), H3 (503.2 nm), and H4 (495.9 nm), where H4 was remarkably strong for three of the diamonds. Interestingly, the diamond with the lowest H4 concentration was also distinctly included (SI1 clarity). Raman spectroscopy identified the inclusions as spessartine garnet (figure 1, bottom). Breeding and Wang also reported the presence of garnet in Si-containing diamonds. The presence of olivine and garnet inclusions in natural diamonds containing SiV– has been suggested to indicate that they crystallized in an area of mixed-composition peridotite in the upper mantle.

These results emphasize that the detection of SiV– in diamonds does not unequivocally signify CVD synthetic origin. Nevertheless, careful analysis of spectroscopic features and crystalline inclusions can be used to separate these natural diamonds and their synthetic counterparts. @chapter:15


Publication Year: 2010 Title: Hibonite: a New Gem Mineral Abstract: A 0.23 g orangy brown crystal, a 0.39 ct step-cut gem later faceted from it, and a 0.71 g crystal—all reportedly from Myanmar—were characterized for this report. Infrared spectroscopy, X-ray diffraction, and chemical analysis dentified the material as hibonite. These samples represent the first gemquality hibonite ever recorded. @chapter:3


Publication Year: - Title: Emerald Journey Abstract: Few people outside the gem industry realize the true nature of a gemstone’s journey from the mine to the counter of a store. Whether the gem is being offered to consumer’s at a traditional jewelry store’s counter, an internet shopping site, or a television broadcast the journey always involves a great deal of effort.  Tons of earth and countless hours of labor are needed to bring a gem from mine to market. @chapter:28


Publication Year: 1986 Title: A Simple Procedure to Separate Natural from Synthetic Amethyst on the Basis of Twinning Abstract: Dr. Karl Schmetzer recently showed how near-flawless to flawless natural amethyst could be separated from synthetic amethyst on the basis of the presence of Brazil twinning in the natural stones. Whereas Dr. Schmetzer's procedure required a special apparatus, the authors have determined that a standard gemological polariscope is more than adequate to make the separation in most cases. Although some synthetic amethyst does show evidence of twinning, in the synthetic stones examined thus far it has taken a form that is distinctly different from the Brazil twinning seen in most natural amethysts. The presence of certain inclusions as well as the nature of the color zoning seen in natural versus synthetic amethysts is of primary use in making a separation. However, where there are no inclusions or color zoning, the presence of Brazil twinning in the natural amethyst will usually make the distinction. @chapter:6


Publication Year: 2016 Title: Macedonian Ruby Specimens Abstract: This 9.93 ct ruby cabochon from Macedonia was seen at the Jewellery & Gem Fair – Europe in Freiburg, Germany. Photo by Russell Shor/GIA.

	The Macedonian town of Prilep has been a source of marble since antiquity, even supplying some Roman settlements. Rubies have occasionally been found within the Bianco Sivec quarry, according to gem dealer Denis Gravier (Gravier & Gemmes, Poncin, France). Although Prilep is mainland Europe’s only known natural ruby source, only in the past 15 years has there been an effort to mine the gems. Gravier offered several rubies from the Prilep quarry at the March 19–22 Jewellery & Gem Fair – Europe in Freiburg, Germany, including the 9.93 ct cabochon seen above. None of the specimens were faceted. Gravier said the deposit produces comparatively few gem-quality rubies, and most are too cloudy for faceting. The best ones have a distinct “raspberry” color. It is unknown whether any of the material is heat treated. Macedonian craftsmen have developed a local industry using these rubies in jewelry and objets d’art. @chapter:1