Publication Year: - Title: GIA Tests Extraterrestrial Gemstones for Down-to-Earth Elements Abstract: This gold pendant is mounted with polished extraterrestrial peridot over mother-of-pearl. Photo by GIA/Robert Weldon.

                      While scientists speculate about diamond planets hurtling through the galaxy, at least one extraterrestrial gemstone is already among us.

Peridot, an olive-green gem also found here on Earth, has been recovered from meteorites on occasion, and even faceted into gemstones, though specimens are so rare that you’re unlikely to find them in a jeweler’s showcase. But researchers at GIA (Gemological Institute of America) assembled 26 extraterrestrial samples to discover the differences between them and their earthly counterparts. The findings are reported in GIA’s Gems & Gemology’s Fall 2011 issue.

Peridot is the gem version of a mineral called olivine, an iron and magnesium silicate -- (i.e. containing silicon). Olivine is part of the makeup of our solar system neighbors, including some metallic meteorites that occasionally fall on our home planet. While such peridot-bearing meteorites are rare enough, the intense heat from their journey to Earth and their explosive impact on contact with terra firma ensure that few specimens survive intact. That’s why peridot pieces from outer space are nearly always quite small.

Peridot from Earth’s own deposits was one of the first gemstones treasured by mankind. The ancient Egyptians called it “the gem of the sun” after discovering a deposit in what’s now known as St. John’s Island in the Red Sea. Today, sources include the United States (Arizona, Texas and Hawaii), China, Myanmar and Pakistan, which produces many of the largest, finest specimens. Peridot’s attractive color and relatively modest price have made it popular with jewelry designers around the world.

GIA researchers Dr. Andy Shen, John Koivula and Dr. James Shigley assembled specimens from several terrestrial locales and compared them with 26 samples taken from the Esquel meteorite, the most notable peridot-bearing extraterrestrial object.

Discovered in Argentina about 50 years ago, this massive meteorite contained numerous peridot crystals. An American collector purchased most of the Esquel in 1992 and divided it into a number of sections for sale. Three of the Esquel samples examined by GIA were faceted gemstones, while the others were part of polished slabs.

Using a laser beam and sophisticated mass spectrometry that can detect tiny amounts of elements within gemstones, the GIA team discovered significant differences between earthly and extraterrestrial peridot. Their tests found different levels of lithium, vanadium, nickel, manganese, cobalt and zinc between the two, allowing researchers and ultimately gem buyers to confidently distinguish between peridot of different worlds.

	A section of the translucent Esquel meteorite reveals a kaleidoscope of peridot crystals from outer space. Courtesy of Robert A. Haag; photo by GIA/Robert Weldon.

	This richly colored 1.12 carat extraterrestrial peridot was extracted from the massive Esquel meteorite, a polished section of which rests behind it. Courtesy of Robert A. Haag; photo by GIA/Robert Weldon. @chapter:0


Publication Year: 2023 Title: Natural Type IIa Diamond with Unusual Red Fluorescence Distribution Abstract: Figure 1. This 3.58 ct natural type IIa diamond with H color and SI2 clarity displayed a unique fluorescence pattern when exposed to deep-UV light. Photo by Diego Sanchez.
The Carlsbad laboratory received a natural type IIa diamond with some unusual characteristics. As part of the standard data collection, the diamond type was determined by Fourier-transform infrared (FTIR) spectroscopy and deep-UV fluorescence images collected using the DiamondView instrument. The DiamondView images revealed predominantly red fluorescence on one side of the diamond and blue fluorescence on the other. This 3.58 ct pear modified brilliant diamond had H color and received an SI2 clarity grade due to cavities, chips, and a feather (figure 1).

Figure 2. 514 nm PL spectra collected on the pavilion of opposite sides of the stone. The spectrum plotted in red corresponds with the red-fluorescing region, and the blue spectrum corresponds with the blue-fluorescing region, with Raman lines at 552 nm scaled as equal. Spectra are offset vertically for clarity. PL analysis spots are circled in the deep-UV fluorescence images. Images by Barbara Whalen.
Type IIa diamonds typically display a blue fluorescence pattern under deep UV as a result of “band A” fluorescence or the N3 defect in the stone (U.F.S. D’Haenens-Johansson et al., “Synthesis of diamonds and their identification,” Reviews in Mineralogy and Geochemistry, Vol. 88, No. 1, 2022, pp. 689–753). High amounts of nitrogen vacancy (NV) centers can cause red fluorescence in diamonds; however, this is rare in type IIa stones, as they are defined by nitrogen concentrations low enough to be undetectable by FTIR (Summer 2016 Lab Notes, pp. 189–190). The NV centers can be detected in a negative charge state (NV–, zero-phonon line at 637 nm) or a neutral state (NV0, zero-phonon line at 575 nm). Photoluminescence (PL) testing revealed much higher concentrations of both NV centers in the red-fluorescing region of the stone (figure 2). This distribution could have occurred if traces of isolated nitrogen were concentrated in one growth area of the stone.

Figure 3. False-color 532 nm PL map showing the Raman-normalized peak area of NV0 (left) and NV– (right). The maps were compiled from 47,040 spectra. The pronounced gradient in NV centers across the diamond resulted in the different fluorescence color observations (see figure 2 insets).
PL mapping using 532 nm laser excitation (figure 3) displayed the relative intensities of these defects, demonstrating the wide distribution of the NV centers in opposite sides of the table and crown facets of this diamond. Analysis of this interesting fluorescence feature demonstrated that nitrogen could have been distributed unevenly in a relatively pure type IIa diamond when it initially formed. @chapter:11


Publication Year: 2016 Title: Book Review: Real or Fake? Moldavites Abstract: By František Funda, softcover 92 pp.illus.publ. by powerprint s.r.o., Prague, 2015.

	Moldavite is an impact glass, produced when terrestrial silica is fused in the intense heat and pressure created by the crash of large meteorites. The identification of faceted moldavite is quite simple. Besides their flow structure and abundant bubbles, moldavites contain “wires” or “corkscrews” of lechatelierite, a high-temperature form of SiO2 that is very easy to see due to its low refractive index. Since identification of unfaceted material can be a real challenge, I was looking forward to finding out whether the book would provide additional data on this subject.

	In Real or Fake? Moldavites, author František Funda discusses numerous topics pertaining to the material in a reader-friendly format. The book covers the materials’s gemological properties and cut and raw moldavites. It then branches out into material from the Besednice deposit in the Czech Republic (famous for its beautiful raw moldavites), handmade glyptic sculptures in natural moldavite, tumbled and broken moldavite, and moldavite in jewelry. It has appendices with an extensive list of worldwide available gemological laboratories and chemical composition of moldavites based upon analytical results from other authors.

	The original Czech text has been translated by a non-native English speaker. This explains the use of the German word schlieren to describe the swirls in the inner structure section.

	The chapter on raw material is informative, as the identification of moldavite with a natural-looking surface is rather difficult. The surface feature of natural moldavite is caused by natural etching, and the author invites us to look for evidence of this process such as sharp protrusions. Other features of natural moldavite include lechatelierite needles and atypical shapes on the surface such as channels, open-ended bubbles, and residues of clay or ferruginous sandstone from the sediment matter in which the moldavites are found. What especially distinguishes a Besednice moldavite from all of the others are the sharp spikes, which have given these moldavites the very unglamorous nickname of “hedgehog.”

	A full chapter is devoted to moldavite’s gemological properties and how they may be used to identify natural specimens. Funda writes that the material’s RI and relative density overlap with artificial glass. While natural moldavites are inert to long-wave and short-wave UV, some imitations have a chalky fluorescence in short-wave UV.

	The text is illustrated with color images throughout, but unfortunately the photos lack any kind of indication on the size of the specimens. The book is being advertised as the ultimate guide for both laymen and professional gemologists that will teach you how to recognize an authentic moldavite from an imitation. This is obviously untrue, as readers are invited to read more about the inhomogeneity and the inner structure of moldavites in a forthcoming book called Facts about Moldavites. The author is passionate about the subject, but the title of the book sets a high expectation which it did not meet. @chapter:10


Publication Year: 2017 Title: Gem Paintings from Thailand Abstract: Figure 1. While her family had been involved in different sectors of the gem industry for more than 70 years, Wanlaya Suwannapirom found a passion for gem paintings such as the one in this pendant. Photo by Albert Salvato/GIA, courtesy of Than Thong Arts.

The 2017 GJX show hosted a new vendor that manufactures and sells gem paintings, merchandise not typically seen in international gem and jewelry shows. Only a handful of companies around the globe are active in this market segment. Than Thong Arts operates its own factory in northern Thailand. Owner Wanlaya Suwannapirom is from a family that has been in the jewelry industry for over 70 years. She started her gem painting business more than a decade ago and gradually became the industry leader, with both international and domestic clientele (figure 1).

These paintings are handmade by highly skilled artisans in Thailand, using natural uncut gem fragments sourced from all over the world. The fragments come from either mining operations or cutting factories. The paintings’ bright colors are generated by colored gem fragments, while the background and skin tones are created by dyed quartz or calcite powder. Artists also use extremely thin 24K gold leaf to color human hair and other details (figure 2). Unlike many other gem paintings, the gemstones are not glued to paper or canvas but attached to the glass and then framed.

Figure 2. By dyeing ground quartz or calcite in slightly different tones, a realistic gradation
of skin tones can be achieved. Here, 24K gold leaf is used to create a beautiful hair
color for the mother. Photo by Eric Welch/GIA.
The process includes several steps: sketching the painting on paper, a reverse transfer to glass, gluing the gem fragments and the dyed quartz or calcite powder, drying the glue, and framing the artwork. The middle steps are the most critical for the quality of the final product. The fragments are sorted into different sizes. Painters need to follow the order to apply the coarser grains first and then gradually go down to smaller sizes to fill the holes in between the fragments. This step continues until no space left between any fragments and the motif is completely colored by gems. Another challenge is to accurately and naturally reflect the human skin tone (again, see figure 2). To achieve this, painters grind quartz or calcite into very fine powder and dye them to slightly different tones for a very gradational transition of skin tone.

	Wanlaya Suwannapirom - Than Thong Arts Co. Ltd.

In this video, Wanlaya Suwannapirom of Than Thong Arts Co. Ltd. explains the fascinating artistry behind making works of art using natural uncut gem fragments. The different gem colors are arranged with such skill and attention to detail that the end results are remarkable exquisite miniatures in themselves.
To cater to a wide range of customers, paintings are produced in many sizes and framed in various ways (figure 3). Besides wall and desk decor, the paintings are framed in jewelry boxes and wearable jewelry. According to Suwannapirom, smaller paintings require more attention to detail. In addition, crystal glass that contains a higher concentration of lead is used on the wearables to give them a glossier look than the pyrolytic glass used for decor. Therefore, the price range of the jewelry is similar to some of the larger desk decor pieces.

Figure 3. Than Thong Arts’ gem paintings are offered in a variety of sizes, frames, and styles. Photo by Tao Hsu/GIA.
Customized gem paintings based on photos can also be specially created. At the booth, we saw some photo-based portraits made by Suwannapirom and her team. Some prominent figures have hired her to produce their portrait in gems, including the kings of Saudi Arabia and Thailand. The finished products look very accurate and natural. The gems in the paintings offered at the show came with a certificate of authenticity issued by a Thai gemological lab. @chapter:21


Publication Year: - Title: Spring 2017 Auction Updates: The Most Expensive Gem Ever and Other Records Abstract: When it sold for $71 million at Sotheby’s in April, the GIA-graded 59.6 ct. Chow Tai Fook Pink Star became the most expensive gemstone ever sold at auction. Photo courtesy of Sotheby’s

The spring 2017 auction season saw two important price records fall and solid, if not rising, prices for top gems across the board
In April, the news was the Pink Star, the 59.60 carat (ct) GIA-graded Fancy Vivid pink diamond that sold for $71.2 million at Sotheby’s Hong Kong, setting the record for the most expensive gemstone ever sold at auction. The diamond is a record-holder in itself, being the largest-known Fancy Vivid pink diamond. Its appearance on the block set bloggers and reporters into action around the world.
The diamond was originally named the Steinmetz Pink, after the firm that purchased and cut the 132.5 ct rough. After it was unveiled in 2003, the stone was exhibited at the Smithsonian Institution with six other extraordinary fancy color diamonds.
The diamond was sent to Sotheby’s in the fall of 2013 where it achieved a top bid of $83 million from a New York diamond cutter. This was nearly double the previous record – a different pink diamond bought by London jeweler Laurence Graff in 2011. After several months, however, the buyer was unable to pay for it, so the diamond was returned to the auction house’s vault until this year.
Bidding on the pink gem was spirited until it approached the $70 million mark, when Hong Kong retail giant Chow Tai Fook called the winning amount and announced it was renaming it the Pink Star.
While news reports noted the world record price for a gemstone, the diamond’s per-carat price, $1.2 million, was actually well under the prevailing market price for similar rare colored diamonds.
The similarly graded 24.78 ct Graff pink sold for $46 million in 2011 at $1.85 million per carat. The previous price record holder, the 14.62 ct Fancy Vivid blue Oppenheimer Blue diamond, brought $57 million in 2015, for $3.93 million per carat – still below the world record price per carat. Both also were graded by GIA.
That record is held by the 12.03 ct Blue Moon diamond, graded by GIA, which sold in 2015 for $48.4 million, or $4.01 million per carat.

Provenance, along with a lack of inclusions, helped the 18.04 ct Rockefeller Emerald achieve a record per-carat price of $304,000 at Christie’s in June. Photo courtesy of Christie’s Images

Had the per-carat price of the Pink Star diamond equaled the world record, the hammer would have come down on a bid of $239 million.
The 18.04 ct Rockefeller Emerald broke the second important record by achieving the highest per-carat amount – $305,000 – for that variety of gemstone. The gem, which was sold for $5.5 million by Christie’s on June 20, was exceptionally free of the fissures found in most emeralds.
First purchased by Harry Winston, the emerald was named after John D. Rockefeller Jr., who acquired the stone in 1930 for his wife, Abby. After she died 18 years later, their son, David Rockefeller had the emerald set into a ring by designer Raymond Yard.
The previous record price for an emerald was Elizabeth Taylor’s Bulgari emerald and diamond brooch, which sold for $280,000 per carat.

The Apollo and Artemis diamonds, twin fancy colored diamonds of 14.54 cts and 16 cts, respectively, sold for $57 million at Sotheby’s in May. Photo courtesy of Sotheby’s

Other highlights of the season included an interesting “mismatched” set of ear-pendants offered by Sotheby’s on May 16. One contains the 16 ct GIA-graded Fancy Intense pink Artemis diamond and the other the 14.54 ct GIA-graded Fancy Vivid blue Apollo diamond. The set sold for a total of $57 million: $15.3 million for the pink ($958,000 per carat) and $42.1 million for the blue ($2.9 million per carat).

The 92 ct La Legende, the costliest heart shaped diamond to sell at auction, drew a winning bid of $14.98 million at Christie’s in May. Photo courtesy of Christie’s Images

Christie’s also sold the GIA-graded 92 ct D-flawless La Legende diamond for $14.98 million in May. While this was a record price for a heart-shaped diamond, its per-carat price of $163,000, fell well below other, similarly graded diamonds. The record per-carat price for a D-flawless diamond is $283,000.
While this season saw fewer records fall and prices slightly below that of pervious auction seasons, it must be noted that prices often fluctuate wildly at this extreme high level – buyers are exceptionally picky, especially those who buy for investment reasons, and the presence or absence of a single well-heeled bidder can make a huge difference in the hammer price. @chapter:30


Publication Year: - Title: Tucson 2015: Gemologists Share the Latest Research Activities Abstract: GIA field gemologist Stanislas Detroyat, lower right, visits a sapphire mining pit worked by a group of artisanal miners near Bepeha village in the Ilakaka sapphire mining area in Madagascar. Photo by Vincent Pardieu/GIA

                      GIA’s research program has grown significantly in the past decade – in both the number of full-time researchers and the scope of activities. The team is comprised of nearly 50 staff members and consultants whose extensive academic and gem-testing backgrounds support the Institute’s wide-ranging research goals. Dr. James Shigley, distinguished research fellow at GIA in Carlsbad, presented an overview of GIA research activities at the 2015 AGTA GemFair in Tucson, Arizona.

He began with a summary of GIA’s major research efforts: to collect and characterize new gem materials to support GIA’s gem identification capabilities; to conduct experiments to determine new methods for identifying treated diamond; to develop standards for calibrating instruments across GIA’s gem identification and grading laboratories; and to examine the appearance of the major categories of fancy-shape diamonds.

One of the most important activities is to build GIA’s gem database by cataloging information from gems submitted to GIA for testing and those collected by GIA field gemology teams at the source in locations around the world. GIA has routinely conducted field expeditions – nearly 60 trips to 16 countries in the last five years – to collect material. Last year, researchers traveled to Brazil, Cambodia, Madagascar, Malawi, Mozambique, Myanmar, Sri Lanka, Thailand, Vietnam and Zambia.

“Travelling to these countries and collecting gem specimens directly at the source – seeing them come from the earth – ensures they have not been treated and are not synthetic,” Shigley said. Knowing without question where a gem was sourced and understanding its distinctive characteristics also helps researchers make country-of-origin determinations, he said.

Researchers archive the rough specimens they collect, characterize them using specialized instrumentation, then record the results in a database shared with all GIA laboratories.

Shigley said one of the biggest challenges is how to identify gem treatments. In a recent study, researchers collected data on unheated (brown) zoisite, and then heated the gems to known temperatures to examine differences in color and spectra after the treatment. The heated gems turned a dark blue and purple color – a variety of zoisite known as tanzanite. Researchers examined the visible spectra and inclusions then compared this information to the data from the same stone before it was heated.

These experiments determined that visible spectra are inconclusive in determining whether a tanzanite has been heat treated or not; the absence of three pleochroic colors may suggest that a tanzanite is unheated, but it can be difficult to observe all three colors in a cut stone; and unaltered fluid inclusions are perhaps the best indication that a stone has not been heat treated, while ruptured fluid inclusions are an indication of heat treatment.

Shigley explained the importance of accurate and efficient instruments in gemological research and the GIA laboratory. Instrumentation at all GIA lab locations are regularly monitored and calibrated to ensure consistent measurements. He mentioned the GIA DiamondCheck, a device introduced in early 2014 that differentiates natural diamonds from those that are potentially synthetic or color-treated, as an example. GIA, working with the World Federation of Diamond Bourses (WFDB), has made the DiamondCheck available on a lease basis at no cost to 20 diamond bourses and industry organizations around the world.

Shigley also reviewed the progress on a cut evaluation system for fancy-shape diamonds. GIA introduced the cut grading system for standard round brilliant diamonds (in the D-to-Z color scale and the Flawless-to-I3 clarity range) in 2006. Since then, the research team has investigated the cut and appearance for the most common fancy-shape diamonds. Researchers interviewed more than 440 experts from different backgrounds in Antwerp, Hong Kong, Mumbai, New York, Tel Aviv and Tucson in 2014. Participants were asked to examine fancy-shape diamonds and record what they saw to help determine industry preferences for certain aspects of diamond appearance.

A GIA laboratory team continues to evaluate client-submitted stones on a daily basis, noting results in a database that contains more than 9,000 observed fancy-shape diamonds. While no decision has been made to offer a cut grade for these diamonds, some basic concepts for an evaluation system are beginning to be uncovered.

Shigley asked Dr. Christopher M. Breeding, a research scientist at GIA in Carlsbad, to share research updates on diamond fluorescence, and synthetic and irradiated diamonds.

Approximately 35% of diamonds on the D-to-Z color grade scale exhibit fluorescence under long-wave ultraviolet (UV) light, Breeding said. Blue is the most common color, followed by yellow. Of the diamonds that fluoresce, 38% are faint and 62% display medium or strong fluorescence. For the majority of diamonds, the strength of fluorescence does not have an effect on appearance except in rare instances of very strong blue fluorescence. Fluorescence is recorded on a GIA Diamond Grading Report as an identification feature.

There are several UV sources that can be used to detect long-wave fluorescence, including hobbyist UV lamps, mercury UV lamps and LED UV loupes. Variations in wavelength in lamp output can affect the observed fluorescence by shifting the fluorescence color. Breeding said GIA is developing a new long-wave LED UV source with no side-bands, a longer operating life, no glass filter and more consistent illumination conditions between units. This new, compact and light-weight source will help standardize the way fluorescence is observed to ensure accuracy and improve consistency.

Breeding also discussed synthetic diamonds, which have become more prevalent and available in recent years. Companies that create colorless HPHT (high pressure, high temperature) and CVD (chemical vapor deposition) synthetic diamonds have produced relatively large diamonds with good color and clarity, he said. The full results of one of the studies – HPHT diamonds from the AOTC Group – were published in the Spring 2014 issue of Gems & Gemology (G&G).

Next, Breeding shared new research on irradiation color treatments, which he said can be challenging to identify because natural radiation in diamond produces a similar green coloration as when one is treated. In recent years, naturally irradiated, light-colored diamonds have been treated to create slightly more intense colors. Research on diamond color treatments remains an ongoing process, but GIA is constantly exploring new ways to ensure that these treatments can be identified.

Shigley closed by stressing that all of GIA’s research efforts – from field expeditions to experiments – serve to protect those who buy or sell gems. The information gained from research ensures GIA’s grading and identification reports are accurate and complete, and is also shared through education, G&G and GIA’s website.

	Dr. James Shigley, left, and Dr. Christopher M. Breeding. Photos by Kevin Schumacher/GIA @chapter:20


Publication Year: 2021 Title: Opal with Fluid Inclusion and Mobile Bubble Abstract: A Mexican opal containing a mobile gas bubble in the lower edge of the void (left). Tilting the stone causes the bubble to change position within the cavity (right). Photomicrographs by Jessa Rizzo; field of view 3.57 mm.

A Mexican opal was recently examined at the GIA laboratory in Carlsbad. The inclusion shows a euhedral void with a mobile gas bubble (see above). The void mimics the shape of a barite crystal that might have once been present in the opal. The barite crystal was likely dissolved during a dissolution phase during the growth of the opal, leaving behind only a fluid-filled void. Toward the end of the opal’s formation, the temperature decreased, causing the trapped fluid to separate into liquid and gas phases. Because of the small size of the bubble relative to the void, rocking and tilting causes it to move about. Fluid inclusions in opal are generally quite rare, and one with a mobile bubble is exceptional. @chapter:13


Publication Year: - Title: Real or Rendered? Abstract: It’s a beautiful tanzanite pendant necklace.

Or is it?

Half of the images in the gallery below are photographs of actual jewelry pieces.

The others are computer renderings created by GIA students.

Jewelry Design & Technology (JDT) students create dozens of jewelry designs by using computer-aided design (CAD) and computer-aid manufacturing (CAM) programs. The technology lets them create a 3-D rendering (image) of their design that is often remarkably realistic.

Each slide in the gallery contains two images – one is a photograph, the other a computer rendering.

These stunning designs all beg the question: Which is real and which is rendered?

View Gallery @chapter:16


Publication Year: 2020 Title: Saltwater Bead Cultured Pearl with Laminated Nucleus Abstract: Figure 1. A white round nacreous pearl weighing 28.89 ct and measuring 16.00 mm. Photo by Nuttapol Kitdee.

The nuclei used for bead cultured pearl production are usually spheres fashioned from nacreous shell (J. Taylor and E. Strack, “Pearl production,” in P.C. Southgate and J.S. Lucas, The Pearl Oyster, 2008, Elsevier, Oxford, UK, pp. 273–302). The majority of this shell is sourced from freshwater mussels found in the Mississippi and Tennessee River systems in the United States (L.E. Cartier and M.S. Krzemnicki, “New developments in cultured pearl production: Use of organic and baroque shell nuclei,” Australian Gemmologist, Vol. 25, No. 1, 2013, pp. 6–13), and the resulting nuclei typically range between 6.0 and 8.0 mm. When a white round nacreous pearl weighing 28.89 ct and measuring 16.00 mm (figure 1) was submitted to GIA’s Bangkok laboratory for identification, the gemologists were intrigued by what the X-rays revealed.
Externally, the pearl showed characteristics typical of bead cultured pearls originating from the silver-lipped variety of Pinctada maxima: large size, symmetrical shape, satiny luster, and white color. Preliminary observation with a loupe and microscope revealed faint and smooth overlapping nacre platelets with some surface blemishes and polishing lines. Energy-dispersive X-ray fluorescence (EDXRF) analysis failed to detect any manganese (Mn) but did reveal high levels of strontium (Sr), while X-ray luminescence revealed a moderate greenish yellow reaction. These results are consistent with those expected for saltwater cultured pearls containing a freshwater shell bead nucleus (H.A. Hänni et al., “X-ray luminescence, a valuable test in pearl identification,” Journal of Gemmology, Vol. 29, No. 5/6, 2005, pp. 325–329).

Figure 2. Real-time microradiography revealed two planes and two recesses (one in the center of each plane) within a large shell bead nucleus. In the optimal direction, one plane (red arrow) shows as a distinct dark line owing to the perfect alignment with the X-ray source relative to the detector, while the other plane (yellow arrow) is less well aligned and hence appears more like a discoid feature. Image by Kwanreun Lawanwong.
However, several interesting features were revealed by examination with real-time microradiography (RTX) (figure 2). The bead nucleus was clearly visible in the RTX images and measured approximately 10.21 mm in diameter. This uncommon size was the first indication that this was not a standard bead. Moreover, two sharp planes were clearly visible, another interesting observation since most shell bead nuclei examined with RTX do not show such defined bands. (These are not to be confused with the mostly weak and more diffused bands sometimes seen that relate to the shell’s layered growth structure.) The parallel lines matched structures observed in GIA’s previous research on known samples of bead cultured pearls in which laminated shell bead nuclei were used. In keeping with samples from that research, the most defined line appears when the nucleus is in the optimal direction (figure 2, red arrow) relative to the X-ray source and detector, while the less defined line (figure 2, yellow arrow) appears more like a discoid feature when the alignment is not so perfect. Additionally, a shallow and circular-looking recessed feature in the center of each plane aroused further curiosity. Such structures are not typical of other laminated beads previously examined by GIA.
Laminated shell bead nuclei originated a few decades ago when some Australian pearl farms attempted to produce large pearls to meet demand. However, the high price of the larger shell bead nuclei needed for this forced them to experiment with other materials such as dolomite (Summer 1998 Lab Notes, pp. 130–131; Winter 2001 Gem News International, pp. 332) to produce the large nuclei. Unfortunately, none of the materials were suitable from a commercial perspective. Some farms started bonding strips of shell together to fashion larger bead nuclei of around 10–10.9 mm. The majority of such pearls were produced from second operations. Since this experiment proved more successful, a number of saltwater bead cultured pearls possessing a laminated shell bead nucleus are still encountered in the market today.
GIA labs globally have encountered numerous laminated shell bead nuclei. However, this is the first example with the unusual recessed features, and the reason for their existence is unclear. They are unlikely to be related to damage caused during the manufacturing of the bead. The almost identical positions and appearances suggest that they were created for some purpose. Since the pearl is undrilled, damage resulting from any drilling process (Summer 1995 Lab Notes, pp. 125) may also be eliminated. Another possibility is that they may be related to placement areas for radio-frequency identification (RFID) chips (see Spring 2020 Lab Notes, pp. 134–136 of this issue). But since it is customary to only use one chip per pearl and the recesses are relatively thin with rounded outlines, which differ from the usual deeper square recesses encountered for RFID pearls, this seems unlikely.
The presence of faint banding within the nucleus and the pearl’s X-ray luminescence reaction prove that the bead was fashioned from freshwater shell. Therefore, even though the nucleus is laminated, the pearl is still classified as a “bead cultured pearl.” The only mystery left is the reason for the two shallow circular recesses in the surfaces of two of the shell pieces used to form the laminated bead nucleus. @chapter:14


Publication Year: - Title: A New Classification for Red-To-Violet Garnets Abstract: The recent article by Manson and Stockton on the classification of red-to-violet garnets should be welcomed by all gemologists. With this work, the Gemological Institute of America has opened the subject for review and revision. The following article presents an overall view of previous red-to-violet garnet classification schemes and proposes a new one that is well within the capabilities of every gemologist. @chapter:6


Publication Year: 2022 Title: Combination of Phenomena in Star and Cat’s-Eye Color-Change Sapphire Abstract: Figure 1. This 20.49 ct star sapphire with a combination of phenomena exhibited a color change from violet (top) to purple (bottom). Side A is shown in these photos. Photos by Shunsuke Nagai.
The Tokyo lab recently examined a transparent 20.49 ct violet to purple color-change double cabochon sapphire, measuring 16.67 × 14.69 × 8.51 mm (figure 1) with a specific gravity of 3.99 and a spot refractive index of 1.77. Usually a star sapphire is only polished on one side, and the unpolished side does not show any phenomena. But this stone was polished on both sides, which resulted in a unique combination of phenomena. Side A displayed a six-rayed star. Side B also displayed a six-rayed star, but one line containing two of the rays was much stronger, which made the phenomenon reminiscent of a cat’s-eye.

Figure 2. Side A: Intersecting sets of parallel needle inclusions producing six-rayed asterism. Photomicrograph by Yusuke Katsurada; field of view 5.8 mm. Inset photo by Shunsuke Nagai. The photomicrograph is not aligned with the inset.
Chatoyancy is displayed when light reflects off a set of dense parallel elongated inclusions, such as needles; asterism occurs when such a set of inclusions is oriented in multiple directions. In the case of this stone, side A with the distinct six-rayed star had three sets of dense parallel needles and platelets close to the surface, intersecting at 60° angles (figure 2), which is common with six-rayed asterism. Side B also had three sets of these needles close to the surface, but the needles were more concentrated in one of the directions, producing a cat’s-eye effect (figures 2 and 3). Interestingly, the chatoyancy in Side B and one line of asterism in Side A are contributed by the same group of needles.

Figure 3. Side B: Set of parallel needle inclusions producing chatoyancy. Photomicrograph by Yusuke Katsurada; field of view 5.8 mm. Inset photo by Shunsuke Nagai. The photomicrograph is not aligned with the inset.
Although color-change star sapphire is not particularly rare, color-change cat’s-eye sapphire is far less common. Color-change sapphire with asterism on one side and chatoyancy on the other is without question a “phenomenal” gem. @chapter:12


Publication Year: 1990 Title: Recent Discoveries of Large Diamonds in Trinity County, California Abstract: Although California has produced over 600 diamonds, some of which have been of gem quality, the largest until recently weighed approximately 6 ct. In the early 1980s, however, Edgar J. Clark found a 3.90 ct stone; in 1987, he discovered three stones weighing 32.99, 17.83, and 14.33 ct. These four diamonds were recovered from stream gravels of Hayfork Creek in Trinity County, California. All four are of industrial grade and all have one interesting feature in common, that is, two generations of diamond growth. The initial crystal, or group of crystals, is encrusted by a later generation of diamond overgrowth that, although it conforms crystallographically to the underlying crystal, shows different crystal forms. This unusual feature, common to all four crystals, would indicate that they originated from the same source. @chapter:29


Publication Year: 2017 Title: Importance of the Secondary Market for Fine Gems Abstract: Figure 1. This exceptional oval-cut, 55.52 ct copper-bearing tourmaline from Mozambique was previously sold by B&B. They recently reacquired it through the secondary market. Photo by Eric Welch; courtesy of B&B Fine Gems.

	At the AGTA show, Dave Bindra (B&B Fine Gems, Los Angeles) showed us some exceptional items he recently sourced from the secondary market. These are previously sold goods recirculated back into the market by the former owners or their heirs.

	Bindra also updated us on his perception of U.S. traders’ reaction the withdrawal of sanctions against Myanmar (Burma) and what that means for U.S. dealers like him. According to Bindra, most U.S. dealers greeted lifting of the trade embargo with enthusiasm as they can legally import and trade Burmese rubies again. Prior to this they were limited to trading items that had come into the country “pre-ban.” Bindra doesn’t expect prices to come down; rather, he projects they will strengthen as American demand and consumption of Burmese goods grows. He noted that during the ban, some consumers and certain major brands stopped consuming rubies altogether, basically because they weren’t open to consuming rubies from sources like Mozambique, which has become a prolific source of commercial-to-fine grade gems. Now that the ban is lifted, Bindra hopes many of these companies will start buying and selling Burmese rubies again. The main issue now is the very limited supply coming out, but he says there’s definitely a strong market for fine-quality stones.

	Dave Bindra - B&B Fine Gems

	In this interview, Mr. Bindra explains the importance of the secondary market as a source for fine gems. He also provides perspective on the recent withdrawal of sanctions against imports of Burmese ruby and the implications for U.S. traders.

	Bindra highlighted some exceptional pieces at his booth to illustrate the importance of the secondary market for his inventory. The company also procures gem materials from currently active mining areas, but the secondary market is important for larger, more important stones, which are scarce as a percentage of new production. As an example, he shows us a fine, oval-cut, 55.52 ct copper-bearing tourmaline from Mozambique (figure 1). He notes this particular stone came out of the original 2007 production from Nampula Province, northeastern Mozambique, near the village of in Mavuco (see B.M. Laurs et al., “Copper-bearing (Paraíba-type) tourmaline from Mozambique,” Spring 2008 G&G, pp. 4–30).

	B&B actually sold this stone about seven years ago, and was lucky to reacquire it when the opportunity arose in 2016. Bindra considers this fortunate as there is no production from this deposit today and it would be impossible for them to find an item like this, other than the secondary market.

	Another example he cites is a beautiful 5.06 ct trillion-cut benitoite (figure 2). This gem—a barium titanium silicate—is typically colorless to blue, and is noteworthy for its high refractive indices, moderate birefringence, and strong dispersion. It comes from just one mine, located in San Benito County, California (see B.M. Laurs et al., “Benitoite from the New Idria District, San Benito County, California,” Fall 1997 G&G, pp. 166–187). The benitoite mine has been closed for years. Bindra describes this 5 ct as an “astronomical size for this deposit”—the typical size range of commercially available finished gems from this mine was between 0.30 and 1.70 ct. He noted that this gem was a prized possession of an original mine owner.

Figure 2. This fine-quality 5.06 ct trillion-cut gem is exceptionally large for benitoite. Photo by Robert Weldon/GIA; courtesy of B&B Fine Gems.

	Bindra also showed us a couple more recirculated pieces: a fine 15.06 ct double-sided black opal cabochon (figure 3) with broad flashes of play-of-color from Australia’s Lightning Ridge and a 19 ct antique-cut Brazilian Imperial topaz. This last stone was old, unheated material from Ouro Preto. The stone came out of an old collection and was a little over 20 ct. They were able to recut it with minimal loss of weight to significantly improve luster and brilliance. Bindra told us these gems underscore the importance of the secondary market for his inventory. While it doesn’t supply the day-to-day production B&B needs, it does produce truly exceptional items from time to time. He noted that fine colored gemstones always retain their value, which is why B&B is often able to reacquire items over a period of time. He always keeps this in mind whenever selling rare, esoteric gemstones.

Figure 3. This 15.06 ct double-sided black opal cabochon from Lightning Ridge was another recirculated gem offered by B&B. Photo by Eric Welch; courtesy of B&B Fine Gems.

	Next, Bindra showed us one of the most exceptional stones he’s had in years: a 10.22 ct cushion-cut Brazilian alexandrite. He adds that B&B has trouble fulfilling orders for 6 mm (approximately 1.00 ct) round alexandrite with current Brazilian production, so finding a 10 ct size is really an anomaly. According to Bindra, it came out of an old collection in Japan, where it sat in a safe for 20 years. He said he “couldn’t write the check fast enough” to get it into B&B’s inventory. In this case, there was no need for repolishing. The gem is unusual not just for its size and the quality of its color change, but also because of its brilliance. He notes that Brazilian alexandrite of this rich blue-green to reddish purple color tend to be “over dark” and lack life. This stone was faceted with a typical Portuguese pavilion, which confers considerable brilliance. Due to these factors, Bindra adds, the wholesale value of a truly fine gemstone like this is well over $55,000 per carat.

	Finally Bindra shows us a 20-ct-plus star sapphire with a sharp six-rayed star, strong blue bodycolor, exceptional translucency, and a well-proportioned, high-domed cabochon shape. It’s another piece that’s “come out of recirculation,” says Bindra. He suspects the current marketplace scarcity of fine blue star sapphires is due to a newly discovered heating process, leading to a lot of fine-color examples being recut into faceted gems. He cites an example of a 23 ct star sapphire, which might be heated and refashioned into a top-gem royal blue color faceted stone in the 10–15 ct range. For some people, that’s more desirable, so stars are becoming rarer. Not every stone can be heated and improved, as they might break due to the unforeseen way inclusions react to the heat.

	Bindra sees strong demand from the top one percent of consumers. He notes that exceptional gemstones are in very high demand, as more than ever people find value in hard assets—fine art, classic automobiles, fine wine, high-end watches, important diamonds—and colored gemstones are “in that same conversation.” Bindra professes some skepticism about the middle of the market, where commercial to mid-grade material is not moving as well. At the top end of the market, high-end colored gemstones are difficult to find because of competition from overseas—from new markets, from new capital—especially in Southeast Asia, where there is a cultural affinity for consuming fine colored gemstones. @chapter:38


Publication Year: 1998 Title: Winter 1998 Gem News International Abstract: Diamonds
            Diamond Production Starts at Canada’s Ekati Mine
Financial Times Diamond Conference
Colored Stones
            Colored Stone Presentations at the International Mineralogical Association Meeting
            Chalcedony with Goethite Inclusions from Madagascar
            Iolite Gemologically Indistinguishable from Feldspar
            New Features of Montana Sapphires: Gold is Where You Find It
            Highly Translucent Green Serpentine from Afghanistan
            Etch-Decorated Topaz
            Red, Pink, and Bicolored Tourmaline from Nigeria
Treatments
            On the Burning of Polymer-Impregnated Synthetic and Natural Opals
            Irradiated Inclusions in Topaz
Synthetics and Simulants
            Obsidian Imitation
            Diffusion-Treated Synthetic Sapphire
Announcements
            Indonesian South Sea Pearl Auction
            Congratulations to Gems & Gemology

To view the full section, download the PDF above. @chapter:23


Publication Year: 2022 Title: Atypical “Box Bead” Cultured Pearls Abstract: Figure 1. The five “box bead” cultured pearls examined ranged from 8.00 × 7.26 × 6.05 mm to 9.93 × 7.86 × 5.86 mm. Photo by Lhapsin Nillapat.
Gemologists are aware of two main types of bead cultured pearls—bead cultured (BC) and atypical bead cultured (aBC). BC pearls are cultured with the typical round, predominantly freshwater shell bead nuclei, while aBC pearls are cultured with any material that is not typical. Atypical bead nuclei include fancy-shaped shell beads, pearls of any kind, plastic beads, gemstones, or other materials of various shapes. GIA’s Bangkok laboratory received five loose undrilled pearls as research samples for examination. These were reportedly sold as “tissue box pearls” in the Indian market by a trader known to some GIA staff. Externally they exhibited a smooth surface with luster resembling that of South Sea Pinctada maxima cultured pearls. The samples ranged from 8.00 × 7.26 × 6.05 mm to 9.93 × 7.86 × 5.86 mm, weighing between 2.50 and 3.49 ct, and exhibited a baroque form with a white to cream color (figure 1).

Figure 2. The five “box bead” cultured pearls (top) together with their X-ray computed microtomography (μ-CT) slices showing the obvious rectangular bead demarcations resembling a box shape (bottom). The red arrow indicates the additional structural feature observed within sample 2. Photos by Lhapsin Nillapat.
Microradiographic examination revealed unusual box-shaped demarcation outlines uncharacteristic of traditional BC pearls (figure 2). To the author’s knowledge, this kind of internal rectangular shape is never seen in natural pearls. Sample 2 revealed an additional structural feature extending from the shorter side of the “box bead” (see red arrow in figure 2). Sample 3 possessed two distinct radio-translucent areas around the box-shaped outline; these are expected for voids or certain organic-rich features in pearls. Samples 4 and 5 also showed similar radio-translucent features, but to a lesser extent. Since the rectangular internal structures are not observed in natural pearls, the clear demarcation features with a box-shaped outline are enough to identify these as aBC pearls.
The box-shaped beads clearly influenced the external shapes of their pearl hosts when they formed within the mollusks, as seen in figure 1. Samples 2 and 3 were cut in half for further examination of their internal structures. Under magnification, each half showed an obvious demarcation between the box-shaped bead and the nacre overgrowth. The “box beads” appeared to be more translucent than traditional beads and exhibited platy structure and banding in some areas, proving they were fashioned from shell. Additionally, the feature in sample 2 possessed a radial structure and appeared somewhat translucent. Observation through a gemological microscope revealed that the gaps around the nucleus in sample 3 were in fact voids with areas of dark organic-rich material, likely conchiolin, present within (figure 3).

Figure 3. A: Cross section of sample 2. B: Radial columnar structures, identified as calcite by Raman, observed in an area within the nacre overgrowth covering sample 2’s bead nucleus. C: Cross section of sample 3. D: Magnified view of one of the void features with dark organic-rich material attached to the inner surface. Photos by Ravenya Atchalak; fields of view 14.40 mm (A and C), 7.20 mm (B), and 2.88 mm (D).
Another point of interest was the inert reaction of the shell nuclei in each half of both samples under optical X-ray fluorescence. Since most freshwater bead nuclei show strong yellowish green or greenish yellow reactions, it was clear that the “box beads” were not fashioned from freshwater mussel shells.

Figure 4. The cross sections of sample 2 (top left) and sample 3 (top right) under white light and their inert reactions under X-ray fluorescence (bottom). Photos by Ravenya Atchalak.
Energy dispersive X-ray fluorescence (EDXRF) results of the “box bead” nuclei, outer nacre layers, and the radial calcitic area revealed major amounts of calcium, along with high levels of strontium ranging from 1209 to 1986 ppm, and manganese below 63 ppm. The low levels of manganese detected by EDXRF corresponded to the inert optical X-ray fluorescence reaction (figure 4), as the intensity of any reaction is directly correlated to the manganese levels (P. Kessrapong et al., “Atypical bead cultured Pinctada maxima pearls nucleated with freshwater non-bead cultured pearls,” GIA Research News, April 6, 2020, https://www.gia.edu/gia-news-research/atypical-bcp-nucleated-with-nbcp). The high strontium and low manganese concentrations indicated saltwater origin.
Under long-wave ultraviolet radiation, the sawn surfaces exhibited a bluish reaction. Sample 2 showed additional very weak orangy reactions associated with the columnar feature partially surrounding the bead (figure 5).

Figure 5. The cross sections of sample 2 (top left) and sample 3 (top right) under white light and their reactions under long-wave UV (bottom). Photos by Ravenya Atchalak.
Short-wave UV fluorescence spectra were also collected from the pearl surfaces using a GIA-developed spectrometer. The spectra showed two distinct peaks around 330 and 360 nm with counts above 10,000, indicating the surfaces were not processed using bleach or any whitening/brightening agents (C. Zhou et al., “Detection of color treatment and optical brightening in Chinese freshwater ‘Edison’ pearls,” Summer 2021 G&G, pp. 124–133).
Raman analysis using 514 nm laser excitation on the “box bead” surfaces and outer nacreous layers of the sawn surfaces showed typical aragonite features at around 701/704 cm–1 (doublet) and 1085 cm–1. The columnar radiating area on sample 2 was also analyzed, revealing features at around 154, 281, 711, and 1085 cm–1 that were consistent with calcite (J. Urmos et al., “Characterization of some biogenic carbonates with Raman spectroscopy,” American Mineralogist, Vol. 76, 1991, pp. 641–646).
All the data obtained from the advanced testing methods as well as observation under magnification prove the “box bead” nuclei were fashioned from saltwater shell.
Although this is not the first time GIA has encountered saltwater cultured pearls containing non-traditional bead nuclei, the box shape of the beads in this sample group has never been documented in the gemological literature and is therefore notable. @chapter:14


Publication Year: 2001 Title: Fall 2001 G&G Book Reviews Abstract: “Gemstones—Quality and Value, Vol. 3: Jewelry”
By Yasukazu Suwa, 144 pp., illus., publ. by Sekai Bunka Publishing, Tokyo, 2001. US$95.00

“Mogôk: Valley of Rubies & Sapphires”
By Ted Themelis, 270 pp., illus., publ. by A & T Publishing, Los Angeles, 2000. US$89.00

“Southwest Silver Jewelry”
By Paula A. Baxter, 212 pp., illus., publ. by Schiffer Publishing, Atglen, PA, 2001. US$49.95

“Jewelry Wax Modeling— A Practical Guide for the Jewelry Model Maker”
By Adolfo Mattiello, 161 pp., illus., publ. by Du-Matt Corp., Guttenberg, NJ, 1999. US$38.95

“Western Queensland Opals— Exploration and Geoscience Data Sets”
CD-ROM, Queensland Government Department of Mines and Energy, 2000, free of charge [e-mail: lcranfield@dme.qld.gov.au]

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


Publication Year: 2022 Title: GIA Alumni Collective Abstract: The new GIA Alumni Collective offers a robust educational and networking platform for GIA graduates worldwide.
GIA’s alumni association has a new name, a fresh look, and up-to-date features. With a mission to connect GIA graduates around the world, provide opportunities for continuing education, and foster networking throughout the gem and jewelry industry, the GIA Alumni Collective (see above) builds on the association’s long history with updates that better reflect the creativity, technical savvy, entrepreneurship, and vitality of GIA’s alumni.
After successfully completing a GIA program or course, alumni can register for the Collective and stay informed about all the resources available to them by visiting the new GIA Alumni Collective website. The new online community, collective.gia.edu, serves as a “central hub” where members can add their profile to the directory, engage and connect directly with other members and global chapters, join “virtual” chapters, register to attend professional events, access more than 20 Continuing Education seminars at a 10% discount, and more.
“The new GIA Alumni Collective website and online community is a reflection of our diverse alumni network. The collaboration with chapter leaders and other members brings new energy and a modern look that connects our global network and provides a space to experience the future of gems and jewelry,” says Cathryn Ramirez, executive director of alumni development and continuing education at GIA.
GIA has more than 155,000 active alumni in 58 chapters spanning the globe—33 in the Americas, 16 in Asia, and three apiece in Europe, the Middle East, and Africa. While chapters host their own meetings and events, chapters often co-host to provide additional networking opportunities. The GIA Alumni Collective hosts annual events at the AGTA Tucson and JCK Las Vegas trade shows where hundreds of alumni from all over the world meet up with longtime friends and colleagues and foster new relationships. @chapter:34


Publication Year: - Title: Texas Jewelers Leave a Legacy of Learning, Bestow Nearly $500,000 for Scholarships Abstract: Charles and Erna Leutwyler, who were married for 50 years, owned the popular Charles Leutwyler Jewelers in Austin, Texas. Beginning in 2018, a perpetual endowed scholarship in their name will be available each year. Photo courtesy of the Leutwyler Estate

Boisterous Charles and soft-spoken Erna Leutwyler may have seemed like polar opposites, but through their shared love of learning and jewelry they were able to create a beloved jewelry store in Austin, Texas and a marriage that their friends still remember fondly.

As owners of Charles Leutwyler Jewelers (Leutwyler’s) for more than 20 years, these GIA alumni were committed to sharing their knowledge with others – whether it was with first-time jewelry buyers who wandered into their store, employees new to the jewelry business or long-time customers looking for the newest designs.

“Charles and Erna believed in teaching others,” says John Sofyanos, a close friend of the couple who knew them for 46 years.

Even after their deaths (Charles in 1996 and Erna in 2015), the couple is sharing their passion for jewelry and legacy of learning through the gift of an annual $18,000 GIA scholarship toward the completion of an on campus Graduate Gemologist, Graduate Jeweler or Jewelry Design & Technology program in the U.S. The first scholarship will be awarded in June 2018 and then each December for the next year’s program.

Funded by the Leutwyler’s bequest of nearly $500,000 to GIA’s Endowment Fund, The Charles and Erna Leutwyler Memorial Scholarship will make sure that the couple’s love of learning and jewelry extends to future generations of aspiring gem and jewelry professionals.
A Very Special Couple
Charles and Erna were raised and spent most of their lives in central Texas. They married in 1946 after Charles returned from serving in the U.S. Army Air Corps during World War II. They enjoyed working together and had a good marriage, Sofyanos recalls.

Charles was exuberant and wore a Mexican-style embroidered wedding shirt every day, often “smudged with fingerprints from wiping his hands while working at the bench,” Sofyanos says. “He was brusque, but with a heart of gold and was well-respected by everyone.”

Erna, on the other hand, was calm and reserved. “She dressed properly in a tailored suit with a string of pearls,” Sofyanos says. “She was a true Southern lady.”

“They were a special couple,” says Sofyanos, who met Charles in the fall of 1969 after returning from Vietnam. The two veterans quickly bonded and became good friends.

Erna managed the front of the store, while Charles worked in the back. “Most days you could see their cat sitting in the window case, wearing a beautiful diamond necklace,” Sofyanos says.

Kay Adamek, a longtime client, first met the Leutwylers in early 1967 at their original shop downtown when Charles designed her solitaire engagement ring and wedding band, “both with his personal hand-Florentine finish.”

“It was such a friendly place and Erna always had the jewelry showing at its best – [She] was the sweet, elegant hostess in the jewelry store. Charles was a master craftsman, obviously happiest with his light and magnifying hood on his forehead,” Adamek says. “In the Leutwyler’s little shop, there was so much trust and honesty.”

Adamek returned to Austin a few years later with her young son after her husband passed away and Charles designed a special ring to incorporate the gold from the original wedding bands into one ring. Over the next few years, she visited them often.

“It was only natural that when I became engaged and later married for the second time, I returned to Leutwyler’s,” she says.

Forty years later she still receives compliments on her rings. “Charles’ selection of diamonds was always exceptional,” Adamek says.
Sharing a Love of Diamonds
Charles, a fifth-generation jeweler, first worked in his father’s watch shop after the war, but his real passion was for jewelry. “Charles enjoyed the industry; he had a good reputation and he liked talking to the diamond dealers,” Sofyanos says.

The Leutwylers opened their jewelry store in the late 1960s in downtown Austin, not far from the state Capitol. After a few years, they decided to move to an area known as “The Drag,” across the street from the University of Texas (UT). The Leutwylers said it made sense financially and it would be more fun, according to Clyde Neal, who worked for the couple from 1972 to 1982. The busy area was popular with students and had a lot of foot traffic.

“Charles loved diamonds,” Neal says. “He realized that being near the university would bring a whole new clientele of young university couples looking for diamond engagement rings.”

That’s exactly how Neal met the Leutwylers in 1972 when he walked into their store as a newly engaged student. He says he left three hours later knowing a lot more about diamonds than he expected.

“Charles sat me down at a microscope and let me see the diamonds for myself. He explained the 4Cs and told me he only sold diamonds cut to ideal proportions,” Neal says. “I asked a lot of questions and he answered them all.”

Charles often took on apprentices, so a few weeks later, Neal came to work in the store. “He taught me how to solder, work with gold, size rings and more about diamonds,” he says. “And he encouraged me to enroll at GIA.”

The Leutwylers wanted all their employees to complete GIA courses, and would reimburse the employee once they completed it. “As soon as he realized someone was good enough, and was going to stick around, he wanted them to start GIA classes,” Neal says.

The Leutwylers also took GIA courses throughout their careers. Charles earned his GIA Graduate Diamonds diploma in 1966 and Erna completed numerous GIA courses. They wanted to make sure they stayed up-to-date with new advancements so they could continue to pass along that knowledge to their customers.

Charles Leutwyler, a fifth-generation jeweler, was invited to examine and photograph the Hope Diamond at the Smithsonian Institution in Washington, D.C.  Photo courtesy of the Leutwyler Estate
Innovative Techniques in Gemology, Business and Jewelry Design
Charles emphasized the importance of selling a diamond that was cut to maximize brilliance, says Neal. “He only wanted the best, most brilliant diamonds” and documented them by regularly photographing his inventory and keeping records on a computer. The Leutwylers used computers before most other small businesses at the time, Sofyanos says.

Charles also taught himself how to photograph the diamonds microscopically – called photomicrography – to see the inclusions, or internal features. According to Neal, his background in gem photography and strong industry relationships led to a remarkable opportunity for Charles to photograph the Hope Diamond

Charles mentioned to an industry friend that he wondered if the Hope Diamond, part of the gem collection at the Smithsonian Institution, had been photographed internally. The friend talked to a connection at the Smithsonian, and soon enough Charles was invited to photograph the Hope Diamond using his techniques, Neal recalls.

“Charles bought a new suit, and he and Erna made the trip to Washington, D.C., going in after-hours with security,” Neal says.

Even in the most formal settings, Charles was not afraid to show his sense of humor. “Charles said he slipped the Hope Diamond into his coat pocket while he set up the equipment,” Neal says. “The security guards were mighty nervous when that happened.”

Charles also enjoyed the mechanical aspect of jewelry making, crafting a work of art and pushing the limits technically. One piece in particular became his “pride and joy,” Sofyanos says.

He designed a Mickey Mouse-character Timex bracelet watch with “gold nugget” band, a style that was popular in the 1980s. The face was surrounded with 36 diamonds totaling more than 2 carats. The extravagant watch was featured in Texas Monthly magazine’s January 1982 issue for its “over-the-top” design.

“Everyone knew the Mickey Mouse watch,” Sofyanos says. “It was ostentatious and definitely one-of-a-kind.”
The ‘Go-to Guy’ for Education and Advice
Charles was friends with a geology professor at UT, Dr. Edward Jonas, who taught a course on colored gems. Charles wanted to share his knowledge of diamonds, so he invited Dr. Jonas and his students to the store one evening for a special diamond session. Neal, who was also enrolled in the class, says many of the students were fascinated learning about diamonds and how they’re graded.

“A lot of people in Austin came to Charlie for advice,” Sofyanos says, and the Leutwylers held diamond education nights for the community so potential buyers were well-informed.

Fellow jewelers also came to Charlie for advice. Neal remembers one occasion when another local jeweler called Leutwyler’s and wanted to come in after hours – when no one would see him. The jeweler had been repairing an antique gold pocket watch and burned a hole through the case. It wasn’t easy, but Charles repaired the gold case of the watch.

“He had that reputation,” Neal says. “He was the go-to guy.”

After more than two decades of business, and their entire careers in the jewelry industry, Charles and Erna closed their store in the early 1990s. Over the years they shared their generosity and knowledge with the many employees, customers and friends who knew them.

“Charles and Erna Leutwyler dedicated themselves to sharing their love of gems and jewelry with their community, their employees and everyone they met,” says Anna Martin, senior vice president of global development. “We are honored that the Charles and Erna Leutwyler Memorial Scholarship will continue that love of learning and spirit of giving. It has the potential to influence countless more future gemologists.”

Kay Adamek says the Leutwylers became a marker in her life, too.

“When Charles died, I wrote to Erna and received a sweet reply that she did remember me,” Adamek says. “I wondered then how many other young people walked through their doors over all those years and how many other stories there are.”

And now with the scholarship, how many more stories there will be. @chapter:36


Publication Year: 2019 Title: Exsolved Particles with Natural Appearance Within Flux-Grown Pink Synthetic Sapphire Abstract: Figure 1. Left: Reflective platinum platelet with negative hexagonal growth within a flux-grown pink synthetic sapphire; field of view 2.34 mm. Right: Channels of exsolved interconnected flux; field of view 4.79 mm. Photomicrographs by Britni LeCroy.
The Carlsbad laboratory recently examined unusual exsolved flux particles in a flux-grown pink synthetic sapphire. The specimen, mounted in a ring, had an estimated weight of 13.07 ct and a refractive index of 1.760–1.770. It displayed a typical pink sapphire spectrum with a handheld spectroscope. Strong red fluorescence was seen under both long-wave and short-wave UV. Laser ablation–inductively coupled plasma–mass spectrometry (LA-ICP-MS) detected high levels of platinum; the concentrations of iron, beryllium, titanium, vanadium, and gallium were either below the detection or quantification limit.
Microscopic examination revealed further evidence of a synthetic origin: a single reflective platinum platelet with negative hexagonal growth through the center (figure 1, left). Also observed were interconnected channels of exsolved flux creating fingerprints (figure 1, right).

Figure 2. Fine rounded flux particles aligned into linear stringers resembling fingerprints and silk clouds seen within natural corundum. Photomicrograph by Britni LeCroy; field of view 1.73 mm.

A potentially challenging inclusion was seen in the form of minute rounded flux particles aligned in organized linear rows (figure 2), which displayed a striking resemblance to fingerprints and silk clouds commonly seen within natural corundum. These particles were observed in relative abundance at varying depths. Grid-like exsolved solid inclusions have been mentioned in the literature as possible properties of synthetic corundum (R.W. Hughes et al., Ruby & Sapphire: A Gemologist’s Guide, Lotus RWH Publishing, Bangkok, 2017). It has not been stated how abundant these natural-looking fingerprints are within flux-grown synthetic material, but this type of inclusion is rarely seen at the Carlsbad laboratory. Identifying the natural or synthetic origin of a stone with this type of natural-looking inclusion can be challenging. If a gem material is suspected of being synthetic, it is advisable to submit it to a gemological laboratory. @chapter:12


Publication Year: - Title: Shipley Shaped GIA Mission on Personal Experience, Commitment to Improvement Abstract: Imagine yourself in his shoes:  You are a successful businessman with the intrinsic charm and charisma of a great salesman. You have created a group of highly successful and well-regarded jewelry stores and are convinced you know all there is to know about gems – until two of your best customers challenge you and reveal your lack of expertise.

Standing in his shoes, how would you feel?

Probably just as Robert M. Shipley did: humbled. And even though his lack of expertise was typical for U.S. jewelers in the mid-1920s, those soul-searching encounters ultimately spurred him into changing the gem and jewelry industry.

First though, Shipley lost the jewelry stores in divorce and headed to Europe to recuperate from years of relentless pursuit of success. While he was there, he completed the Great Britain National Association of Goldsmiths gemological correspondence course, the foundation for his personal reinvention from jeweler to teacher and gemology expert.

Shipley returned to the U.S. in 1929 and launched his “preliminary course in gemology” in Los Angeles on Sept. 16, 1930. In the years that followed, he covered thousands of miles in secondhand cars, aggressively promoting – with the single-mindedness of a zealot – the professionalization of the jewelry industry through gemological education.

His goal was to restore the public’s trust in the jewelry trade by training “certified” jewelers who would eventually be united in a national guild.

“Like the physician, the architect and the engineer, the gemologist must complete prescribed studies and examinations in order [to be] of exceptional service to the public [in] the new profession of Gemology,” Shipley said.

His concept was the seed for GIA and would transform the gem and jewelry industry in the U.S. and, ultimately, around the world.

Shipley’s quest for expertise, his commitment to improving his knowledge and skills, and his belief that jewelry customers should know what they are buying are the central principles of GIA’s mission. Today, we apply these same principles in our daily work and in our planning for GIA’s future. @chapter:34


Publication Year: 2003 Title: Fall 2003 G&G Lab Notes Abstract: Dyed Black Chalcedony
Some Unusual Type II Diamonds
A Faceted Leadhillite
Cultured Pearl Mystery
Treated-Color “Golden” South Sea Cultured Pearl
Quartz Crystal with “Lizard” Inclusion
Unusual Mottled Pink Quartz
Quartzite Dyed to Imitate Ruby
Unusual Inclusions in a Beryllium-Diffused Sapphire
Stichtite Flowers
Addendum: Cat’s-Eye Opal

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


Publication Year: 2023 Title: Xenomorphic Garnet in Diamond Abstract: A purplish pink xenomorphic octahedral garnet crystal seen in a diamond. Note the trigons on the upper right octahedral face and stress fractures around the intersections of the crystal faces. Photomicrograph by Britni LeCroy; field of view 1.26 mm.
Garnet is a nesosilicate mineral belonging to the cubic crystal system. The crystal habit most commonly assumed by this mineral is a dodecahedron. A garnet crystal with rare octahedral morphology was recently encountered in the form of a xenomorphic inclusion within diamond. Xenomorphism is the process by which a growing mineral forces a syngenetic mineral inclusion to adopt a crystal habit familiar to the host (J.I. Koivula, The MicroWorld of Diamonds, Gemworld International, Northbrook, Illinois, 2000). Xenomorphic crystals may also be referred to as “anhedral” since they lack their own characteristic crystal shape in favor of the host’s. However, it should be noted that not all anhedral included mineral crystals are xenomorphic. As an octahedron is the most common diamond habit, the garnet inclusion grew into this form, complete with triangular growth marks visible on one of the octahedral faces (see above). Xenomorphism in diamond can also occur with mineral inclusions that do not belong to the cubic crystal system, and these can be forced into other diamond habits. For example, a monoclinic crystal of diopside may be forced into a cuboctahedral habit. Xenomorphic crystals are just one of many unique inclusion types possible within diamond. @chapter:32


Publication Year: 2019 Title: Gem Art of the Taj Mahal, Fancy White and Black Diamonds, and Unique Inclusions in Thai Corundum Abstract: Welcome to the Fall 2019 issue of G&G! Inside you’ll find eight articles on a variety of gemological topics, plus dozens of brief reports and discoveries from contributors around the world.
Our lead article delves into the gem art of the iconic Taj Mahal. Dona Dirlam and co-authors examine the intricate gem inlay that graces this architectural treasure, as well as the gem connoisseurship of the Mughal dynasty and how it influenced global gem commerce in the seventeenth century.
In the second article, Sally Eaton-Magaña and Christopher M. Breeding continue their series of colored diamond characterization studies with an in-depth look at Fancy white and Fancy black diamonds. Their systematic study, based on GIA’s data for approximately 500 Fancy white and 1,200 Fancy black diamonds, is the first of its kind for these uncommon diamonds.

“A systematic study, based on GIA’s data for approximately 500 Fancy white and 1,200 Fancy black diamonds, is the first of its kind for these uncommon diamonds.”

Next, Yang Hu and Ren Lu offer a gemological, spectroscopic, and chemical analysis of emeralds from Malipo County in Yunnan Province of southwestern China. Among notable deposits worldwide, Malipo emerald has a unique chemical composition: a combination of high vanadium, low chromium, and moderate iron, as well as high lithium and cesium concentrations.
Supparat Promwongnan and Chakkaphan Sutthirat use Raman spectroscopy and electron probe micro-analysis to identify mineral inclusions in alluvial corundum from the Bo Welu gem deposit in Thailand’s Chanthaburi Province. Several of the inclusions they identify are reported for the first time in Thai corundum.
Next are a pair of studies on organic gem materials. Yamei Wang and co-authors explore hydrothermally treated “beeswax” amber, offering a series of comprehensive tests to identify this product and separate it from untreated material. Kannika Kanjanachatree and co-authors follow the operations at a pearl farm in Phuket, Thailand, to determine the effects of mollusk size on growth and color of half-cultured pearls from Pteria penguin.
The issue rounds out with two brief but informative studies. Wenqing Huang and co-authors investigate a hydrogen-rich faceted green diamond color-treated by a complex multi-step process that has not previously been reported in the gemological literature. Last, Hanyue Xu and Xiaoyan Yu analyze a new rhodochrosite imitation composed of pressed gibbsite and calcite powder with a granular structure.
Highlights from the Lab Notes section include a faceted diamond with a star-shaped cloud inclusion, new resin imitations of ivory, and cobalt-coated sapphire. Micro-World once again offers up a variety of beautiful and unusual scenes from the inner world of gemstones. Among the many Gem News International reports are a new source of Nigerian aquamarine, black non-nacreous pearl imitations made of beads cut from shell, and the new mineral johnkoivulaite. This member of the beryl family is named in recognition of distinguished researcher and longtime G&G contributor John Koivula. Congratulations to John for this exceptional honor—well deserved! @chapter:3


Publication Year: - Title: Books: In Praise of Hands: The Art of Fine Jewelry at Van Cleef & Arpels Abstract: By Franco Cologni, 199 pp., hardcover, illus., publ. by Marsilio Editori, S.p.a. Venice, 2012, $90.00.

                      Van Cleef & Arpels, born from the matrimonial alliance of two prominent Dutch jewelers’ families in 1895, opened their boutique in Paris’s Place Vendôme in 1906 and quickly gained international acclaim. Over the years, the maison created iconic jewelry pieces, such as invisibly set floral brooches, fashionable minaudières and cigarette cases, Ludo Hexagone bracelets, and zipper necklaces. One of the forces behind the firm’s meteoric rise was its excellence in design and craftsmanship. As part of its public relations and branding strategy, Van Cleef & Arpels emphasizes quality craftsmanship and respect for traditional techniques. In Praise of Hands embodies this branding effort. This luxurious book, titled in honor of art historian Henri Focillon’s 1943 philosophical essay on how hands shape art, celebrates Van Cleef & Arpels’s Mains d’Or, or most skilled craftspeople.

The book’s first eleven chapters correspond to various specialized crafts: “The Designer,” “The Mock-Up Maker,” “The Jeweler,” “The Setter,” “Mystery Setting,” “The Stone-Cutter,” “The Diamond-Cutter,” “The Polisher,” “The Smelter,” “The Sculptor-Engraver,” and “The Boîtier.” Each explains, in great detail, a given stage of the design and manufacturing process. Some chapters are of particular interest for jewelers, such as “The Designer,” “The Smelter” and “The Polisher.” These craftsmen are instrumental in creating and giving shape to all jewelry pieces, so it is important to have them featured. For gemologists, “The Stone-Cutter” and “The Sculptor-Engraver” are extremely informative, providing great detail on both processes. The most stimulating and revealing chapters to jewelry enthusiasts are “The Mock-Up Maker,” “Mystery Setting,” and “The Boîtier.” These allow the reader to uncover some of Van Cleef & Arpels’ manufacturing secrets and better fathom its high level of craftsmanship. For instance, the systematic use of mock-ups, made of alloy and rhinestones, demonstrates the utmost attention to detail and practicality. This rendering technique is poles apart from today’s abstract 3D CAD/CAM projections. It allows design and production teams to spot potential technical problems and even provides for price estimates of jewelry pieces at an early stage.

One of the book’s strong points is its display of artful color jewelry renderings. Given the Place Vendôme’s world of secrecy, it is worth noting that some of the sketches feature serial numbers, names of patrons, and details on gemstone costs and corresponding vendors. This type of information is useful to anyone involved in jewelry pricing.

The book is selectively illustrated with three categories of photos. The first type consists of original color sketches with corresponding magnified shots of antique pieces, many of them from the jewelry house’s archival collection. The second type consists of black-and-white photos, using the chiaroscuro technique, of the Mains d’Or craftspeople at work. The third type, appearing at the end of each chapter, features a general shot of a recent piece alongside a detailed photo (showing individual gemstones in some cases). The opening and ending chapter photos are well suited to the chapters’ topics, proving that the craftsmanship inherent in past masterpieces is still alive.

On the down side, there is a relative disconnect between the photos of artisans’ hands and the contemporary jewelry pieces shown at the ends of sections. There would have been greater impact if the book had shown the same piece twice, once between the hands of a jeweler during its making and once completed. The photos of jewelers’ hands, though certainly a strong homage to their skills and dedication, are a superficial representation. At best, these pictures convey the contrast between rugged hands and delicate jewelry components in various stage of completion, as well as the artisans’; strength and dexterity. Yet focusing on their hands is too restrictive, and does not convey the physicality involved in jewelry making. The process is not limited to the hands; rather, it is a constant connection between hands, eyes, and brain, which is difficult to capture in photos. The concluding chapter, “The Crafts,” presents photos of all the craftsmen’s hands. This allows the reader to envision the actual handling of a piece through the different steps.

The text is extremely informative and detailed on all the phases of jewelry manufacturing. It does not shy away from technical descriptions—including an impressive list of tool names—while remaining inviting and accessible. It gives way, however, to the repetition of clichés, such as the poetic vision of the maison’s single-minded pursuit of perfection, beauty, and total control over its whole manufacturing process.

Despite these few shortcomings, the book is a must-have for jewelry students, bench jewelers, and gem experts who wish to become more familiar with this exclusive brand. Cologni describes a level of craftsmanship and organization that is almost extinct in the industry today. Van Cleef & Arpels’s variety of inspirations, design creativity, and manufacturing quality are among the very highest, and this opus is a beautiful tribute. @chapter:16


Publication Year: 2022 Title: Large Orange Rutile Inclusion in a “Chameleon” Diamond Abstract: An orange rutile crystal partially enclosed on the crown of a faceted diamond (the sharp line from top left to bottom right is the facet junction). Photomicrograph by Tyler Smith; field of view 0.8 mm.
The author recently received for analysis a 1.51 ct round brilliant diamond with very light green color and SI2 clarity. The diamond exhibited “chameleon” properties, showing a clear color change from green to yellow upon heating with an alcohol lamp. An ~0.2 mm orange inclusion was clearly visible on the crown (see above). The crystal was partially enclosed, confirming it was an actual inclusion rather than a crystal adhered to the diamond surface. It was also partially exposed, enabling simple Raman spectroscopy for identification without the spectra showing any contribution from the diamond itself. The crystal was determined to be rutile (TiO2), suggesting an eclogitic origin.
Rutile inclusions in diamond are themselves relatively uncommon, and we rarely see such a large, eye-catching crystal. Rutile inclusions can also provide useful clues about a diamond’s age. Geochemists can determine the age of rutile crystals by measuring the concentration of isotopes of various elements that are present at parts-per-million concentrations, allowing for constraints on the age of the diamond itself (see A.K. Schmitt et al., “U-Pb ages of rare rutile inclusions in diamond indicate entrapment synchronous with kimberlite formation,” Lithos, Vol. 350-351, 2019, article no. 105251). It will be interesting to see what scientific information this rare inclusion in diamond may reveal. @chapter:35


Publication Year: 2022 Title: Unusual Cat’s-Eye Omphacite Fei Cui Jade Abstract: Figure 1. This green omphacite fei cui jade (7.4 × 7.0 mm) displayed chatoyancy under fiber-optic light. Photo by Bowen Zhao.
A round cabochon set in a ring with round brilliant and rose-cut diamonds (figure 1) was recently submitted to the National Center of Quality Inspection and Testing on Gold-Silver Products (NGGC) for examination. The center stone, measuring approximately 7.4 × 7.0 mm in diameter, possessed a vivid green bodycolor and exhibited pronounced chatoyancy with a vibrant green sheen. FTIR analysis (figure 2) revealed that the stone was natural untreated omphacite-type fei cui jade, with a typical fingerprint spectrum corresponding with omphacite, a broad absorption band centered at 3500 cm–1 caused by the hydrous interstitial minerals, and the functional group region showing no absorption of any organic filling material commonly used in bleaching and filling treatment, such as Bisphenol A epoxy resin. Subsequent micro-Raman imaging and spectroscopic analysis confirmed the sample as a fairly pure omphacite aggregate, considering that no other mineral impurity was observed or identified (figure 3). The strongest Raman peaks at 682 cm–1 and 1023 cm–1 were attributed to symmetrical Si-Ob-Si stretching/bending and symmetrical Si-Onb stretching, respectively. Ob refers to the bridging oxygens, while Onb represents non-bridging oxygens in silicon tetrahedra.

Figure 2. Both the functional group region (left) and the fingerprint region (right) of the sample’s IR absorption spectrum were collected with a diffuse reflectance accessory. A K-K transform was applied to the fingerprint spectrum collected.

Figure 3. The sample’s Raman shift confirmed its mineral species. The sample matched well with the RRUFF spectrum for omphacite but differed considerably from the RRUFF spectrum for jadeite. The spectra are shifted vertically for clarity.
Element analysis with energy-dispersive X-ray fluorescence (EDXRF) showed that the sample’s major elements were silicon, calcium, aluminum, magnesium, and iron, consistent with omphacite, whose IMA formula is (Ca,Na)(Mg,Fe,Al)Si2O6). It is well known that the Fe2+-induced grayish bluish green bodycolor is most common among the green omphacite varieties. However, this chatoyant sample was characterized by a relatively high chromium content (Cr2O3 ≈ 0.22 wt.%), producing a more saturated and purer green bodycolor rather than a dull green one. This color feature was confirmed by UV-Vis-NIR spectroscopy, with only a single transmittance band centered at 535 nm appearing in the visible range (figure 4).

Figure 4. Two broad absorption bands centered around ~430 and ~650 nm were formed with the contributions of both iron and chromium. The 692 nm peak convincingly indicated the presence of Cr3+.
Microscopic observation with finely tuned fiber-optic light revealed a parallel-arrayed fibrous texture throughout the sample (figure 5). Meanwhile, a vague honeycomb-like pattern was observed at two specific sides near the girdle (the 12 and 6 o’clock positions of the cabochon in figure 1). Thus, under reflected light the stone presented a chatoyant sheen parallel to the ring band.

Figure 5. The omphacite fei cui jade’s parallel-arrayed fibrous texture (left) and vague honeycomb-like pattern (right), shown in fiber-optic illumination. Photomicrographs by Bowen Zhao; fields of view 10.45 mm (left) and 8.81 mm (right).
Based on our current knowledge, this green omphacite fei cui jade was probably from Guatemala. Translucent fei cui jade with such fine texture, vivid green bodycolor, and even color distribution has always been considered of high quality and rarity, but the chatoyancy of this sample offered additional value. @chapter:37


Publication Year: 2018 Title: Natural Blister from Entombment of a Pearlfish Within a Pinctada Maxima Shell Abstract: Figure 1. A natural blister that took the form of a pearlfish on the inner surface of one Pinctada maxima valve. Photo by Jian Xin (Jae) Liao, courtesy of ECIJA.

Pearlfish are marine fish of the Carapidae family that live symbiotically inside various invertebrate hosts. Occasionally, the remains of these fishes may be found completely covered by mother-of-pearl on the inner surfaces of some bivalve mollusks (J. Ballard, “The pearlfish,” African Wildlife, Vol. 45, No. 1, 1991, pp. 16–19). The New York laboratory recently had the opportunity to examine a unique Pinctada maxima shell with a clear blister that took the form of a fish (figure 1). The shell dimensions were approximately 21 × 19 cm, and the entombed fish measured approximately 10 cm in length.

Figure 2. An example of a living pearlfish with a slender, elongated shape and translucent body, found residing inside a P. maxima shell during a 2013 GIA field expedition to Broome, Australia. Photo by Areeya Manustrong.
The P. maxima bivalve’s soft internal body organs are enclosed and protected by the outer shell that is secreted by the mantle to form the beautiful inner nacreous mother-of-pearl layers and the pearls that are familiar to most (P.C. Southgate and J.S. Lucas, The Pearl Oyster, Elsevier, Oxford, UK, 2008, pp. 57–58). The hard surface of the oyster shell and the nooks within the shells provide places where a host of small animals such as pea crabs, shrimp, and fish can live. Pearl gemologists from GIA in Bangkok observed these within numerous P. maxima mollusks during a 2013 field expedition 80 miles off the coast of Broome, Western Australia. The shape and size of an example recorded from the trip (figure 2) closely resembles the one examined by the lab.

There is a delicate harmony and balance between the mollusk and fish in their cohabitation. The pearlfish has been known to settle in the oyster shell for shelter and live in symbiosis without either one harming the other (E. Parmentier and P. Vandewalle, “Morphological adaptations of Pearlfish (Carapidae) to their various habitats,” in A.L. Val and B.G. Kapoor, Eds., Fish Adaptations, Science Publishers, Enfield, New Hampshire, 2003, pp. 261–276). When the pearlfish eventually dies, the oyster cannot eject the organism and its self-healing mechanism kicks into action. The mollusk begins to deposit layers of nacre over the irritant to ease the likely discomfort experienced. The organism decomposes over time and the skeletal remains are left encased underneath the nacre to form a “blister” (GIA and CIBJO definition) on the inner surface of the shell.

Figure 3. Microradiographic image of the pearlfish on the shell revealing the preserved details from head to tail beneath the nacre. Photo by Jian Xin (Jae) Liao.
The microradiographic images obtained for this sample examined by the New York laboratory show the fish’s skeletal remains very clearly (figure 3). This extraordinary specimen is another prime example of Mother Nature’s fascinating manifestations and was something out of the ordinary for everyone who handled and examined it in the laboratory. @chapter:14


Publication Year: - Title: Tanzanite Description Abstract: Tanzanite can have an intense and deep violetish blue color.

Tanzanite is the violet blue to blue violet variety of the mineral zoisite. It is mined commercially only in one area of the world: the Merelani Hills of Tanzania, which is where it gets its name.

When blue-to-violet crystals were first discovered in Tanzania in the 1960s, no one
was quite sure what the new crystals were. Careful gemological study determined
that they were a transparent variety of zoisite, and the gem came to be known as
tanzanite. - Jeff Scovil, courtesy Marcus Budil Collection
Tanzanite's appearance is influenced greatly by its pleochroism, which is the ability of a gemstone to show different colors when viewed in different crystal directions. Tanzanite's pleochroism was documented in scientific papers not long after its discovery. In 1969, American Mineralogist described the gem's pleochroic colors as `red-violet, deep blue, and yellow green.' Today, most gems are heat treated, which removes or reduces the yellow green or brownish pleochroic color, maximizing the blue and violet.

Top-quality tanzanite can be violetish blue --similar to a fine sapphire color --or a unique, predominately violet hue all its own. Some stones might also appear more purplish depending on how the cutter chooses to orient the fashioned gem. Both the violet and blue pleochroic colors are readily visible in a fashioned stone when it is gently rocked and tilted. This means that every tanzanite is a blend of these pleochroic colors. The exact face-up color depends on the inherent color of the original rough, its size, the pleochroic colors the cutter favors when they orient the fashioned stone, and the light the finished gem is viewed  under. Cool lighting --like daylight equivalent fluorescent --will emphasize tanzanite's blue, while warm lighting --like incandescent --will make it appear more violet-to-purple.

Just like other colored gemstones, vivid strongly-colored tanzanites are highly sought after. Lighter toned pastel hues are more plentiful and affordable than vivid colors and have a subtle appeal of their own.

This 29.22-carat tanzanite has a deep violetish blue color sometimes described as midnight blue. - Courtesy Tanzanite Foundation ™ @chapter:0


Publication Year: 2018 Title: Synthetic Moissanite Coated with Diamond Film Imitating Rough Diamond Abstract: Figure 1. This 5.35 ct sample, submitted as a rough diamond, was identified as synthetic moissanite coated with a diamond film. Photo by V. Pakhomova.

A transparent yellowish octahedral (sawable) crystal (figure 1) weighing 5.35 ct was submitted as a rough diamond to the Far East Geological Institute (FEGI) for examination.
The faces of the octahedron showed a stepped appearance, and the edges had parallel grooves and combinational surfaces. The faces and edges were smooth except for one face where mechanical damage was noticeable. Initially, the specimen was examined using conventional gemological instruments. It was inert to long-wave UV (365 nm) and anisotropic. Thermal conductivity testing indicated diamond. Tests for electrical conductivity were not convincing, however: Some areas (mostly on the edges) corresponded to diamond, but others (on smooth faces and dimples) indicated synthetic moissanite. There were no inclusions associated with natural diamond. Only small parallel needle-like inclusions, typical for synthetic moissanite, were found using a gemological microscope (figure 2).

Figure 2. Needle-like inclusions in the rough synthetic moissanite sample. Photo by V. Pakhomova.

Figure 3. Three-dimensional X-ray tomography rendering of the reconstructed sample. The coloring of the image corresponds to the degree of X-ray permeability. The green color represents the SiC crystal, and the blue color represents the film.
X-ray tomography showed that the inner part of the sample was distinguished by its X-ray density from the outer shell, which had a variable thickness from 19 to 115 microns (figure 3). Microprobe analysis with a JEOL JXA-8100 four-channel microanalyzer revealed the presence of up to 61 wt.% silicon on some polished faces of the crystal, along with titanium in the composition of the surface layer (figure 4 and table 1). Some polished faces showed a diamond chemical signature.

Figure 4. A fragment of the synthetic moissanite crystal, viewed with the electron probe microanalyzer. The crystal was analyzed on the surface. Spectrum numbers correspond to the analysis numbers in table 1.
Based on these results, we identified the sample as synthetic moissanite that had been covered with a thin diamond film. Based on the study by T. Teraji et al. (“Chemical vapor deposition of 12C isotopically enriched polycrystalline diamond,” Japanese Journal of Applied Physics, No. 51, 090104, 2012, pp. 1–7), the diamond coating was likely applied using polycrystalline diamonds. The top layer was made of a composite material consisting of metal matrix and nano-diamond particles.
A diamond imitation such as synthetic moissanite coated with a thin diamond film is challenging to identify, since its luster and thermal properties correspond to diamond. Even with a very thin coating that did not exceed 0.001 mm, the sample tested positive for diamond. This application of thin diamond films onto non-diamond material could be an issue for gemologists in the future.
This work was supported by the Russian Foundation for Basic Research (grant N 16-05-00283) and the Far Eastern Branch of the Russian Academy of Sciences (N 15-1-2-003). @chapter:32


Publication Year: 2013 Title: The Yellow Color Center and Trapped Electrons in Beryl Abstract: Investigations continue into the cause of yellow color in beryl. The generally accepted explanation is that it is related to the charge-transfer between Fe3+ ions substituting for octahedral Al3+ ions in the crystal and the surrounding oxygen ions.

							Using electron paramagnetic resonance (EPR), an absorption technique that uses magnetic fields to measure transition energies in atomic defect centers, this study contradicts the accepted interpretation, proposing an alternate model.

							Although a strong EPR signal from octahedral Fe3+ ions can be found in beryl of all colors, including colorless, the study determined that Fe3+ ions substituting for Al3+ at the octahedral position cannot be the cause of the yellow color. There is, however, a signal unique to yellow beryl that comes from Fe3+ ions at a tetrahedral site.

							The author proposes a simple model describing the oxidation and reduction processes involving iron electrons trapped in the crystal structure to explain the creation and decay of the yellow color. This study discusses reinterpretations of other experimental findings that lead to different explanations for beryl’s colors.

Abstracted by Edward R. Blomgren @chapter:9


Publication Year: 2019 Title: Dendritic Inclusions of Thorianite in Heated Blue Sapphire Abstract: Figure 1. Thermal enhancement and unusual inclusions were detected in this 2.05 ct blue sapphire, measuring 7.07 × 6.55 × 4.99 mm. Photo by Kaiyin Deng.

Recently, a 2.05 ct blue sapphire was sent to Guild Gem Laboratories for identification (figure 1). Standard gemological testing confirmed it was corundum, with a refractive index of 1.762–1.770 and specific gravity of 4.00. Under microscopic observation, cloudy particles and diffuse straight color zoning were seen, as well as fingerprint-like fluid inclusions as shown in figure 2, indicating that this stone had undergone thermal enhancement. This sapphire exhibited chalky greenish fluorescence around the girdle under short-wave (254 nm) ultraviolet fluorescence light. Further UV-Vis spectroscopic testing suggested a metamorphic origin, while FTIR spectra (figure 3) showed a distinct 3309 series at 3185, 3232, 3309, and 3367 cm–1, confirming heat treatment. Energy-dispersive X-ray fluorescence (EDXRF) showed an Fe content around 300–500 ppm. Neither U nor Th was detected.

Figure 2. Left: Dendritic inclusions consisted of dot-like minerals showing a “melted and diffused” appearance. Photo by Yujie Gao; field of view 2.68 mm. Center: Resembling a tree root, these dendritic inclusions showed relatively strong metallic luster under reflected light. Photo by Yizhi Zhao; field of view 2.52 mm. Right: Dendritic inclusions coupled with blurred blue color zoning. Photo by Yujie Gao; field of view 9.73 mm.

Figure 3. The sapphire’s FTIR spectrum exhibited a distinct 3309 series at 3185, 3232, 3309, and 3367 cm–1.

Figure 4. Raman spectra of the sapphire’s dendritic inclusions matched with thorianite (ThO2).
Also observed were interesting dendritic inclusions, which are not very common in sapphire. These inclusions showed relatively strong metallic luster under reflected light, and they appeared to be opaque under transmitted light. Lines of small dots were seen under higher magnification. These dot-like inclusions exhibited a blurred surface and a rounded shape. Raman analysis at the National Gemstone Testing Center (NGTC) using a 473 nm laser showed three distinct peaks at 466, 552, and 607 cm–1, matched very well with thorianite, according to the RRUFF online database (rruff.info), as shown in figure 4. Thorianite (ThO2) is an oxide mineral mainly composed of Th and O, first found in an alluvial deposit in Sri Lanka (D. Wyndham, “The occurrence of thorium in Ceylon,” Nature, Vol. 69, 1904, pp. 510–511). A melted appearance of a mineral inclusion and/or unnatural-looking discoid fractures around inclusions can be indicative of heat treatment in corundum. Such phenomena are normally attributed to the breakdown of mineral inclusions at high temperature. However, the thorianite inclusions here did not have the typical appearance of inclusions that have been altered by high-temperature heat treatment. The diffuse appearance of thorianite is unlikely to be an indicator of heat treatment. Further experiments and tests on thorianite in unheated sapphire would give us more clues in the future. @chapter:12