Title: Ruby with Interesting Synthetic Overgrowth Abstract: A large cavity partially filled with synthetic overgrowth on the pavilion of a heated Burmese ruby in darkfield lighting (left) and reflected lighting (right). Photomicrographs by Nicole Ahline; field of view 7.19 mm.
The Carlsbad laboratory received a 3.02 ct ruby for a colored stone identification and origin report. Standard gemological testing was consistent with ruby: a hydrostatic specific gravity of 3.96 and a ruby spectrum in a handheld spectroscope. Internally, the stone displayed white flakes in a hexagonal formation and roiled graining. Partially healed fissures with residue, which result from heating in the presence of a flux, were also documented. The inclusion scene, along with the stone’s trace element chemistry collected using laser ablation–inductively coupled plasma–mass spectrometry (LA-ICP-MS), were consistent with Burmese ruby. This ruby was not treated by beryllium diffusion, as no beryllium was detected by LA-ICP-MS. The curious feature of this stone was a large cavity on the pavilion that was partially filled with synthetic overgrowth that was observed in the microscope (see above).
Synthetic overgrowth can be a byproduct of heating a piece of corundum at high temperatures, with or without the presence of a flux. This creates an environment in the crucible that allows for the partial dissolution of corundum and can result in synthetic corundum overgrowth on the surface and in cavities of the heated stone. Synthetic overgrowth is typically an aggregated structure of hexagonally shaped, platy crystals (Fall 2002 G&G Lab Notes, pp. 255–256). When viewed in reflective lighting, there is no luster difference between the host corundum and the synthetic overgrowth, as the two materials have the same refractive index. The gaps that could be observed between the crystals in this stone showed how they grew in different orientations.
Synthetic overgrowth is common enough that it should always be looked for in corundum that has undergone high-temperature heat treatment. There are cases where synthetic overgrowth can be observed using polarized light, but careful analysis is required because the overgrowth can completely fill cavities and be inconspicuous. Source: GIA @topic:3


Title: Iridescent Scapolite Abstract: Figure 1. These two scapolite cabochons (7.30 and 30.22 ct) displayed prominent iridescence in reflected light. Photo by Don Mengason.

GIA’s Carlsbad laboratory recently examined two cabochons from L. Allen Brown (All That Glitters, Methuen, Massachusetts) that exhibited prominent iridescence in reflected light (figure 1). Standard gemological testing of the 7.30 and 32.22 ct specimens revealed a spot RI of 1.55 and a hydrostatic specific gravity of 2.67. Fluorescence was inert to long- and short-wave UV light. The stones also showed a very weak reaction to a strong magnet.

Under magnification, the most distinctive internal characteristic was the presence of dark brown exsolution stringers of a secondary mineral. Larger tabular dark brown crystals were also observed (figure 2, left). Under reflected light, these exsolution stringers proved to be the source of the iridescent colors (figure 2, right). Similar material has been reported to occur in India, by G. Choudhary (Spring 2013 GNI, pp. 58–59), but the identity of the phenomenon causing inclusions was not determined.

Figure 2. Dark brown exsolution stringers of magnetite (left), also viewed with oblique fiber-optic illumination (right), were the source of iridescence in this scapolite. Photomicrographs by Nathan Renfro; field of view 4.37 mm.
Raman spectroscopy confirmed that the stones were scapolite. To identify the color causing inclusions, the smaller stone was selected for destructive testing. Windows were polished to expose some of the inclusions to the surface of the stone. The exposed surface of the inclusion showed a metallic luster (figure 3), which was identified as magnetite by Raman spectroscopy, and was explanatory of the magnetic reaction observed.

Figure 3. Under reflected light, the exposed surface of the inclusion showed a metallic luster. Photomicrograph by Ziyin Sun; field of view 0.25 mm.
Laser ablation–inductively coupled plasma–mass spectrometry (LA-ICP-MS) analysis was used to further support the identity of the inclusions. While the exposure of the inclusions on the stone’s surface was too small for a clean analysis without a contribution from the scapolite host, the results showed a significant increase in iron as the laser ablated through the brown inclusion and decreased afterward.

Scapolite occurs in a number of rock types as a product of regional metamorphism or metasomatism. The close association of magnetite with scapolite has been noted before, particularly in some skarn deposits and some hydrothermally altered volcanic formations (J.A. Naranjo et al., “Subvolcanic contact metasomatism at El Laco Volcanic Complex, Central Andes,” Andean Geology, Vol. 37, 2010, pp. 110–120). Choudhary reported similar material, but the inclusions that caused the iridescence were not identified. This scapolite with iridescence, also known in the trade as rainbow scapolite, is a very interesting example of a phenomenal gemstone. Source: GIA @topic:2


Title: Vanadium and Chromium-Bearing “Color-Change” Pyrope Garnet Abstract: An interesting type of pink pyrope garnet, probably mined in Morogoro, Tanzania, is shown under incandescent light A (left) and daylight-equivalent light D65 (right). A noticeable difference in color can be seen. Left to right: a 2.51 ct modified round brilliant faceted by Todd Wacks, a 7.61 ct modified round brilliant faceted by Meg Berry, a 13.09 ct modified round brilliant faceted by Todd Wacks, and 31.90 ct and 6.00 ct rough. The 2.51 ct and 13.09 ct faceted stones were included as part of this study. Photos by Robert Weldon/GIA.

	This peer-reviewed feature article—by three of GIA’s young research scientists, Ziyin “Nick” Sun, Aaron Palke, and Nathan Renfro—profiles interesting and attractive Tanzanian color-change garnet that recently reentered the colored gem market at the 2015 Tucson gem shows. The paper is provided here as a PDF download and will be a part of Gems & Gemology’s print and online Winter 2015 issue.

	Gem dealers and cutters Todd Wacks, Jason Doubrava, Jeff Hapeman, and Meg Berry provided the samples for the study. According to Wacks, these garnets were mined in Morogoro, Tanzania, around 1988 and were kept a safe deposit box for nearly 30 years. The group was able to obtain the rough three to four months prior to the 2015 Tucson gem shows. After cutting stones from the material, they found the gems showed a striking purple-to-pink color change. Realizing they were unlike any other garnet he’d seen, Wacks resolved to build a market for them. Under fluorescent-equivalent lighting, the larger gems look like fine purple amethyst, while under incandescent they resemble hot pink tourmaline.

	This material came to the authors’ attention when Wacks submitted a stone to GIA’s Carlsbad laboratory for analysis. A follow-up with the rest of the group yielded a representative suite of samples for more detailed examination. This study of 32 rough and polished samples up to 31.90 ct provides a comprehensive review of this attractive material’s inclusions along with a quantitative analysis of its color under different lighting conditions. Standard testing showed properties consistent with pyrope garnet, along with the noticeable color difference between incandescent and daylight-equivalent light. A key finding is that larger stones—including two faceted gems of 13.88 and 13.90 ct—appeared to show the most striking “color change.”

	Rough stones were fabricated into wafers to orient the inclusions for the best possible photomicrography. The gems were found to contain a wide array of mineral crystals including quartz, apatite, sulfides, and rutile. Raman spectra were collected to conclusively identify these mineral inclusions. Growth tubes, fingerprint-like inclusions, and negative crystals were also observed.

	The researchers performed laser ablation–inductively coupled plasma–mass spectroscopy (LA-ICP-MS) on 11 samples to determine their chemical composition. LA-ICP-MS analysis confirmed the garnets were predominantly pyrope (68.92–72.90 mol.%), grossular (4.88–5.61 mol.%), spessartine (9.55–15.08 mol.%), and almandine (5.66–10.14 mol.%), with minor amounts of other garnet species. Compared to more common gem-quality pyrope, this material had higher vanadium and chromium concentration.

	Three samples were cut into wafers of various thicknesses for UV-Vis-NIR spectroscopy. This was done to investigate the perception that larger stones, where the light travels a longer through the material, produced the most striking color change. Spectra for the larger gems were extrapolated by multiplying the spectra collected from wafers of known thickness. This allowed the authors to calculate the optimal size for a round brilliant cut from this material to produce the maximum separation between the colors shown under different lighting conditions for the strongest “color-change” effect. The researchers’ colorimetric analysis is informed by the work of physicist and longtime G&G contributor Dr. John Emmett.

	“This was an exciting project for us to work on, not only because we got to study such wonderful gem material, but also because we got the chance to hone our skills and adapt our advanced testing methodologies for an in-depth study of color perception,” said Mr. Sun. “For one thing, we had to develop a technique to accurately correct UV-Vis spectra for reflection light loss so we could extrapolate the color of a thin garnet wafer to a faceted stone of a specific size and shape. Understanding the color behavior of this material required us to be able to measure the chemistry accurately. This is where we had to develop our own method to determine the concentrations of chromophores in a complex solid solution like garnet using LA-ICP-MS.” Source: GIA @topic:3


Title: Garnet Description Abstract: Most people do not realize garnets come in a wide variety of gem types and colors, with many cutting options.

                      Garnets are a set of closely related minerals that form a group, resulting in gemstones in almost every color. Red garnets have a long history, but modern gem buyers can pick from a rich palette of garnet colors: greens, oranges, pinkish oranges, deeply saturated purplish reds, and even some blues.

Red garnet is one of the most common and widespread of gems, found in metamorphic rocks (which are rocks altered by heat and pressure) on every continent. But not all garnets are as abundant as the red ones. A green garnet, tsavorite, also occurs in metamorphic rocks, but it’s rarer because it needs unusual rock chemistries and special conditions to form.

Demantoid is a rare and famous green garnet, spessartine (also called spessartite) is an orange garnet, and rhodolite is a beautiful purple-red garnet. Garnets can even exhibit the color-change phenomenon similar to the rare gemstone alexandrite.

All garnets have essentially the same crystal structure, but they vary in chemical composition. There are more than twenty garnet categories, called species, but only five are commercially important as gems. Those five are pyrope, almandine (also called almandite), spessartine, grossular (grossularite), and andradite. A sixth, uvarovite, is a green garnet that usually occurs as crystals too small to cut. It’s sometimes set as clusters in jewelry. Many garnets are chemical mixtures of two or more garnet species.

Garnets are a group of closely related mineral species with many different color varieties. Source: GIA @topic:2


Title: Sillimanite in Ruby Abstract: Figure 1. Bundles of fine sillimanite needles clash within their ruby host. Photomicrograph by Tyler Smith; field of view 1.76 mm.

Recently, the New York laboratory received for origin determination a ruby whose unusual lathe-like inclusions caught the authors’ eyes. The inclusions were long, prismatic, and transparent, often accumulating in small bundles throughout the stone (see above). Luckily, a few needles broke the surface, allowing laser Raman spectroscopy to identify the mystery inclusions as sillimanite, an aluminosilicate mineral that forms in high-grade metamorphic rocks, including the amphibolite facies. With a chemical formula of Al2SiO5, sillimanite, a polymorph of andalusite and kyanite, is frequently found with ruby.
Laser ablation–inductively coupled plasma–mass spectrometry (LA-ICP-MS) of the host ruby revealed a particularly high iron concentration of 7100–7410 ppmw. The combination of the elemental composition and inclusions indicates the stone is from an amphibolite host rock, a non-classic metamorphic formation (NCL). NCL ruby sources include East African countries such as Mozambique, Madagascar, and Tanzania, as opposed to classic metamorphic sources such as Myanmar (formerly Burma) and Vietnam.
Such a high density of these inclusions is rarely observed in stones submitted to GIA. Sillimanite itself is not a particularly uncommon mineral, especially in amphibolite host rocks, so why has it been missing from previously analyzed East African rubies at GIA? Due to its preferred habit of densely packed needles, sillimanite in ruby likely affects transparency, potentially resulting in non-gem-quality translucent to opaque rubies. Such stones are not frequently submitted to GIA. It is refreshing to see less common mineral inclusions in the lab, as they provide a greater understanding of East African rubies. Source: GIA @topic:2


Title: Books: Jewels of Ancient Nubia Abstract: By Yvonne J. Markowitz and Denise Doxey, 184 pp., publ. by Museum of Fine Arts, Boston, 2014, $45.00.

              Nubia, known as Kush in antiquity, was a flourishing civilization for more than three millennia. It encompassed an area from south of Egypt to northern Sudan. Among the thousands of Nubian archaeological remains, their jewelry and personal adornment items stand out for their beauty, elegance, innovation, and technical mastery.

Modern-day knowledge of the kingdom is limited to accounts contained in ancient Egyptian records. Even though Nubia was a rival and a frequent enemy, the Egyptians referred to it as “the gold lands” for its precious metal and mineral resources. The Nubians themselves left very few written accounts, and their language is yet to be deciphered and translated. Appreciation of this fascinating culture later suffered the Eurocentric favoring of Ancient Egypt, and the modern world has known little about the region until recently. Jewels of Ancient Nubia provides the first comprehensive introduction to Nubian history through its artifacts.

The book features items made of gold, silver, and electrum (a natural gold and silver alloy) that illustrate the resources and the sophisticated goldsmithing techniques of the Nubian civilization. Similarly, local gems such as quartz, amazonite, ivory, mica, and malachite were used in many forms. There seems to have been an interest in lapis lazuli and carnelian beads, possibly influenced by the neighboring Egyptians. To the modern observer, the most outstanding jewelry pieces were created by glazing clear quartz. Faience, an ancient type of ceramic adopted from Egypt, was used to glaze quartz beads. In particular, they mastered the blue glazing technique, not only on beads but also on quartz sculptures and crystals. Quartz presumably held a deep religious significance for Nubians. These fascinating objects are beautifully photographed for the book and offer a visual delight.

It is fascinating to learn about the ancients’ degree of sophistication in creating imitation gems. Yet some of the descriptions of gemstones, minerals and rocks do not justify the detailed research of the subject. For example, the term “amethystine” is outdated, yet surprisingly used in this modern publication. A number of mineral and rock descriptions given in the glossary are inconsistent with modern mineralogical and gemological terminology. But given the significance of this subject, the nomenclature issues do not detract from the importance of this publication and the quality of the authors’ work. Jewels of Ancient Nubia deserves a place in any gemologist and jewelry historian’s library. Source: GIA @topic:9


Title: Burmese Star Peridot Abstract: Figure 1. The 20.13 ct star peridot (left) and the 7.67 ct peridot exhibiting weak asterism with more prominent chatoyancy (right), presumably due to cutting style. Photos by Bear Williams.
Asterism in peridot is a rare treat that has been reported on occasionally (S. Borg, “An unusual star peridot,” Journal of Gemmology, Vol. 17, No. 1, 1980, pp. 1–4; Summer 2009 Lab Notes, pp. 138–139). In January 2020, Tom Trozzo submitted to Stone Group Laboratories a 20.13 ct oval cabochon peridot (figure 1, left) that exhibited a soft yet prominent four-rayed star. Comparisons were made with an in-house lab sample that also exhibited reflection effects from tiny acicular inclusions. For purposes of this study, this comparison stone was recut to a 7.67 ct pear-shaped cabochon (figure 1, right) to enhance any potential asterism. However, the result appeared to be more of a cat’s-eye effect, presumably due to the prominent keel from the original faceted pear shape. It is presumed that, based on the arrangement and concentration of inclusions, a more prominent asterism will be revealed upon further cutting. Apparent clarity was good on both stones, but with a slightly diffused effect; no large eye-visible inclusions were present. While the asterism was more pronounced on the oval, the acicular inclusions were more plentiful and of higher relief in the pear-shaped stone. Both stones had a yellowish green color, with the oval exhibiting a very slight grayish modifier.

Figure 2. Brownish, acicular inclusions in the 20.13 ct star peridot (left, field of view 4 mm). Short, feathery, whitish needle-like inclusions in the 7.67 ct pear-shaped peridot (right, field of view 3.5 mm). Photomicrographs by Bear Williams.
Microscopic observation of the larger oval peridot revealed evenly distributed concentrations of extremely fine, short, brownish, acicular inclusions oriented in two directions (figure 2, left). In the pear shape, the needles were evenly dispersed throughout and oriented in three directions. The needles were also short and whitish to colorless (figure 2, right). Reflection effects in some materials may be difficult to define. There may be reflection effects from nonacicular inclusions, creating schiller as well as asterism. This was the case with the oval peridot, although asterism was clearly the dominant phenomenon.
The spot RI reading of approximately 1.65 and hydrostatic SG of 3.33 were consistent with peridot. The identification of both peridots was confirmed by Gemmo-Raman532-SG. Their provenance was reportedly Myanmar (Burma), and all tests were consistent with a Burmese origin. Interestingly, all known star peridots to date have been of Burmese origin. Although Pakistani peridot may often feature acicular inclusions of ludwigite, these are presumably protogenetic and not oriented consistently to the crystal structure of the host peridot. Source: GIA @topic:3


Title: Sunstone Plagioclase Feldspar from Ethiopia Abstract: Figure 1. Left: Forty-four Ethiopian rough sunstones exhibiting different colors and clarities. The largest stone weighs 54.41 ct. Right: Four Ethiopian rough sunstones ranging from 9.92 to 35.42 ct. All 48 rough stones were identified as labradorite by LA-ICP-MS, except for one spot as bytownite. Photos by Diego Sanchez (left) and Shunsuke Nagai (right).
Ethiopia, traditionally known for opal, has become an important source for emerald and sapphire. After these significant discoveries, a new type of Cu-bearing sunstone feldspar, first shown in 2015 to Tewodros Sintayehu (Orbit Ethiopia Plc.), was discovered in the Afar region (L. Kiefert et al., “Sunstone labradorite-bytownite from Ethiopia,” Journal of Gemmology, Vol. 36, No. 8, 2019, pp. 694–695). This material made its way to the jewelry market last year in Tucson.
To fully characterize this new production, GIA obtained 48 Ethiopian sunstones for scientific examination. Among them, 44 rough stones (figure 1, left) were borrowed from Stephen Challener (Angry Turtle Jewelry), who acquired them from an Ethiopian gem dealer in Tucson in February 2019. Another four rough stones (figure 1, right) were purchased by author YK from Amde Zewdalem (Ethiopian Opal and Minerals) and Benyam Mengistu, who facilitates mining and exporting samples from Ethiopia, at the Tokyo International Mineral Association show in June 2019. Prior to this discovery, the only verified occurrences of Cu-bearing feldspar were from Lake and Harney Counties in Oregon (e.g., the Dust Devil and Ponderosa mines). However, more than a decade ago there was a controversy about Cu-bearing feldspar on the market purportedly from Asia or Africa with an undetermined color origin, presumably Cu-diffused (G.R. Rossman, “The Chinese red feldspar controversy: Chronology of research through July 2009,” Spring 2011 G&G, pp. 16–30; A. Abduriyim et al., “Research on gem feldspar from the Shigatse region of Tibet,” Summer 2011 G&G, pp. 167–180). Gemological testing and advanced analytical methods helped distinguish this new Ethiopian material from the Oregon material and the controversial feldspar of questionable color origin mentioned above in order to ensure GIA’s accurate reporting of the natural origin of Cu-bearing feldspar.

Figure 2. Left: Clouds of copper platelets were observed in numerous Ethiopian sunstones. Field of view 3.13 mm. Center: Dense networks of reddish wispy dislocations were seen in some Ethiopian sunstones, along with a slightly greenish blue bodycolor. Field of view 2.72 mm. Right: Yellowish crystals of what are likely fayalite were seen in one Ethiopian feldspar. These inclusions have also been documented in Oregon sunstone. Field of view 2.82 mm. Photomicrographs by Nathan Renfro.
Two polished rough Ethiopian samples gave RI readings of nα = 1.562 and nγ = 1.571 and birefringence of 0.009. Optic signs were biaxial positive. Hydrostatic SG measurements were 2.70 and 2.72. These RI and SG ranges overlapped with Oregon sunstone (RI—nα = 1.560–1.570, nγ = 1.568–1.579; birefringence—0.006–0.012; SG—2.70–2.72) but were significantly higher than other Cu-bearing feldspars with undetermined natural or treated color origin (nα = 1.551–1.559, nγ = 1.559–1.566; birefringence—0.004–0.010; SG—2.68–2.69). A total of 18 Ethiopian sunstones were tested under a desktop UV lamp. Eleven showed very weak orange fluorescence, while seven were inert under long-wave UV. All showed very weak red fluorescence under short-wave UV. Under magnification, many showed dense clouds of reflective copper platelets, much like those observed in material from Oregon (figure 2, left). Some stones also showed an interesting wispy network of reddish dislocation stringers with a greenish blue bodycolor in transmitted light (figure 2, center). Another example revealed several yellow crystals of what appeared to be fayalite, an inclusion also observed in Oregon sunstone (figure 2, right).

Figure 3. Chemical comparison of Oregon and Ethiopian sunstone and Cu-bearing feldspar with undetermined color origin. Mg (A and C) is the key trace element that separates Ethiopian from Oregon sunstone. The unknown Cu-bearing feldspar has a much higher Cu and Sr concentration than other natural untreated sunstones (A, D, E, and F). For major elements, Ethiopian sunstone overlaps with Oregon sunstone, with a slight lower Ca concentration (B and D). The unknown Cu-bearing feldspar contains more Na and less Ca than other natural untreated sunstones (B, D, and F).

Figure 4. Illustration of solid solution in the feldspars, modified after Deer et al. (Rock-Forming Minerals, Volume 4: Framework Silicates, 1963). The nomenclature of the plagioclase series and the alkali feldspars is also shown. All 48 Ethiopian rough stones (yellow dots) were classified as labradorite except one bytownite. Forty-five Oregon sunstones (blue and green dots) were classified as labradorite-bytownite. Twenty Cu-bearing feldspars with undetermined color origin (red dots) were classified as andesine-labradorite. Ethiopian sunstones are less calcic than Oregon sunstones. Variation of refractive indices ng and specific gravity with composition of feldspars were plotted in the ternary plot as pink and blue straight lines, respectively. Note: nγ = gamma, the highest RI of a biaxial crystal, light vibrating parallel to the Z optical direction.
Laser ablation–inductively coupled plasma–mass spectrometry (LA-ICP-MS) was used to measure the chemistry of all 48 Ethiopian sunstones, 26 Dust Devil sunstones, 19 Ponderosa sunstones, and 20 Cu-bearing feldspars with undetermined color origin. NIST 610 and USGS GSD-1G and GSE-1G glasses were used as external standards. 29Si was used as an internal standard. Ponderosa and Dust Devil sunstones yielded an end member composition of Ab28–32An67–72 Or0.3–0.4 and Ab28–36An64–72Or0.3–0.8, respectively (table 1). They are classified as labradorite-bytownite using an albite-anorthite-orthoclase (Ab-An-Or) ternary diagram (figures 3B and 4, blue and green dots). Ethiopian sunstones yielded an end member composition of Ab30–39An60–70 Or0.4–1.4, which is generally similar but less calcic than Oregon sunstones (table 1). All analyses of Ethiopian material indicated classification as labradorite except one spot that gave bytownite (figure 3B and figure 4, yellow dots). The Cu-bearing feldspar with undetermined color origin yielded an end member composition of Ab46–51An46–51Or2–3 (table 1). They were classified as andesine-labradorite, distinct from the Oregon and Ethiopian material (figure 3B and figure 4, red dots). In addition to the differences with major elements Na, Ca, and K, the analyses revealed that the trace elements Mg, Cu, Ga, and Sr were the four best discriminators providing clear separations among Oregon and Ethiopian sunstone and Cu-bearing feldspar with undetermined color origin. All Ethiopian sunstone had a lower Mg concentration (261–686 ppmw, table 1) than Oregon sunstone (>810 ppmw, table 1) (figure 3A). The Cu-bearing feldspar with undetermined color origin had a higher Cu (>405 ppmw) and Sr (>1120 ppmw) concentration than Oregon and Ethiopian sunstone (figure 3, A, D, E, and F). Interestingly, Ponderosa samples (figure 3, C and E) had a lower Ga concentration (<14.0 ppmw) than the Ethiopian sunstone and Cu-bearing feldspar with undetermined color origin. A group of Dust Devil stones with higher Mg, Ga, and Sr concentrations were separated from all other sources in figures 3A and 3C, further differentiating them from Ponderosa stones.
Copper-bearing sunstones from different sources are visually indistinguishable from one another. Gemological properties are usually sufficient to separate Ethiopian and Oregon sunstones from these Cu-bearing feldspars with undetermined color origin. However, accurate major and trace element chemical analysis obtained by methods such as LA-ICP-MS, XRF (Ga and Sr were first identified as reliable discriminators for separating Ethiopian from Oregon sunstones using XRF by author GRR before this work), or electron microprobe is critical to separating Ethiopian, Oregon, and Cu-bearing feldspar with undetermined color origin. Source: GIA @topic:1


Title: Blue Amblygonite-Montebrasite from Rwanda Abstract: The newly discovered variety of amblygonite-montebrasite is unique for its blue color. It often has a mottled appearance with alternating blue and creamy white patches. The faceted stone weighs 0.83 ct. Photo by Lhapsin Nillapat.
Amblygonite-montebrasite, with the formula LiAlPO4(F,OH), is a fluorophosphate mineral series found in granitic pegmatites and pegmatite-related environments. The Pala district in California and the Black Hills in South Dakota are historic U.S. sources of amblygonite-montebrasite for industrial use, but most of the world’s well-known pegmatite districts have also produced considerable quantities of amblygonite-montebrasite.
A relatively common rock-forming mineral in these specific environments, the mineral is typically opaque and contains abundant fractures. Its color is often an unremarkable creamy white, causing it to blend in with associated feldspars. All of these factors limit its use as a gemstone. When used as a gem material, it is often colorless to yellow-green.
Geologists are interested in this mineral because of its high lithium content (up to 10%), which often suggests the presence of other (and easier to process) lithium minerals nearby. With increasing demand for lithium ores, exploration teams around the world are paying closer attention to amblygonite-montebrasite as an indicator of high lithium content in geological environments. This was the case in western Rwanda, an area known for its pegmatite-related tin deposits, where local geologists discovered an unusual variety of amblygonite-montebrasite in multiple pegmatites and sent it to mineral traders in Bangkok.
The new material (see above) differs from classic varieties in that its color is bright blue, sometimes associated with creamy white patches in a mottled pattern. All other characteristics match the known properties of amblygonite-montebrasite.
Confocal Raman spectroscopy showed a perfect match with amblygonite for several of the whitish and all of the bright blue patches. The position of certain peaks is related to the fluorine concentration in the mineral and can help to estimate the distribution between both end members (B. Rondeau et al., “A Raman investigation of the amblygonite-montebrasite series,” Canadian Mineralogist, Vol. 44, No. 5, 2006, pp. 1109–1117). The position of the peak around 1060 cm–1 was in the lower range (1052 cm–1 or lower), which points to a very fluorine-poor composition, near pure montebrasite. Raman spectroscopy performed at GIA’s Bangkok laboratory also revealed the presence of other minerals in the creamy white matrix. This included a mix of complex phosphates that share mineralogical and chemical similarities (e.g., berlinite, souzalite, and trolleite, confirmed by Raman spectroscopy) as well as feldspar. The only exception in terms of coloration consisted of small dark blue spots of the mineral scorzalite, with the formula (Fe2+,Mg)Al2(OH,PO4)2, a common secondary phase in complex, phosphate-rich pegmatites.
Despite advanced techniques indicating that this newly discovered variety, as well as the majority of previously documented gems, are closer to montebrasite (the OH-rich end member), the gemological community keeps referring to these materials as amblygonite. Amblygonite-montebrasite remains a rare gem that is unfamiliar to the general consumer. It requires considerable care due to its perfect cleavage and hardness of approximately 6, making it less suitable for daily wear. With this new addition to its color range, amblygonite-montebrasite might gain more recognition. Source: GIA @topic:2


Title: Spurrite Abstract: Figure 1. A 19.68 ct gray-purple spurrite that was submitted to GIA’s Carlsbad lab. Photo by Robison McMurtry.

Recently, a 19.68 ct gray-purple stone (figure 1) was submitted to the Carlsbad laboratory for identification. The square cabochon was semitranslucent and had wispy white features throughout.

Figure 2. Raman spectroscopy identified the gray-purple stone as spurrite.
It had a refractive index of 1.68–1.64 and a hydrostatic specific gravity of 3.00. Raman spectroscopy identified it as spurrite (figure 2), which aligned with the gemological properties already measured. Spurrite is a nesosilicate with a chemical composition of Ca5(SiO4)2CO3 (J.W. Anthony et al., Handbook of Mineralogy, Vol. 2, Mineral Data
Publishing, 1995). Analysis by energy-dispersive X-ray fluorescence (EDXRF) showed high amounts of calcium and silicon.

Figure 3. Magnetite, identified using Raman spectroscopy, breaks the surface of the spurrite. Photomicrograph by Nicole Ahline; field of view 4.79 mm.

Figure 4. Raman spectroscopy identified the inclusion in the spurrite as magnetite.
Spurrite occurs in high-temperature thermal metamorphism along the contact between carbonate rock and mafic magma (Anthony et al., 1995). A common inclusion found within spurrite is black metallic magnetite crystals. Raman spectroscopy identified the metallic opaque inclusions that broke the surface (figure 3) as magnetite (figure 4), further evidence that this stone was a spurrite.
Encountering stones that require more research and a little detective work, such as this spurrite, can enhance one’s curiosity about gemology. Source: GIA @topic:2


Title: Alexandrite Description Abstract: This 7.19-carat alexandrite was cut to feature its beautiful color change. When the light source changes from daylight to incandescent light, the gem’s color changes from bluish green to reddish purple.

                      Alexandrite, with its chameleon-like qualities, is a rare variety of the mineral chrysoberyl. Its color can be a lovely green in daylight or fluorescent light, changing to brownish or purplish red in the incandescent light from a lamp or candle flame. This is a result of the complex way the mineral absorbs light.

Alexandrite’s dramatic color change is sometimes described as “emerald by day, ruby by night.” Other gems also change color in response to a light-source change, but this gem’s transformation is so striking that the phenomenon itself is often called “the alexandrite effect.”

	Even in its rough form, this 70.94-carat alexandrite shows attractive color change.
Alexandrite is also a strongly pleochroic gem, which means it can show different colors when viewed from different directions. Typically, its three pleochroic colors are green, orange, and purple-red. However, the striking color change doesn’t arise from the gem’s pleochroism, but rather from the mineral’s unusual light-absorbing properties.

Because of its scarcity, especially in larger sizes, alexandrite is a relatively expensive member of the chrysoberyl family. It shares its status as a June birthstone with cultured pearl and moonstone. Source: GIA @topic:3


Title: Sunstone Description Abstract: A graceful carving displays this Oregon sunstone’s bright, reflective copper inclusions, its intense color, and its pleochroism. – Robert Weldon, courtesy Oregon Sunstone

                      Gem connoisseurs and innovative jewelry designers often seek the subtle beauty of lesser-known—but still intriguing and unique—gemstones. Some of those are members of the feldspar group.

The feldspar group’s wide variety of unusual gems includes moonstone, non-phenomenal orthoclase, phenomenal and non-phenomenal labradorite, sunstone, and amazonite. Of these feldspars, moonstone is a constant favorite, while sunstone from Oregon is gaining attention as a natural and untreated product of the United States.

Although sunstone and moonstone are both members of the feldspar group, the resemblance stops there. While cool moonstone’s phenomenal varieties offer a soft and gentle adularescent glow, warm sunstone’s phenomenal varieties show a distinct and lively glitter called aventurescence.  Aventurescence is a sparkly, metallic-looking luster caused by flat, reflective inclusions, sometimes called “schiller” by sunstone fanciers.

	Copper inclusions create a schiller effect in this Oregon sunstone from the Ponderosa Mine. – Eric Welch, courtesy Desert Sun Mining & Gem Co., Inc.
The feldspar group has many members. Some are suitable for jewelry use, some aren’t. Members of the feldspar group vary slightly in chemical composition, and those variations produce a variety of gemstones that differ widely in appearance.

There are two main branches of the feldspar family tree—feldspars that contain potassium and feldspars that contain a mixture of calcium and sodium.

Two species of feldspars contain potassium. These are orthoclase, which includes the gem varieties moonstone and orthoclase sunstone; and microcline, which includes the gem variety amazonite. A non-phenomenal form of orthoclase feldspar appears in jewelry on rare occasions. Sometimes faceted, its hue is usually a transparent yellow.

Plagioclase feldspars contain a mixture of calcium and sodium, and they have slightly different compositions. The gem species in this feldspar family include labradorite and oligoclase.

	Rough Oregon sunstones display a variety of colors in a range of tones from light to dark. – Valerie Power, courtesy Desert Sun Mining & Gem Co., Inc.
Not all feldspars that bear the name “sunstone” are from the same side of the feldspar family—both the orthoclase and the plagioclase species boast a sunstone feldspar variety. The name sunstone refers to the gem’s appearance rather than to its chemical makeup.

There are many sunstone varieties. If aventurescence is present, gemologists call it aventurine feldspar. The aventurine feldspar from India has a red-brown bodycolor and sunny glitter. It’s perhaps the best-known sunstone variety, but that situation has been changing.

	The 2.39-ct. aventurescent sunstone (right) is from the state of Tamil Nadu, in southern India. It’s accompanied by a cat’s-eye moonstone from the same area (left). – Shane F. McClure

	Tiny platelets in this photomicrograph are responsible for the sunstone’s aventurescence.
The US state of Oregon produces a number of sunstone varieties. The increasing supply from the area has made sunstone more available to the general public. Because many of the sunstone types are unique to the rugged high-desert area in South Central Oregon, they’re being marketed as “all-American” gemstones.

	This Oregon sunstone (about 2 cm across) has been fashioned with some matte-finished facets to bring out the appearance of the copper inclusions. – Maha Tannous, courtesy Klaus Schafer
Although most sunstones have yellow, orange, or brown bodycolor, not all sunstones are aventurescent. The appearance of the phenomenon depends upon the size of the inclusions. Small inclusions create a reddish or golden sheen on top of any bodycolor. Larger inclusions create attractive, glittery reflections. Sunstone inclusions can be hematite, copper, or some other mineral.

	The color of these rough and fashioned sunstones is influenced by their inclusions. – Robert Weldon, courtesy Becky Booker

	A suite of gem-quality sunstones from the Ponderosa mine in the US state of Oregon
	shows the range of colors found in that area. – Tino Hammid
In the early 2000s, a material marketed as Tibetan sunstone or Tibetan andesine generated an ongoing controversy. Experts from several gemological laboratories examined the stones, visited the areas said to be their sources, and investigated recently developed gem treatment processes. Their findings indicated that the material might have been pale andesine from Mongolia that had been treated by infusion with copper to give it lively coloring.

	These attractive gems are part of an ongoing controversy. They were represented as untreated plagioclase sunstone from Tibet. – Robert Weldon, courtesy Do Win Development Co. Ltd. Source: GIA @topic:1


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. Source: GIA @topic:13


Title: Robert Weldon Receives Bonanno Award Abstract: G&G contributor Robert Weldon received the 2020 Bonanno Award for Excellence in Gemology.
Longtime Gems & Gemology  author and photographer Robert Weldon (see above) has received the Accredited Gemologists Association’s 2020 Antonio C. Bonanno Award for Excellence in Gemology. The award was presented during AGA’s annual gala in Tucson on February 5.
During his more than 30-year career, Weldon has contributed scores of publications, serving as colored gemstone editor at JCK and senior writer at Professional Jeweler. His photography has appeared on more than 30 G&G  covers, and he has written numerous feature articles for the journal. He coauthored, with Dona Dirlam, Splendour & Science of Pearls (2013). Since 2017, Weldon has been director of GIA’s Richard T. Liddicoat Gemological Library and Information Center. In recent years he has also been closely involved in providing gemological training to independent African miners. Source: GIA @topic:7


Title: Soweto Jeweler is a Symbol of Hope for South Africa Abstract: Nkosi at his studio in Soweto, South Africa. Photo by Robert Weldon, © GIA 2012

Robert Weldon, manager of photography and visual communications for GIA, met Nqobile Nkosi on a trip to South Africa in 2012. Nkosi is a self-made jeweler from Soweto, South Africa, who is hoping to create jobs and opportunities in his township.

	Soweto’s first home-grown jeweler has set his goals high and his aspirations even higher.

	Nqobile Nkosi, who is a jewelry designer, manufacturer and retailer, embodies the spirit of entrepreneurship that is characteristic of the new South Africa.

	His story focuses as much on jewelry education and innovation as it does on the dismantling of social barriers. It is the story of a man who simply does not recognize impediments, be they financial or social. Instead, his vision is clear: to build a business, create new jewelry, disseminate his ideas globally through cooperation and friendships, and most importantly, to create jobs locally.

	Soweto, southwest of Johannesburg, was formed at the intersection of repression, activism – and now – hope. Home to an agglomeration of townships that coalesced in 1961 as a sprawling suburb of South Africa’s capital, its population of more than one million includes many African miners who toil daily in the nearby gold and diamond mines.

	Soweto, site of the now-famous uprising that eventually helped bring an end to the apartheid system, was also home to Nelson Mandela and other leaders of the anti-apartheid movement. Though enormously underdeveloped still, entrepreneurship and business creation is on the rise, and Soweto is slowly emerging as the country’s breathing symbol of hope and freedom.

	“Everyone can rise above their circumstances and achieve success if they are dedicated to and passionate about what they do,” Mandela has said.

	Nkosi has translated those words into action.

Cakes, Biscuits, and a Window

	Nqobile Nkosi, like hundreds of thousands of South Africans in 2004, found himself at a crossroads.

	“I was unemployed, at home, and it came to a point where I really had to do something with my life,” he said. A friend suggested taking courses at the Soweto Jewellery Training School, which Nkosi immediately pursued.

	“Some months before the training ended, I started selling cakes and biscuits at school to make ends meet and to be able purchase my first polishing motor and ultrasonic cleaner. I made small space in my bedroom for a torch and a small bench,” he said. “I was a one-man-band jeweler.”

	As improbable as it might seem for a jeweler to set up shop in the township, Nkosi said there was no shortage of business, even before his studies were concluded.

	The requests came steadily: “Could you please size this ring for me?” “Could you polish this, or do that?”

	Nkosi seized the opportunities as they arose. Talking with people, being introduced to the trade, and being able to contribute to his community was a turning point for Nkosi. “It is really all about what you want to achieve. For me, the jewelry business was different. It opened a new window in my life and I just wanted to go further with the experience.”

		This Cornerstone design, left, called a “vuvuzela,” or a fanfare, is used in stadiums to make noise while rooting for a favorite soccer team. South Africa hosted the 2010 FIFA World Cup in soccer. The Silver Flame ring, right, is set with citrine. Photos courtesy of Cornerstone.

		Success followed, and he began to earn local awards and recognition: a South African Breweries Kickstart Award (a cash prize given to young entrepreneurs), a Jet Community Award and a nomination as a Gauteng local business leader. Other forms of recognition followed as well.

	He invested all of his cash prizes in the business, making it possible for it to grow and for him to be able to hire additional people.

	“For me, success isn’t driving a new car,” Nkosi said. “I see success as being able to move this business from one generation to the next.”

	Nkosi’s studio is small and bursting at the seams. As he reaches towards an international audience for his jewelry, Nkosi’s space considerations, tools, security and further training for his workers become his principal focus. Photo by Robert Weldon, © GIA 2012.

Growth and Future

	Nkosi established a new company, NQ Jewellery, in 2007, and its success soon required additional support. “My brother came to help out, and soon I was training yet another colleague,” he said. “Now we have six people working for the studio.”

	The main challenge he now faces is logistical: he needs a new space in which to grow and needs training for his workers.

	Nkosi has also begun to establish connections internationally. Award-winning U.K. jeweler Paul Spurgeon met Nkosi on a business trip to South Africa and the two became immediate friends and business partners. Together they formed a separate international company called Cornerstone, and soon thereafter Nkosi traveled to Birmingham, U.K. to train at Spurgeon’s manufacturing facilities. The plans are for additional workers at Nkosi’s studio to do the same in coming years.

	This design features a Pagoda pendant with oxidized chain detail. Paul Spurgeon, an award-winning designer based in the UK, is business partner with Nkosi in a separate company called Cornerstone. Photo courtesy of Cornerstone.

	Spurgeon wrote about his partnership with Nkosi in the UK-based trade magazine Professional Jeweller: “My personal commitment to Cornerstone is based on my desire to help provide skills and jobs to a people that have so often been marginalized and forgotten, in a continent that has given us in the trade all the materials needed.”

	The Cornerstone collaborative project and jewelry brand launched their first products at the Springfare trade show in Birmingham, and a new international line of products was shown to GIA when we visited Nkosi in Soweto in late 2012.

	Spurgeon’s and Nkosi’s Cornerstone initiative has gathered steam in the U.K. community as well: In February, 2012, Spurgeon organized a sponsored bike ride from Goldsmiths’ Centre in London, to Paris. Weston Beamor, a precious metals casting house in Birmingham, offered free casting services to the group so the first international collection could be launched.

	Nkosi poses with the team at Weston Beamor, a precious metal casting house located in Birmingham, UK. Photo courtesy of Cornerstone.

	Nkosi is ready to launch his full collection of South African-inspired motifs in 2013. “Our products aim to have a unique African look, but with a European appeal,” he said. “This is the launch of a brand.”

	Nkosi met with GIA’s late Vice President of International Operations, Tawfic Farah, as well as a few members of GIA’s Board of Governors, in 2013. GIA provided Nkosi with an AJP education scholarship, which he completed soon after and has taken on the role of president for GIA’s Alumni Africa chapter.

	Nqobile Nkosi, the first designer and jeweler from Soweto is clearly not looking back. He is joining the international community of jewelers, with an eye towards furthering his and his team’s education – and creating much-needed jobs at home. Source: GIA @topic:10


Title: Color-Change Pink Pyrope Garnet Update Abstract: This 20.00 ct oval color-change pyrope garnet was cut by Victor Tuzlukov. Photo by Kevin Schumacher, courtesy of Jewels from the Woods.

Jewels from the Woods (Blanco, Texas) displayed color-change pink pyrope garnets (see above) at the AGTA show. Their color changes from purple in daylight-equivalent light to pink in incandescent light. This was the first time there had been such a large selection of the stones at AGTA, according to independent gem cutter Desmond Chan, who was assisting Jewels from the Woods. He said the material had been very well received.

	Desmond Chan tells us about the color-change pink pyrope garnets.

The stone had been slow to come onto the market, Chan said, because not much rough was available, and the deposit—believed to be in Morogoro, Tanzania—has been depleted. The garnets are said to have been mined in 1988. Initially assumed to be rhodolite, they were put in a safe deposit box until 2014, when they were acquired by cutters Meg Berry, Todd Wacks, and Jason Doubrava. Wacks (Tucson Todd’s Gems, Tucson and Vista, California) was the first to detect the color change, and he introduced the garnets in 2015 at the Riverpark Inn (Pueblo) show (Spring 2015 GNI, pp. 88–89). GIA performed a gemological study of the material (Z. Sun et al., “Vanadium- and chromium-bearing pink pyrope garnet,” Winter 2015 G&G, pp. 348–369). One interesting finding was that two of the larger stones had the strongest color change.
Garnets have been “on fire” the last four or five years, according to Doubrava (Jason Doubrava Gems & Minerals, Poway, California). He said the public is more aware of garnets and more appreciative of their varied colors than in the past. “These just absolutely glow,” he said of the color-change pink pyrope garnets at the booth.

	Jason Doubrava shares his experience with the garnets. Source: GIA @topic:3


Title: Milestones of 2014, Exciting Announcements for 2015 Abstract: View Gallery

The new year brings a time of reflection and anticipation for the future. As we all emerge from the blur of year-end, the alumni office is pleased to report that 2014 was a stellar year of milestones and highlights. It is impossible to summarize all of the accomplishments of our committed alumni around the world ‒ or the effect of their outreach as ambassadors supporting GIA’s mission ‒ but I’ve outlined a few below. Please take some time to view photos of alumni events in the gallery above.

The Numbers

The active number of GIA Alumni members reached 100,000 and continues to grow!
More than 25,000 members are listed in our Alumni Online Directory.
The GIA Alumni Association has 71 chapters on 5 continents.
More than 175 Alumni Events offering continuing education and networking opportunities worldwide were held.
GIA connected with our alums at nearly 100 tradeshows in 2014.
Nearly 1,500 members took a moment in 2014 to manage their Alumni Membership and let GIA know the alumni benefits that are most important to them.

Tribute

Susan Jacques was appointed GIA president and CEO on Jan. 1, 2014, the sixth leader in GIA’s 83-year history. Susan is a GG from the Santa Monica campus class of 1980 and proof positive that hard work, ethics and staying connected to GIA is a benefit for our alumni.
Robert “Bob” Earnest, who advocated for a GIA Alumni Association and was its first executive director, passed away in December. Learn more about his special relationship with GIA alumni.

Bob Earnest, left, with Richard T. Liddicoat’s support helped establish the GIA Alumni Association in 1982.
In Review
Here are some of the chapter news and events from 2014:

Travel excursions and alumni tours to China, Germany, the Gulf of Mexico, Malaysia, Burma, Taiwan and U.S. tradeshows were planned by various chapters.
Chapters continue to expand their collaborations and co-host events across the globe, including Shanghai and Taiwan; Africa’s Johannesburg, Cape Town and Botswana chapters; Hong Kong and mainland China; Malaysia and multiple southeast Asia chapters; Houston and North Texas; and southern California chapters in San Diego, Orange County and Los Angeles.
New York classmates organized a 40th reunion for the 1974 Graduate Gemologist class.

Top chapter meeting topics:

Technical instrumentation and hands-on events
Jewelry history, museum tours and visits to lapidary and diamond cutting houses
Gemstone buying, excursions and collecting from industry experts
Research news on treatments and synthetic diamonds and colored gems
Security, law enforcement seminars and understanding UL & Trade commission rulings
Mentorship from experienced alumni graduates for students and grads seeking refreshers

Looking Ahead in 2015
We’re excited to share a bright launch to 2015:
GIA Events

Tucson’s gem, mineral and jewelry fairs are quickly approaching Feb. 2-15. GIA’s presence and activities are extensive, but the Party at the GIA Gem Mine: Rocking Down Under is the most fun you’ll have. The annual dinner, dance and auction is really a large reunion party, where more than 250 alumni, students and industry friends gather to celebrate. We hope to see you there!

Please note: Jan. 15 is the deadline to purchase tickets early and save. It is also the deadline to submit auction items, with guaranteed donor recognition online and in print

Gemfest Basel is scheduled for March 22; global alums and industry members are invited to an afternoon of education followed by a reception.

Make Travel Plans

The Malaysia chapter is planning an international gathering for alumni in late August in conjunction with the Malaysia International Jewelry Fair, held Aug. 21-24, and all global alumni are invited to participate.

In closing, I would like to applaud all of our members around the globe for their support and attendance at alumni events and for following their commitment to educate and professionalize the industry. I most especially want to thank the dedicated chapter leaders who plan and execute these events to build camaraderie among industry professionals. Thank you.

Personally, I welcome 2015 and look forward to the advancements and opportunities that are sure to come! Source: GIA @topic:11


Title: Romancing the Source: Myanmar Abstract: Myanmar

	Mogok, Myanmar, is perhaps the world’s most exotic and romantic gem-producing area.

	This series of articles and videos follows a team of GIA Field Gemologists on their travels from the mountains of Afghanistan to the jungles of Sri Lanka in search of the sources of colored gemstones and the people who pursue them. This thrilling journey will take you to remote gemstone-mining areas, where you’ll witness the extreme effort required to wrestle nature’s treasures from the earth.

Mogok, Myanmar, also known as The Valley of Rubies, is perhaps one of the world’s most exotic locations. Photo by Andrew Lucas/GIA.

	The romance of a colored gemstone arises from its beauty, the exotic qualities of its source’s location, the adventure leading to its discovery, and the stories of the people who seek it. These factors have united to create the allure of gemstones through the ages, and continue to do so even in modern times.

	Mogok, Myanmar, has become as famous as the magnificent rubies, sapphires, spinels, and other gems it produces. It is an amazing area, dotted with pagodas, temples, Buddha statues, and outcroppings of marble rock.

	The people are as exotic as the location, blending populations of Burmese, Shan, Lissu, Karen, and former British Nepalese troops called Ghurkas. Most exotic of all are the Kanase women. By tradition, these women have the right to mine the tailings of mining operations in search of gemstones, surrounded by what often appears to be a sea of white marble. They wear traditional painted or cone-shaped hats and decorate their faces with a white paste.

	Mogok miners engage in all types of colored gemstone mining, and the local gem markets are as colorful as the miners. Source: GIA @topic:7


Title: Cuprian Liddicoatite Tourmaline Abstract: Six of the 13 cuprian liddicoatite tourmalines from this study. The faceted stones weigh 1.59–9.63 ct (average 3.95 ct). They are transparent and have greenish blue, green-blue, and green colors. Photos by Masumi Saito.

	This peer-reviewed article by two GIA research scientists, Yusuke Katsurada and Ziyin Sun, reports on copper-bearing tourmaline that belongs to the liddicoatite species. It is provided here as a PDF download and will be part of Gems & Gemology’s print and online Spring 2017 issue.

	Cuprian tourmaline with vivid blue, green, and violet colors, known as “Paraíba” or “Paraíba-type” tourmaline in the trade, was first discovered in 1989. Until now, nearly all of this material has been classified as the elbaite species of tourmaline. In this article, Katsurada and Sun report on 13 samples that were submitted to GIA’s Tokyo lab by several different clients in 2016. The stones’ geographic origin is unknown.

	The samples’ gemological properties and copper and manganese concentrations were consistent with copper-bearing elbaite. Liddicoatite is separated from elbaite only by quantitative chemical analysis—in this case, laser ablation–inductively coupled plasma–mass spectrometry (LA-ICP-MS). When compared against 26 other cuprian tourmalines, the new material showed stronger fluorescence under long-wave UV light; this may be caused by a high concentration of rare earth elements. The 13 samples were further classified as calcic-group tourmaline, as opposed to the alkali-group classification of the 26 stones used for comparison.

	This material may have already entered the gem market as “Paraíba” or “Paraíba-type” tourmaline. Further analysis is required to identify geologic origin and growth conditions. Source: GIA @topic:12


Title: A Sapphire with a Negative Crystal Containing a Mobile Graphite Daughter Crystal Abstract: This opaque hexagonal daughter crystal, of what is likely graphite, moves within the large negative crystal in the metamorphic star sapphire. Photomicrographs by Makoto Miura; field of view 4.0 mm.
Mineral and fluid phases within negative crystals in metamorphic sapphires provide us with general information on the sapphire and the trapped fluid itself. Such inclusions indicate a stone has not been heated when intact negative crystals are observed containing carbon dioxide (e.g., Fall 1986 Lab Notes, pp. 152–155). The author recently had an opportunity to identify a natural star sapphire containing a unique daughter crystal phase within a negative crystal.
This stone, which measured 22.20 × 18.00 × 14.05 mm with an estimated weight of 62 ct, was set in a ring. It displayed a six-rayed asterism due to light reflection from numerous long intersecting needles. Gemological observation and properties confirmed that this stone was a natural sapphire. The presence of unaltered mineral crystals and the chromophore cannibalization pattern around dense clouds of needles indicated the stone had not been heat treated (J.I. Koivula, “Internal diffusion,” Journal of Gemmology, Vol. 20, No. 7/8, 1987, pp. 474–477). Notably, this stone had one large negative crystal containing an opaque hexagonal crystal (see above). The hexagonal daughter crystal was free to move within the negative crystal when the stone was rocked and tilted. Careful infrared spectroscopic measurements suggested that this negative crystal was mainly filled with water and CO2 based on water-related peaks at 3706 and 3605 cm–1 and a large CO2 broad band at 2340 cm–1. However, the opaque daughter crystal was not identified by Raman spectroscopy because the negative crystal containing this daughter phase was located in a deeper section of the stone. Its hexagonal crystal shape and appearance suggested that the mobile hexagonal daughter crystal was graphite, which has been previously documented (E.J. Gübelin and J.I. Koivula, Photoatlas of Inclusions in Gemstones, Vol. 3, Opinio Verlag, Basel, Switzerland, 2008, p. 268). This is the first example of a negative crystal with a mobile solid phase in corundum that the author has encountered. Source: GIA @topic:3


Title: Dyed and Natural Green Jadeite Abstract: Figure 1. Left: In natural light, the green band in the lower right section of the jadeite specimen is caused by natural chromium, while the other green spots are the result of a dye treatment. Right: Long-wave UV light shows a strong fluorescence from the dyed areas, with little to no fluorescence from the natural green area. Photo by Robison McMurtry.

The most coveted jadeite stones possess a deep rich green color. Lower-quality jadeite specimens are often treated with acid bleaching, polymer impregnation, and dyes to obtain this sought-after hue (E. Fritsch et al., “Identification of bleached and polymer-impregnated jadeite,” Fall 1992 G&G, pp. 176–187). It is quite unusual to see stones with even a small amount of natural green color further altered with dyes. When this does happen, the natural properties of the untreated area can make it especially challenging to properly identify the stone as dyed.

Recently, the Carlsbad laboratory examined a carved jadeite specimen (figure 1). Standard gemological testing and Raman spectroscopy confirmed that the specimen was jadeite; infrared spectroscopy indicated the specimen had been polymer impregnated. Observation with a desktop spectroscope revealed lines at 630 and 655 nm, which are associated with chromium impurities in naturally colored green jadeite. Observation under long-wave UV light revealed strong green-yellow fluorescence from most green areas of the stone, but not from the area where Cr lines were seen in the spectroscope. The colorless portions of the stone were also inert to UV light. Strong fluorescence in jadeite is often indicative of either polymer impregnation or a dye treatment; however, fluorescence from polymers would be evenly distributed throughout the stone due to the nature of impregnation. The fact that this stone only fluoresced from the green areas was strong evidence of dyeing rather than impregnation.

Figure 2. Left: A close-up of the natural green area shows a smooth, diffused color texture. Photomicrograph by Jonathan Muyal; field of view 7.19 mm. Right: A close-up of a dyed area shows color concentrations in the thin gaps between the crystal grains of jadeite. Photomicrograph by Jonathan Muyal; field of view 3.57 mm.
Microscopic observation (figure 2) revealed concentrations of green color in the boundary gaps in between grains, typical of dyed jadeite. The green area without fluorescence possessed a smoother, more consistent green color, which is customary for natural jadeite. Absorption spectroscopy in the UV, visible, and near-IR range confirmed that the natural area contained an absorption band from 530 to 740 nm, punctuated by natural chromium peaks at 691 and 655 nm (figure 3). The dyed green areas contained a double band around 627 and 665 nm, which is typical of dyed green jadeite.

Figure 3. UV-Vis-NIR spectra of the jadeite in the 250–850 nm range showed chromium
lines at 655 and 691 nm in the natural green area and double broad bands around 627
and 665 nm in the dyed green area.
The proper treatment identification of jadeite is essential to the consumer’s confidence in this stone. Testing only a portion of this material might convince an observer that no dye had been applied. One must always expect the unexpected when attempting to determine treatments in any gemstone. Source: GIA @topic:13


Title: Three Faceted Collector Specimens Abstract: Left to right: 0.60 ct golden yellow wagnerite, 1.72 ct colorless thaumasite, and 1.41 ct pale yellow strontianite. Photo by Robison McMurtry.

	Three stones recently submitted to GIA (see above) were found to be rare mineral species that had not previously been examined at the Carlsbad laboratory. Standard gemological testing and Raman analysis identified these specimens as wagnerite, thaumasite, and strontianite.

	A 0.60 ct transparent golden yellow pear brilliant cut with vitreous luster was identified as the phosphate monoclinic crystal wagnerite, (Mg,Fe2+)2(PO4)F. Though uncommon, wagnerite occurs in various geologic settings, such as granitic pegmatites, gneisses, eclogites, and hydrothermal environments (P. Korbel and M. Novak, The Complete Mineral Encyclopedia, Gramercy, Lisse, the Netherlands, 2003). It had a specific gravity (SG) of 3.15, a refractive index (RI) of 1.568–1.580, and a biaxial positive optic nature. Wagnerite is a relatively soft and brittle mineral with a Mohs hardness of 5.0–5.5. The stone was inert under both long-wave and short-wave UV radiation. Multiphase fluid inclusions, fingerprints, graining, and color zoning features were observed with magnification.

	The largest stone, a 1.72 ct transparent colorless octagonal step cut, had a relatively low SG of 1.90, an RI of 1.470–1.515, and a biaxial negative optic nature. It was inert to long-wave and short-wave UV. These properties, along with Raman testing, led to its identification as thaumasite, a silicate mineral with the chemical formula Ca3(SO4)[Si(OH)6](CO3)·12H2O belonging to the hexagonal crystal system. Magnification revealed strong doubling, spectacular radiating fibrous inclusions, reflective films, tiny crystal inclusions, and strong hexagonal angular graining. Thaumasite has a vitreous luster and a brittle nature due to its low hardness of 3.5 on the Mohs scale. Thaumasite occurs in geothermal waters or seawaters reacting with basalt and tuffs, or in areas of contact metamorphism (J.W. Anthony et al., Handbook of Mineralogy: Volume II: Silica, Silicates: Part 2, Mineral Data Publishing, Tucson, Arizona, 1995, p. 790).

	The last stone we observed was a transparent pale yellow octagonal step cut with vitreous luster. It proved to be strontianite, SrCO3, an orthorhombic carbonate mineral member of the aragonite group with a Mohs hardness of 3.5. The 1.41 ct specimen was highly birefringent, with an RI of 1.511–1.661, an SG of 3.76, and a biaxial negative optic nature. It fluoresced red under long-wave UV but displayed a weak whitish reaction under short-wave UV. The stone exhibited strong doubling and fluid inclusions under magnification. Raman spectroscopy confirmed its identity. Strontianite occurs together with calcite and zeolites in hydrothermal, low-temperature veins and in cavities of volcanic rocks (Korbel and Novak, 2003).

	Wagnerite, thaumasite, and strontianite are rarely seen as faceted gems due to their softness and brittleness. These collector specimens were the first of their kind to be submitted to GIA’s Carlsbad laboratory for testing. Although challenging to identify without advanced testing techniques, they bring excitement to gemologists searching for unusual faceted gems. Source: GIA @topic:2


Title: Enormous Cat’s-Eye Aquamarine Abstract: Figure 1. Left: A 586.43 ct cat’s-eye aquamarine donated by Gary Bowersox and Kathleen Kolt-Bowersox to the Smithsonian National Museum of Natural History gem collection. Photo by Robert Weldon; courtesy of the Smithsonian National Museum of Natural History. Right: Dr. Jeffrey Post (left) and Gary Bowersox with the cat’s-eye aquamarine. Photo by Kathleen Kolt-Bowersox.
On the AGTA show’s opening day, we were on hand as Gary Bowersox and Kathleen Kolt-Bowersox donated an extraordinary cat’s-eye aquamarine to Dr. Jeffrey Post, mineralogist and curator-in-charge of gems and minerals at the Smithsonian National Museum of Natural History (figure 1).

Figure 2. Left: Kathleen Kolt-Bowersox holding the 7,700 ct aquamarine rough before it was cut. Right: The rough aquamarine was cut and polished in Sri Lanka by Rohitha Perera. Photos by Gary Bowersox.
The 586.43 ct untreated transparent light greenish blue aquamarine with a sharp cat’s-eye is from the Pech Valley pegmatite mine in Afghanistan. The rough (figure 2, left) weighed approximately 7,700 ct and was kept for 15 years before it was finally cut in 2017 by Rohitha Perera in Sri Lanka (figure 2, right). The Bowersoxes have several other cut gems from this find, with the next largest weighing in at 541.96 ct. Source: GIA @topic:1


Title: Agate Inclusion in Quartz from Brazil Abstract: Two faceted quartz with agate inclusions from Brazil, weighing 66.61 ct and 12.28 ct (shown in two positions and in short-wave UV). Photos by Jaroslav Hyršl.
Agates are undoubtedly one of the most common precious stones from Brazil. They come from basalts in the state of Rio Grande do Sul, on the border with Uruguay. This region is probably also the source of several unusual faceted quartz samples, purchased by the author in Brazil in 2019. These stones are up to 35 mm long and, except for abundant two-phase inclusions, contain flat, irregularly shaped inclusions. On two stones (see above), these inclusions reach the surface and show a typical agate structure, with several black, gray, and light brown layers. Their identity was proved by very weak quartz peaks in the Raman spectrum. Unexpected was their strong fluorescence in UV light, which is much stronger in short-wave UV. This fluorescence is concentrated in gray layers and is very likely caused by a trace presence of uranium, quite common in many agates and opals. Source: GIA @topic:2


Title: The Spirit of Jadeite Carving Abstract: The classic jadeite cut is the cabochon. Some high-quality cabochons are worth a fortune. Photo by Eric Welch, ©GIA, courtesy of Mazu Jade Articleco., LTD

                      Jade is often considered synonymous with China. The country’s worship and appreciation of jade can be tracked back about 8,000 years. Nephrite dominated the jade trade until jadeite was first imported into China from across the border with Myanmar. Exactly when this happened is still very debatable, but most people agree that it was not later than the Ming Dynasty (around 1475).

For a long time, jadeite was traded mainly out of the palace. When the Empress Dowager Cixi ruled China at the end of the Qing Dynasty (1861 to 1908), she started to collect high-quality jadeite from all over the country to satisfy her own desires. This trend also swept over the whole royal family and the upper social class. By 1908, jadeite was already the most expensive jade sold in Beijing’s most famous antique market, Liu Li Chang. Jadeite and nephrite have shared high market status ever since.

	Three-dimensional jadeite carving: Shan Zi
It’s well known that jadeite can be shaped into different jewelry styles such as bracelets, rings, cabochons, and more, but China’s cutters also process this material into larger-scale decorations. These decorations are called “Shan Zi” in Chinese. “Shan” means hills or mountains, indicating that the jadeite was carved to preserve its original outline and shape. Compared to other methods, Shan Zi is probably the most natural way to process jadeite rough, but it is also the most expensive and time-consuming process.

There are also other ways to fashion jadeite. For example, some people slice jadeite rough into thin plates and then create cameos on the surface. This produces more-finished products from the same amount of material and can increase transparency as well.

Small pendants, decorations, and bracelets are typical products for the jadeite market. Photo by Eric Welch, ©GIA, courtesy of Mazu Jade Articleco., LTD
Carvers need relatively large materials with ideal outlines for carving Shan Zi. The rough was hard to find and transport, and multiple carvers had to work together for long periods of time to design and carve an individual piece. In the past, only the royal family or extremely rich people could afford Shan Zi, especially the largest carvings. The result is that, along with its use as decoration, Shan Zi is also a symbol of wealth and power.

This is a typical jadeite Shan Zi. The piece preserved the original shape and outline of the rough. A Shan Zi is usually carved in three dimensions. Its large size is impressive, even when viewed from a distance. Photo by Eric Welch, ©GIA, courtesy of Mazu Jade Articleco., LTD
Common Shan Zi themes include scenic views, plant life, traditional symbols, ancient famous paintings, and more. The choice of theme depends entirely on the shape and outline, and sometimes the color, of the rough material. The planning process and tools needed for 3-D carving originated with the carving of nephrite, as did theme selection.

High-quality jadeite is used to make 3-D carvings. When examined closely, this carving displays some precise details of individual characters. Photo by Eric Welch, ©GIA, Courtesy of Mazu Jade Articleco., LTD

	Acquiring the material
In June 2013, a group of GIA staff members visited one of southern China’s jadeite hubs. In Sihui, the authors were introduced to Mr. Zheng, the president of Mazu Jade Articleco., Ltd., and his close friend Mr. Fang, the president of Jingyu Mantang jadeite carving workshop. These two gentlemen warmly welcomed us and hosted our visit and showed us one of their ongoing carving projects.

They obtained the jadeite they were working on in 2004, at a public auction in Myanmar. It was separated from an even bigger jadeite boulder. They were not able to get the other half, which remained in Myanmar. The boulder they brought back weighed about eight tons, and they cut it into two pieces. One is now being carved to make a huge jadeite Shan Zi. The other part was further divided into three pieces to be carved into the three Chinese gods: Fu, Lu, and Shou.

Workers designed a special platform for this Shan Zi. The platform allows three carvers to work on the same side at the same time. The pencil sketch and some carving work have been completed. Photo by Eric Welch, ©GIA, Courtesy of Jingyu Mantang Jadeite workshop
When they purchased the rough, it had dark skin and a small window. When they brought it back and cut it open, they knew that they had won the auction gamble. The entire piece is full of purple and green colors. They built a special working platform to accommodate the three-ton segment along with the carvers. It will be carved into a jadeite Shan Zi. Mr. Fang told us that, to their knowledge, this is probably the largest jadeite Shan Zi in Asia.

Mr. Fang also pointed out that they would have profited more if they had used this material to make bangles, since bangles with full green or purple colors are usually worth several million RMB each. They could have produced a large number of bangles from this giant piece of rough. The reason they decided to make it into a Shan Zi was that, as an artist, Mr. Fang had always dreamed of finishing a masterpiece in his lifetime and both gentlemen sensed that this might be the opportunity to do it.

	Inspiration and theme selection
Mr. Fang is the chief designer of the piece. Working along with two other designers and six highly skilled carvers, it will probably take about five to six years to finish.

When asked about his design inspiration, Mr. Fang became very excited. This rough sat in the workshop from 2004 to 2010 because he could not find a suitable theme to base its design on. Then, in 2010, he attended the Shanghai Expo. In the China pavilion, he saw an amazing 3-D dynamic painting called Qingming Shanghe Tu (Along the River During the Qingming Festival). The 3-D painting inspired Mr. Fang, and he returned to Sihui the same day to plan the execution of this theme on his jadeite rough.

The original painting is full of people, which makes some of the carving detail extremely complicated. The finished product will show not only people’s individual facial expressions, but also the details of their clothing and even the jewelry they wear. Photo by Eric Welch, ©GIA, Courtesy of Jingyu Mantang Jadeite workshop
The original painting, Along the River During the Qingming Festival, is attributed to the great Northern Song Dynasty artist, Zhang Zeduan. It is 528 cm long and 24.8 cm high. It shows active scenes of life in Bianjing, the capital city during the Northern Song Dynasty. From 960 to 1279, China was the most developed and powerful country in the world. Mr. Fang loved the idea of using his favorite jadeite rough to represent the most prosperous period in China’s history. Since the original painting was too long to fit this jadeite, he decided to use its most eye-catching parts. The two main scenes are the city gate and the bridge.

The visiting team was shown the pencil sketch on the jadeite and some parts that have been worked on already. Mr. Fang also showed us the back of the rough, which will also be carved to represent parts of the painting.

In the room next to the workshop, progress was being made on the carving of the three gods: Fu, Lu, and Shou, made from a portion of the same rough material. The first pencil sketch has been finished. Mr. Fang pointed out that the design might be changed here and there as work progresses because jadeite color distribution is very complex and it can change within centimeters.

Part of the rough was divided into three pieces to carve the three gods, Fu, Lu, and Shou. Large statues like these are very rarely seen on the market. Photo by Eric Welch, ©GIA, Courtesy of Jingyu Mantang Jadeite workshop.
In Chinese culture, Fu is the god of happiness and good luck, Lu is the god of fortune and social class, and Shou is the god of longevity. Decorations with these three as the theme can be seen everywhere and are made of a variety of materials, including china and wood. In the past, almost every family had a set of the three in different formats or materials. According to Mr. Fang, the sizes of these carvings of the gods make them extremely rare. Also, the material being used is of abnormally high quality. This is another dream project he is working on at the same time as the main carving.

The god Lu is the symbol of good fortune and high social class. The sketch shows a lot of the details that will be incorporated into the finished product. Photo by Eric Welch, ©GIA, Courtesy of Jingyu Mantang Jadeite workshop

	A dedicated jadeite carver
Mr. Fang’s full name is Xingchun Fang. He was born in 1975 in Putian, Fujian province, which is a town that’s famous for its wood carvings. Mr. Fang began learning wood carving when he was very young. This gave him a very solid base in the art and led him to the world of jadeite carving later in his life.

Mr. Fang arrived in Sihui as a 17-year-old in 1992. He started his jadeite carving career as a worker in various workshops. He practiced jadeite polishing and simple carving techniques every day. Many people felt that the job was too boring and left, and Mr. Fang was one of the very few who stayed.

After a year or so, he opened his own small business, carving small pendants for dealers to sell. Although small pendants were the mainstream products on the market back then, Mr. Fang felt that it was not what he wanted to do as an artist. Finally, he successfully persuaded a dealer to let him make a small-scale 3-D Shan Zi for him. The dealer sold the product and made a good profit. This inspired more dealers to ask Mr. Fang to make large jadeite carvings for them.

With the development of his own business, Mr. Fang gradually gained the purchasing power to buy his own jadeite rough. After experiencing ups and downs, he finally got the business on the right track. In 2003, he started to collaborate with Mr. Zheng from Mazu. Mr. Fang was in charge of design. During their collaboration, Mr. Fang created many award-winning masterpieces that helped Mazu gain its fame and status in Sihui as the best jadeite carving company.

Mr. Fang introduces the ongoing project to the visitors from GIA. Photo by Eric Welch, ©GIA, Courtesy of Jingyu Mantang jadeite workshop
Although Mr. Fang left Mazu to form his own company, Jingyu Mantang, his friendship with Mr. Zheng never ended. Now Mr. Fang is heading toward his next dream: to turn his company into a museum of high-end jadeite carving and to attract the most skilled carvers from all over the country to come and work together.

As a successful young jadeite carving artist, Mr. Fang has always kept in mind that to become a great jadeite carver, one should have the same strong properties as jadeite. He also believes that there is a subtle connection between him and jadeite, and between him and his friends who share the same interests and passion. Source: GIA @topic:13


Title: Ponderosa Sunstone Update Abstract: Figure 1. A new test pit on Desert Sun's Ponderosa claim has produced much larger rough, with a high proportion of large dichroic stones. The largest recovered so far was approximately 1,800 ct. Photo by Kevin Schumacher.

John Woodmark, president of Desert Sun Mining & Gems (Depoe Bay, Oregon), provided an update on the Ponderosa mine. According to Woodmark, the mine is Oregon’s most prolific sunstone source, producing about 95% of all material currently on the market. He explained that the mine’s operations have changed to compensate for the characteristically short May-to-October mining season at the Ponderosa, which is at an elevation of 6,000 feet. In September 2015, Woodmark contracted with a sand and gravel company to bring a much larger excavator on site along with a high-capacity screen. This allowed the operators to stockpile a large enough volume of concentrate to sustain production through the entire following season.

News from the Ponderosa Mine
John Woodmark provides a status report of activities at Oregon’s Ponderosa mine.
In years past, even though the miners had access to the site as soon as the snow cleared in mid-May, they had to wait for the ground to dry out before they could mine. Now they can process the prior year’s stockpiled concentrate through a wet trammel—which removes some of the volcanic crust on the rough feldspar—and pickers can start work immediately. The new process ensures more production: During the five-month 2017 season, Ponderosa produced 4,400 kg of rough labradorite feldspar.

In September 2017, the combination of the bigger excavator and the high-capacity screen produced approximately 5,000 cubic yards of concentrate in just under a month. Woodmark estimated that the concentrate contains 5 kg of Oregon sunstone per cubic yard, and the new process has dramatically increased production of Ponderosa sunstone.

Figure 2. Oregon sunstone retains its rich orangy red hues even in smaller sizes. Photo by Kevin Schumacher.
Another development has been extensive test digging to determine gem potential over Desert Sun’s existing 60-acre claim. Woodmark explained that these test digs located a promising area of approximately one quarter of an acre, which has been developed into an open pit about 50 feet deep. Woodmark’s miners are finding larger stones as they go deeper, including one that weighed approximately 1,800 ct (figure 1). In addition, many of these larger gems are red/green dichroic stones, along with approximately 18 kg of extremely rare fine red and orangy red material (figure 2).

Woodmark has streamlined the company’s operations in other ways. He now contracts with a cutting house in India that grades the rough gems into categories. This frees Woodmark’s team from having to grade and allows them to focus on mining and production. It also allows the cutting company to respond more quickly to customers’ requests for a particular color or grade of finished gems. According to Woodmark, this development helps manufacturers use sunstone more effectively. He mentioned that sales have increased year-on-year since the andesine controversy earlier in the decade as trust in the natural-color Oregon gem has increased. He noted that 2017 was the company’s most successful year to date.

Woodmark noted that sustained production has been a major factor in this renewed confidence. He also told us that recent interest in North American gemstones, especially among TV merchandisers, has driven sales. He says that when clients see the quality of an untreated red Oregon sunstone and compare the pricing for a one-carat stone to that of an equivalent-color ruby or spinel, they realize the $150-per-carat price tag is an absolute bargain.

Woodmark added that consumer concern about the integrity of the gem supply chain has fostered interest in domestic gems. People are looking for gems that can be followed “from the dirt to the finger."

Figure 3. Desert Sun hires Native American teenagers from the local community to separate sunstone from ore. Photo by Duncan Pay.
Desert Sun Mining & Gems hires local Native American teenagers to help pick the sunstones from the processed ore (figure 3), which helps the local community. Woodmark explained that each picker can typically produce between 10 and 11 kg per day, but some might pick as much as 17 kg. He mentioned that the company had recently raised the pickers’ hourly wage by 20%, citing the community unemployment rate of 87%. He told us, “They’re always available…and they’re good kids.”

Woodmark told us the operation had recently hosted a PhD geoscience student from Washington State University who was studying the volcanism of the area. The student determined that the flow that hosts the sunstone at Ponderosa is approximately 18 million years old, and that the mine sits atop a vent, which is why those searching for similar deposits nearby have yet to find anything. As Woodmark said, “It just came up, and we’re right on it.” He added that the deposit “looks inexhaustible. From the bores that we’ve done, we have over a trillion carats.” Source: GIA @topic:1


Title: “Nebula” Inclusion in Ruby Beryllium-Diffused to Heal Fractures Abstract: Figure 1. An unusual ruby with coloring reminiscent of a nebula found in the depths of outer space. Photo by Adriana Robinson.
Recently the Carlsbad laboratory received a 4.12 ct purple-red stone measuring approximately 11.50 × 7.70 × 4.72 mm (figure 1) for identification services. It featured unusual veil-like reddish color zoning wafting throughout a purple bodycolor. The refractive index measured 1.760–1.770, identifying the stone as a ruby.

Figure 2. Fingerprints resulting from flux-assisted heating of a beryllium-rich flux. Photomicrograph by Nathan Renfro; field of view 7.19 mm.
Microscopic examination indicated that the reddish color zoning was associated with altered fingerprints that resembled a cosmic nebula due to a flux-rich residue (figure 2). These fingerprints appeared to be consistent with fractures that had been healed using a flux-assisted heating process in a high-heat environment.
Due to the indications of high heat, laser ablation–inductively coupled plasma–mass spectrometry (LA-ICP-MS) chemical analysis was performed to check for the presence of beryllium diffusion. Initially, LA-ICP-MS conducted on two spots revealed beryllium concentrations of <0.019 ppma and 60.87 ppma. This significant discrepancy prompted additional LA-ICP-MS testing in three spots, revealing beryllium concentrations of <0.19 ppma, 1780 ppma, and <0.19 ppma. Microscopic observation of the testing spots showed areas of high beryllium on or near the reddish color zones, while areas of very low beryllium were associated with testing areas on the purple areas of the stone.
Therefore, it was concluded that a beryllium-rich flux was used to heal the fractures naturally present in the stone. The ruby was likely heated in this flux at temperatures high enough to allow the beryllium to seep from the flux into the stone, but not long enough for the beryllium to infiltrate its entirety. Source: GIA @topic:3


Title: Imitation Rainbow Moonstone Assemblage Abstract: Figure 1. These assembled cabochons (1.74–10.57 ct) with multicolor iridescence are a skillful imitation of rainbow moonstone. They are composed of a natural rock crystal quartz base with an iridescent coating cemented to a gypsum top, and the entire assemblage is coated in colorless plastic. Photo by Don Mengason.

              The Carlsbad laboratory recently received for examination four semi-transparent to translucent cabochons with a white bodycolor (figure 1), ranging from 1.74 to 10.57 ct. These stones appeared similar to white plagioclase feldspar with multicolor iridescence, known in the trade as “rainbow moonstone” (Summer 1997 Gem News, pp. 144–145). However, a cursory examination proved they were distinctly different: assembled materials composed of a colorless, transparent base cemented to a fibrous white top and coated with a colorless plastic. The stones also displayed an unusual iridescence.

The colorless plastic coating had an RI of 1.55, but this was not useful in identifying the substrate components. The assembled stone fluoresced medium blue to long-wave UV and weak blue to short-wave UV. In polarized light, a bull’s-eye optic figure was resolved in the colorless base material, confirming rock crystal quartz; small fluid inclusions and reflective particles in the bottom sections indicated natural origin. Raman spectroscopy conclusively identified the fibrous top as gypsum.

Microscopic examination revealed an iridescent coating on the quartz section, much like that used on “Aqua Aura” quartz (Fall 1990 Gem News, pp. 234–235). Closer inspection revealed that the iridescent coating was located on the quartz in the join. The colorless plastic coating contained numerous gas bubbles and was easily deformable with a pointer probe. This plastic layer was apparently added to give a vitreous luster to the otherwise dull, waxy gypsum. Gas bubbles in the colorless cement layer made it quite easy to recognize these stones as assemblages.

When viewed face-up, the assemblages made an attractive imitation of rainbow moonstone due to their white bodycolor, milky appearance, and rainbow iridescence. This is the second time the Carlsbad laboratory has examined an assemblage containing plastic-coated gypsum (Fall 2012 Lab Notes, pp. 210–211). Coupling a luster-enhancing coating with an iridescent layer created an interesting imitation rainbow moonstone from two common materials. Source: GIA @topic:2


Title: Honduran and Turkish Opal Abstract: Left: This Honduran banded opal, 10 cm in height, shows a 1–3 mm thick stratified opal layer attached to matrix. Right: Turkish dendritic opal was available as cabochons. Photos by Donna Beaton.

	Harald Mühlinghaus (Opal Imperium, Enkirch, Germany) has been exhibiting at the Pueblo Gem & Mineral Show for more than 20 years. The company sources, fabricates, and sells a number of colored gemstones, but their main focus is opal from Australia, Mexico, Honduras, and other locales. At the booth were some unusual examples that have rarely been documented, such as the banded opal in the left-hand image, obtained about 30 years ago from an unrecorded Honduran location. This material occurs as solid vertical veins in matrix with approximately 1 cm stratifications of play-of-color, which indicate the cyclical concentration and the formation of the silica spheres that form opal. The phenomenon is most distinct in fairly sizable pieces of rough, with 1–3 mm opal layers on matrix measuring 5–15 cm across, which makes these specimens more suitable for display than for jewelry. Some of the smaller examples displayed only nonphenomenal layers, while others had play-of-color fading to potch at each cycle.

	Also on display were dendritic opal cabochons (right) from rough obtained from Simav, Turkey, about four years ago. This material, which Mühlinghaus called “Turkish dendritic opal,” has been cut so that each piece shows clearly delineated opaque white and semitransparent areas, embedded with fine branched black inclusions reminiscent of traditional Japanese tategaki characters. Source: GIA @topic:12


Title: Sunstone History and Lore Abstract: Discoveries of glittery sunstone rough led miners to establish claims in the US state of Oregon. – Robert Weldon, courtesy Sunstone Butte Mine

                      In the early 1800s sunstone was a little-known, rare, and costly gemstone. It wasn’t until finds in Norway, Siberia, and other parts of the world that sunstone became somewhat more widely recognized, more available, and less expensive. In the US state of Oregon in the early 1900s, there were reports of sunstone finds in ancient lava fields in a desert area called Warner Valley. Even earlier, Native Americans in that area might have been the first collectors of Warner Valley sunstones.

According to Native American legend, the blood of a great warrior – wounded by an arrow -  dropped onto pieces of Oregon sunstone. The blood carried his warrior spirit into the stones, coloring them with shades of red and giving them sacred power. A museum in Jacksonville, Oregon, includes sunstones in its display of Indian artifacts. In Oregon today, several mining claims produce enough of this unique material to supply mass marketers as well as carvers and high-end jewelry designers.

	This photo shows a large sunstone fragment said to be from among the early discoveries in Oregon’s Warner Valley.

	Ore Pit, a publication of Oregon State University’s mineralogy department, published this picture of a collection of sunstones from a Jacksonville, Oregon, museum’s display of early Native American sunstone artifacts. Source: GIA @topic:1


Title: Large Cat’s-Eye Emerald from Brazil Abstract: Figure 1. This emerald from Itabira–Nova Era in Minas Gerais weighs approximately 43 ct (approximately 25.30 × 18.10 × 13.75 mm) making it one of the largest Brazilian cat’s-eye emeralds examined by the Gübelin Gem Lab. Photo by Janine Meyer.

              Gübelin Gem Laboratories (GGL) in Hong Kong and Lucerne recently had the opportunity to examine a translucent emerald, weighing approximately 43 ct, that exhibited a pronounced and well-centered chatoyancy (figure 1). The stone had a spot RI of 1.57 and a hydrostatic SG of 2.73, and it was inert under long- and short-wave UV radiation. Microscopic observation in reflected and transmitted light presented a series of dense elongated, rectangular, and square multiphase inclusions (figure 2).

Figure 2. Multiphase inclusions of different shapes and sizes, seen in reflected light (left) and brightfield illumination (right), gave rise to the cat’s-eye effect in the Brazilian emerald. Photomicrographs by Wenxing Xu (left) and Stefanos Karampelas (right). Image width 2 mm (left) and 1.2 mm (right).
The UV-Vis absorption spectra showed the characteristic Cr3+- as well as Fe2+- and Fe3+- related bands. In the FTIR absorption spectra, type I and type II water molecules were observed. An intense band at around 2360 cm–1 indicated the presence of CO2, most likely in the multiphase inclusions. Trace-element analysis of the sample with laser ablation–inductively coupled plasma–mass spectrometry (LA-ICP-MS) showed contents consistent with schist- and pegmatite-related emeralds. It also showed lower Li, Cs, and Rb than in emeralds related to highly evolved pegmatites, such as those from Sandawana (Zimbabwe) and Kafubu (Zambia); see J.C. Zwaan et al., “Emeralds from the Fazenda Bonfim region, Rio Grande do Norte, Brazil,” Spring 2012 G&G, pp. 2–17. The stone’s composition was consistent with emeralds from Itabira–Nova Era, Minas Gerais, based on GGL’s reference collection and the published literature on the pegmatites of the area (C. Preinfalk et al., “The pegmatites of the Nova Era–Itabira–Ferros pegmatite district and the emerald mineralisation of Capoeirana and Belmont (Minas Gerais, Brazil): geochemistry and Rb-Sr dating,” Journal of South American Sciences, Vol. 14, No. 8, 2002, pp. 867–887). This exceptional stone is one of the largest Brazilian cat’s-eye emeralds examined by GGL to date. Source: GIA @topic:3