Publication Year: 2006 Title: The Effects of Heat Treatment on Zircon Inclusions in Madagascar Sapphires Abstract: Zircon inclusions in sapphires from Madagascar were studied to investigate the effects of heat treatment on their gemological and spectroscopic features. Progressive decomposition of zircon and chemical reactions between zircon and the host sapphire occurred at temperatures between 1400°C and 1850°C. In unheated sapphires, transparent zircon inclusions displayed euhedral slightly elongated forms and clear interfaces with their corundum host. Most were confined within the host under relatively high pressures (up to 27 kbar), and showed evidence of natural radiation-related damage (metamictization). Subsolidus reactions (i.e., the decomposition of zircon into its component oxides without melting) of some zircon inclusions started at temperatures as low as 1400°C, as evidenced by the formation of baddeleyite (ZrO2) and a SiO2-rich phase. Differences in the degree of preexisting radiation damage are the most likely cause for the decomposition reactions at such relatively low temperatures. Melting of zircon and dissolution of the surrounding sapphire occurred in all samples at 1600°C and above. This resulted in the formation of both baddeleyite and a quenched glass rich in Al2O3 and SiO2. From these data and observations, a systematic sequence of both modification and destruction of zircon inclusions with increasing temperature was compiled. This zircon alteration sequence may be used (1) as a gemological aid in determining whether a zircon-bearing ruby/sapphire has been heated, and (2) to provide an estimate of the heating temperature. @chapter:12


Publication Year: 2016 Title: Color-Change Glass as a Zultanite Imitation Abstract: Figure 1. These glass imitations of Zultanite are shown in fluorescent (left) and incandescent light (right). The color-change effect is apparent when switching between the two illumination types. Photos by Xiaoyan Yu.
Diaspore, a relatively common mineral with the chemical formula AlO(OH), is found in metamorphic bauxite deposits (A.A. Calagari and A. Abedini, “Geochemical investigations on Permo-Triassic bauxite horizon at Kanisheeteh, east of Bukan, West-Azarbaidjan, Iran,” Journal of Geochemical Exploration, Vol. 94, No. 1, 2007, pp. 1–18), and usually appears as a mineral inclusion in sapphire, ruby, and spinel (V. Pardieu, “Hunting for ‘Jedi’ spinel,” Spring 2014 G&G, pp. 46–57; Spring 2016 GNI, pp. 98–100; Summer 2016 GNI, pp. 209–211). However, gem-quality transparent diaspore is rare and appears to be unique to the Ilbir Mountains area in southwest Turkey (M. Hatipoglu et al., “Gem-quality transparent diaspore (zultanite) in bauxite deposits of the Ilbir Mountains, Menderes Massif, SW Turkey,” Mineralium Deposita, Vol. 45, No. 2, 2010, pp. 201–205). Zultanite is the trade name of diaspore that exhibits a color-change effect; the material appears yellow, pink, or green in different light sources. Zultanite has only been found in the Anatolian Mountains of Turkey (M. Hatipoglu and M. Akgun, “Zultanite, or colour-change diaspore from the Milas (Mugla) region, Turkey,” Australian Gemmologist, Vol. 23, 2009, pp. 558–562).

The Gemological Institute of China University of Geosciences in Beijing recently received two samples, an unmounted 8.44 ct 10 × 12 mm faceted pear-shaped specimen and a ring with an 8 × 10 mm faceted oval, that displayed a color-change effect. The material was reportedly purchased from Turkey as Zultanite, a designation the client wished to confirm. Both samples were yellowish green in  fluorescent light with a color temperature of 5500 K (figure 1, left) and brownish yellow in incandescent light (figure 1, right). The specimens were fairly clean, with no obvious inclusions and no obvious scratches on the surface. Facet junctions were generally smooth, with small chips. A series of absorption lines related to rare earth elements (REE) were observed by a handheld prism spectroscope. These properties, along with electron microprobe analysis, indicated that the two samples were not diaspore or any other natural material, but rather man-made glass. The infrared spectrum of the unmounted specimen, with peaks at 1037, 462, 443, and 430 cm–1, confirmed the material was glass.

LA-ICP-MS data of three points on the loose sample are reported in table 1. The main trace elements were Nd (102,792 average ppmw) and Pr (68,500 average ppmw), both rare earth elements. Other REE included Gd (1473 average ppmw) and Ce (135 average ppmw). Nd and Pr are the chromophores that cause color change in material such as synthetic cubic zirconia (Fall 2015 GNI, pp. 340–341).

TABLE 1. LA-ICP-MS data of glass sample (ppmw).

Element
TG1-01
TG1-02
TG1-03

Ti
65.55
64.02
64.13

V
0.618
0.614
0.621

Cr
0.740
0.832
0.818

Mn
0.882
0.861
0.756

Fe
50.68
49.78
51.31

Co
0.0462
0.0444
0.0444

Ni
0.2291
0.2124
0.2062

Cu
13.14
12.80
13.02

Se
0.75
0.75
0.71

Rb
3.63
3.51
3.50

Sr
68.23
66.01
66.26

Y
2.381
2.29
2.319

Cs
0.028
0.0273
0.028

La
4.78
4.55
4.56

Ce
139.42
133.47
134.65

Pr
69,791.21
67,327.64
68,381.69

Nd
104,391.56
100,985.23
103,001.10

Sm
0.307
0.311
0.301

Eu
0.372
0.356
0.353

Gd
1482.77
1452.45
1480.22

Tb
24.41
23.51
23.85

Dy
8.42
7.98
7.92

Ho
0.658
0.617
0.611

Er
31.30
30.25
31.00

Tm
bdl
bdl
bdl

Yb
0.2224
0.1979
0.2197

Lu
bdl
bdl
bdl

Rare earth elements are displayed in bold text. bdl = below detection limit.

The visible-range absorption spectrum of the loose material (figure 2) showed a typical spectrum of glass with rare earth elements. This spectrum showed bands at 443, 479, 529, and 587 nm. The bands at 443, 479, and 529 nm indicate the presence of Pr3+, which caused the green or yellowish green color. The brownish yellow color is related to the 587 nm absorption peak, which is induced by Nd3+.

Figure 2. The visible absorption spectrum of the unmounted pear-shaped sample shows
four absorption bands at 443, 479, 529, and 587 nm. The peak at 587 nm is associated
with Nd3+, while the bands at 443, 479, and 529 nm are attributed to Pr3+. @chapter:4


Publication Year: 2002 Title: Chart of Commercially Available Gem Treatments Abstract: This chart combines a comprehensive listing of the commercially available treatments for the most commonly used gem materials with an indication of the current status of their detectability. Designed as a supplement to “Gemstone Enhancement and Detection in the 1990s,” from the Winter 2000 issue of Gems & Gemology, this chart makes the key information available in an easy-to-use reference tool. @chapter:23


Publication Year: 2013 Title: Faceted Wurtzite from Tanzania Abstract: Figure 1. These wurtzites are from Merelani, Tanzania. The crystal measures 17 mm across, and the cut stones weigh 1.74 and 1.59 ct. Photo by Jaroslav Hyršl.

Wurtzite is the hexagonal polymorph of ZnS. It is far less common than sphalerite, the cubic polymorph of ZnS. All previously identified wurtzite has been opaque to translucent, and therefore not facetable. Layers of wurtzite and sphalerite can alternate in so-called Schalenblende, a colloidal sphalerite variety used only rarely for cabochons. The first transparent wurtzite crystals were found in 2012, at the tanzanite deposit at Merelani Hills, south of Arusha, Tanzania (for identification, see www.rruff.info). The crystals, which measure up to 2 cm in diameter, are very rare. They have a tabular shape, with pyramidal faces. Some crystals from Merelani have clean parts, and several gemstones were faceted from them (figure 1).

Eight cut stones weighing 0.30–1.74 ct were studied. They were orange-brown, with a submetallic luster and very weak, almost invisible, pleochroism. Refractive indices of these stones were well over the refractometer limit, listed as 2.36 and 2.38 in the literature (J. Bernard and J. Hyršl, Minerals and their Localities, Granit, Czech Republic, 2004, p. 666). They had very low birefringence, confirmed by a lack of doubling of facet edges. The determined specific gravity values of two of the crystals were 3.78 and 3.85; their measured hardness was 3.5. The stones were uniaxial positive and inert under both long- and short-wave UV. Their UV-Vis-NIR spectrum (figure 2) exhibited a high cut-off at 545 nm. The stones showed anisotropic crystals and hexagonal growth structures when viewed under a microscope. Because of the rarity and high value of the Tanzanian crystals, the faceted wurtzites are sure to catch the attention of gemstone collectors.

Figure 2. The UV-Vis-NIR spectrum of a 1.74 cut wurtzite from Tanzania. @chapter:5


Publication Year: 2022 Title: Barite-Calcite Composite as Imitation “Wulanhua” Turquoise from Hubei Province, China Abstract: Figure 1. The bracelet submitted as “Wulanhua” turquoise. Photo by Shu-Hong Lin.
“Wulanhua” turquoise is well known in the Taiwan and mainland China market. It has also been called “Ulan flower” turquoise in previous publications (L. Liu et al., “Unique raindrop pattern of turquoise from Hubei, China,” Fall 2020 G&G, pp. 380–400). The term “Wulanhua” is a Chinese transliteration that means black orchid, and it usually refers to turquoise of medium dark to very dark blue color with a black spiderweb pattern found in Hubei Province.
A bracelet recently submitted to Taiwan Union Lab of Gem Research (TULAB) as Wulanhua turquoise (figure 1) contained dark blue opaque beads with a black spiderweb pattern on the surface. The spot refractive index of these beads was about 1.62–1.63, close to that of turquoise. EDXRF analysis determined that the composition of the beads was inconsistent with that of turquoise (CuAl6(PO4)4(OH)8•4H2O). Instead, it was composed mainly of barium (Ba) and calcium (Ca).

Figure 2. A bead from the bracelet was cut into two halves. One half was immersed in 95% ethanol for 72 hours, clearly extracting the blue dye. Photos by Yu-Ho Li.

Figure 3. Raman spectra comparisons between the bead, the blue dye precipitate, and those of barite and calcite from the RRUFF database suggest that the bead consisted of barite, calcite, and blue dye. The stacked spectra are baseline-corrected and normalized.
To further identify the composition, Raman spectra (785 nm laser) were analyzed and compared with those from the RRUFF database. The beads displayed mixed spectra of barite, calcite, and other unknown materials. With the consent of the client, a bead was cut into two halves and polished for more testing. One half was immersed in 95% ethanol for 72 hours to extract the dark blue dye (figure 2). After the ethanol volatilized, the blue precipitate was analyzed with Raman spectroscopy and the spectrum was compared with that of the bead and the spectra from the RRUFF database. Raman analysis and the extraction experiment revealed that this material was composed of barite and calcite with an unidentified blue dye (figure 3). Microscopic observation of the cross section suggested that the beads were made of irregularly shaped barite and barite with minor calcite particles with an unknown black filling as a bonding material (figure 4).

Figure 4. The cross section of one bead showed irregularly shaped barite and barite with minor calcite particles, along with a black filling that could be some unknown bonding material. Photomicrograph by Shu-Hong Lin; field of view 8.56 mm.
The beads could be defined as a composite material made of barite (BaSO4), calcite (CaCO3), and blue dye. While visual observation and refractive index might not be enough to distinguish these beads from true Wulanhua turquoise, Raman spectroscopy and EDXRF analysis were able to reveal their true identity. @chapter:5


Publication Year: 2021 Title: Novelty Cut Diamond Faceted as Iconic Apple Logo Abstract: Figure 1. This 1.13 ct Fancy yellow diamond resembles the iconic Apple logo. Photo by Diego Sanchez.

A novelty cut 1.13 ct Fancy yellow diamond was recently submitted to the Carlsbad laboratory for color origin and identification service. The diamond was cut in the shape of a bitten apple and bore a striking resemblance to the iconic Apple logo found on Apple Inc. products (figure 1). Standard FTIR absorption spectrum identified it as a type Ia diamond with high nitrogen concentration. Standard UV-Vis spectroscopy revealed the typical UV-Vis absorption spectra of cape diamond, with the N2 (478 nm) and N3 (415.2 nm) defects that are responsible for the fancy yellow color in the “Apple” diamond. The stone showed strong blue fluorescence when exposed to long-wave UV radiation, typical of cape diamond (figure 2).

Figure 2. The novelty cut diamond showed strong blue fluorescence under long-wave UV light. Photo by Diego Sanchez.
New cutting styles of diamonds are often designed either for efficient light return and weight retention properties or to resemble other items. Examples of the latter include the sword-shaped diamond with “fire and ice” fluorescence (Fall 2020 Lab Notes, pp. 416–419) and the “seated Buddha” (Fall 1996 Gems News, p. 215). This particular diamond was most likely fashioned in the shape of an apple as a novelty and to retain weight, as the stone showed significant windowing, which suggests that the rough was too shallow to allow for more efficient light return. This unique shape for a faceted diamond is a welcome addition to the wide range of novelty cut diamonds currently available in the trade. @chapter:31


Publication Year: 2023 Title: Apatite in Hackmanite Abstract: Figure 1. A hackmanite with a faded purple color after storage in the dark (left), illuminated with long-wave UV light (center), and after removal from a few seconds of exposure to the long-wave UV light (right). The color has deepened after exposure to UV light. Photos by Ronnakorn Manorotkul.
Hackmanite, Na8Al6Si6O24(Cl2,S), is a variety of sodalite notable for its tenebrescence. When kept in darkness, samples can fade to pale purple and even gray or translucent to opaque white. When exposed to long-wave ultraviolet illumination, they can display a strong orange fluorescence reaction. After exposure to sunlight or artificial light with a UV component, samples can quickly develop a much stronger color. One hackmanite sample recently examined by the author (figure 1) showed this phenomenon.

Figure 2. Left: In darkfield illumination, a white apatite crystal is visible in the hackmanite. Right: After exposure to long-wave UV light for approximately one second, a dramatic change can be seen. The overall color of the hackmanite is now a more vivid shade of purple. Photomicrographs by E. Billie Hughes; field of view approximately 5 mm.
Another hackmanite was submitted that displayed an interesting elongated white inclusion (figure 2, left) that was identified by micro-Raman as apatite. As we examined the sample in the microscope, we tried exposing it to a 6-watt long-wave UV light for approximately one second. Almost immediately, a change was observed. The hackmanite developed a more vibrant purple color that is clearly displayed in figure 2 (right). @chapter:13


Publication Year: 1984 Title: The First-Order Red Compensator: An Effective Gemological Tool Abstract: This note deals with some gemological applications for a tool well known to microscopists: the first-order red compensator. In gemological microscopy, the compensator can be useful in locating interference colors and optic figures in birefringent materials and in delineating strain in gemstones. In polarized light photomicrography, a properly positioned compensator can reduce the exposure time required and thus the risk of film reciprocity failure and of poor-quality images resulting from random vibrations of the microscope and its accessories. @chapter:17


Publication Year: - Title: Jeweler Creates ‘Medal of Honor’ Pin to Recognize Coronavirus Health Care Fighters Abstract: The Defeating the Coronavirus pin by Franco Valobra and his team at Valobra Master Jewelers. Valobra is making a gift of this pin to front line heath care workers taking care of COVID-19 patients. Photo courtesy of Valobra Master Jewelers

Franco Valobra, like many of us, stayed home during the global coronavirus pandemic. New Orleans, which was hit hard and fast by the virus in the early days of March, ordered businesses to shut down March 15 and Valobra quickly closed his boutique on Royal Street.
“I vowed to keep all of my staff on full payroll and I did the same for our showrooms in Houston and Switzerland,” he said. The Lugano, Switzerland boutique closed first, in early March, because of its proximity to Lombardy, the region hardest hit in Italy. “Fortunately none of my staff and family have been infected by the virus, but I have had lots of friends’ families in Italy who directly experienced the malignity of COVID-19. Thankfully, no one has died.”
Valobra, restless at home in his living room “quarantine office,” watched the images of front line health care workers and first responders fighting to save lives. He also saw people around the world sharing expressions of gratitude for their immense sacrifice and commitment.
“The passionate serenading from balconies, the protracted applauses from windows and the flyovers of the Air Force jets, are, indeed, great pronouncements of universal gratitude and heartfelt appreciation,” he said. “But the musical notes are so regretfully and quickly lost in the air and the rumble of the airplanes turns into fleeing plumes of jet exhaust.”

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Valobra, a GIA graduate, wanted to create a more durable symbol of gratitude for health care workers fighting the coronavirus.
“It took me no more than a few minutes to conceptualize the ‘Defeating the Virus’ pin,” he said. “I had a clear image of the symbol of medicine (the caduceus, a commonly used symbol), stabbing through the coronavirus, but also clearly towering over and overpowering it. The ratios needed to be better than 2:1 — the caduceus being at least twice as big as the virus.”
Once the final drawing was done, Valobra asked his in-house CAD designer to create a rendering and his team of bench jewelers in Houston (which re-opened on May 1) started to manufacture them. The pins are completely hand-made and cast in sterling silver and then are gold-plated. Each features a round garnet, the gemstone that symbolizes health and crisis resolution.

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The team has been able to produce 25 to 35 pins a day and to-date more than 500 have been shipped all over the world: Saudi Arabia, Pakistan, Israel, Canada, Italy, most countries in Europe and virtually every state in the U.S., including Alaska. All of the pins are a gift from Valobra to the recipients.
“Naturally lots of them were sent to Texas, Louisiana and New York,” Valobra said, adding that the first five celebratory pins were shipped to the Coronavirus Task Force at the White House (President Trump, Vice President Pence, Dr. Anthony Fauci, Dr. Deborah Birx and Surgeon General Dr. Jerome Adams).
Valobra originally committed to make and give away 1,000 pins, but has decided to gift as many as he can. He said anyone is welcome to contact wecare@valobrajewelry.com to nominate a worthy recipient (someone who is going above and beyond the call of duty in a hospital, health care center, testing facility, laboratory, etc.).
Valobra has received many notes of thanks from health care workers who have received the Defeating the Coronavirus pin.
“As respiratory therapist, we are usually not mentioned as frontline health providers, but the word “ventilator” is mentioned often. Respiratory therapists specialize in the skills of cardiopulmonary care that determine the appropriate ventilator settings to match the patient’s needs. We stand with the warriors of the frontline and we are an essential component for the patients,” said Rosalind Lyssy, of Houston. “To me, the pin is a symbol of being appreciated and recognized on the front line. Thank you for the honor of letting me wear it.”

Franco Valobra in the Valobra Master Jewelers showroom in Houston, Texas. Photo courtesy of Valobra Master Jewelers
Valobra hopes the “Defeating the Virus” pin will be worn on lapels of medical scrubs and lab coats for years to come.
“To me, it represents the soon-to-materialize defeat of the virus, a symbol of human triumph through science and medicine,” he said. “I wanted to gift these modern-day heroes with my own style of the Medal of Honor.” @chapter:34


Publication Year: 2017 Title: Yellow, Green, and Blue Sapphires Reportedly from Antang and Gombe, Nigeria Abstract: Figure 1. These sapphires (0.64–8.27 ct) are from Antang and Gombe, in northern Nigeria. Photo by Shunsuke Nagai.
GIA’s Tokyo laboratory borrowed 19 sapphires (figure 1) from gem dealer Ambrose & Co. in Kofu, Japan. The samples consisted of eight blue, one bluish green, eight yellow, and one greenish yellow/blue bicolor sapphires, all faceted. They were reportedly from Antang and Gombe in northern Nigeria (figure 2). Mambilla, in the southeastern part of the country, is the only well-known Nigerian sapphire source (V. Pardieu et al., “New Nigerian source of blue sapphire,” 2014, https://www.gia.edu/doc/Nigeria_Mambilla_Sapphire_US.pdf; Spring 2017 GNI, pp. 134–135), and the two new sources are not well documented.

Figure 2. Map of Nigerian sapphire sources. Sapphires from the new deposits at
Antang and Gombe have potentially high quality.
Sapphires from both Antang and Gombe are basalt related. The mines are located in a basement complex and on Cretaceous/Tertiary sedimentary rocks near volcanic rocks. The sapphires are mined in alluvial deposits or unconsolidated sediments. According to the dealer, the blue sapphires were from Antang and the yellow sapphires and bicolor sapphire from Gombe. Brume Jeroh, the supplier in Nigeria, mentioned that Antang produces blue, green, yellow, and parti-color sapphires, while Gombe produces mainly yellow sapphires and a few blues. He also noted that stones from these sources may have been mixed together at the market in the city of Jos.

The samples’ standard gemological properties are listed in table 1. Refractive index and specific gravity values were all within the range of corundum. Representative inclusions observed in these sapphires are shown in figures 3 and 4. Quantitative analysis of trace elements was carried out with LA-ICP-MS, and the results are summarized in table 2 and figure 5.

TABLE 1. Standard gemological properties of sapphires from northeastern Nigeria.

Samples
Color
Weight (ct)
Refractive index
Specific gravity
Source

N01
Yellow
2.84
1.763–1.770
4.00
Gombe

N02
Yellow
2.07
1.765–1.773
4.02
Gombe

N03
Yellow
2.06
1.764–1.772
4.00
Gombe

N04
Yellow
1.84
1.764–1.771
4.00
Gombe

N05
Yellow
1.28
1.764–1.772
4.01
Gombe

N06
Yellow
1.21
1.767–1.772
3.99
Gombe

N07
Yellow
1.03
1.762–1.770
4.00
Gombe

N08
Yellow
0.94
1.762–1.770
4.00
Gombe

N09
Yellow
0.78
1.762–1.770
3.99
Gombe

N010
Greenish yellow and blue
2.04
1.762–1.770
4.03
Gombe

N011
Bluish green
3.51
1.764–1.772
4.01
Gombe*

N012
Blue
2.09
1.763–1.772
4.00
Gombe*

N013
Blue
8.27
1.760–1.768
3.99
Antang

N014
Blue
2.15
1.762–1.770
4.00
Antang

N015
Blue
1.82
1.762–1.770
4.00
Antang

N016
Blue
1.16
1.762–1.770
4.00
Antang

N017
Blue
0.97
1.765–1.770
3.99
Antang

N018
Blue
0.88
1.764–1.771
3.99
Antang

N019
Blue
0.64
1.760–1.768
3.98
Antang

*Samples N11 and N12 were supplied as Antang sapphires but could be Gombe sapphires that were mixed at the market in Jos. This study identified their origin as Gombe based on LA-ICP-MS results.

Figure 3. Inclusions in sapphires from Gombe: healed fissures with hazy edges (A), irregular particles and short needles (B), wavy graining (C), and flake-like particles (D). Photomicrographs in darkfield illumination (A–C) and diffused brightfield illumination (D) by Shunsuke Nagai. Fields of view 1.95 mm (A), 2.15 mm (B), 2.80 mm (C), and 2.80 mm (D).

Figure 4. Inclusions in sapphires from Antang: zircon crystals (A), reflective thin films with hexagonal patterns (B), bands of minute particles and short needles (C), and angular banding and perpendicularly oriented particles (D). Photomicrographs in darkfield illumination by Yusuke Katsurada (A–C) and Shunsuke Nagai (D). Fields of view 2.80 mm (A), 1.00 mm (B), 4.00 mm (C), and 4.30 mm (D).

Figure 5. LA-ICP-MS quantitative analysis allowed the separation of blue sapphires from Antang and yellow sapphires in some trace elements (e.g., Fe vs. V and Fe vs. Ga). The two parts (N10Y and N10B) of the bicolor sapphire show a close trend. The bluish green sapphire (N11) and blue sapphire (N12) are considered to be from Gombe. Results are not averaged.

TABLE 2. Trace element concentrations (in ppma) obtained by LA-ICP-MSa.

Sample no.
Be
Mg
Ti
V
Cr
Mn
Fe
Ga

N01
0.38
11.4
10.9
1.65
bdl
0.18
2610
68.9

N02
bdl
14.2
12.6
2.0
0.28
0.21
2790
60.9

N03
bdl
15.8
12.1
0.47
bdl
0.08
2970
36.7

N04
bdl
22.8
21.4
1.51
2.36
0.25
3860
39.0

N05
bdl
16.0
13.3
1.88
1.05
0.03
2660
71.6

N06
0.45
20.2
17.6
2.27
3.36
0.04
2667
66.1

N07
bdl
14.9
12.4
1.69
bdl
0.13
2900
70.7

N08
bdl
12.3
33.8
1.04
bdl
bdl
1930
89.9

N09
bdl
16.2
14.2
1.82
0.61
0.11
2760
71.0

N010Y
bdl
15.4
13.7
1.66
bdl
0.10
2740
68.0

N10B
bdl
8.98
40.2
1.67
bdl
0.03
2490
66.6

N011
bdl
10.8
14.6
2.04
21.9
0.27
4000
67.9

N012
1.19
6.88
17.5
1.80
bdl
bdl
2380
78.9

N013
bdl
2.25
21.2
4.79
20.9
0.06
807
45.6

N014
bdl
12.8
21.4
6.82
0.37
0.06
1290
49.7

N015
bdl
7.37
92.0
8.79
3.27
bdl
924
56.4

N016
bdl
13.4
60.6
7.22
bdl
0.11
1280
61.0

N017
bdl
8.16
18.4
5.20
5.03
0.03
1470
54.1

N018
bdl
5.10
30.0
6.47
18.3
bdl
1190
49.7

N019
bdl
4.27
30.1
5.89
4.81
bdl
1260
52.7

aAverage of three spots
			bdl: below detection limit

The yellow sapphires and the greenish yellow part of the bicolor sapphire showed a typically high Fe, and their Mg concentration is greater than Ti except for one sample (N08; again, see table 2). As shown in figure 5, the high Fe (approximately 2000 ppma) and medium V (approximately 0.50–2.00 ppma) of all the yellow sapphires (N01 to N09) and the greenish yellow part of the bicolor sapphire (N10Y) showed the same trend as those of a bluish green sapphire (N11) and one blue sapphire (N12). The greenish yellow part of the bicolor sapphire (N10Y) matches other yellow sapphires in all elements, and the blue part of the bicolor (N10B) overlaps with N11 and N12. The titanium levels are significantly different between the two parts of N10. This matters, as the titanium is necessary for blue coloration in sapphire with iron. N11 and N12 show different trends from other blue sapphires (from N13 to N19) for V, Fe, and Ga. This suggests that these two samples originated from a different locality. Given that these two samples’ trace element composition is close to that of the blue part of the bicolor sapphire (N10B) and different from the rest of the blue sapphires, we considered them to be from Gombe (again, see table 1). In addition, inclusions exhibited in figure 4 in N13–N19 were not seen in N11 and N12, and these two samples had similar features to each other, as shown in figure 3. Greenish blue and blue sapphires (N11 and N12) and the blue part of the bicolor sapphire (N10B) from Gombe show high Fe (approximately 2000 ppma) and medium V (approximately 1.50–2.00 ppma). Blue sapphires from Antang (from N13 to N19) show lower Fe (approximately 800–1500 ppma) and high V (approximately 4.50 ppma).

Although sapphires from these two new Nigerian sources are limited in quantity and color range, they are potentially high quality. The importance of the sources is not yet known, and more field data and advanced testing data such as quantitative analyses of trace elements are needed. Despite the different trends in some trace elements between the localities, as this study revealed, they still overlap with trace elements of different magmatic origins including Mambilla (data not shown). Since characteristic inclusions are not always present in basalt-related sapphires and trace elements cannot always be separated, origin determination of these sapphires remains challenging. Interpretation of trace element data such as discriminant analyses and the building of a rich database are necessary. @chapter:0


Publication Year: 2011 Title: GIA’S Symmetry Grading Boundaries for Round Brilliant Cut Diamonds Abstract: Grade boundary limits are presented for 10 symmetry parameters of the round brilliant cut diamond. Starting in early 2012, these values will be used to support and constrain visual symmetry grading on GIA diamond reports. For manufacturers, the boundaries provide useful predictions of symmetry grades. Other symmetry features of faceted diamonds will continue to be evaluated visually. @chapter:31


Publication Year: 2023 Title: The history of gemstones in Chanthaburi_22 Abstract: In the early 2500s, many believe it marked the beginning of a new decade for gemstone production and trade in Chanthaburi. This could be attributed to a coup d'état in Myanmar during that period, which led to several ruby mines becoming inaccessible. As a result, some gemstone producers and traders moved from Myanmar to Thailand. Additionally, Thailand itself had ruby mines located along the Thai-Cambodian border. @chapter:25


Publication Year: 2013 Title: Cobalt-Doped Composite Sapphires: A Blessing or a Curse? Abstract: Gem mining is expensive and it is economically important to be able to enhance stones of lower quality. Treatments allow increasing the supply of gemstones making them available at affordable prices. Treated gemstones have been flooding the markets. The potential damage is a loss of consumer confidence. Are cobalt-doped composite sapphires a blessing or a curse? Only time will tell.

		Treatments of corundum are meant to enhance transparency, color, and stability, or to create optical effects.  Treatment options include: fissure filling with oil, dying, heating, irradiation, surface diffusion, heating with borax, lattice diffusion of beryllium, lead glass fissure filling, and cobalt glass fissure filling.

		Glass infilling in blue sapphire was developed by Tanusorn Lethaisong in Chantaburi in 2007, and in May 2012, a “new” type of cobalt-colored sapphire became available in the Bangkok market. Christopher P. Smith, in his recent article (“Cobalt-Colored Composite Sapphires,”InColor, Spring 2013,No. 22, pp. 32−37), explains what the fuss was all about.

		He discovered the sapphires to be a composite of natural, low-grade corundum and a high-lead glass that induces blue coloration and enhances clarity. The result is a sapphire with a medium-saturated color.

		These stones are not a challenge for a trained gemologist to identify. Gemological properties include readily evident color concentrations in surface reaching fissures and cavities, innumerable spherical to flat contraction bubbles, a “flash effect,” naturally occurring crystals, and short, fine unaltered rutile needles. The intact rutile indicates that the treatment takes place at relatively low temperatures.

		Figure 1:  Spherical to flattened contraction bubbles, irregular black reflective particles, “flash effect,” and color concentrations are observed in these glass-filled sapphires. Photo courtesy of Christopher P. Smith, InColor.

		The refractive index of the lead glass is similar to that of the host corundum, but the glass has a lower hardness. As a result, the polished surfaces of the stones reveal a mosaic network of narrow to thick tracks of glass. The stones glow bright red with the Chelsea filter. Using a standard hand-held spectroscope, a series of three distinct absorption bands positioned at approximately 528, 588, and 635 nm readily identify cobalt to be the main coloring agent. Such cobalt-related absorption bands do not occur naturally in sapphire.

		Figure 2:  Broad absorption bands centered at approximately 528, 588 and 635 nm identified the coloring agent as cobalt. Photo courtesy of Christopher P. Smith, InColor.

		Infrared spectroscopy recorded absorption bands at approximately 2290, 2620 and 3490 cm-1. These bands are related to the glass component of the composite sapphires. These specimens require special care, as standard manufacturing and bench jeweler practices, as well as household products can readily cause damage by etching the glass. The product has been classified as “composite sapphire” by the AGL (American Gemological Laboratories).  An in-depth study by Leelawatanasuk et al. (“Cobalt-doped glass-filled sapphires; an update”, The Australian Gemmologist, ,Vol. 25, No. 1, 2013, pp. 14–20)  provided additional information on the properties of the cobalt-colored composite sapphires. The report noted slightly elevated specific gravity in some specimens and a lack of pleochroism.DiamondView images showed a chalky blue fluorescence caused by the glass-filled fissures, and filled fractures appeared white on X-ray images.

		The value of a gemstone depends on its inherent beauty and rarity. The artificial modification of a gemstone greatly reduces the rarity and therefore lowers the value. Treatment of these “composite sapphires” requires special care to retain it, or else the benefit of the treatment will be lost over time. The Federal Trade Commission therefore requires proper disclosure to buyers. @chapter:12


Publication Year: - Title: Sri Lanka: From Mine to Market, Part 1 Abstract: Sri Lanka’s gemstone and jewelry industry blends traditional practices and experience with the needs of the modern global market. Photo by Andrew Lucas/GIA.

                      To visit Sri Lanka is to experience one of the great gem sources and trading centers in the world. This country has a rich, almost unparalleled tradition and remains vitally important to the modern gemstone market. Sri Lanka has a true mine-to-market industry, both domestically and for export. Its evolution over the last two decades blends the best of traditional practices with modern technologies and business models.

In this field report, we take you on an expedition to this magnificent island and its remarkable mine-to-market industry.

Sri Lanka has produced a wide variety of gemstones, including cat’s-eye chrysoberyl. Photo by Andrew Lucas/GIA.

	An Amazing Island
Traveling in Sri Lanka, you realize it is a large island with very diverse environments. Most of the terrain consists of flat or rolling hills, but there are beautiful mountains in the southern central interior. Agriculture is a constant presence as you drive around the country, with intense green rice fields and rubber tree plantations.

In Elahera’s rice fields, there are treehouses for agricultural workers to climb into when a herd of wild elephants passes through. In Ratnapura, Elahera, and Balangoda, green rice fields also enclose small pit-mining operations, sometimes covered with V-shaped roofs for a little protection from rain and sun. Gaining elevation, you encounter beautiful tea plantations where it is common to see workers picking tea leaves by hand. Driving along the coast offers views of Sri Lanka’s beautiful coastline and fishing industry.

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	Island Images
Sri Lanka has two monsoon seasons that occur at different times of the year depending on the part of the country. The northeast has monsoons from December through March. In the southwest, where most of the mining takes place, the monsoon season lasts from June to October. As in many places throughout the world, weather patterns in recent years have not been as predictable as they were in the past. We encountered mostly good weather, but intermittent rainstorms occurred regularly, interrupting mining operations.

	History, Culture, and People
It is believed that Sri Lanka has been inhabited by humans for more than 300,000 years. The main ethnic group is the Sinhalese, representing about 73 percent of the population. They arrived from India in about the late sixth century BC. Buddhism came to Sri Lanka around the third century BC, and today it is the main religion of the Sinhalese people and the island. The Tamil people, from the Tamil area of India, are primarily Hindu. There is also an important Muslim and Christian population, leading to a rich diversity that is reflected in domestic jewelry design preferences, especially for weddings.

Sri Lanka's rich cultural heritage has become a major tourist attraction as visitors seek to learn more about this island and its people, which in turn has stimulated the economy. One of the cultural heritage sights we visited as we traveled to gem mining areas was Sigiriya, a UNESCO World Heritage site.

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	Sigiriya Images

	Experiencing Sigirya

	Tradition, Experience, and Modernization: The Best of All Worlds
In documenting Sri Lanka’s entire mine-to-market industry, one of the most fascinating aspects is the harmonious and productive blend of tradition, experience, and modernization. This was apparent in the mining, trading, cutting, treatment, jewelry manufacturing, and retail sectors. Mining is done primarily by traditional methods, and it is small-scale by choice and design. Cutting is a fascinating blend of hand-powered techniques, utilizing some of the world’s greatest expertise in orientation of rough, and a growing precision cutting and recutting industry that maintains the strictest tolerances.

	Cutting in Sri Lanka often relies on decades of experience rather than sophisticated or automated techniques. Photo by Andrew Lucas/GIA.
The trading sector combines knowledge and experience acquired over decades, if not centuries, with modern global business models. Just as mastering sapphire heat treatment helped the Thais become dominant players in the global corundum market, the Sri Lankans have great expertise in getting the best yield and color out of sapphire.

Jewelry design and manufacturing is directly tied to the domestic retail market as well as the market for Sri Lankans living abroad. Traditional 22K gold jewelry is in high demand for weddings as well as for investments and as a financial asset to pawn in times of need. At the same time, the market has adjusted to a younger generation with more varied tastes, while aiming to increase tourist purchases and broaden export markets.

	Pits, Mud, Gravel, and Gemstones
Gemstone mining in Sri Lanka is mostly from secondary deposits. The gravels yield sapphire, ruby, cat’s-eye and other chrysoberyls, spinel, garnet, beryl, tourmaline, topaz, quartz, and many other gemstones. Sri Lanka’s gem-bearing gravels, called illam, are some of the richest in the world. The island was blessed with geological conditions that provide an ideal blend of chemistry, heat, pressure, time for gem crystals to grow, and weathering for the gem crystals to be deposited and concentrated in gravels.

Gemstone deposits in Sri Lanka contain gem-bearing gravels called illam. Photo by Andrew Lucas/GIA.
Besides the well-known Pangaea, which existed about 300 million years ago, there were several other supercontinents in Earth’s early history. Their assembly and breakup cycles helped form most of the world’s gem deposits. Some of these cycles are directly related to gem formation in Sri Lanka.

Assembly of the Gondwana supercontinent was a slow process that took place over millions of years, between 550 and 950 million years ago (Ma), when global forces led to large-scale structural changes in the earth’s crust and upper mantle. The resulting collisions formed the Mozambique Belt, which extends from Mozambique to Ethiopia and Sudan, and also covers most of Madagascar, the southern tip of India, Sri Lanka, and the east coast of Antarctica. Sri Lanka occupied a critical area of Gondwana, and many of its gemstones are believed to have formed between 539 and 608 Ma, a time of peak metamorphism for the area.

Most of the gem deposits are in an area called the Highland Complex, extending northeast to southwest and containing high-grade metamorphic rocks. One major primary sapphire deposit was discovered by accident in 2012 near Kataragama, but it was not producing at the time of our visit, and subsequent mining of the area has produced no commercial yields. A full geological study of the deposit has not been performed, however, so the true potential of this area remains unknown.

	The Highland Complex of Sri Lanka is the most important area for formation of
	gemstone deposits. Illustration by Peter Johnston, © GIA.

Sri Lanka’s commercially important colored gemstone deposits come from weathered alluvial gravels. We visited the mining areas around Ratnapura, Balangoda, and Elahera. Although these make up only a small percentage of the island’s gem deposits, they gave us a representative overview of mining operations throughout the country. All of these were secondary gravel deposits. We did not find any active primary deposits at the time of our visit.

The mining operations we visited represented all three types of Sri Lankan gemstone mining: pit, mechanized, and, in this case, river. Photo by Andrew Lucas/GIA.

	Mining
Mining licenses in Sri Lanka are regulated by the National Gem and Jewellery Authority (NGJA). Of the more than 6,500 licenses issued in 2013, more than 6,000 were for pit-mining operations using traditional methods. The remainder went to river and mechanized mining. Licensing for mechanized mining follows very strict guidelines, and only about ten were issued in 2013.

	Most of the gemstone mining in Sri Lanka done by hand in open pits. At this larger pit,
	miners toss up the gravel in baskets. Photo by Andrew Lucas/GIA.
Many of the trade and regulatory bodies in Sri Lanka are against large-scale gemstone mining. They consider traditional small-scale mines less harmful to the environment and a more stable source of employment for more people.

To give an idea of scale, the standard pit mine in Sri Lanka consists of a vertical shaft that measures two by four meters. If the pits are deep and in harder ground, the miners might dig a two by two meter square pit or a two-meter round pit. Depth can range up to 50 meters, though most pits are between 5 and 25 meters.

	Most pit-mining operations in Sri Lanka are relatively small vertical shafts. Mining relies
	on muscle power, not mechanization. Photo by Andrew Lucas/GIA.
Many of the licensees have four to five traditional mining pits on their property. It’s estimated that more than two million pits have been dug over the last 50 years. Compared to gem mining in many African countries, there are hardly any unfilled, abandoned pits. This is partly because the National Gem and Jewellery Authority (NGJA) collects a cash deposit when a license is issued. If the mine owner does not rehabilitate the land after mining is complete, the NGJA uses the deposit money for that purpose.

There are usually several people involved in the venture, including the landowner, the holder of the mining rights, the person who supplies the water pump to remove water from the pit, and the miners. They all receive a share of the proceeds from the sale of the gemstones.

Although not as prominent, river mining is another traditional form of gem mining in Sri Lanka. Rivers in gem-producing areas can contain alluvial deposits where the river bends or otherwise slows down. The river miners pick these slow-moving areas in relatively shallow waters and build a dam of wood or rock where the water slows, allowing it to escape from one side while trapping the gravels.

Mechanized gem mining is very limited in Sri Lanka. Photo by Andrew Lucas/GIA.
Using metal blades attached perpendicularly to long wooden poles called mammoties, the miners scoop up the gravel and remove the overburden until they reach the illam. Then they use long pointed steel rods to loosen the illam and drag it up, allowing the rushing water to wash the gem-bearing gravel. They remove any visible gemstones, and the remaining gravel can undergo further washing.

Mechanized mining occurs when it’s determined that traditional methods won’t apply to the deposit at hand, if the concentration of gems is too low for pit mining, or if the threat of illegal mining activity requires quick mining of the deposit. There are a limited number of mechanized operations, and the requirements are stringent.

	Cutting
It is easy to overlook the importance of traditional cutting in Sri Lanka, which is often associated with bulky cuts. These traditional cutters use simple hand-powered cutting machines to produce some of the best-oriented stones in the world. Their ability to orient a stone for the best face-up color or placement of a star or cat’s-eye, while retaining maximum weight from the rough, is remarkable.

	Their equipment appears primitive, but the skill level of Sri Lanka’s traditional cutters is unsurpassed among traditional cutters. They have a wealth of experience in orienting a rough stone to obtain the best face-up color. Photo by Andrew Lucas/GIA.

	Expert Cutting in Colombo

Traditional cutting may in fact be the best technique for some high-end sapphires or stones where the placement of color is critical. There is also a growing demand for Sri Lankan recutting to meet customer specifications. Global clients have different proportion expectations—some allow windows, for instance—and recutting stones that have already been oriented for best color can make them less bulky. The cutters can remove enough windowing to suit a customer’s needs while retaining as much weight as possible. There is also a growing precision-cutting industry in Sri Lanka that meets the strictest tolerances of proportion, symmetry, and calibrated size tolerances.

	Precision Cutting

	Interviewing a Master Cutter

	Trading
Surpassed by Thailand in the 1970s and ’80s, Sri Lanka has modified its business strategy and import/export regulations to restore its position as a major global power in colored gemstone trading. By simplifying the import process and removing prohibitive duties, Sri Lankan dealers are now able to buy rough sapphire from anywhere in the world, including major sources such as Madagascar. They can apply their knowledge and be competitive in obtaining the raw materials to fuel their industry. Abandoning protectionist import regulations on rough from foreign sources has actually saved Sri Lanka's gemstone industry from remaining a smaller player. A smoother export process has also attracted foreign buyers to the country.

Foreign buyers often work with trusted local contacts who bring in a wide variety of inventory from other dealers to their offices. Photo by Andrew Lucas/GIA, courtesy Sapphire Capital Group-Sapphire Cutters.
We visited Sri Lankan dealers in Colombo and Beruwala, as well as mine markets in Ratnapura, Balangoda, and Elahera. The mine markets were bustling with activity among Sri Lankan dealers and foreign buyers. The dealers were often in the outdoor street markets and in offices or cutting facilities. There were also heat treaters, known as burners, at all of the major markets. Many of the foreign buyers sought the guidance of a trusted local dealer who would have other dealers bring in goods for sale. These trusted dealers would also be consulted for quality, price, and the potential for recutting and further heating.

Beruwala has a large, bustling street market for gemstones. Photo by Andrew Lucas/GIA.
New consumer markets such as China have revitalized gem trading in Sri Lanka. This has led to increased imports from global sources, while fueling the need for Sri Lankan dealers’ expertise and experience to satisfy the demands of Chinese manufacturing and domestic consumption.

	Inside the Sri Lankan Gem Trade

	Coming Next
In Part Two, we will reveal aspects of the Sri Lankan gemstone and jewelry industry that have seldom been covered, especially by outsiders. The country’s jewelry manufacturing and retail industries are very dynamic, blending strong traditions with important innovations. These sectors of the Sri Lankan industry are very different from their counterparts in other parts of the world such as the United States, Europe, Japan, and China. We will show you the sites we visited so you can get a better sense of this famous and exotic trade center. @chapter:22


Publication Year: 1989 Title: Emerald and Gold Treasures of the Spanish Galleon Nuestra Señora de Atocha Abstract: During the 1970s and 1980s, treasure hunters discovered the centuries-old remains of the sunken Spanish galleons Nuestra Señora de Atocha and Santa Margarita. Not only did they find massive amounts of silver and gold in coins, bars, and chains, but they also uncovered a number of rough emeralds and several pieces of emerald-set jewelry. Recently, some of the treasures recovered from the Atocha were examined at the Santa Monica office of the GIA Gem Trade Laboratory. Gemological testing of the emeralds revealed inclusions typical of stones mined in Colombia as well as possible evidence of extended submersion in seawater. Study of the jewelry revealed a high-karat gold content and fine workmanship that represented methods typical of the era. @chapter:25


Publication Year: - Title: Professional Jewelry Designers Offer Tips to Students Abstract: Paul Klecka encouraged students to focus on what they do best. “You can always hire out the rest,” he said. Photo by Eric Welch/GIA

                      Learn as much as you can. Understand that you’re probably going to have to start at the bottom. Follow your passion. And most importantly, believe in yourself.

This is just some of the advice members of the American Jewelry Design Council (AJDC) shared with GIA students when they visited the Carlsbad campus last week. The designers were in California for their annual meeting and took the opportunity to tour the campus and participate in a panel discussion on how to succeed as a designer. Here are more of their tips:

DON'T STOP LEARNING

Get as much education as you can in all aspects of the jewelry business. -- Mark Schneider

Learn as much as possible about what you’re interested in. “Learn through academic classes -- stone setting, rubber mold making, design, fabrications -- so you can speak the language. Then you can speak to your customers, vendors, suppliers or people who are going to work for you, and fully understand this medium. The more knowledge you have, the broader base you have and the more appealing you’ll be to somebody else. Then, if an opportunity comes up, you’ll be able to fill it.” -- Alan Revere

Figure out what your strengths are and focus on them. Get other people to help you with the other aspects of your business (managing, selling, etc.). “It’s hard to have (and use) the left brain and the right brain in the same person.” -- Scott Keating

Learn how to render your designs digitally. “There are jobs out there, but they want you to know Photoshop and Rhino on the computer.” -- Diana Vincent

GET YOUR NAME OUT THERE

Use Facebook and Twitter. “You can do a lot and get your name out there and get exposure for very little money.” -- Keating

Send your portfolios to jewelry magazines. “You’ll be surprised how much they use them; they’re looking for things to talk and to write about.” -- Susan Sadler

Get your jewelry on people. “If that means giving it away, give it away. If it means selling it, sell it. It doesn’t do any good to be in your drawer, so try and spread it around.” -- Revere

Go to every trade show you can. “Have your resumes ready -- it’s face-to-face-contact and exposure.” -- Schneider

Connect and network at conferences. (Two suggestions: Society of North American Goldsmiths, American Craft Council). “Go and see what everyone else is doing and you’ll meet an enormous number of people who have the same questions and problems, but they share their solutions.”  -- George Sawyer

Wear your own jewelry. “Everybody should be wearing their jewelry -- it attracts people’s attention … and they’ll ask about it.” -- Revere

	Students hung on every tip the designers offered. Photo by Kevin Schumacher/GIA
BECOME BUSINESS-SAVVY

You will have to pay your dues. “No one here is an overnight success. Keep your faith and plan on working extremely hard. Take entry-level jobs. They may not pay very well, but it’s the best information and you’ll learn more from on-the-job experience than anything else.” -- Schneider

Don’t try to chase the market – chase your own ideas. “Always reserve a portion of your life for the reason you probably started out, and that is to make things that you like to make. Don’t try to chase the market to see what’s selling … it’s a mistake a lot of people make and you can never catch up. To make yourself be original is more fun.” -- Sawyer

There is no specific formula for success. “There is no specific data that will tell you: you do one, and then after one, you do the second, third, fourth and fifth steps and you’ll become a successful designer or businessman.” -- Alishan Halebian

Make the leap from artist to business negotiator. “If a buyer is wowed by your work, approach [the negotiations] from a reality base and say ‘Look I’m a young artist, I’m just starting out, you love what I did, so you need to buy it because I can’t afford to finance your store. You need to pay me up front or you need to pay me half now so I can make the pieces, then pay me half on delivery. If you cannot do that, I’ll take my fabulous piece and market it elsewhere.’ And believe me, if it’s that fabulous, someone will want it and go on those terms. Don’t be afraid to explain that you're small and starting out or don’t have the ability to financially make the deal the way they might expect. Don’t undersell yourself and always base your negotiations on your own capabilities based on reality.”  -- Paul Klecka

Get it in writing. “You might want to have a consignment contract in place if you leave your work with the store. Talk to other artists about what the wording of a contract would be or ask the gallery or store if they have a contract.” -- Barbara Heinrich

Work within your ability to fulfill orders. “Grow within the abilities you have. If [the order] is going to be something that can’t be fulfilled or you can’t make it to the quality and controls you want, I would advise you to stay within your abilities to fulfill it. Then you’ll grow. Every sale you make you’ll learn something from.” -- Schneider

Jump in with both feet. “Don’t hold back. Don’t wait for anyone to come to you. It doesn’t matter what you do, but you have to be true to yourself and do it with a lot of enthusiasm and then it will come to you.” -- Sawyer

	Christoph Krahenmann acknowledged the difficulty of getting started in a down economy, but urged students to believe in themselves. Photo by Kevin Schumacher/GIA
IT'S ALL ABOUT THE DESIGN

Design drives the planet. “It’s what makes people want to buy the new iPhone 3GS --they’re sleeping on the sidewalk to get it, right? Look at a company like Crocs that came out of nowhere with innovative rubber footwear … it’s great stuff and it’s for a lot of people. It’s not exclusive, it’s inclusive. Somewhere someone was inspired to do it, whether it’s a phone or shoes.” -- Klecka

Find your own style. “Look what’s out there so you know what not to do, then find your own truth and try to be original, then you’ll stand out.” -- Vincent

Brand your designs. “Put a design element in that is uniquely yours, you’ll develop a brand that will be recognizable for you.” -- Schneider

Spend your time on design pieces you love. “When you say, ‘Oh, I’m going to design something that’s going to sell in this price range,’ you’re starting from the bottom [of your ideas]. That energy comes out in the piece and I can guarantee nobody’s going to want it. You have to love that piece, and when you love it -- even when you’ve scaled it down [from your original idea] to meet the [market] criteria -- that energy will get across to the customer. They’ll feel it without even knowing it, and it will sell.” -- Vincent

Trust yourself and your message. “You matter and your unique vision of this world and what’s important and your values, matter. It’s important that you trust yourself and connect with yourself to bring your vision forward to make this world a more joyful, wonderful place. There is no right or wrong. ” -- Heinrich

Create an emotional response. “If what you do in your designing, or in your career, can create an emotional response with others, then you’ve succeeded.” -- Klecka @chapter:36


Publication Year: 2016 Title: Trapiche Rhodochrosite Abstract: Figure 1. The trapiche-like rhodochrosite “flower” on the left, measuring 30 mm across and weighing 35 ct, is from Argentina’s Capillitas mine. This piece appears to be formed by the intersection of three crystals, with 60° of separation. The 56 ct rhodochrosite specimen on the right, also from the Capillitas mine, measures 40 mm across. Photos by Russell E. Behnke; from the author’s collection.

	It is not often that a very old locality produces a gem material previously unrecorded in the literature. Yet the Capillitas mine in Argentina’s Catamarca Province, once mined by the Incas and long known for its fine rhodochrosite stalactites, has yielded two trapiche-like rhodochrosite gemstones, first observed by the author in August 2014.

	The stalactite that produced these two slices was reportedly found in the 1980s. The smaller of the two specimens, a 30 mm round weighing 35 ct (figure 1, left), is a symmetrical example of this rhodochrosite’s cogwheel habit. The 40 mm oval, which weighs 56 ct (figure 1, right), was cut from the same stalactite; it is the only other example of this formation the author could locate.

	Rhodochrosite from the Capillitas mine typically consists of minute crystalline grains. These two examples, however, are very coarsely crystalline and are quite possibly twinned, which would explain both the unusually large size of these crystals and their obvious symmetry.

	Dr. Carl Francis, former curator of the Mineralogical Museum of Harvard University, points out that stalactites of calcite, which are chemically and structurally similar to rhodochrosite, rarely exhibit this type of growth (pers. comm., 2014). The floral pattern of these red gemstones makes them beautiful and incredibly rare. @chapter:5


Publication Year: 2017 Title: The World’s Biggest Diamonds: Windows into the Earth’s Deep Mantle Abstract: For geoscientists and gemologists alike, the origins of large, high-clarity, and relatively pure diamonds, like the Cullinan and the 812.77 ct Constellation on the cover of this issue, have long been an enigma. In a December 2016 Science article, a team of researchers led by GIA’s Dr. Evan Smith provided important insights into how these rare and extraordinary gems form deep in the earth’s mantle.

Natural diamonds are science’s best tools for understanding the depths of the earth.

That article presented evidence that such Cullinan-like, nitrogen-poor “CLIPPIR” diamonds contain high-pressure mineral inclusions that are only stable at depths of 360–750 km (approximately 225–465 miles). By contrast, the bulk of gem-quality diamonds form in the base of continental tectonic plates at depths of 150–200 km (95 to 125 miles). Inclusion-bearing CLIPPIR diamonds constitute only 1 in 10,000 of those submitted to GIA’s laboratories. The inclusions these big diamonds carry—iron-nickel metal with minor sulfur and carbon—truly are a window into the earth’s deeper mantle. In our lead paper, Evan Smith and Wuyi Wang partner with Steven B. Shirey of the Carnegie Institution for Science to build on the landmark Science article. They provide more detail on the key features of these remarkable diamonds as well as data on additional samples.

Our second paper, by Robert Weldon, Cathleen Jonathan, and Rose Tozer of GIA’s Richard T. Liddicoat Library, explores the astonishing work of a multigenerational family of gem carvers: the Drehers of Idar-Oberstein, Germany. The authors focus on the contemporary craft of Gerd Dreher and his son, Patrick, artisans with an unerring ability to channel the spirit of the animals they model from high-quality rough gem minerals and richly patterned agates.

In our third paper, Laura Otter, Oluwatoosin Agbaje, Le Thi-Thu Huong, Tobias Häger, and Dorrit Jacob present the first gemological characterization of Australian akoya cultured pearls using Raman, photoluminescence, FTIR, and UV-Vis spectroscopy. Unlike many other akoyas, these Australian examples are marketed without any post-harvest treatments involving dyes or bleaches.

Next, Jennifer Stone-Sundberg, Timothy Thomas, Ziyin Sun, Yunbin Guan, Zachary Cole, Randy Equall, and John Emmett introduce a set of new reference standards designed to improve the quality of trace element analysis in ruby and sapphire. These standards use corundum substrates rather than the typical silicate glasses produced by the National Institutes of Standards and Technology (NIST). This important paper documents the development of corundum sets with precisely known levels of beryllium, magnesium, titanium, silicon, vanadium, chromium, iron, and gallium using secondary ion mass spectrometry (SIMS).

Stefanos Karampelas, Abeer Tawfeeq Al-Alawi, and Ali Al-Attawi provide a comparison of real-time X-ray microradiography (RTX) units fitted with different detectors. Their analysis demonstrates the superior resolving power of a flat panel detector (FPD) over an image intensifier (II) for interpreting fine detail in a pearl’s internal growth structure.

And to complement our emerald and sapphire charts from Winter 2016 and Summer 2017, we present a new one featuring some characteristic internal features of natural, treated, and synthetic ruby. This chart is from GIA’s team of inclusion specialists, led by Nathan Renfro and John Koivula.

As always, there’s something for every gemological taste in our Lab Notes, Gem News International, and Micro-World sections.

Finally, I encourage you to join us for the 2018 GIA Symposium, October 7–9 in Carlsbad, California. This promises to be an unforgettable learning and networking event. You can register to attend or submit an abstract for an oral or poster presentation at symposium.gia.edu. @chapter:29


Publication Year: - Title: Winter 2016 G&G: Exploring Jaipur’s Gem Industry, New Gem Sources, and Inclusions in Emerald Abstract: In recent years, the Indian city of Jaipur has emerged as a cutting, manufacturing, and retail powerhouse. The lead
article in this issue looks at the city’s history and profiles some of its more prominent jewelers. The cover shows a
bracelet created by Jaipur’s Birdhichand Ghanshyamdas Jewellers. Inspired by the Amer Fort, a UNESCO World
Heritage Site, the bracelet is comprised of canary diamonds, polki diamonds, and a stunning emerald at its center.
Photo by Robert Weldon/GIA, courtesy of Birdhichand Ghanshyamdas Jewellers.

	The Winter 2016 issue of Gems & Gemology boasts a wealth of information blending the old and the new. The lead article profiles the emerging powerhouse of Jaipur, India. The legendary colored gemstone cutting center has become a jewelry manufacturing and retail giant to rival other major players in the industry. Other features include the early synthetic emeralds of Richard Nacken, Vietnamese danburite, and field report from Mozambique, and a wall chart of emerald inclusions.

	JAIPUR, INDIA: THE GLOBAL GEM AND JEWELRY POWER OF THE PINK CITY

	Rubies in a modern invisible setting are combined with polki diamonds in this fusion-style ring. Photo courtesy of Birdhichand Ghanshyamdas Jewellers.

The northern Indian city of Jaipur, long a center for colored gemstone cutting, has expanded to include jewelry design, manufacture, and retail. A team led by Andrew Lucas and Nirupa Bhatt explores the city’s historical relevance to the gem trade and visits several local manufacturers and retailers to examine the scope and impact of their operations.

	SYNTHETIC EMERALDS GROWN BY RICHARD NACKEN

	Synthetic emeralds produced by Richard Nacken in the mid-1920s. Nacken left these and other samples to his family, and they are now in the possession of his grandsons. Photo courtesy of E. Schlatter.

	Dr. Karl Schmetzer and his coauthors recount an important milestone in gemology: the first gem-quality synthetic emeralds of facetable size. The article reviews the events that led to Nacken’s successful emerald growth, along with the chemical, morphological, and microscopic properties of his production. They also address longstanding speculation that Nacken collaborated with IG Farben on synthetic emerald growth.

	A NEW FIND OF DANBURITE IN THE LUC YEN MINING AREA, VIETNAM

	Five rough danburite crystals, in sizes up to 2.5 cm, were found at the Bai Cat deposit in Luc Yen, Vietnam. One, weighing 26.3 ct in rough form, was cut into the 4.6 ct faceted oval. Photos by Le Thi-Thu Huong.

Danburite has been discovered in the gem-rich region of Luc Yen, Vietnam. The rare material, found in 2015, is honey yellow in color and shows excellent transparency. A team led by Le Thi-Thu Huong investigates the properties of this new find.

	INCLUSIONS IN NATURAL, SYNTHETIC, AND TREATED EMERALD

	This emerald contains a brown crystal of the rare mineral parisite. There is also an oil-filled cavity showing a blue and orange flash effect, along with two large trapped gas bubbles. This inclusion suite verifies the natural origin of this emerald; it also confirms that the stone, which shows signs of clarity enhancement, is from Colombia. Photomicrograph by John I. Koivula; field of view 3 mm.

	The Winter issue boasts a new wall chart displaying common inclusions found in natural, synthetic, and treated emerald. Among the contributors to the chart are inclusion specialists John Koivula, Nathan Renfro, Jonathan Muyal, and Shane McClure. The accompanying article provides a brief overview of inclusion studies.

	UPDATE ON GEMSTONE MINING IN NORTHERN MOZAMBIQUE

	A parcel of mainly green and yellow tourmaline from Ocua, Mozambique. Photo by Vincent Pardieu/GIA.

	In 2016, a field gemology team from GIA Bangkok traveled to northern Mozambique to visit the world’s largest ruby source and to observe developments at various new deposits. The resulting field report by Wim Vertriest and Vincent Pardieu documents production of ruby, spinel, and tourmaline in the region, as well as plans for future operations.

	LAB NOTES

	Updates from GIA’s labs around the world include reports on a CVD synthetic diamond weighing over 5 ct, the largest HPHT synthetic diamond to date, and synthetic sapphire and synthetic spinel doublets.

	MICRO-WORLD

G&G’s photomicrography section features entries on chalcedony with quartz windows showing Brazil-law twinning, a demantoid from Namibia with sphalerite inclusions, and a feldspar with an apatite cluster just below the surface.

	GEM NEWS INTERNATIONAL

	Sapphire production from one day of mining in Tasmania. The trapiche-type sapphire in the center weighs 2.73 ct. Photo by Vincent Pardieu/GIA.

	The Winter GNI section includes a crystal of blue dravite-uvite tourmaline from Afghanistan’s Koksha Valley, a look at “trapiche-type” sapphire from Tasmania, and an investigation of “decorated” jadeite jade.

	2016 DR. EDWARD J. GÜBELIN MOST VALUABLE ARTICLE AWARD

	Readers are invited to vote for the Most Valuable Article from 2016. Click here to vote for the top three articles from our contributors; voting will remain open until Monday, March 7, 2017. All ballots will be entered into a drawing to win a one-year subscription to G&G. @chapter:28


Publication Year: - Title: Consumer Confidence, Jewelry Sales, On the Rise Abstract: The rough diamond market has been buoyed by a strong U.S. holiday season and anticipation of improving Chinese demand. Photo courtesy of Rio Tinto

The improving economy and continued employment growth in the U.S. have Americans looking past the news of the day to go out and spend money. In Asia, the revival in the Chinese consumer market seems to be picking up as large retailers there report strong sales gains.

U.S. consumer confidence edged upward in January, though a significant percentage of Americans remain ambivalent, probably over the long-term effects of the tax bill that took effect at the beginning of the year, according to the Conference Board’s monthly Consumer Confidence Survey.

“Overall, however, consumers remain quite confident that the solid pace of growth seen in late 2017 will continue into 2018,” the board said.

Tiffany & Co, reported an overall sales gain of 8% in its holiday sales report, with same-store revenues up 6% in the U.S. and 7% in Asia, noting that some “exceptional high jewelry creations” helped sales increase. The company expects sales to continue trending upward “in the middle single digits,” but said that “evolving product offerings and customer service experience” will be necessary to sustain this growth.

In addition, LVMH, the luxury conglomerate which owns Cartier, Bulgari and a number of high-market watch brands, reported a 12% same-store sales increase in its jewelry and watch division. Sales were up strongly in every market, the company reported.

Sales of jewelry in China took a sharp upturn in December, totaling just under $5 billion, nearly $1 billion higher than each of the previous six months, according to government statistics. The major Chinese jewelry retailers reported 5% to 12% growth in same store sales during the third quarter, following nearly two years of sales declines, and are generally expected to match or exceed those results when the year-end results are announced.

De Beers’ first cycle of the year totaled $665 million, which includes sights and other sales. Typically for January, it was a large allocation that was readily absorbed into the market after a successful fall season that saw some reductions in rough and polished inventories and improved cash flow that eased pressure from banks. The total was down significantly from the January 2017 cycle of $729 million, but De Beers’ CEO Bruce Cleaver noted that last year’s numbers were boosted by the take up of goods that had been deferred because of India’s demonetization of larger denomination rupee notes.

De Beers’ diamond production increased 22% to 33.5 million carats (valued at about $5.7 billion) last year after the opening of its Gahcho Kue mine in Canada and restoration of full production at Orapa in Botswana, the company announced. De Beers’ total rough sales came to 35.1 million carats as it marketed goods that were deferred from 2016. The discrepancy between De Beers’ rough production and sales may rise this year after it announced it would auction rough diamonds consigned by other mining companies.

Alrosa remained the world’s largest diamond producer by volume, mining 39.6 million carats, though, like De Beers, it sold about 1.5 million carats it had previously stockpiled. Its output rose 6% last year, despite a disastrous flood at Mir Mine that killed eight workers and forced the closure of its operations. Mir produced higher-value diamonds and its closure will likely result in a lower average per carat price for Alrosa’s production this year. The accident also postponed Alrosa’s plans to further privatize the company, reducing the government stake from 43.9% to 29%.
TUCSON SHOW
Reports from the Tucson gem shows indicate that demand for higher quality gems, untreated in particular, and popularly priced stones was strong, with the middle market remaining weak.

Demand for ruby, sapphire and emerald was good, according to trade press reports, though prices have declined because of increasing supplies.

With the growth in the market for distinctive jewelry at affordable prices, calls for amethyst, citrine, blue topaz and other less expensive gems have increased. Additionally, the market for unusual gemstones from designers who create limited or one-of-a-kind pieces is strong.

The Centurion Show in nearby Scottsdale saw lighter traffic, but much stronger buying than last year. Exhibitors noted that retailers seemed much more confident of a good year at this show. @chapter:27


Publication Year: 2013 Title: Peridot, Pyroxene, and Plagioclase: Mantle Megacrysts from Lunar Crater Volcanic Field in Nevada Abstract: Megacrysts within xenoliths transported by explosive volcanic eruptions to the surface are fingerprints of the earth’s upper mantle and possible collectors’ items.

Lunar Crater is located in Nye County, Nevada. It is a Quaternary alkali basaltic field with lava flows, cinder cones, and maars covering more than 100 square miles of Nevada desert. At numerous alkali basaltic volcanic fields in the western United States, ultramafic mantle xenoliths of peridotite, dunite, lherzolite, and monomineralic xenocrysts are found in lunar craters. Olivine, pyroxene, plagioclase, hornblende, and magnetite ranging from a few millimeters to centimeters are common megacrysts. These megacrysts are usually ejected from the volcanic vent as the cores of volcanic bombs. Bomb morphology can vary considerably due to different viscosities of lava. While these magacrysts can provide scientific information on the upper mantle composition, the authors are interested in their possible gemological significance. Peridot, the green variety of olivine, is reported to occur in nodules up to 50 cm. But the crystals are highly fractured, making them unfit for faceting. Plagioclase crystals from the lunar crater can be clear to translucent white and show typical feldspar twinning. Pyroxene megacrysts found in the lunar crater are usually the augite variety and apple green, bottle green, or nearly black.

Minerals in the Lunar Crater volcanic field are abundant and easily accessed. Volcanic bombs contain exotic xenocrysts of possible gem significance, making this a worthy destination for rock hunters.

Abstracted by Tao Hsu @chapter:4


Publication Year: - Title: Buried Treasure: GIA Team Documents Cheapside Hoard Abstract: This enameled gold hat ornament in the form of a salamander is one of the Cheapside Hoard’s most iconic pieces. The enameling on the front shows an open mouth with tiny black flecks resembling teeth. The pin is decorated with cabochon emeralds from Colombia, and the tail contains table-cut diamonds. Courtesy of the Museum of London; photo by Robert Weldon/GIA.

GIA photographer Robert Weldon and videographer Kevin Schumacher traveled to the Museum of London to learn about the Cheapside Hoard, an extraordinary treasure that had been buried under a London tenement house for centuries.  The duo spent 10 hours interviewing, photographing and filming museum staff about the collection before it went on exhibit in October 2013.

The significance of this find is summed up best by Hazel Forsyth, the Museum of London’s senior curator of medieval and post-medieval collections, who has devoted her life to uncovering the mystery of the Cheapside Hoard:

“This collection is unique in the world. It is the largest hoard of its kind, dating from the very late
16th to the early 17th century. Part of the reason why it’s so important is that jewelry tends to be broken up, refashioned, reworked, and so therefore doesn’t survive. Because this was buried and lay undisturbed for the better part of 300 years, it survived in the condition that it has. And it covers a huge spectrum of jewelry designs and types, but also gem material from many parts of the world, which really underlines London’s role in the international gem and jewelry trade in this period.”

Weldon and Cathy Jonathan, a research librarian for GIA, share the history of the Cheapside Hoard in the Fall 2013 issue of Gems & Gemology. @chapter:21


Publication Year: 2022 Title: Two Black Non-Nacreous Bead Cultured Pearls from Pinctada margaritifera Abstract: Figure 1. Left: Two black pearls, a 15.16 ct near-round and a 22.19 ct button, shown on the nacreous interior surface of a Pinctada margaritifera shell. Right: The pearls both had a similar vitreous luster and a non-nacreous surface. Photos by Annie Haynes.

Figure 2. The button-shaped pearl displayed two different surface appearances. The main body was composed of a non-nacreous surface with calcite cellular structure, while the circled area at the base of the pearl had a nacreous surface with an aragonite platelet structure. Photomicrograph by Artitaya Homkrajae; field of view 16.24 mm.
The laboratory in Carlsbad recently received for identification two black pearls, one near-round and one button. The near-round pearl weighed 15.16 ct, while the button weighed 22.19 ct, with dimensions of 13.17 × 13.02 mm and 14.81 × 14.52 mm, respectively. Both displayed a similar vitreous luster and a non-nacreous surface appearance (figure 1). The button-shaped pearl also exhibited a nacreous surface on a small circled area at the base (figure 2). Microscopic examination using fiber-optic illumination revealed that the non-nacreous surface was composed of a mosaic or cellular pattern, resulting from the acicular nature of the individual calcite crystals. Some fine surface lines were also present in random directions across the cellular structures (figure 3). These cellular structures resembled those commonly observed on pen pearls from the Pinnidae family (N. Sturman et al., “Observations on pearls reportedly from the Pinnidae family (pen pearls),” Fall 2014 G&G, pp. 202–215).

Figure 3. The non-nacreous surface of both pearls exhibited a similar cellular structure that could be viewed under high magnification using fiber-optic illumination. Some fine surface lines were present in random directions across the cellular structures. Photomicrograph by Artitaya Homkrajae; field of view 1.59 mm.
A Raman spectrometer with 514 nm argon-ion laser excitation was used to examine the surface composition. The non-nacreous surfaces of both pearls showed a calcite spectrum with peaks at 712 and 1085 cm–1, and aragonite peaks at 705 and 1085 cm–1 were recorded on the nacreous surface at the circular base of the button-shaped pearl. Energy-dispersive X-ray fluorescence chemical analysis showed low levels of manganese and high strontium content, confirming the pearls formed in a saltwater environment.

Figure 4. RTX imaging revealed a round bead nucleus in the center of each pearl, indicating the pearls were bead cultured. Images by Stephanie Shaw.
The large size, black bodycolor, and cellular structure of the pearls looked similar to the unusual non-nacreous natural pearls reportedly from Pteria species (S. Karampelas and H. Abdulla, “Black non-nacreous natural pearls from Pteria sp.,” Journal of Gemmology, Vol. 35, No. 7, 2017, pp. 590–592) and a bead cultured (BC) pen pearl (Winter 2014 GNI, pp. 305–306) previously reported. Under long-wave ultraviolet radiation (365 nm), the pearls exhibited very weak yellow fluorescence that differed from the strong orangy red fluorescence observed in non-nacreous Pteria pearls. Real-time microradiography (RTX) revealed a round bead nucleus in the center of both pearls, indicating BC pearl origin (figure 4) similar to the previously reported BC pen pearl. Nevertheless, the ultraviolet/visible reflectance spectrum collected on the button pearl’s nacreous surface showed a typical reflectance feature at 700 nm, a key mollusk identification feature attributed to Pinctada margaritifera pearls (K. Wada, “Spectral characteristics of pearls,” Gemological Society of Japan, Vol. 10, No. 4, 1983, pp. 3–11, in Japanese). The reflectance features at 405 and 495 nm normally observed in naturally colored gray to black nacre of P. margaritifera shells were also present. Combining the cellular surface structures, BC origin, saltwater environment, and spectroscopic characteristics, we were able to conclude that both were non-nacreous BC pearls from the P. margaritifera mollusk.
All pearls are formed from calcium carbonate (CaCO3) polymorphs such as aragonite and calcite together with organic substances as well as water. The most common form of CaCO3 in pearls is a layered structure of aragonite platelets. This structure is the reason pearls display a nacreous surface and pearly luster. A non-nacreous surface indicates a pearl that formed from CaCO3 but not with an aragonite platelet microstructure. Conch and Melo pearls are non-nacreous pearls that possess an aragonite fibrous or lamellar structure that display flame-like surface patterns. Scallop pearls are non-nacreous pearls made of calcite in a honeycomb patchwork of cells. Pen pearls mentioned previously are another type of calcite pearls with a cellular structure.
These two special occurrences are the first non-nacreous BC pearls from P. margaritifera identified by GIA. Cultured pearls from this mollusk, both BC and non-bead cultured, typically display a nacreous surface and are often referred to as “Tahitian” pearls in the market. Genetics is probably the most important factor influencing the biomineralization of a pearl, yet many other factors can be involved such as water environment and health of the mollusk. Organic substances also play an important role in the biomineralization process (C. Jin and J. Li, “The molecular mechanism of pearl biomineralization,” Annals of Aquaculture and Research, Vol. 4, No. 1, 2017, p. 1032). In nature, many living organisms elaborately control the formation of biominerals for specialized functions such as mechanical support, protection, and mineral storage. Some mollusk species may produce different structures under certain circumstances. @chapter:14


Publication Year: 2023 Title: Unusual Solid Inclusions in Flame-Fusion Ruby Abstract: Figure 1. Numerous natural-looking dark red solid inclusions were observed in a flame-fusion laboratory-grown ruby. Photomicrograph by Ezgi Kiyak; field of view 2.9 mm.
The author recently examined unusual dark red solid inclusions in a flame-fusion laboratory-grown ruby. Standard gemological testing yielded a refractive index of 1.760–1.768, a chromium emission line in red using a handheld spectroscope, medium red fluorescence under long-wave UV, and weak red fluorescence under short-wave UV. These properties were consistent with ruby. Microscopic examination using brightfield illumination revealed numerous dark red inclusions (figure 1) that resembled crystals commonly seen within natural corundum.

Figure 2. Strong curved growth lines and numerous gas bubbles and dark solid inclusions were present in the flame-fusion ruby. Photomicrograph by Ezgi Kiyak; field of view 2.9 mm.
Furthermore, magnification showed characteristic internal features of flame-fusion ruby such as curved striae and gas bubbles. The strong curved growth lines and numerous gas bubbles (figure 2) suggested that this was an early type of flame-fusion ruby. Although flame-fusion corundum is widely available in the marketplace, it is unusual to encounter a specimen containing natural-looking dark red solid inclusions. These inclusions are possibly unmelted alumina powder, and the fact that Raman was unable to identify something other than alumina supports this (E.J. Gübelin and J.I. Koivula, Photoatlas of Inclusions in Gemstones, Volume 3, Opinio Publishers, Basel, Switzerland, 2008).
Identification of the natural or laboratory-grown origin of a stone with this type of natural-looking inclusion can be difficult. Careful observation is needed to correctly identify such a specimen’s origin. @chapter:12


Publication Year: 2023 Title: Sean Hill: Exquisite Jewelry Designs Abstract: Figure 1. The “Seven Sisters” ring in 18K gold with 17 bezel-set diamonds (0.55 carats total) and 22 sapphires ranging in size from 2.5 to 4.0 mm in blue, orange, mandarin, pink, and green (3.15 carats total). Photo by Robert Weldon; courtesy of Sean Hill Designs.
At the GJX show, Sean Hill of Tucson presented some striking jewelry designs with masterful control of shape and line. A gold ring set with diamond, blue sapphire, and fancy-color sapphire (figure 1) drew us into his booth. Dr. Hill, a self-taught jeweler, has been active designing and handcrafting jewelry since 1998, after a previous career as a university professor in literature and philosophy. His academic and philosophical nature is immediately evident when discussing design, and his meticulous attention to space and volume becomes more apparent the longer one studies his pieces. The “Seven Sisters” ring in figure 1 raises each stone to a unique height above the flat base, filling the rectangle with an appealing placement of 17 colorless diamonds interspersed among 22 sapphires.

Figure 2. “Rose Cut” 18K white gold and diamond earrings. The faceted diamonds are 1.5–2.0 mm in diameter. Photo by Robert Weldon; courtesy of Sean Hill Designs.
A stunning pair of 18K white gold earrings featuring both diamond slices and faceted diamonds (figure 2) is a case study in filling a plain geometric shape to bring it to life. As Dr. Hill said in describing the piece, “A rectangle is a basic shape, a self-imposed constraint. It is how you choose to fill it that makes it interesting.” Adding to the design quality, the rectangles are not actually flat but gently curved so that the earrings fit seamlessly on the ear.

Figure 3. “Event Horizon” earrings in 18K gold, diamond (0.07 carats total), and orange, mandarin, pink, green, and blue sapphire (5.2 carats total). Photo by Robert Weldon; courtesy of Sean Hill Designs.
A pair of 18K gold earrings with brilliant-cut diamonds and sapphires (figure 3) illustrates a modern and considered take on the classic chandelier earring, with squares and rectangles outlining floating round gems on delicate strings of gold. Dr. Hill explained some of his jewelry philosophy: “You can always take a stone for its beauty, color, and cut, set it into a finding, and it is all about the stone. But how do you make it into art?” @chapter:16


Publication Year: 2019 Title: Rough Diamond Crystal with an Unusual Coating of Fake Green “Radiation Stains” Abstract: Figure 1. This 6.49 ct rough diamond with patchy green surface color was submitted to GIA’s Carlsbad laboratory for a Colored Diamond Grading Report. Photo by Diego Sanchez.

Due to their rare occurrence and the environment required to create their color, natural green diamonds are some of the world’s most beautiful and sought-after gems. Most diamonds acquire their color from impurities or defects incorporated into the diamond lattice when the material is hundreds of kilometers deep in the earth’s mantle. But most natural green diamonds are colored by radiation damage that occurs at very shallow depths in the earth’s crust over long periods of time. Commonly accompanying this exposure to radioactive minerals and fluids are surface patches of green or brown color that gemologists call “radiation stains.” These are simply areas of extreme damage to the diamond structure caused by alpha particle radiation. Initially green, they turn brown immediately after exposure to temperatures above 500°C. These surface features indicate that a diamond has been exposed to a source of natural radiation; green stains are commonly associated with naturally colored green diamonds.

Figure 2. The diamond’s patchy green coloration is caused by interlocking platy crystals of chromium oxide, visible with magnification. Photomicrograph by Nathan Renfro; field of view 0.72 mm.

Figure 3. The Raman spectrum (514 nm laser excitation) of the rough diamond’s green coating shows clear peaks from chromium oxide (552 and 613 cm–1) as well as the underlying diamond (1332 cm–1). The specific positions of the chromium oxide peaks suggest the coating has been annealed to ~700°C (Mohammadtaheri et al., 2018).
Recently, GIA’s Carlsbad laboratory examined an interesting attempt to imitate a natural green diamond when a 6.49 ct green crystal was submitted for a Colored Diamond Grading Report (figure 1). The surfaces of the resorbed octahedron were covered by uneven patches of green color. Fourier-transform infrared (FTIR) analysis revealed a typical type Ia diamond with abundant nitrogen and hydrogen impurities. However, the ultraviolet-visible (UV-Vis) spectrum was very unusual and did not show any of the bands that are produced by radiation damage in diamond (e.g., the GR1 defect). Careful examination under magnification found that the green color was not due to radiation stains, but instead to groupings of emerald-green platy crystals, ~40 μm in size, attached to the diamond surface (figure 2). Individual platy crystals could easily be flaked off using tweezers or a pointer probe, but they remained adhered to the surface under normal gem testing situations, including wiping the diamond with a stone cloth. X-ray fluorescence (XRF) analysis indicated high concentrations of chromium, and Raman analysis identified the green plates as chromium oxide (figure 3). The Raman peak positions correlated very well with chromium oxide powder that had been heated to ~700°C to produce a crystallized coating (M. Mohammadtaheri et al., “The effect of deposition parameters on the structure and mechanical properties of chromium oxide coatings deposited by reactive magnetron sputtering,” Coatings, Vol. 8, No. 3, 2018, Article No. 111). A small H1b defect present in the diamond’s FTIR spectrum supports this annealing temperature.
Most colored coatings encountered in the lab are on faceted stones and are pink, orange, red, or blue. The warmer hues are typically created by sputter-coating techniques involving metals and the colder hues by inks or other organic dyes. The use of chromium oxide powder to produce a green coating—along with annealing of the powder to produce crystallized plates that adhere to the rough surface to resemble radiation stains—represents a significant attempt to artificially reproduce the features seen on natural green diamonds. While the unique coating is easily discerned from natural green radiation stains under magnification, this stone is a strong reminder to carefully examine any green diamond, even rough crystals, in order to know exactly what you are buying. @chapter:11


Publication Year: - Title: Alexandrite History and Lore Abstract: A 43-carat alexandrite in the collection of the British Museum.

                      Abundant alexandrite deposits were first discovered in 1830 in Russia’s Ural Mountains. Those first alexandrites were of very fine quality and displayed vivid hues and dramatic color change. The gem was named after the young Alexander II, heir apparent to the throne. It caught the country’s attention because its red and green colors mirrored the national military colors of imperial Russia.

	Alexander II was still a youngster in 1830, when a never-before-seen color-change gem
	was discovered in the Ural Mountains of Russia. - Corbis
The spectacular Ural Mountain deposits didn’t last forever, and now most alexandrite comes from Sri Lanka, East Africa, and Brazil. The newer deposits contain some fine-quality stones, but many display less-precise color change and muddier hues than the nineteenth-century Russian alexandrites. You’ll still find estate jewelry set with some of the famed Ural Mountain alexandrites. They remain the quality standard for this phenomenal gemstone. @chapter:6


Publication Year: 2012 Title: Recent Advances in CVD Synthetic Diamond Quality Abstract: Synthetic diamond growth was first documented in 1952 by William Eversole of the Union Carbide Corporation, but it took another two decades before GIA issued the first grading report for a laboratory-made diamond (Crowningshield, 1971). Virtually all single-crystal synthetic diamonds are made by two very different processes. High-pressure, high-temperature (HPHT) synthesis mimics some of the key conditions for natural diamond formation, with pressures of 5–6 GPa and temperatures of 1400–1600ºC applied to a carbonaceous source material. The second method, chemical vapor deposition (CVD), involves growing synthetic diamond as thin-film layers at moderate temperatures and low (i.e., below atmospheric) pressures. One of the main advantages of the CVD procedure over HPHT is the superior flexibility of synthetic diamond size and geometry produced. Furthermore, intentional doping with impurity elements can be controlled by the addition of gases containing those atoms. @chapter:15


Publication Year: 2024 Title: Pink and Red Epidote in Quartz Abstract: Figure 1. Bright pink to red epidote crystals as “firework” sprays were a surprising discovery in rock crystal quartz. Photomicrograph by Nathan Renfro; field of view 2.16 mm.
We recently discovered very photogenic clusters of hot pink to red crystals as “firework” sprays (figure 1) in two transparent cabochons of rock crystal quartz. The cabochons weighed 5.47 ct and 11.18 ct and measured 15.85 × 9.87 × 5.92 mm and 16.06 × 11.49 × 7.83 mm, respectively (figure 2). These cabochons, which came from Sara Crystal in Shanghai, are thought to be from Chenzhou in China’s Hunan Province.

Figure 2. Weighing 11.18 ct (left) and 5.47 ct (right), these two rock crystal quartz cabochons play host to very unusual pink crystal sprays. Photo by Adriana Robinson.
After performing gemological testing and optical microscopy, we thought the inclusions might be piemontite based on their behavior in polarized light and the monoclinic morphology of the individual terminated crystals. Because some of the pink crystals reached the surface of their polished hosts, we decided to analyze them using Raman microanalysis. The result was a close match for epidote, which was surprising since epidote is normally thought of as a dark brownish green mineral.
The results of chemical analysis using laser ablation–inductively coupled plasma–mass spectrometry were consistent with epidote, but with one additional element present: manganese, which caused the pink to red color in these microcrystals. We concluded that the inclusions were indeed epidote instead of piemontite, but pink to red epidote was something completely new to us.
Searching the literature for piemontite and epidote uncovered the following statement from Mindat.org, which seemed to explain the existence of these pink to red epidotes:
“Piemontite” has two different uses: Piemontite (sensu stricto) is the mineral species described here, but more commonly “piemontite” refers incorrectly to deep red colored, -bearing epidotes that are really varieties of the species epidote, and not strictly speaking piemontite. “Piemontites” rarely contain more than 40% of the piemontite molecule, so many “piemontites” in collections (and pictured here in Mindat) are really Mn-rich red varieties of epidote.
To our knowledge, this pink to red epidote-quartz inclusion-host association has not previously been reported. @chapter:13


Publication Year: 1993 Title: Winter 1993 G&G Lab Notes Abstract: Cubic Zirconia Carved to Imitate an Ancient Buddha
Cyclotron-Treated Diamond
Fancy-Color Diamond with Unusual Radiation Stains
Unusual "Melted" Cavity in a Diamond
Faceted Yellow Synthetic Diamond
Emerald with Large Filled Etch Channels
Fracture Filled Garnets
Iridescent Orthoamphibole, "Nuummite"
Orthopyroxene, a Carved Mask
Some Pearl Observations
Synthetic Ruby: Striae Resolution Technique
Sapphire: A Difficult Identification
Diffusion Treatment in Sapphire Obscured by Mounting
Yag with Unusual Inclusions

To view the full section, download the PDF above. @chapter:32


Publication Year: - Title: Summer 2009 Gem News International Abstract: Colored Stones and Organic Materials
	            Andradite from Erzincan, Eastern Turkey
	            Star Apatite: First Occurrence in the Gem World
	            A Chalcedony-Opal Cameo with Remarkable Inclusions
	            Citrine from Andongologo, Madagascar
	            “Sugarcane Emerald” from Brazil
	            Orange Kyanite from Tanzania
	            Rare Optical Phenomenon in Play-Of-Color Opal
	            Cultured Pearls from Fiji
	            Rare Necklace Made Of Natural Pearls from Different Mollusks
	            Colorless Petalite and Pollucite from Laghman, Afghanistan
	            Serpentine Cat’s-Eye
	            Zircon Mining in Cambodia
Conference Reports
	            GIT 2008
	            Sinkankas Spinel Symposium
Announcements
	            Gems Issue of Elements
	            Responsible Jewellery Council Announces Code of Practice

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	DATA DEPOSITORY

Andradite from Erzincan, Eastern Turkey - Electron Microprobe Data
	Submitted by Alethea Inns and Brendan M. Laurs
	Summer, 2009
Colorless Petalite and Pollucite from Laghman, Afghanistan - Infrared Spectra
	Submitted by Erica Emerson and Paul Johnson
	Summer, 2009
Colorless Petalite and Pollucite from Laghman, Afghanistan - Faceting Notes
	Submitted by Robert C. Buchannan
	Summer, 2009
Cambodian Zircon Mining - Supplementary Photos
	Submitted by M. H. Smith and W. A. Balmer
	Summer, 2009 @chapter:3