# Publication Year: 2015
# Title: Assembled Cultured Blister Pearl with an Unusual Component
# Abstract: Figure 1. This blue-violet assembled cultured blister pearl (mabe) weighed 2.44 carats and measured 10.23 × 5.86 mm. Photo by Lhapsin Nillapat.

	GIA’s Bangkok laboratory recently examined a blue-violet assembled cultured blister pearl (mabe) weighing 2.44 ct and measuring 10.23 × 5.86 mm (figure 1). The specimen had the appearance of a typical mabe pearl, exhibiting a boundary line between the nacre face and shell base. 2D microradiography showed a component with an unusual fluted shape, with radio-translucency similar to that of the CaCO3 nacre and the shell (figure 2).

Figure 2. A microradiograph of the intact assembled cultured blister pearl prior to sawing revealed an internal component. The radio-translucency of the object, the nacre, and the shell base are similar. Image by Areeya Manustrong.

	GIA has examined the characteristics of mabe pearls used in commercial jewelry over the years (see Lab Notes: Summer 1981, pp. 104–105; Summer 1991, pp. 111–112; Fall 1991, p. 177; Summer 1992, pp. 126–127; Fall 1992, pp. 195–196; Fall 1996, p. 210), but none of these notes mentioned this unusual component. In Bangkok, this feature has been seen five times in mabe pearls submitted for testing since 2010; questions about its identity and purpose have been raised since the first observation.

	Out of curiosity, one client decided to cut their sample in half in order to examine the interior in more detail (figure 3, left). The two halves consisted of a thin nacre dome top, which was coated with a dark layer on the inner surface; an artificial resinous material; and the white fluted object bordering the shell base. The fluted object was translucent, and a clear spiderweb structure was visible at 10× magnification. When exposed to standard short-wave UV radiation (254 nm) and examined in the DiamondView, this object showed a moderate white blue reaction that followed the spiderweb pattern (figure 3, right).

Figure 3. Left: The cross-section revealed the white fluted object with a spiderweb structure bordering the shell base. Photo by Sasithorn Engniwat. Right: DiamondView imaging showed a moderate white blue reaction following the spiderweb pattern. DiamondView image by Artitaya Homkrajae.

	Further investigation with Raman spectroscopy using a 488 nm laser revealed a calcite spectrum with peaks at 159, 285, 716, 1088, and 1750 cm–1, similar to white coral (Corallium secundum). A small peak related to carotenoid pigments was present at 1020 cm–1 (e.g., J. Urmos et al., “Characterization of some biogenic carbonates with Raman spectroscopy,” American Mineralogist, Vol. 76, 1991, pp. 641–646).

	Based on the spiderweb structure, radio-translucency, calcite spectrum, and general appearance, the object appeared to be a biogenic carbonate. White coral was the first material considered. Further research revealed accounts of sea urchin sections used in some assembled cultured blister pearls from Bali, Indonesia, in “Kuta” pearls (E. Strack, Pearls, Ruhle-Diebener-Verlag, Stuttgart, Germany, 2006, p. 605). Regardless of identity, the reason for including this material within some mabe pearls remains uncertain. It does not appear related to either the formation of the mabe pearl component or its weight and stability. @chapter:54 @chapter:4 @chapter:54


# Publication Year: -
# Title: Spring 2011 Gem News International
# Abstract: 2011 Tucson
Colored Stones and Organic Materials
	            Faceted Cavansite
	            New Find of Green Grossular at Merelani, Tanzania
	            Blue Quartz Colored by Trolleite and Lazulite Inclusions
	            Spectral Interference in Quartz from India
	            Scapolite from India
	            Spinel from Northern Vietnam, Including a New Mine at Lang Chap
	            Gem Zektzerite
Synthetics and Simulants
	            “Coral Sea” Agate
	            Dendritic Agate in Doublets, Inlays, and Jewelry
GNI Regular Features
Diamonds
	            Artisanal Diamond Mining in Liberia
Colored Stones and Organic Materials
	            Update on Emerald Mining at Kagem, Zambia
	            Pargasite from Tanzania
	            Scapolite from Afghanistan
	            Tourmaline Finds at Mt. Marie, Paris, Maine
	            The Origin of Color in Tourmaline from Mt. Marie, Maine
Synthetics and Simulants
	            Trapiche Emerald Imitation
	            A New Rough Nephrite Imitation
	            A Skillfully Crafted Non-Nacreous Pearl Imitation
	            Plastic-Coated Quartz, Imitating Emerald
Treatments
	            Lead Glass-Filled Trapiche Ruby
Miscellaneous
	            Myanmar Gem Emporium
In Memoriam
	            Kurt Nassau (1927-2010), scientist, contributor, and review board member for G&G

To view the full section, download the PDF above.

	DATA DEPOSITORY

Electron Microprobe Analyses of Inclusions
	May 2, 2011 @chapter:0 @chapter:0 @chapter:0


# Publication Year: 2018
# Title: GSA 2018 Report
# Abstract: Figure 1. Each year, the GIA booth at the GSA exhibition hall attracts participants from all over the world. Here, Paula Rucinski (left) and Dona Dirlam (right) speak with a visitor to the booth. Photo by Cathy Jonathan.

The Geological Society of America (GSA) annual meeting took place in Indianapolis November 4–7. GIA participated as both exhibitor and technical session holder. In total, 21 presenters reported new findings on a broad range of research topics. The GIA booth and the two technical sessions attracted a large audience with an interest in gemology (figure 1).

Figure 2. Richard Berg from the Montana Bureau of Mines and Geology presented his poster on Montana sapphires at the GSA annual meeting. Photo by Tao Hsu.
The “Gemological Research in the 21st Century” technical program included both poster and speaker sessions. Seven posters were presented on the second day of the conference (figure 2). Kyle Tollefson (Louisiana State University) and Phillip Ihinger (University of Wisconsin-Eau Claire) reported their characterization study on watermelon tourmaline. Their spectroscopic measurements showed that the chromophores Fe and Mn correlate to green and pink colorations, as expected. The infrared spectroscopy and microprobe analyses showed similar trends of hydroxyl occupancy on the V site in this type of tourmaline. Nikita Kepezhinskas (University of Florida) presented the results of petrographic, geochemical, and isotopic analyses of moissanite and diamond from the shoshonite dike in eastern Finnmark, Norway. The shoshonite host of these minerals is a type of Mg- and K-rich basaltic rock, which is indicative of a subduction-modified mantle source. This study proved that carbonate recycling into the lower mantle through subduction, followed by the formation of superdeep diamonds, moissanite, and other carbides, plays an important role in the global carbon cycle. Paul Johnson and Kyaw Soe Moe (GIA, New York) showed an unusual find of a natural diamond with a cuboctahedral growth habit. This diamond should alert gem labs to the fact that cuboctahedral growth does not occur just in HPHT synthetic diamonds. This special diamond also indicated a potentially very interesting and uncommon growth history before it was lifted to the surface of the earth. Richard Berg (Montana Bureau of Mines and Geology) described significant magmatic splitting of sapphire xenocrysts in basaltic trachyandesite sill. Through extremely careful examination of in situ sapphires in their host rock and advanced instrument analyses such as SEM, XRD, and EDS, he was able to assemble a sequence of what happened to the sapphires before emplacement into their current location. Ying Song (China University of Petroleum) introduced a newly designed and developed computer-vision based intelligent RI measuring system. This system aimed to enhance the clarity and efficiency of RI and other optical measurements. Classroom demonstration, rapid crystal identification, optic axis characterization, and crystal orientation determination are the four modes currently implemented in this instrument. Ziyin Sun and coauthors (GIA, Carlsbad) displayed their study on chromophore strength in pyralspite garnet. Since multiple color-causing elements work singularly or together to color garnets, the authors isolated each of them and performed quantitative study by experimenting with various combinations of these chromophores’ UV-Vis-NIR spectra under different lighting conditions. Aaron Palke and coauthors (GIA, Carlsbad) reported on a Montana sapphire study aiming to unravel its gemological mysteries. Based on their inclusion and geochemical study, the authors proposed a new model of sapphire formation through peritectic melting reactions during partial melting of an Al-rich protolith.

Figure 3. Presenters, guests, and advocates from the GSA poster and speaker sessions. Left to right: Peter Heaney, Dona Dirlam, Mandy Krebs, Richard Berg, Mike Breeding, Jim Shigley, Tingting Gu, Tyler Sundell, Rachelle Turnier, Nancy McMillan, Evan Smith, Chunhui Zhou, Barbara Dutrow, and Sally Eaton-Magaña. Photo by Tao Hsu.
This year’s speaker session attracted 14 presenters from multiple research institutes and universities (figure 3). Mike Breeding (GIA, Carlsbad) kicked off the session with an overview of colored diamonds formed at different depths within the earth. He elaborated on the defects that cause diamond’s blue, pink, yellow, brown, and green colors. The audience was given a grand tour of colored diamond formation, from the transition zone all the way to the surface of the earth. Next, Sally Eaton-Magaña (GIA, Carlsbad) presented her photoluminescence study on pink diamonds based on GIA’s uniquely large database. She explained the cause of pink color as a 550 nm absorption band and explored the difference of pink coloration in various diamond types. She also showed some visual clues that can help to separate pink diamonds from different sources. Tyler Sundell (Missouri State University) talked about the feasibility of using time-of-flight secondary ion mass spectrometry (ToF-SIMS) to image diamonds, especially on their trace-element composition and isotope analyses. Evaluation of this method focuses on its spatial resolution and analytical precision. Results show that this method lacks the precision to quantify carbon isotope values. Karen Smit (GIA, New York) presented her research on natural black diamonds found in the billion-year-old Marange conglomerate (Zimbabwe). Diamonds from this source are full of fractures and can be easily treated to achieve a more valuable fancy black color grade, which makes identification challenging without characterization of the natural stones. Visual observation of graphite grain size and the detection of methane associated with the micro-inclusions are necessary to distinguish between natural and treated Marange diamonds. Evan Smith (GIA, New York) delivered his research on carbonatitic melt inclusions he discovered in partially healed cracks within a CLIPPIR diamond (for more on these diamonds, see Winter 2017 G&G, pp. 388–403). The characterization of these inclusions is consistent with carbonatitic melt, providing direct evidence of this melt’s existence at mantle depths. Russell Harmon (North Carolina State University) evaluated the potential of handheld laser-induced breakdown spectroscopy (LIBS) to identify garnets associated with kimberlites, the host rock of most diamond deposits. This study aims to test whether this instrument will help diamond exploration in the field. Initial results showed that it works very well on garnets from the South Africa kimberlite field but not as well on some other samples, especially those from extensive solid solution. Rod Smith (Geological Survey of Canada) presented field and lab research on the Banks Island region in the western Canadian Arctic, aiming to find promising diamond-bearing kimberlite. Based on newly found stream sediments and till samples, geothermometry data, and Lu-Hf geochronology results, the research group demonstrated the need to continue the search for potential diamond-bearing kimberlite in this region and presented a potentially unknown kimberlite glacial dispersal model. Tingting Gu (GIA, New York) talked about inclusion studies on type IaB diamonds. This study offered the first piece of evidence that hydrous phosphate can subduct to the depth of the transition zone. It also showed the first ringwoodite found in diamond, which proved that this diamond formed in the deep mantle.
The second half of the speaker session started with Mandy Krebs (GIA, New York), who showed the application of Sr-Pb isotope data to colored gemstones’ country-of-origin determination. The analyses were done by thermal ionization mass spectrometry (TIMS) to precisely measure the Sr-Pb isotope compositions in gem corundum for the first time. The separation is promising for certain sources but less so for others. Rachelle Turnier (University of Wisconsin-Madison) used Raman spectroscopy to evaluate the depth of zircon inclusion formation. These zircons are inclusions in corundum sourced from different deposits. Her study is based on an ideal linear upshift of Raman band of zircon with increasing pressure. However, many other factors can influence this ideal situation, such as radiation damage, stress, and internal heterogeneity. With careful consideration of these influencing factors, using Raman as a zircon barometer can help to distinguish corundum from various sources. William Nachlas (Syracuse University) presented the three different formation mechanisms for rutilated quartz. These include the overgrowth/entrapment mechanism, the precipitation mechanism, and the grain boundary migration mechanism, each with different relative timing of quartz and rutile growth. All three mechanisms were reproduced with well-designed experiments. Peter Heaney (Penn State University) explored the reason behind the striking iridescence displayed by some ochre-colored botryoidal goethite. Dr. Heaney applied focused ion beam (FIB) milling and scanning electron microscopy (SEM) to zoom in on the internal structure of this gem. With these powerful tools, some subsurface void layers were revealed to be responsible for the angle-independent iridescence. The origin of these voids remains a mystery. Barbara Dutrow (Louisiana State University) reported a geochemistry study on some uncommon tourmaline + corundum–bearing rocks from Afghanistan’s Badakhshan Province with randomly oriented phlogopites as the matrix. Major, minor, and trace elements were measured with electron microprobe and laser ablation–inductively coupled plasma–mass spectrometry (LA-ICP-MS). The results indicate the involvement of boron-bearing fluids at the beginning of tourmaline growth and continuous infiltration of this fluid. The bulk composition of this rock is consistent with metasomatism of a clay-containing metacarbonate rock with a metamorphic overprint. Chunhui Zhou (GIA, New York) gave the first-ever pearl presentation in this technical session. Three American freshwater cultured pearls were sliced open and their oxygen isotopes were analyzed using SIMS, aiming to reconstruct the ambient water temperature when the nacre formed. This method is very useful in terms of growth cycle determination and can potentially shine a light on pearl origin determination. @chapter:2 @chapter:0 @chapter:2


# Publication Year: 2018
# Title: Quarterly Crystal: Bubble in Fluorite
# Abstract: Figure 1. This 41.98 ct cluster of transparent green fluorite cubes contains a large primary two-phase fluid inclusion that was trapped between the cubes as they developed. Photo by Diego Sanchez.

The very lightly etched green fluorite crystals that come from the Rogerley mine, located in Rogerley Quarry, Weardale, County Durham, England, are well known for the beautiful bright fluorescence they display. Rogerley mine fluorite is highly fluorescent, turning bright bluish white on exposure to long-wave ultraviolet radiation.
The fluorescent fluorite from this locality will also take on a purplish color in sunlight. This effect, known as “daylight fluorescence,” appears to be unique to fluorite from the Weardale area. Research has shown that this intense fluorescence is due to an elevated rare-earth element (REE) content, including the elements cerium, lanthanum, neodymium, samarium, and yttrium.

Figure 2. In this registered pair of images, the movement of the gas phase in the fluorite cluster can be easily seen. Photomicrographs by Nathan Renfro; horizontal field of view 6.54 mm.
The Rogerley fluorite specimen shown in figure 1 measures 17.68 × 17.38 × 13.50 mm and weighs 41.98 ct. What makes this specimen the subject of this issue’s “Quarterly Crystal” is the presence of an eye-visible primary fluid inclusion with a moving gas phase. Along the interface, where the two growing crystals came together, negative space was created. This form of primary fluid inclusion hosts fluid remnants that were present when the fluorite was growing. When comparing the two photomicrographs in figure 2, the movement of the gas phase can be clearly seen. Fluid inclusions like this are not at all common in fluorite. @chapter:15 @chapter:0 @chapter:15


# Publication Year: 2019
# Title: Chatoyant Quartz/Tourmaline Doublet
# Abstract: Figure 1. This 4.86 ct cabochon displays unusual yellowish chatoyancy against a predominantly purple bodycolor. Photo by Shunsuke Nagai.

Doublets are assemblages of two different materials, often joined with cement. Historically they were composed of inexpensive materials used to imitate precious stones. Recently new combinations have been reported, such as a beryl/topaz doublet (Winter 2014 GNI, pp. 306–307), synthetic sapphire/synthetic spinel doublets (Winter 2016 Lab Notes, pp. 418–419), and a beryl/glass complex assemblage (Summer 2018 Lab Notes, pp. 206–208).
GIA’s Tokyo laboratory had the chance to examine a unique doublet. The 4.86 ct purplish cabochon, measuring 11.07 × 10.00 × 5.94 mm, appeared to display chatoyancy with a yellowish sheen (figure 1). The hydrostatic specific gravity (SG) and spot refractive index (RI) readings were 2.66 and 1.54, respectively. Assembled features with a cemented plane were easily recognized when viewed from the side, as shown in figure 2. Standard gemological testing, microscopic observation, and infrared spectra revealed that the cabochon segment was a natural amethyst. There were no parallel inclusions that might have caused chatoyancy in this segment. On the other hand, the semitransparent yellowish base had parallel striations and tube-like inclusions throughout (figure 3). Raman spectroscopy identified the base as tourmaline.

Figure 2. Viewed from the side, the assemblage was obvious. Trapped bubbles in the cemented plane can also be seen. Photo by Shunsuke Nagai.

Figure 3. Cavities on the base show the parallel striations and columnar or tube-like inclusions. Photomicrograph by Yusuke Katsurada; field of view 1.88 mm.
Parallel inclusions located near the bottom of a cabochon can create a chatoyant phenomenon (Winter 2017 Lab Notes, pp. 459–460). This assembled item displayed a similar effect due to the flat tourmaline base with parallel structures. When light was reflected through the amethyst by the tourmaline base, the parallel striations and tube-like inclusions in the tourmaline created the band of reflected light that appeared on the cabochon. Transparent amethyst and semitransparent yellow tourmaline are an uncommon combination. This doublet is an example that assemblages are not always aimed to imitate precious stones but can be creative artworks. @chapter:26 @chapter:0 @chapter:26


# Publication Year: 2021
# Title: Flux-Induced Fingerprints in Flame-Fusion Synthetic Sapphire
# Abstract: Figure 1. Face-up view of the 2.81 ct flame-fusion synthetic sapphire with flux fingerprints. Photo by Diego Sanchez.

The Carlsbad laboratory recently received a blue cushion mixed cut measuring 9.07 × 7.07 × 4.62 mm (figure 1). Standard gemological testing gave a refractive index of 1.760–1.768, consistent with sapphire. Microscopic examination uncovered a fingerprint resembling those found in natural sapphires (figure 2). Closer examination revealed the fingerprint to be a flux fingerprint. When the stone was immersed in mineral oil, curved color banding diagnostic of flame-fusion lab-grown sapphire became visible (figure 3).

Figure 2. This flux fingerprint in the lab-grown sapphire is similar to the fingerprints found in natural sapphire. Photomicrograph by Nathan Renfro and Michaela Stephan; field of view 1.76 mm.

Figure 3. When immersed in mineral oil, curved color banding is visible along with a natural-looking flux fingerprint and large gas bubbles. Photomicrograph by Nathan Renfro and Michaela Stephan; field of view 7.19 mm.
Typically, a flame-fusion-grown ruby or sapphire with healed fractures has undergone a process known as “quench crackling,” where fractures are created in the stone by heating and subsequent rapid cooling. This stone did not show the characteristic cellular fracturing created by this process, making the healed fractures appear even more natural. The randomly fractured stone had been immersed in a flux melt. The flux melt filled and partially healed the fractures while the stone gradually cooled, which resulted in natural-looking fingerprints of residual flux. This treatment is usually seen in flame-fusion synthetic rubies (K. Schmetzer and F.-J Schupp, “Flux-induced fingerprint patterns in synthetic ruby: An update,” Spring 1994 G&G, pp. 33–38). @chapter:19 @chapter:1 @chapter:19


# Publication Year: -
# Title: Get Started on 2017 Continuing Education Recognition Program
# Abstract: The first three assignments from the 2017 Continuing Education Recognition Program cover American freshwater pearls, diamond jewelry manufacturing in India and how to get the most from diamond rough.

Natural American Freshwater Pearls. Diamond Jewelry Manufacturing in India. Diamond Cutting in India.

These are just some of the gem and jewelry topics you will learn more about as you complete this year’s Continuing Education Recognition Education Program. Created for GIA graduates who hold a Graduate Gemologist or Gemologist diploma, the continuing education program includes a variety of engaging slideshows and animation, interactive self-testing, instructional videos and expert interviews, featuring the most up-to-date discoveries and research from GIA field gemologists who have traveled to the source. The program is designed to help graduates stay up to date with the latest gem and jewelry news and information.

You will have continuous access to the entire course – including the assignments, GIA eLearning courses and previous years' continuing education assignments and the multimedia archive – until the end of the calendar year. Each graduate who completes the Continuing Education Recognition Program will receive a certificate that displays their expertise and commitment to staying on top of gemological developments.

“The word is out amongst our graduates and corporate education clientele about the value and importance of this program,” says Kate Donovan, alumni relations manager. “Relevance is key in a competitive market, and this program gives GIA graduates the opportunity to keep up the standard of education they worked so hard to achieve. Having access to the entire gemological course data that new GIA students are currently using is invaluable.”

Be sure to complete all eight assignments by Dec. 31 to receive your Continuing Education Recognition Program certificate.

Here’s a brief overview of the 2017 assignments to date:
Assignment 1: Natural American Freshwater Pearls
From the unassuming rivers and lakes of America come the most sublime treasures: natural American freshwater pearls. They have been prized for centuries as evidenced by the numerous pearls found in Native American burial mounds. At one time, these treasures were more readily available, a byproduct of a once-thriving shell harvesting industry. Today there is less demand for mussel shells and many fewer shell divers. The result is that the recovery of natural pearls has become much more uncommon. In this interview, Gina Latendresse, president of the American Pearl Company, shares some unique and rare natural American freshwater pearls.
Assignment 2: Diamond Jewelry Manufacturing in India
The creation and use of jewelry for adornment has a tradition dating back thousands of years in India. Additionally, Indian jewelry is used to signify status and is often seen as a source of financial security. Indian jewelers have proudly upheld and continue to pass down traditional jewelry making methods, but they have also evolved and today, take advantage of a wide range of modern jewelry manufacturing technologies. A team from GIA visited a number of modern jewelry manufacturing companies in India in 2016. This video highlights some of what they witnessed.
Assignment 3: Getting the Most from Diamond Rough
India’s love affair with diamonds goes back thousands of years. Historians believe India was trading diamonds as early as the fourth century BCE. Culled from its streams and rivers, diamonds found their way into the hands of Indian royalty and gem lovers throughout the Western world. It is fitting that some of today’s most advanced technology is being utilized in the diamond manufacturing companies of India. Advances in diamond scanning and planning have resulted in a marked increase in yield from rough. This assignment tours several diamond cutting factories to observe some of this technology in action.

Don’t miss this chance to learn more valuable and exciting information from GIA’s top experts. Find out more about GIA’s Continuing Education Recognition Program. You can also contact the GIA Alumni Association at +1 760 603 4145 or email alumni@gia.edu. @chapter:34 @chapter:3 @chapter:34


# Publication Year: 2014
# Title: Dyed Bone as a Red Coral Imitation
# Abstract: Figure 1. This 8.86 ct orange-red cabochon, submitted as coral, was identified as dyed bone. Photo by Gagan Choudhary.

Numerous materials have been widely used to imitate red coral: glass, plastic, ceramics, composites, and dyed shells. Recently, the Gem Testing Laboratory in Jaipur examined an 8.86 ct orange-red cabochon measuring 16.56 × 12.19 × 7.34 mm (figure 1) that was presented as red coral but proved to be dyed bone, an unusual imitation.
Initial observation showed a strong resemblance to red coral, but careful microscopic observation proved otherwise. The sample lacked the typical “tree ring” or striated growth structure seen in corals, though it did display a network of fine veins throughout. Viewed from above, these veins appeared subparallel and were oriented along the length of the cabochon (figure 2). The veins also displayed orange-red color concentrations against the cabochon’s whitish bodycolor (again, see figure 2), suggesting that the material was both dyed and organic.

Figure 2.  The dyed bone displayed subparallel veins oriented along the length of the cabochon; also note the orange-red color concentrations against the sample’s whitish bodycolor. Photomicrograph by Gagan Choudhary; magnified 48×.
Detailed observations of the sample from all sides revealed that the subparallel veins were confined to circular concentric planes oriented along the length of the cabochon (figure 3, top); the individual veins were further surrounded by concentric whitish rings (figure 3, bottom). These structural features ruled out the possibility of coral, but the identity had yet to be established.

Figure 3. Subparallel veins were confined to circular concentric planes oriented along
the length of the cabochon (top), while the individual veins were surrounded by concentric whitish rings (bottom). Photomicrographs by Gagan Choudhary; magnified 40× (top) and 56× (bottom).
The sample’s spot RI was approximately 1.56, without any noticeable birefringence blink, while its hydrostatic SG was 2.01. Under a UV lamp, it displayed pinkish orange patchy fluorescence (which was stronger under long-wave UV). This characteristic is typically associated with dyes. Qualitative EDXRF analysis revealed the presence of phosphorus and calcium. Chemical, gemological, and observational features indicated bone, which was further confirmed by Raman spectroscopy. Raman spectra (figure 4) obtained using a 785 nm laser in the 200–2000 cm–1 region displayed a strong peak at approximately 960 cm–1, with weaker peaks at approximately 430, 586, and 1072 cm–1. Also present were a few indistinct features in the 1200–1700 cm–1 region. The peaks at approximately 960, 586, and 430 cm–1 were attributed to PO3–4 bending and stretching, and the one at 1072 cm–1 to CO3–4 stretching. The indistinct features between 1200 and 1700 cm–1 were due to collagen—the essential component of bone tissue (C. Kontoyannis et al., “Analysis of bone composition with Raman spectroscopy,” Proceedings of the 13th Panhellenic Pharmaceutical Congress, 2012, http://nemertes.lis.upatras.gr/jspui/bitstream/10889/5187/1/PMO031.pdf).

Figure 23. The bone’s Raman spectrum showed major PO3–4 peaks at about 960, 586, and 430 cm–1; a CO3–4 peak at 1072 cm–1; and collagen-related peaks in the 1200–1700 cm–1 region.
Bones have been used as jewelry since ancient times, and some specimens are dyed or stained to make them appear older (Summer 2006 Lab Notes, p. 160). Bone is used to imitate ivory, but this is the first time we have seen a bone dyed red and presented as coral, an interesting and unusual imitation. Although the market penetration of this material is unknown, we cannot rule out the possibility of it being mixed in packets of red coral, and this separation would pose a challenge for jewelers and gemologists. @chapter:54 @chapter:4 @chapter:54


# Publication Year: 2024
# Title: Morganite from Blue Star Gems
# Abstract: Figure 1. The 236.27 ct pear-shaped untreated morganite from old Madagascar stock was designed by Prakash Chand Vijay, who also oversaw the cutting. Photos by Jennifer Stone-Sundberg (left) and Robert Weldon (right). Courtesy of Blue Star Gems.
Morganite, a pink gem discovered in 1910 in Madagascar, was identified as a new variety of beryl by George Kunz, who named it in honor of his friend J.P. Morgan. Morganite has since been found in several other countries, most notably Brazil, Mozambique, Afghanistan, China, Russia, and the United States. The most productive mine today is in Minas Gerais, Brazil.
At the GJX show, an extraordinary morganite stood out at the Blue Star Gems (New York City) booth (figure 1). Owner Prakash Chand Vijay indicated that the 236.27 ct stone was from vintage stock from the original morganite mine in Madagascar. This one-of-a-kind untreated stone had a particularly pleasing deep warm pink color and a striking constellation of small inclusions scattered throughout. With Vijay’s expertise in the selection and cutting of stones from Africa, he participated in and oversaw the cutting of this exceptional gem.

Figure 2. Left: Suite of morganite from Mozambique ranging from 27.90 ct (the center rectangular step cut) to 92.34 ct (the largest pear). These stones underwent a lengthy heating and electron radiation treatment to bring out the best color and clarity. Right: Suite of aquamarines from Madagascar. Clockwise from left: 31.88 ct oval brilliant cut, 49.08 ct cushion cut, 35.80 ct rectangular step cut, and 24.51 ct pear brilliant cut. Photos by Prateek Vijay; courtesy of Blue Star Gems.
Vijay’s daughter, Jyoti Vijaywargi, said that this year they brought more than 100 pieces of attractively colored purplish pink morganite in sizes of over 20 carats each (figure 2, left). These stones came from Mozambique and underwent a lengthy heating and electron irradiation treatment in Germany to bring out the best color and clarity.
The enhancement of morganite color has been shifting from neutron irradiation to electron irradiation, avoiding the risk of a radioactive product (T. Stephan et al., “Irradiation treatment and gamma-ray spectroscopy of morganite,” 37th International Gemmological Conference Proceedings, Tokyo, 2023, pp. 123–125). Vijaywargi noted that due to the large sizes of their morganites, the entire process takes about five years to produce the quality seen, attesting to the value of the material and the patience of the vendor. The treatment itself takes about three and a half years, followed by an additional 18 months to let the stones cool down and be tested before they can be sold. Sometimes the stones do not respond to the treatment, and there is no color improvement at all. To date, there is no pretreatment testing to indicate whether the stones will respond to the treatment, so each run is a financial risk.
In addition to morganite, Blue Star Gems had extensive offerings of aquamarine (figure 2, right)—one of this year’s most popular stones—and tanzanite. The aquamarine comes from Madagascar. Despite global business challenges, the show proved successful for Blue Star Gems, particularly for high-end stones. The company was also able to attract new buyers this year.
Vijaywargi described the recent challenges around the pricing of wholesale versus retail items. On the wholesale side, prices for all goods have increased, yet these price changes have not been reflected at the retail end. As a vendor carrying substantial inventory of rare gemstones, Vijaywargi anticipates an increase in the value of Blue Star’s collection, which will require patience as a seller. @chapter:0 @chapter:0 @chapter:0


# Publication Year: 2017
# Title: Christmas Tree–Shaped Internal Feature In Diamond
# Abstract: Left: A 3.32 ct fancy-color diamond hosts a laser manufacturing remnant of unusual shape; here, it is seen with diffused fiber-optic illumination. Right: Rheinberg illumination accentuates the LMR’s resemblance to an evergreen tree. Photomicrographs by Jonathan Muyal; field of view 2.90 mm.
A 3.32 ct Fancy yellow marquise diamond recently submitted to GIA’s Carlsbad laboratory for color origin determination was of particular interest for its large, eye-visible laser manufacturing remnant (LMR). This LMR extended along a relatively straight path from a star facet through the pavilion and featured lily pad stress fractures stacked in parallel along its length, a composition reminiscent of a Christmas tree preserved within the diamond. With its resulting “green foliage” against a dark blue night, the use of Rheinberg color contrast illumination technique (N. Renfro,“Digital photomicrography for gemologists,” Summer 2015 G&G, pp. 144–159; Fall 2015 Micro-World, pp. 328–329) dramatically accentuated this already evocative scene (see above).

Unlike the remnants of laser drilling used to remove small inclusions, LMRs are an unintended consequence of either carelessness or unpredictable laser optics. As such, they are graded as clarity characteristics that can reduce the overall quality and value of a diamond. LMRs can occur during the laser cutting of a diamond. They appear in a variety of shapes but often resemble the remnants of internal laser drilling (Fall 2013 Lab Notes, p. 174).

Ironically, an accidental feature that might otherwise downgrade a diamond’s value can have a positive outcome. This unique and aesthetically pleasing internal feature has created an interesting collector’s gemstone, a perfect gift for the Christmas season! @chapter:41 @chapter:1 @chapter:41


# Publication Year: -
# Title: Green Nephrite Jade Attracts Buyers in Tucson
# Abstract: Figure 1. For the first time in the history of the Olympics, the medals from the 2008 Beijing Games were mounted with gemstones. The nephrite jade bi, or flat rings, used in the medals were all from China’s Qinghai province. The gold medal was mounted with white nephrite, the color favored by the Chinese, while the silver and the bronze used greenish white and green nephrite, respectively. Courtesy of China Gems Magazine.

                      The Jade West Group, a leading nephrite jade company in North America for the past 30 years, drew many buyers at their 2015 GJX booth. Prized in Chinese culture for over 5,000 years, nephrite regained its momentum in the domestic Chinese market after the 2008 Beijing Olympics, when it was used in the gold, silver, and bronze medals (figure 1). The Chinese government launched a campaign promoting the significance of nephrite jade in the country’s history. This reignited the love of nephrite among the Chinese people, and the increasing demand and price drove a new surge of jade rush in northern British Columbia (BC).

A tectonic belt running from Alaska through British Columbia to Mexico favored the formation of nephrite. Tectonic and lithological contacts are the predominant ore body controls. BC has more than 50 known nephrite deposits, distributed mainly along tectonic inclusions of country rocks, dikes, and mafic rock layers within serpentinites, or along the contact between serpentinite and the wall rocks. This formation is very similar to other green nephrite occurrences all over the world. Nephrite is found both in situ and as boulders; the Polar Pride boulder, found in BC’s Polar mine, is a well-known example of the latter (figure 2).

Figure 2. Half of the Polar Pride jade boulder discovered in the Polar jade mine. The original boulder weighed 18 tons. Courtesy of Jade West Group.
Nephrite boulders are the products of erosion from the last ice age. They are usually drilled or sawed to test the quality, and only the good-quality material is transported for sale. While some of today’s nephrite is from boulders, primary deposits supply the bulk of BC’s production. This is partially due to the lack of high-quality boulders; however, the growing demand and price for nephrite also make it profitable to mine the primary deposits.

According to Kirk Makepeace, president of Jade West Group, the price of jewelry-grade jade from BC (figure 3) experienced at least a tenfold increase from a decade ago. Before 2008, top-quality nephrite from BC sold for about $20 a kilo; equivalent stones now range from $200 to $2,000 a kilo.

Figure 3. This strand of 41 nephrite beads is comprised of material from British Columbia’s Polar Mine. Photo by Robert Weldon; courtesy of Jade West Group.
The annual production of BC nephrite jade is about 400 tons. Most of the production comes from four active mines; together, they produce about three-quarters of the world’s high-quality green nephrite. Of these four, Jade West operates the Polar, Ogden, and Kutcho Jade mines. Jade West also deals with material from Wyoming and Siberia. Over the last 10 years, approximately 90% of the company’s BC production was exported to mainland China; the remaining 10% was sent to Taiwan, Vietnam, and Thailand.

	Figure 4. This Canadian Jade Fish Hook pendant features a piece of nephrite from the
	Kutcho Mine. This is one of the styles Jade West has customized for the North American
	market. Photo by Robert Weldon, courtesy of Jade West Group.
Jade West sends almost all of its rough nephrite to Guangdong for carving and jewelry manufacturing, with designs customized for different markets (figure 4). In addition to traditional carvings and jewelry, there is demand from Southeast Asian countries for giant Buddha statues and from Western countries for home decorations. This demand leads Mr. Makepeace to be very optimistic about the future availability of BC nephrite. @chapter:51 @chapter:0 @chapter:51


# Publication Year: 2013
# Title: Titanium-Bearing Synthetic Alexandrite and Chrysoberyl
# Abstract: This Inamori synthetic cat's-eye alexandrite appears dark purple-red in incandescent light. Photo by Tino Hammid.

              Chrysoberyl, whether natural or synthetic, displays distinct pleochroism. The alexandrite variety is strongly trichroic and exhibits red/green color change. Phenomena such as chatoyancy and asterism can occur when oriented needle-like inclusions—mainly of rutile—are present. Chrysoberyl has the chemical formula BeAl2O4 and is orthorhombic. Its various colors are generally due to substitution of octahedrally coordinated Al3+ cations with chromophores such as the transition metal cations Cr3+ and Fe3+. Synthetic green chrysoberyl is known to sometimes have V3+ as a chromophore substituting for Al3+ in the crystal structure.

This work investigated Czochralski-grown synthetic reddish violet chrysoberyl, transparent alexandrite, and phenomenal alexandrite (both cat’s-eye and star) manufactured by Kyocera. This material entered the marketplace in the late 1980s with the Inamori brand name. The authors noticed unique pleochroism and spectroscopic features in the visible range in all of the samples except the transparent alexandrites—an indication of an unusual chromophore. Specifically, orange coloration influenced the hues observed in incandescent lighting in all three crystallographic directions, and absorption bands at around 500 nm were observed in these samples. It was noted that titanium, an element found in chrysoberyl generally in the form of rutile precipitates, was detectable in elevated concentrations in all of the samples with unusual pleochroism.

As mentioned above, rutile, or TiO2, is the common mineral inclusion that gives rise to asterism and chatoyency in chrysoberyl and other gem minerals, especially in the corundum varieties ruby and sapphire. In natural crystals of virtually all minerals, titanium is found as Ti4+, as Ti3+ is less stable (especially in the presence of iron) and readily oxidizes to Ti4+ (see R.G. Burns, “Intervalence transitions in mixed-valence minerals of iron and titanium,” Annual Review of Earth and Planetary Sciences, Vol. 9, 1981, pp. 345–383). However, titanium-doped synthetic laser crystals of both sapphire and chrysoberyl have been developed with titanium in the trivalent state, as this is the desired oxidation state to produce tunable lasing. In the case of Czochralski-grown titanium sapphire laser crystals, it is well documented that much of the material is grown in a virtually inert atmosphere, and post-growth annealing is conducted in a reducing atmosphere to convert the Ti4+ to Ti3+ (M. Kokta, “Process for enhancing Ti:Al2O3 tunable laser crystal fluorescence by annealing,” US Patent 4,587,035 A, May 6, 1986). Note: This contributor has observed that as-grown titanium sapphire crystals are generally milky and slightly purple in color before annealing. After annealing in a strongly reducing atmosphere such as hydrogen, the corundum crystals become clear and orangy red in color.

An investigation of the literature and comparison to spectroscopic data of the authors’ samples showed that the synthetic reddish violet chrysoberyl crystals and faceted gems and the phenomenal alexandrite samples do appear to have Ti3+ as a chromophore, which leads to the unusual pleochroism observed. In the case of the reddish violet samples, Ti3+ seems to be the predominant chromophore, as only traces of chromium, iron, vanadium, and manganese were detected. The cat’s-eye and star alexandrite samples appear to have a combination of Ti3+ and Cr3+ chromophores (with additional rutile precipitates being responsible for chatoyancy and asterism). The transparent alexandrites, meanwhile, appear to have a combination of Cr3+ and V3+ as chromophores. The detection of trace levels of Ti3+ in chrysoberyl strongly suggests a synthetic origin and possibly further heat treatment in a reducing atmosphere (to form reddish violet samples with predominant Ti3+ contents), and in an oxidizing atmosphere (to form rutile precipitates). @chapter:24 @chapter:0 @chapter:24


# Publication Year: 2023
# Title: Texas Topaz, Slovak Opal, a Beryl Inclusions Chart, and More
# Abstract: Welcome to the Winter 2023 edition of Gems & Gemology ! This issue brings an exciting conclusion to the volume year with three feature articles, a field report, a colorful new inclusions chart, and the return of the Colored Stones Unearthed column along with our other regular columns.
“…a prized gemstone from the United States: Texas topaz, sought after for its domestic provenance and rare natural blue color.”
Our first article explores a prized gemstone from the United States: Texas topaz, sought after for its domestic provenance and rare natural blue color. Dr. Roy Bassoo and coauthors begin with a historical account of topaz from Mason County, Texas, followed by discussion of its geologic origin, compositional characteristics, manufacture, and significance to the gem trade. In addition, the authors seek to provide a basis for determining geographic provenance.
Next, Dr. Karl Schmetzer and fellow researchers investigate a technique for setting cut garnets on glass objects, invented by Claudius vom Creutz of Nuremberg in the late sixteenth century. Examining two glass vessels at museums in Germany, the authors analyze the stones decorating the objects and the methods used to attach them.
Petrified tree fern from northeast China is the topic of our next article. A team led by Ying Yan reports on the gemological properties, chemical composition, and appearance of this material, which displays a beautiful pattern and is being used in intricate carvings in China.
Our fourth article, a field report from Dr. Peter Semrád, presents the revival of Slovak opal mining. It provides a brief history of mining in the area and details on geology and mineralogy, followed by coverage of recent mining activity, production, and marketing.
To close out our features, GIA researchers led by Nathan Renfro and John I. Koivula offer a captivating look at the internal features of beryl, with a foldout chart featuring 30 remarkable photomicrographs. Laminated versions of the chart, along with the six other inclusion charts in the series—emerald, sapphire, ruby, diamond, opal, and spinel—are available at store.gia.edu.
G&G’s regular columns continue to provide the latest gemological findings. Noteworthy updates from GIA laboratories are summarized in Lab Notes, including an HPHT-treated laboratory-grown diamond featuring dramatic color zoning, an antique Indian-style headdress decorated with seed pearls, and a rare faceted thomsonite. Micro-World showcases the inner landscapes of gemstones with striking hollandite crystals in a Brazilian amethyst, a stress halo resembling a butterfly in a natural diamond, a metal sulfide crystal suspended in a padparadscha sapphire, and more. Colored Stones Unearthed returns in this issue, covering the formation and mining of gemstones from sedimentary rocks. Finally, highlights from the Gem News International section include reports on pyritized triceratops fossils from South Dakota, training for artisanal diamond miners in Liberia, and a recent discovery of blue amblygonite-montebrasite from Rwanda.
We hope you enjoy the latest edition of Gems & Gemology ! @chapter:17 @chapter:0 @chapter:17


# Publication Year: 2019
# Title: E. Alan Jobbins (1923–2019)
# Abstract: E. Alan Jobbins
Alan, as he was known to his friends and colleagues, passed away February 2 at the age of 95. He was internationally respected for his lasting achievements in the fields of mineralogy and gemology. He started down his lifelong career path at the age of 13, when his geography professor showed him some attractive crystal specimens of the mineral mimetite from the Cumberland area of England. This immediately sparked his interest and led to a lifetime devoted to mineralogical and gemological studies, and his career appointment from 1950 to 1983 as curator of minerals and gemstones at the Institute of Geological Sciences in London. There he was responsible for organizing the extensive gemstone and mineral collection and exhibitions.
Over his 33 years at the museum, Alan conducted numerous important gemological and mineralogical research projects, such as a major study of East African garnets, research into the characteristics of synthetic opals, the discovery and description of the mineral magnesio-axinite, and the geological field study of the meteorite in Barwell Parish, England.
Alan’s work took him on many assignments for the United Nations and the British government. These included gemological and geological surveys of gem deposits in Brazil, Cambodia, Guyana, India, and Sri Lanka for the United Nations and the British Overseas Development Administration.
In the late 1960s, Alan set up a mineralogical and gemological training and research laboratory in Burma, guiding that country’s first gemologists to FGA diplomas. Some students went on to obtain doctorates at English universities. Alan led a study of Pailin ruby and sapphire deposits in Cambodia, resulting in a detailed monograph and important recommendations for improved recovery methods. He also spearheaded an assessment of diamond and opal deposits in PiauíState, Brazil, and a survey of the Sri Lankan gemstone industry in which he recommended improved mining methods and cutting techniques.
In 1988 and 1989, he initiated gemological training with new laboratory facilities at the China University of Geosciences in Wuhan. In the UK, his record includes 32 years as a gemological lecturer at the Sir John Cass College (now London Metropolitan University), 20 years as chief examiner for the Gemmological Association of Great Britain (now Gem-A) gemology examinations, and eight years as editor of The Journal of Gemmology (1985–1993). He was also president of Gem-A from 2004 to 2008, and vice president from 2009 until his death.
Alan held various posts throughout his career, including executive member of the International Gemmological Conference (IGC) and past president of the Society of Jewellery Historians. He was also part of the team that conducted the first comprehensive gemological examination of the British Crown Jewels from 1986 to 1989, which led to the publication of an important illustrated catalogue. Among Alan’s major literary contributions were very thorough revisions of B.W. Anderson’s Gem Testing and Robert Webster’s Gemmologists’ Compendium.
In 1984, Alan became a founding member of the ICA (International Colored Gemstone Association). In 2005 the Accredited Gemologists Association (AGA) awarded him its sixth annual Antonio C. Bonanno Award for Excellence in Gemology. He served as a member of G&G’s editorial review board from 1994 on.
In addition to gemology and mineralogy, our dear friend Alan was an avid bird-watcher, an explorer of churches and cathedrals, and a wine aficionado. He was a devoted and loving husband to his wife, Mary. In his honor I will carry the moniker he bestowed upon me many years ago, “Young Buzzard.” Alan passed away peacefully with Mary by his side. Rest in peace, dear friend. @chapter:30 @chapter:0 @chapter:30


# Publication Year: 2013
# Title: Diamond with Extremely Strong 578.9 nm Emission Center
# Abstract: Figure 1. This 4.72 ct Light blue type IIb diamond displayed some of the strongest dislocations ever observed in natural diamonds by GIA. This resulted in a hazy impression and a lower transparency than other type IIb diamonds. Photo by Jian Xin (Jae) Liao.

              Photoluminescence analysis at liquid-nitrogen temperatures and varying laser excitations has become increasingly important in diamond color origin testing. The 578.9 nm emission normally occurs with many other emission lines, and it is usually weak in natural type IIa and IIb diamonds. Meanwhile, the physical model of this optical center is unclear. The New York laboratory tested a very rare diamond that showed extremely strong 578.9 nm emission.

This 4.72 ct rectangular diamond (9.75 × 8.90 × 5.92 mm) had a color grade of Light blue and an even color distribution (figure 1). Infrared absorption spectroscopy analysis identified it as a type IIb diamond with a boron concentration of about 16 ppb. This stone showed very strong dislocations, resulting in a hazy impression and a lower degree of transparency than most type IIb diamonds. Microscopic observation revealed very strong linear graining and related high interference colors. The intensity of the dislocations was among the strongest ever observed in natural diamonds at a GIA laboratory.

The outstanding feature of this diamond was the extremely strong emission at 578.9 nm, with possible side bands at 586 and 593 nm (figure 2). No other emission line was detected in the visible light region, which is very unusual for a natural type IIa or IIb diamond. This feature was confirmed with 457 and 488 nm laser excitations. The exclusive occurrence of the 578.9 nm emission and the very strong lattice dislocations suggested that this emission was a dislocation-related optical center.

	Figure 2. The diamond showed extremely strong emission at 578.9 nm and its possible side bands at 586 and 593 nm. The exclusive occurrence of the 578.9 nm emission and the very strong lattice dislocations in this diamond suggested that the emission was a dislocation-related optical center. @chapter:22 @chapter:1 @chapter:22


# Publication Year: 1995
# Title: Winter 1995 G&G Book Reviews
# Abstract: “Photo Masters for Diamond Grading”
By Gary A. Roskin, 94 pp., illus., publ. by Gemworld International, Northbrook, IL, 1994. US$75.00

“A Sparkling Age, 17th Century Diamond Jewellery.”
223 pp., illus., pulbl. by the Diamantmuseum, Antwerp, Belgium, 1993, US$65.00

To view the full section, download the PDF above. @chapter:50 @chapter:3 @chapter:50


# Publication Year: -
# Title: CVD-Grown Synthetic Diamonds, Part 2: Properties
# Abstract: These CVD synthetic diamonds produced by Gemesis Corp. range in size from 0.24 to 0.90 ct. Photo by Robert Weldon

Part 1 of this series provided a brief history of CVD synthetic diamonds.

The physical properties of CVD synthetic diamond fall well within the range for natural diamonds in terms of hardness, thermal conductivity, strength, and so forth. Therefore, CVD synthetics are as hard and durable as natural diamond and display the same brilliance and fire when cut as a gemstone. The optical properties can be varied over a wide range through the controlled introduction of impurities. For example, crystals can be made colorless to near-colorless by controlling the residual nitrogen level of the gas in the growth chamber. Blue diamonds can be created by adding boron to the gas, while pink, yellow, or other variations can be achieved using mixtures of gases, including high nitrogen concentrations. One particular advantage of CVD diamond production is that all crystals in a growth batch have the same color and clarity, making them easier to grade and match. And the color can be accurately repeated over an endless number of growth runs, ensuring reproducible color, clarity, and size, and an ongoing supply of high-quality synthetic diamonds for the gem industry. In addition, the ability to control size and purity will expand the uses of synthetic diamond beyond what is possible with natural diamonds, into new areas in optics, medical devices, electronics, and applications yet to be identified.

Other Properties
Colorless and near-colorless CVD synthetic diamonds are usually type IIa, while only 2% of natural gem diamonds are type IIa. Type IIa diamonds are characterized by high purity (low nitrogen) and transparency in specific parts of the ultraviolet and infrared optical spectrum. Numerous UV detection instruments on the market can provide the first indication of a possible CVD synthetic. Obviously, additional tests would then be required to confirm whether the sample is CVD-grown or natural. If the gem is not IIa, it is most certainly natural. There will be additional discussion about non-IIa synthetic diamonds and the properties of blue, pink, yellow, and other colors in a future article.

A common question in the diamond trade and among consumers is whether CVD synthetics will eventually be manufactured so inexpensively that the value of natural diamonds endangered. The answer to that question is no. While CVD growth will become more efficient due to scale and manufacturing experience, several factors will only become more expensive with time and inflation. First, the cost of cutting and polishing CVD products is essentially the same as for natural diamond, and highly skilled artisans will still be needed to create beautiful goods. A second factor is that the electricity required to produce one carat of diamond does not scale significantly with the number of seeds or chamber size. Electricity is a major cost, one that is expected to continue rising in the future, and there is little room for cost reduction here. A third cost is that of producing seeds. This is a significant overhead, and it is unlikely that an inexpensive alternative for a diamond seed will ever be found.

A more persistent threat to integrity and pricing in the diamond industry will be the misrepresentation of cubic zirconia and other imitation materials as “synthetic diamond.” While there are adequate tests for these imitations, they are not readily available for purchases made on the web.

Conclusions
CVD synthetics can be grown in a range of colors and sizes, with high clarity. The gemstones produced are as beautiful and durable as natural diamond, and they are expected to fill an important market niche in the near future. It is important to note that GIA has the ability to detect and grade CVD synthetics, which will continue to protect buyers and the integrity of the diamond industry.

In the next installment of this series, we will discuss detection of CVD synthetic diamonds. @chapter:9 @chapter:1 @chapter:9


# Publication Year: 1995
# Title: Summer 1995 Gem News International
# Abstract: Diamonds
            More Firms Processing Fracture-Filled Diamonds
            Synthetic Diamonds Misrepresented as Canadian Rough
Colored Stones
            Large Aquamarines from Nigeria
            Clinochlore and Other Rare Collector Stones from the Former Soviet Union
            Other Unusual Gems Seen at Tucson
            Phenomenal Feldspars from India
            Parti-Colored Fluorite from Brazil
            Unusual Opal Carvings
            Update on Opal from Ethiopia
            Sapphires from Madagascar
            Sapphires and Other Gems from Tanzania
            Spessartine Garnet from Namibia
Synthetics and Simulants
            Amber Simulant: Natural Resin in Plastic
            Update on "Recrystallized" Corundum
            Laser-Inscribed Synthetic Colored Stones
            Partially Devitrified Glass Imitation of Jadeite
            Iridescent Hematite Simulant
            Kyocera Plastic-Impregnated Synthetic Opals
            Platinum Alloy as an Ornamental Material
Instrumentation
            New Gemological Spectrometer at Tucson

To view the full section, download the PDF above. @chapter:4 @chapter:0 @chapter:4


# Publication Year: -
# Title: Moonstone Care and Cleaning Guide
# Abstract: While requiring care to avoid damage, moonstone lends an almost magical sheen to jewelry. - Courtesy Richard Krementz Gemstones

Hardness and toughness
Gem and mineral hardness is measured on the Mohs scale. The numbers are based on the relative ease or difficulty with which one mineral can be scratched by another. But the Mohs scale is deceptive. The steps between the minerals are not evenly spaced. For example, diamond is only one number away, but it’s many times harder than gems in the corundum family.

Moonstone falls between 6 and 6.5 on the Mohs scale. It also has poor toughness.

	Moonstone ranks 6 to 6.5 on the Mohs scale.
Moonstone has two cleavage directions, a trait it shares with the other members of the feldspar family of minerals. Cleavage is a direction of atomic weakness that makes a crystal more prone to breaking. Cleavage can affect durability, so manufacturers usually set moonstone into pendants, earrings, and pins rather than rings, which are more likely to receive knocks and bumps.

	Due to a property called cleavage, a hard blow can break a moonstone.
Stability
High heat or sudden temperature change can cause breaks in moonstone. It is stable to light but is harmed by exposure to hydrofluoric acid.

Cleaning
Warm soapy water is the only recommended substance for cleaning moonstones. Ultrasonic and steam cleaners are never recommended. @chapter:27 @chapter:0 @chapter:27


# Publication Year: 2017
# Title: Magnificent Sapphires from Montana’s Rock Creek Mine
# Abstract: Figure 1. This 12.61 ct blue sapphire and 7.90 ct orange sapphire recently mined by Potentate show that large material still comes out of Rock Creek, Montana. Photo by Eric Welch/GIA, courtesy of Potentate Mining.

Potentate Mining marketing director Warren Boyd presented two magnificent sapphires (figure 1) and a suite of fancy sapphires extracted from the company’s Rock Creek operation in Montana in 2016. He also updated the authors on this past mining season.

The larger of the two stones is the 12.61 ct blue sapphire, one of the largest of its kind from Montana. It was faceted from a 6.37 g rough that had been heated. The rough showed strong blue color before heating but had a core with heavy silk inclusions. Heating dissolved the silk and enhanced the blue color. The 7.9 ct orange oval is the largest of this color ever recovered from Montana, to Boyd’s knowledge. This stone was faceted from a 5.2 g rough of pale greenish color with a dark brownish core. While the rough was of very low transparency, the results of heating were better than expected. The heated rough showed a royal blue rim surrounding a bright orange core. Both stones were faceted by Jeff Hapeman (Earth’s Treasury, Westtown, Pennsylvania).

	Warren Boyd – Potentate Mining LLC

In this interview, Mr. Boyd delivers an update on Potentate Mining’s production of Montana sapphire and the importance of maintaining consistent levels of production for supply to the jewelry industry. He also provides background on some remarkable sapphires: fashioned 7.90 ct orange and 12.61 ct blue sapphires and a pristine pale blue 59.50 ct crystal, the largest transparent crystal the company has recovered to date.
Most of the Rock Creek sapphire is small, and larger stones with spectacular colors are very rare. Because the bulk of the production comes out of the ground with greenish pastel colors, natural stones with bright colors are also very valuable. Boyd and his clients from Americut showed us a suite of natural fancy sapphires (figure 2) recovered in 2016. The company had produced sapphire rough from its Rock Creek deposit for two consecutive mining seasons and gradually built up a large inventory. Potentate is not planning to increase production but to keep it stable in the near future. The company installed a new water clarifier in its washing plant at Eureka Gulch, which recycles the water used in ore washing. The company will keep its focus on building inventory and bridging the gap between supply and demand.

Figure 2. As displayed by these rough and cut sapphires, Potentate’s sapphire
production includes a wide variety of colors. Photo by Eric Welch/GIA, courtesy of
Potentate Mining. @chapter:21 @chapter:0 @chapter:21


# Publication Year: 2018
# Title: Strong Fluorescence in B-Jade Impregnated with Wax
# Abstract: Figure 1. Left: The wax-impregnated jadeite jade bangle submitted for identification. Right: The bangle exhibited strong bluish fluorescence under long-wave UV radiation. Photos by Lai Tai-An Gem Lab.
Fine-quality jadeite jade is known for its high value in the market. “A,” “B,” and “C” jade are classifications applied to jadeite that relate to various states of enhancement. However, many in the market may not understand the real meaning of the terms. A-jade shows no indications of having undergone modification through the impregnation with colorless or near-colorless wax, resin, or any other agent. When the material has been treated through bleaching and the impregnation with colorless or near-colorless wax, resin, or any other agent, it is described as B-jade. When it shows indications of having fissures or fractures filled with a color agent, it is defined as C-jade. B and C areas may exist in the same specimen; this is described as B+C-jade. A bangle submitted to the Lai Tai-An Gem Laboratory (figure 1, left) illustrates the common misconception that B jade is only impregnated by resin. In fact, wax-impregnated jadeite jade is also defined as B-jade.
The client who submitted the bangle believed it was resin-impregnated jadeite owing to its suspiciously strong fluorescence reaction. The item possessed an uneven green and white color with a greasy luster and weighed 277.14 ct. It measured approximately 76 mm with a thickness of 9–10 mm. A refractive index (RI) reading of 1.66 was obtained from five random spots on the bangle, and a specific gravity (SG) of 3.34 was also recorded. The most interesting feature was an unusually strong reaction under long-wave UV (figure 1, right), indicating it was probably treated and should be examined with more care. This material was determined to be jadeite jade when subsequently tested by Fourier-transform infrared (FTIR) spectroscopy, but the FTIR results also revealed some features other than the jadeite-related peaks.

Figure 2. Microscopic observation revealed obvious acid etching marks, coarse pits, and cobweb-like surface fissures. Photo by Lai Tai-An Gem Lab; field of view 4.6 mm.
FTIR analysis confirmed that the jadeite bangle was heavily impregnated with wax. The absorption peaks at 2850, 2920, and 2965 cm–1 differed from those expected in resin-impregnated material—which usually exhibits peaks at 3061 and 3040 cm–1—and they were intense and sharp enough to indicate that a significant quantity of wax had been applied. Microscopic examination revealed obvious acid etching marks, coarse pits, and cobweb-like surface fissures (figure 2). Wax residues were also found within pits and fissures when poked. Additional unseen wax was apparently within the structure according to the wax pattern revealed by FTIR analysis, typical for wax-impregnated B-type jadeite, which clearly explains the strong reaction under long-wave UV.
While the term B-jade is meant to be applied to wax- and/or resin-impregnated material (Laboratory Manual Harmonisation Committee Information Sheet #11, http://www.lmhc-gemology.org/pdfs/IS11_20111215.pdf), many traders misleadingly describe B-type jadeite jade as resin-impregnated only. This leads the unsuspecting buyer to believe that wax-impregnated jadeite jade is A-jade. This case clearly shows that those dealing in jadeite should be aware of the differences between resin- and wax-impregnated materials, even though both are considered B-jade, and understand that confusion may arise if items are not carefully checked. @chapter:46 @chapter:4 @chapter:46


# Publication Year: -
# Title: Iolite Quality Factors
# Abstract: The cutter took full advantage of this iolite’s color and transparency, fashioning it into a uniquely carved gem, ready for use in jewelry. – Lydia Dyer, Gem courtesy John Dyer & Co.

                      Affordable and attractive, iolite can be used in many types of jewelry. It’s sometimes found in large sizes and beautiful, intense colors that satisfy even the most discriminating colored gemstone connoisseur.

Color
Iolite possesses two distinctive features—a beautiful, violetish blue through slightly violetish blue hue derived from iron and a striking, eye-visible pleochroism. Its pleochroic colors differ with its bodycolor. Iolites that appear violet display light violet, dark violet, and yellow-brown pleochroic colors.  Bluish iolites display colorless to yellow, blue-gray, and dark violet pleochroic colors. From some angles, then, a bluish iolite can actually appear completely colorless or yellow, and a violetish iolite can look brown. Some gems can look grayish or nearly colorless.

	This attractive iolite was skillfully cut to show its best color face-up.
Clarity
Iolite is commonly transparent, with relatively few inclusions. It can be found in all shapes and has even been carved to beautiful effect.

Iolite can contain inclusions that cause various phenomena. Occasionally, iolites with long, parallel, tubular inclusions are found. When the cut is oriented properly, these stones yield cat’s-eye gems.

Iolite containing numerous metallic, plate-like inclusions can be cut to display a sparkly effect known as aventurescence. When the platelets are brownish or reddish in color, the gem might be marketed as “bloodshot” iolite.

	The brownish and reddish inclusions make this a “bloodshot” iolite.
Cut
Because it is commonly transparent with relatively few inclusions, iolite is most often faceted. However, iolites can be cut into cabochons or carvings as well. They are frequently seen as beads, especially when the material is of somewhat lower quality.

Carat Weight
The size range for a fashioned iolite is anywhere from 1 to 10 carats, but fine iolites over five carats are rare. @chapter:27 @chapter:0 @chapter:27


# Publication Year: -
# Title: Ruby History and Lore
# Abstract: To commemorate the 50th anniversary of The Wizard of Oz, Harry Winston created real ruby slippers set with 4,600 rubies. - Courtesy Harry Winston

                      Red is the color of our most intense emotions—love and anger, passion and fury. It’s associated with objects of power and desire—like fast cars and red roses. Early cultures treasured rubies for their similarity to the redness of the blood that flowed through their veins, and believed that rubies held the power of life.

Ruby is one of the most historically significant colored stones. Rubies are mentioned four times in the Bible, in association with attributes like beauty and wisdom. In the ancient language of Sanskrit, ruby is called ratnaraj, or “king of precious stones.”

In the first century AD, the Roman scholar Pliny included rubies in his Natural History, describing their hardness and density. Ancient Hindus believed that those who offered fine rubies to the god Krishna were granted rebirth as emperors.

Hindus divided ruby into four castes, calling the true Oriental ruby a Brahmin. Someone in possession of a Brahmin was believed to have the advantage of perfect safety.

Ruby has accumulated a host of legends over the centuries. People in India believed that rubies enabled their owners to live in peace with their enemies. In Burma (a ruby source since at least 600 AD—now called Myanmar), warriors possessed rubies to make them invincible in battle. However, it wasn’t enough to just wear the rubies. They had to insert them into their flesh and make them part of their bodies.

The name ruby comes from the Latin word ruber, which means “red.” The glowing red of ruby suggested an inextinguishable flame burning in the stone, even shining through clothing and able to boil water.

Ruby has been called the most precious of the 12 stones created by God.

Ruby retained its importance with the birth of the western world and became one of the most sought-after gems of European royalty and the upper classes. Many medieval Europeans wore rubies to guarantee health, wealth, wisdom, and success in love.

Desire for ruby is just as great today as it always has been. As a symbol of passion, ruby makes an ideal romantic gift. Consumers are drawn to the lush color because it also signifies wealth and success. @chapter:40 @chapter:2 @chapter:40


# Publication Year: -
# Title: Bridges Family and Tsavorite Update
# Abstract: Bruce BridgesBridges Tsavorite

Interview with Bruce Bridges, Bridges Tsavorite
There are moments in GIA’s compelling interview with Bruce Bridges that the son of legendary gem pioneer Campbell Bridges speaks optimistically about finally getting some justice in the brutal killing of his father in August 2009.  Eight suspects, who were named, photographed and eye-witnessed at the time of the crime, were arrested almost immediately. Yet the case has dragged on for more than three years, not only leaving the Bridges family in torment, but the Kenyan mining economy in a state of suspended animation.

Bridges reflects on his father’s life and work, which led him from his native Scotland to Africa, where he made his mark in the gem world with the discovery of tsavorite. For all the fame the discovery brought him, it seemed cursed from the start. His first discovery in Tanzania in 1969 went nowhere when the country refused to grant him a mining permit. His second discovery in Kenya in 1971 demanded eternal vigilance from poachers, thus giving his mine the name Scorpion after the poisonous creatures he would leave to guard it. Ultimately tsavorite led to his death at the hands of thuggish competitors.

In the interview Bridges also talks about the finer points of tsavorite—its shape and color—and describes the grading system used. He also discusses their use of master stones in grading and gives insight into tsavorite quality.

A truly special treat in the following video is the first-time unveiling of a brilliant umbalite specimen with tremendous sentimental value. When they were cleaning out his father’s belongings, Bruce tells us, they came upon a camera film canister labeled “2 pcs rgh.”  When they opened it, they found the umbalite rough. They had it cut and polished and here it’s on full display before our GIA camera. @chapter:23 @chapter:0 @chapter:23


# Publication Year: 2016
# Title: GILC 2016
# Abstract: The International Colored Gemstone Association (ICA) held its annual Gemstone Industry & Laboratory Conference on February 1 during the Tucson shows. Invited participants included jewelry trade association leaders, laboratory representatives, academic institutions, and ICA members. This year, other industry members were welcomed into the afternoon open discussion session.

Lore Kiefert (Gübelin Gem Lab, Lucerne, Switzerland), presenting on behalf of her colleague Daniel Nyfeler, spoke on age determination by radiogenic isotopes. Laser ablation–inductively coupled plasma–mass spectrometry (LA-ICP-MS) has enabled the Gübelin Lab to use radiometric dating to test inclusions at or near the surface of materials such as corundum and emerald, which do not have radioactive atoms. When traditional methods such as observation of inclusions and growth structure and trace element analysis lead to more than one possible country of origin, radiometric dating can furnish the decisive data. U/Pb decay in zircon has been well documented as a means to establish an approximate timeline for known sapphire and emerald populations. The corundum timeline established the oldest population as African, with an age of 450–650 million years (Ma), and the youngest as Colombian, at 10 Ma. Emerald formation ranged from South Africa at 2900 Ma to Colombia at 65–35 Ma. This method is limited when the gemstone presents no analyzable inclusions or has been treated.

James Shigley (GIA, Carlsbad) presented the Institute’s latest research findings. GIA’s work with color analysis has its foundation in observation and color grading of colored diamonds. Dr. Shigley noted that the visible spectrum is not the only cause of color; in fact, the face-up appearance is influenced by about 15 factors, including the emission spectrum of the light source, the absorption spectrum of the stone, and the color sensitivity of the eye. Since humans are more adept at distinguishing differences than similarities, the use of master stones and bracketing between pairs is well suited for visual grading. GIA uses instrumentation to supplement visual grading in face-down evaluation of round near-colorless D to Z diamonds; however, fancy-color diamonds are graded face up. GIA has been working on analytical tools that can “detect” color in the same way that the human eye processes it.

Bruce Bridges (Tsavorite USA, Inc.) asked whether gems can be reliably traced from the source to the consumer. Today’s consumer wants to know where products come from and how their manufacture affects both the environment and workers. Vertically integrated companies can promote traceability and control over ethical sourcing, but the business model cannot be applied to the small-scale operations that characterize most of the industry. Bridges outlined the convoluted path from small-scale or individual miner through a series of brokers to cutting and the “end user” market, where it may go through another series of dealers before reaching a consumer. Most colored stone sources are overwhelmingly alluvial or placer deposits in remote areas, making them difficult to centralize. Traceability is even challenging at the mine, where it is not uncommon for material from a different location to be sold without disclosure. Traceability from cutting centers can improve as host countries introduce limits on rough exports and begin developing cutting facilities, which has happened in parts of Africa, South America, and Asia.

	The conference proceeded to an open session for invited participants to discuss topics of concern, including:

		The increasing use of color enhancement and “anti-scratch” (silicon carbide) coatings, which are virtually invisible and sometimes too thin to be detected with instruments. With advances in nanotechnology, more research is needed to develop detection strategies.

		The inconsistent use of descriptive terminology in laboratory reports, a topic carried over from the 2015 conference. The laboratories maintained that they were responding to the demands of the trade. One participant pointed out that the terms “pigeon’s blood” and “royal blue” had no meaning in Chinese culture until about ten years ago. Since then, they have become “deeply implanted,” and a seemingly irreversible demand has been created for the level of distinction that these terms confer.

		Unethical or fraudulent use of lab reports. An example cited is the treatment of a gemstone after it had received a “clean” report. Another is the manufacture of both treated and synthetic diamonds to match an existing natural diamond report. GILC participants stressed the importance of checking reports against stones through every phase of the grading process.

		The use of “undetermined” on a lab report in regard to treatment or synthetic origin. Some participants voiced concerns that such determinations are beyond the technologies of labs, or that the word “undetermined” left untreated natural diamonds vulnerable to being matched with treated or synthetic stones.

	At the conclusion of the conference, it was announced that AGTA had revised its code of ethics and principles of fair business practice. ICA is proposing to adopt AGTA’s code of ethics, due diligence protocol, and source disclosure language as a basis for its own code. @chapter:1 @chapter:0 @chapter:1


# Publication Year: 2017
# Title: Chalcedony Beads Coated With Titanium Nitride
# Abstract: Figure 1. The beads in this necklace, ranging in diameter from 12.0 to 12.5 mm, have a submetallic luster and a gray tinge with goldish reflection. Small vugs lined with sparkling crystals are clearly visible in most of the beads. Photos by Raffaella Navone.

Recently, RAG Gemological Laboratory in Turin received a necklace of unusual metallic appearance (figure 1). The beads showed irregular surfaces that were actually small geodes with shiny and well-shaped crystals. The cavities in the beads (figure 2) were reminiscent of the small quartz-lined holes that are often formed in agates and chalcedony. The necklace consisted of 29 beads ranging from 12.0 to 12.5 mm in diameter, with a total weight of 84 g.

Figure 2. SEM imaging shows the small, well-shaped quartz crystals within the
cavities. The crystal in the lower middle clearly displays the classic “flute”
termination typical of quartz. Image by Emanuele Costa; field of view 1 mm.
Some loose opaque beads provided by the necklace’s owner allowed us to measure the material’s density. The value of 2.60 g/cm3 was in agreement with chalcedony. Refractive index was not measurable on the beads due to their rough surface. No fluorescence reaction was observed under long- or short-wave UV. A sawed bead revealed that the inner part consisted of light gray chalcedony without zonation (figure 3). Observation of the area near the drill holes showed discoloration and the true color of the underlying material. The coating on these grayish gold chalcedony beads in this necklace had an unusual composition. The unusual color and reflectivity of the external surface, clearly not inherent to chalcedony, warranted investigation.

Figure 3. This sawed cross-section clearly demonstrates the homogeneity and light gray color of the chalcedony that constitutes most of the bead. Photo by Emanuele Costa.
The chemical composition of the bead was confirmed by energy-dispersive spectroscopy (EDS) using a Cambridge Stereoscan 360 scanning electron microscope equipped with an Oxford Inca Energy 200 EDS and a Pentafet detector for the determination of elements from boron to uranium. The results showed homogeneous composition on the sample surface, with titanium, oxygen, and silicon as major elements. No known compound of Ti and Si could explain the nature of the bead’s surface or the goldish gray metallic tinge.

Low-acceleration voltage conditions in EDS analysis (4kV) allowed us to enhance the X-ray emission yield of lighter elements and reduce the penetration depth of the electron beam at around 100 nm into the bead’s surface. The EDS spectra at low acceleration voltage showed the presence of nitrogen and titanium, suggesting a coating of titanium nitride (TiN) on the beads. At low potential the electron beam could pass through the thin layer of TiN, so the oxygen and silicon peaks from the underlying silica were still visible in the spectra. We calculated the thickness of the coating by acquiring several EDS spectra at different acceleration voltages (from 4 to 10 kV). The presence of the silicon peak even at 4 kV suggests that the electron beam could penetrate the layer and generate the signal through the TiN coat. The Casino software package evaluated the corresponding excitation depth of the electron beam using a Monte Carlo simulation. The calculated maximum thickness in our samples was less than 200 nm.

TiN is a very difficult material to analyze due to the presence of nitrogen, which is not always revealed with standard gemological techniques. To confirm the presence of a TiN film coating, we performed micro-Raman investigations. Spectra were obtained using a micro/macro Horiba LabRAM HR 800 (UV-Vis-IR) equipped with an Olympus microscope. The backscattered Raman signal was collected with a 50× objective and the 632.8 nm line of a He-Ne laser. The spectra were collected with multiple and repeated acquisitions to improve the signal-to-noise ratio, but even with these precautions the quality of the spectra is very poor due to the low intensity of Raman response from TiN. The Raman spectrum was recorded from 100 to 1200 cm–1. Spectral manipulation such as baseline adjustment, smoothing, and normalization were performed using LabSpec 5 software. Band component analysis using the Fityk software package enabled the type of fitting function to be selected and specific parameters to be fixed or varied accordingly.

The Raman spectrum of a deposited TiN film is shown in figure 4. The Raman spectrum of the TiN layer can be fitted with Gaussian-Lorentzian peaks at 260, 330, 418, and 584 cm–1. The spectrum is the same as those of TiN films reported, also with very poor quality, in the literature (Y.H. Cheng et al., “Substrate bias dependence of Raman spectra for TiN films deposited by filtered cathodic vacuum arc,” Journal of Applied Physics, Vol. 92, 2002, pp. 1845–1849). Slight variations in peak position, shape, and relative intensity can be influenced by thickness (C.C. Chen et al., “Raman spectra of titanium nitride thin films,” Chinese Journal of Physics, Vol. 32, No. 2, 1994, pp. 205–210), treatment time, and deposition temperature of TiN films (R.R.M. de Sousa et al., “Cathodic cage plasma deposition of TiN and TiO2 thin films on silicon substrates,” Journal of Vacuum Science & Technology A, Vacuum, Surfaces and Films, Vol. 33, No. 4, p. 041502), as well as substrate bias.

Figure 4. Raman spectrum of the TiN film in the 100–800 cm–1 region. The Raman
bands are related to transverse acoustic (at 260 cm–1), longitudinal acoustic
(330 cm–1), second-order acoustic (418 cm–1), and transverse optical (584 cm–1)
modes of TiN, respectively (Cheng et al., 2002). The poor quality of the spectrum,
despite a long collection time and enhanced sensitivity, is due to the faint response
of the TiN to Raman investigation (as well as to the extreme thinness of the coating);
it is comparable to the reported spectra available in the literature.
The TiN films also contained a small quantity of crystalline phase of TiO2 (i.e., brookite) that was identified in the bead coating using Raman spectroscopy. There was a close match between the collected spectrum and that of brookite available in the RRUFF database (R050363). The association of TiN and TiO2 films is well known and widely studied (de Sousa et al., 2015).

TiN deposition is widely used for the coating of small mechanical parts or tools, giving them a higher resistance to corrosion and scratching. Therefore, TiN films are essential for applications such as wear-resistant coatings, diffusion barriers, and optical coatings. The coating typically produces a golden hue, but other colors are also possible. Even though TiN films are common in industrial applications, this may be the first time such a coating has been reported in gemology. @chapter:2 @chapter:0 @chapter:2


# Publication Year: 2015
# Title: A Remarkably Large Amblygonite-Montebrasite Carving
# Abstract: Figure 1. This 1,871 g amblygonite-montebrasite carving (18.50 × 15.10 × 7.30 cm) is unusual for its size and transparency. Photo by Gagan Choudhary.

Recently the Gem Testing Laboratory in Jaipur had an opportunity to examine an unusually large yellow, semitransparent to translucent carving (figure 1). This 1,871 g (9,355 ct) piece measuring approximately 18.50 × 15.10 × 7.30 cm was fashioned after Lord Mahavira, one of the ancient Indian sages who established the tenets of Jain Dharma. Initial observations suggested beryl due to the color, medium heft, and cloudy liquid inclusions visible to the unaided eye. Gemological testing ruled out that possibility, however. Spot RI was approximately 1.61, with a small but distinct birefringence blink, while hydrostatic specific gravity measured 3.00. The carving was inert to UV radiation.

Examination with a hand loupe revealed reflective liquid films (figure 2, left), fingerprints composed of phase droplets, elongated phase/short tubes oriented in one direction, aligned in planes intersecting at approximately 65/115° angles (figure 2, center). Also present were parallel reflective films that appeared to be incipient cleavage (figure 2, right). The overall inclusion pattern was typical of gems found in pegmatitic bodies such as beryl, tourmaline, and topaz.

Figure 2. Examination of the carving with a hand loupe revealed reflective liquid films (left), elongated phase/short tubes oriented in one direction and aligned in planes intersecting each other at approximately 65/115° (center), and parallel reflective films that appeared to be incipient cleavage (right). Photos by Gagan Choudhary; image width 25 mm.
The carving was identified as amblygonite-montebrasite by Raman spectroscopy in the 200–2000 cm–1 region, which revealed distinct peaks at ~297, 425, 481, 600, 643, 797, 1011, 1058, 1107, and 1186 cm–1 (figure 3). Amblygonite and montebrasite are both lithium phosphates with a common chemical formula of (Li, Na)AlPO4(F, OH), forming an isomorphous series between F-rich amblygonite and OH-rich montebrasite. The two minerals can be colorless, yellow, or green. High-quality crystals are prized by collectors but rarely seen in the gem trade (R. Webster, Gems: Their Sources, Descriptions and Identification, 5th ed., rev. by P.G. Read, Butterworth-Heinemann, Oxford, UK). The amblygonite and montebrasite end members can be differentiated on the basis of peaks at ~600 and 1060 cm–1 and a peak at ~3370 cm–1. With an increasing percentage of fluorine, the 600 cm–1 peak shifts from 599 to 604 cm–1 while the 1060 cm–1 peak shifts from 1056 to 1066 cm–1 (B. Rondeau et al, “A Raman investigation of the amblygonite-montebrasite series,” The Canadian Mineralogist, Vol. 44, No. 5, pp. 1109–1117). According to the RRUFF database, however, the peak for montebrasite is at 1047 cm–1 while amblygonite’s is at 1060 cm–1. This is possibly due to different instrument settings. Although the ~3370 cm–1 peak was not studied here, the 600 and 1058 cm–1 peaks in this carving suggested that it belongs to an intermediate state in the amblygonite-montebrasite series.

Figure 3. The carving’s Raman spectrum showed major peaks at around 297, 425, 481, 600, 643, 797, 1011, 1058, 1107, and 1186 cm–1. The peaks at approximately 600 and 1058 cm–1 suggest an intermediate member of the amblygonite-montebrasite series.
Amblygonite-montebrasite is known from many localities, especially the United States and Brazil, but the client did not know the source of the carving. A few faceted samples have been examined at this laboratory, but the carving documented here was exceptional for its large size and transparency, despite its brittleness and tendency to crack. @chapter:1 @chapter:0 @chapter:1


# Publication Year: 2015
# Title: Nonbead-Cultured Pearls from Strombus Gigas
# Abstract: Figure 1. These two nonbead-cultured pearls (1.40 and 2.22 ct) from a parcel of eight specimens produced by Strombus gigas show a light pink and yellowish orange color with a discreet flame pattern. Photo by Olivier Segura.

Among the saltwater porcelaneous (non-nacreous) pearls, those of Strombus gigas gastropods are probably the best known among jewelers and collectors because of their vivid to pastel colors ranging from pink to white to brownish. Also known as “pink pearl,” “conch pearl,” or “Queen conch pearl,” this material was used extensively in Art Deco jewelry, and many designers are now incorporating them into modern pieces. Various articles and books have described the extraordinary beauty, use and related traditions, and early attempts at cultivation of pink pearls (see E. Fritsch and E. Misiorowski, “The history and gemology of the queen conch ‘pearls’,” Winter 1987 G&G, pp. 208–231). The typical structure responsible for the sought-after “flame pattern” was detailed extensively a decade ago (S. Kamat et al., “Structural basis for the fracture toughness of the shell of the conch Strombus gigas,” Nature, Vol. 405, No. 6790, 2000, pp. 1036–1040; H. Hänni, “Explaining the flame structure of non-nacreous pearls,” The Australian Gemmologist, Vol. 24, No. 4, 2010, pp. 85–88). Found in the Caribbean region, where Strombus gigas live and are fished for meat, the pearls had no documented cultured counterpart until the work of Hector Acosta-Salmon and Megan Davis at Florida Atlantic University in 2009.

The Laboratoire Français de Gemmologie (LFG) recently had the opportunity to analyze a parcel of eight samples, presented as cultured conch pearls, from a new farm based in Honduras (figure 1). The colors ranged from white and pinkish white to yellowish orange. The shapes varied from oval to baroque, and weights ranged from 0.21 ct (2.7–3.4 × 4.1 mm) to 3.13 ct (6.5–7.6 × 9.3 mm). Their luster was porcelaneous, and the surface was very smooth and homogenous with no defects. Almost all the samples possessed a typical but subtle flame pattern (figure 2).

Figure 2. These six nonbead-cultured pearls from Strombus gigas range from 0.21 to
3.13 ct. Inset: Detail of a 0.47 ct pearl, showing a typical thin flame pattern. Photo by
Olivier Segura.
Initial examination revealed no indication of the culturing process, but X-radiography analysis left no doubt about the material’s origin. The samples’ inner structures revealed a darker central zone, suggesting a less dense material, typical of the graft remainder of the nonbead culture process (figure 3, left). This kind of pattern is not found in the natural conch pearls we have examined in the laboratory (figure 3, right).

Figure 3. Left: An X-ray of the pearl seen in the figure 9 inset. It shows clear evidence of a nonbead culturing process. Right: An X-ray of a natural conch pearl. Images by Olivier Segura.
According to the farm owners, queen conch pearl culture is undergoing intensive development, and the quality—size, flame pattern, and color—improves with each harvest. While current laboratory techniques are adequate to unambiguously identify nonbead cultured pearls from Strombus gigas, the LFG has established a close working relationship with the pearl farm, paying close attention to possible developments in their distinctive inner structures. @chapter:11 @chapter:4 @chapter:11


# Publication Year: 2013
# Title: New Find: Blue “Cloud Agates” from Weierbach near Idar-Oberstein, Rhineland-Palatinate
# Abstract: The agate deposits that formed the basis of the lapidary and cutting industry at Idar-Oberstein until the 19th century are mostly depleted. What reaches the market today is the result of rockhound activities. This article reports on a remarkable find from 2012 along a road construction site at Weierbach, near Idar-Oberstein. Found in a small outcrop of volcanic rocks, the nodules showed diameters of 2–12 cm (0.8–4.8 in.). While agates from Idar-Oberstein generally have a fine banding and pastel tones, most of these agates were not banded but showed cloud-like structures and striking sky blue and red colors. The article contains numerous images of the splendid agates and the deposit.

Abstracted by Rolf Tatje @chapter:2 @chapter:0 @chapter:2


# Publication Year: 2016
# Title: Iridescent Inclusions in Scapolite
# Abstract: Figure 1. Orange platelet inclusions give this 2.21 ct scapolite an orange color and aventurescence similar to that of Oregon sunstone. Photo by Jonathan Muyal.

	A 2.21 ct phenomenal scapolite (figure 1), reportedly from Tanzania, was recently examined by this author. Of particular interest was its striking resemblance to Oregon labradorite feldspar, which displays aventurescence and is known in the trade as sunstone. Raman microspectrometry confirmed the stone’s identity as scapolite. Vibrant thin-film iridescence created by brownish orange exsolution platelets (figure 2) was revealed by microscopic examination; these platelets are responsible for the stone’s orange bodycolor. The exsolution platelets are presumed to be hematite based on their color, morphology, and high levels of iron detected by energy-dispersive X-ray fluorescence (EDXRF), although it was not possible to confirm this identity through Raman analysis. This scapolite’s aventurescence and pleasing orange bodycolor make it an interesting collector’s gemstone.

Figure 2. Under magnification with oblique illumination, the platelet inclusions reveal vivid multicolor iridescence. Photomicrograph by Jonathan Muyal; field of view 1.42 mm. @chapter:8 @chapter:0 @chapter:8


# Publication Year: 2023
# Title: Rare Faceted Thomsonite
# Abstract: Figure 1. A rare 1.04 ct semitransparent thomsonite measuring 7.53 × 6.15 × 4.67 mm. The inset shows the typical appearance of thomsonite. Photos by Adriana Robinson and Scott Lewis (inset).

Figure 2. A fibrous snowflake-like inclusion found within the semitransparent thomsonite. Photomicrograph by Michaela Damba; field of view 3.57 mm.
The Carlsbad laboratory recently examined a colorless semitransparent 1.04 ct oval modified brilliant (figure 1). Standard gemological testing gave a specific gravity (SG) of 2.47 and a refractive index of 1.520–1.538. These properties suggested the stone was a rare faceted thomsonite, which was confirmed by Raman spectroscopy. There are two types of thomsonite: the more common thomsonite-Ca with the chemical formula NaCa2Al5Si5O20 • 6(H2O) and the less common thomsonite-Sr with the chemical formula of Sr1.4Ca0.6NaAl5Si5O20 • 7.1(H2O). X-ray fluorescence was not run on this stone to determine which, for fear of damaging the potentially fragile stone. The SG reading was slightly higher than the expected value of 2.35 (+0.05/–0.10). Multiple surface scratches and abrasions indicated a relatively soft material, consistent with thomsonite’s hardness of 5.0–5.5 on the Mohs scale. This specimen featured a radiating fibrous inclusion resembling a snowflake (figure 2). Although the identity of the inclusion could not be confirmed with Raman spectroscopy, it was likely a member of the zeolite group.
Thomsonite is a rare member of the zeolite group named for Scottish chemist and mineralogist Thomas Thomson (1773–1852). While the source of this specimen is unknown, thomsonite is typically found in Minnesota along Lake Superior. It usually occurs as semitranslucent to opaque rounded crystal aggregates (figure 1, inset) with a fibrous structure. Thomsonite has also been known to appear as part of a rock aggregate (B.M. Laurs et al., “Benitoite from the New Idria District, San Benito, County, California,” Fall 1997 G&G, figure 13) or as rare needle inclusions in Canadian sapphires (Winter 2004 Gem News International, pp. 344–345). Semitransparent and faceted thomsonite is very unusual. To the best of our knowledge, this is the first faceted thomsonite examined by GIA. @chapter:15 @chapter:0 @chapter:15


# Publication Year: 2004
# Title: Winter 2004 G&G Lab Notes
# Abstract: Faceted Apophyllite with “Crop Circles”
Diamond Luminescent “Hopper” Diamond
“Magnetic” Natural Pink Diamond
Diamond with Many Microscopic Carbonate Inclusions
Unusual Near-Colorless Synthetic Diamond
Orangy Brown Iolite from Madagascar
Flashing Labradorite
Natural Saltwater Mussel Pearls
Treated-Color “Golden” South Sea Cultured Pearls
Quartz in Three Colors
Erratum

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