Title: Visit to Zbird in Shanghai: Unlocking the Chinese Retail Diamond Industry Secrets Abstract: The retail company Zbird is synonymous in China with online sales of diamond and wedding jewelry. Photo courtesy of Zbird.

                      The story of Zbird is really the story of an amazing brother and sister partnership that built one of the most successful retail jewelry businesses in China. It is also the story of the evolution of the Chinese retail jewelry industry, and how this sibling pair not only seized opportunities but was also instrumental in setting the course of the industry. They have been a leading force in the internet diamond and wedding jewelry business in China. A GIA team had the opportunity to interview them both in Shanghai and to visit two of their retail stores.

	Zbird is known in China as a trend setter among diamond wedding jewelry styles and business models. Photo courtesy of Zbird.

	Starting Out : The Online Diamond Business in China
Zbird was founded in 2002. The company name is a combination of the names of the brother, Xu Lei, and his sister, Xu Xiao. Xu Lei’s Chinese name contains three characters that mean “stone,” which connects it to diamonds and gemstones. Xu Xiao’s English name is “bird,” which also connotes a highly efficient ecommerce business. The company’s name set the course of the business.

	Zbird has become a leader in China for online sales of diamond jewelry. Photo courtesy of Zbird.
When the company was founded, there was no EBay or Taobao, and only one online trading company called YiQu. Three months after posting its first loose diamond on the internet, Zbird had its first sale, which launched the online diamond business.

Xu Lei said that, at first, their biggest challenge was to inspire confidence in their customers. They were selling diamonds online at about half the price charged by most department stores in China. Zbird had to reassure potential clients about the quality of the diamonds they were offering for sale online. Since Xu Lei was a gemology major and GIA Diamonds graduate, he had confidence in the GIA grading system and the value of its diamond-grading reports.

In 2002, he rarely saw loose diamonds being sold with diamond grading reports. Most diamonds sold with reports were over 1 carat, while most diamonds sold in China were 30 points to 1 carat. Xu Lei decided to import diamonds in that size range with GIA grading reports. He said most dealers laughed at him at the time due to the cost difference but he was sure that the grading reports would add value.

	In China, most of the diamonds sold for engagement rings weigh less than one carat. Photo courtesy of Zbird.
Through the years, Chinese consumers became more educated about diamonds, and the reports became crucial to sales. Xu Lei believes that GIA reports play a very important role in today’s Chinese diamond market. Almost all online diamond dealers now sell loose diamonds with GIA reports as well as reports from other professional grading laboratories.

	“Clicks and Mortar”
According to Xu Xiao, Zbird pioneered the sales model they call “Clicks and Mortar” in the China retail diamond market. Clicks and Mortar combines the ease and speed of online sales with a physical offline experience. The internet makes it possible to combine a wide range of diamond products with fast, high-quality service. This makes it very popular with the younger generation, which is a very important demographic for Zbird’s business.

Most of their younger customers were introduced to Zbird through the internet, which provides Zbird with a convenient way to quickly contact and interact with their customers. The “mortar” portion of Clicks and Mortar encompasses what Zbird calls their Experience Stores, which provide customers with a real-world environment where they can physically connect with the brand and products.

	Zbird calls their retail stores Experience Stores. Photo courtesy of Zbird.
While the products offered for sale are often the same, there are shopping differences between online and Experience Stores. Customers looking for engagement and wedding rings are more likely to actually buy the ring in the Experience Store. Online customers tend to buy more personalized diamond jewelry like pendants, earrings, and other pieces that are less likely to require opinions from family members.

	Zbird designs their stores to provide a quality experience for the customer. In their retail stores, Zbird combines website choices with an actual salesperson presence. Photo courtesy of Zbird.
This explains why the per-transaction value of their online products is lower than in the store. More rings, especially engagement and wedding rings, are sold offline, while more diamond accessory jewelry is sold online. In 2007, Zbird received its first international venture-capital investment, which allowed for Experience Store expansion. Further venture-capital investment came in 2008 and 2010, helping to fuel 200% growth in the last few years.  Zbird currently has 15 Experience Stores in 14 cities, with approximately 500 employees to service the offline business.

	Customer Demographics
Zbird has worked hard for more than 11 years to develop their online business, which is why most of their customers are younger—ages 25 to 35—and so-called “white collar.” They became familiar with Zbird through the internet. Zbird was ranked number one in China for both quantity of jewelry sales and customer satisfaction, and their status has grown steadily. According to Google, Zbird is the internet’s most popular brand for diamond wedding rings in China. Zbird also uses the internet to make after-sale follow-up contacts with their customers and build long-term relationships.

Most of Zbird’s individual in-store wedding ring sales amount to about $10,000 RMB, about equal to a young man’s three-month salary. The average is a bit lower for internet purchases. The customers are often couples. They come in together to look at engagement and wedding rings, but it is usually the woman who makes the final choice.

When it comes to other diamond jewelry decisions, the woman almost always decides and often shops alone or on the internet. A woman might put the jewelry item on her online wish list for her boyfriend or husband to check and buy for her. Ultimately, however, it is the woman who makes the buying decision and women are the majority of Zbird’s customers.

	Xu Lei’s Vision of the Chinese Diamond Market
Xu Lei describes his vision of the Chinese diamond market’s potential with great enthusiasm:

	“China still has lots of potential because we have an enormously huge population base. Our population is three times that of the US. China’s internet-using population is equal to the population of the US. In terms of the market’s future, I think that the wedding jewelry market will still be very important. The VIP market is a new possibility for exploration, but we will keep focusing on the wedding jewelry market. In China, about 15 million couples get married every year. Thirty- to 50-point diamonds are the mainstream products for young Chinese couples. We know that this range in the US is 80 points to 1 carat. If young couples in China start buying larger diamonds, the market will double and it will soon catch up to the US. Moreover, current Chinese consumers are mostly made up of the so-called “white collar” group, who work in big cities. Although the tradition of diamond as the main wedding jewelry stone comes from the western world, the concept has deeply influenced Chinese couples and they have accepted it completely. So, along with white-collar workers, more and more young couples from rural areas will start buying diamonds as well. Zbird is ready to take on this market.”

	Xu Lei is in charge of maintaining a constant supply of high-quality diamonds for Zbird’s jewelry lines. Photo courtesy of Zbird.
Zbird places a lot of focus on the wedding jewelry market. Xu Lei feels the market has changed. He explains: “Before, couples would primarily pick a simple solitaire mounting in 18K and platinum with a center stone.” Today he sees more interest in design. He feels the design of the company’s wedding jewelry is one of the leading features attracting young customers today.

	Zbird’s Jewelry Designs and Lines
Xu Xiao says that Zbird’s design style is primarily contemporary. They offer jewelry themes such as their “Promise of Love” wedding ring line, a joint effort between Zbird and international designers. This series of wedding jewelry features flowers surrounded by diamonds and symbolizing lovers’ hugs and kisses. These themes are created for eye-catching effect and to add deeper meaning to the jewelry. They also market a diamond brand called “Aurora Borealis” for their top-cut-grade diamonds.

	The “Promise of Love” campaign has been very well received by the Chinese bridal market. Photo courtesy of Zbird.

	Zbird offers their top-cut-grade diamonds under the “Aurora Borealis” brand. Photo courtesy of Zbird.
Zbird offers classic and traditional jewelry along with its more fashion-forward designs. An example of the latter is called “Angels and Demons.” During the day at a typical white-collar office in China, a woman can wear the Angel design as a stylish diamond accessory. At night, she can wear the more edgy Demon design to after-work parties.

	“Angels and Demons” is a versatile jewelry design concept for day and evening wear. Photo courtesy of Zbird.
Besides style, another design consideration is cost. Today’s customers in China want expensive and elegant jewelry for formal occasions and less expensive, more fashion-forward pieces for casual wear. Xu Xiao says that Chinese customers generally prefer simpler and smaller jewelry pieces than customers in the West, and far less extravagant styles than customers in India.

Recently, Zbird’s chief designer worked with Platinum Guild International to jointly launch a series called “Two People One World.” There is a Chinese saying, “Fly next to each other,” which refers to two people moving through life together toward a better life. The style resembles a bird's wings to symbolize two people pursuing happiness in their lives. It also symbolizes the Zbird brand’s brother and sister team.

	Zbird works with Platinum Guild International to promote platinum bridal jewelry in China. Photo courtesy of Zbird.
Zbird also sells a series of personalized jewelry called “In Fashion,” which can convert into different styles to coordinate with different outfits, allowing every woman to find her own jewelry style. The Zbird slogan is “Shine for You,” and Xu Xiao strives to deliver that feeling to her customers in the company’s products and service.

Over the past 20 years, Chinese customers have come to realize the importance of jewelry design. Twenty years ago, jewelry was valued for just the quality of the components, and customers based their buying decisions on that. For example, if they wanted to buy a gold ring, they would pick a simple band. But now, with the promotion of fashion concepts, they don’t just want the material to be real and valuable, they want its design to reflect their personality and taste. This is why Zbird has been creating different styles beyond the classics.

	Today’s Chinese consumers look for both intrinsic value and design quality in jewelry. Zbird provides fancy-colored diamonds for their most discriminating customers. Photo courtesy of Zbird.
Zbird thinks that there has been a lot of progress in all aspects of Chinese jewelry design over the past 20 years. Xu Xiao feels that jewelry design in China is getting better in terms of originality. There are more and more opportunities and levels of artistic freedom for young designers. And the market is also more and more open to original product designs.

	Design and fashion sense have become important considerations for Chinese consumers looking for their own jewelry styles. Photo courtesy of Zbird.

	Customized Designs and VIP customers
Even with all these design choices, some customers still want unique custom jewelry that expresses their personalities and attitudes. To meet this need, Zbird has set up a platform for them to work with skilled designers and other professionals. This provides Zbird with many design options to appeal to a wide range of customers’ tastes and help them show their individuality. Xu Xiao says, “Today, customers want to buy more personalized products, not the same ones everyone else has. So we’ve introduced the design-it-yourself service. They can select a diamond and then choose a setting for it.”

	Zbird is involved in uniquely designed jewelry as well as classic and contemporary styles. Photo courtesy of Zbird.
Zbird also creates special customized products for VIP customers. Along with custom jewelry design, the company provides a global diamond-search service for them, including a search for the finest-quality colored and fancy-shape diamonds. The designs are all one-of-a-kind, so VIP customers receive the most exclusive service and choice possible.

	Quality Service
In addition to providing customers with superior jewelry values, Zbird strives to provide good service. In Xu Xiao’s opinion, “Our promise that we will provide worry-free follow-up service is just as important as the diamonds they buy from us.” Zbird offers their customers a lifetime guarantee. When customers buy products from Zbird, they can enjoy services that include maintenance, upgrading, and more. Xu Xiao believes that a wise customer considers not only the price but also the whole package. “And only a good brand can provide the whole package, which is the thing that keeps our customers coming back and makes our business a success.“

	New Opportunity: Diamond Investment Business
Xu Lei describes how, a year and a half ago, the company decided to seize another business opportunity. With the rise of the wealthy class in China came the rise of investment options. Xu Lei said, “They all have their own individual ways to invest their money. Some of them buy property, stocks, or gold. China recently applied a lot of new policies to try to control land prices, so property is not as good an investment as it was before. The stock market is not very thrilling either. Gold prices are not that stable. We thought that maybe we could educate those wealthy people to purchase collections of diamonds as part of their investments.”

	Zbird works with major banking institutions in China to provide diamond investment
	services. Photo courtesy of Zbird.
Zbird took action by contacting several well-known Chinese banks. Two of them agreed to work with Zbird: China Merchants Bank and China Construction Bank. Currently, Zbird services and supports both banks’ personal diamond investment businesses.

Xu Lei elaborated, “We made a lot of progress during the past year and a half. In the first year, we launched a team of 10 staffers to work on this investment project. This team’s sales figures for a year were 100 million RMB—about 15 million US dollars. The largest stone they sold was over 23 carats. It sold for over 13 million RMB—about 2 million US dollars. Today, there are many wealthy people in China who can afford this type of diamond, but they need a convenient way to buy and also to know more about diamonds. The most important thing is to have someone trustworthy to serve them and help them manage their money. Our team is more like a private jewelry consultant team.”

	Promoting the Brand
Zbird constantly advertises their brand, including sponsoring national concert tours in 2010 and 2011 for a domestically well-known singing star, Wangfei. Every year Zbird takes part in charitable activities, including the launch of a fund for blind children and financial aid to poor children. They have also promised to donate a tree whenever they sell a diamond, and today the “Yellow River Love Forest of Zbird” covers 300 acres. According to Xu Xiao, “As a jewelry brand, we consider love to be our eternal theme, and we hope our team and customers can sense and share it.”

	Zbird is involved with charitable projects for children. Photo courtesy of Zbird. Source: GIA @topic:8


Title: Visit to Chow Tai Fook Diamond Cutting Factory in Foshan, China Abstract: Chow Tai Fook is a vertically integrated manufacturing-to-retail jewelry company. Their value chain includes state-of-the-art diamond cutting. Photo by Pedro Padua, © GIA, courtesy of Chow Tai Fook, Yueshun Fook Jewellery and Diamond Co.

                      Chow Tai Fook Jewellery Group Limited is widely considered to be China’s largest jewelry retailer. It’s part of Chow Tai Fook Enterprises Ltd., a diversified Hong Kong based company that’s also engaged in property development, hotels and casinos, and transportation, port, and telecommunication businesses.

Chow Tai Fook Jewellery Group Limited had retail sales of $7.4 billion US in 2012, with a profit of $730 million. The company has been listed on the Main Board of The Stock Exchange of Hong Kong since December 2011 and it’s the world’s largest jeweler based on its market capitalization. Chow Tai Fook is a member company of the Hang Seng China 50 Index and Hang Seng Mainland 100 Index.

	Chow Tai Fook Jewellery Group Limited is one of the best-known jewelry companies in Asia. The company is known globally for its success.
Along with its extensive retail network, the company covers the entire value chain, including raw material procurement, design, diamond cutting, jewelry manufacturing, marketing, and sales. Its principal products are mass-market and high-end luxury jewelry, including gem-set, gold, and platinum styles, and watches.

	Company Milestones
Chow Tai Fook had its start in the jewelry industry in 1929. In 1938 and 1939, respectively, they opened their first retail stores in Macau and Hong Kong. They introduced a line of 999.9 fine gold jewelry in 1956. This purity guarantee was highly successful at creating customer trust and building a loyal clientele.

Foshan Yushunfu Jewellery and Diamond Company Limited, a then-related part of the company, opened its first diamond processing and jewelry manufacturing factory in Shunde in 1988, thereby strengthening the vertical integration of the Group's business model. Foshan Yushunfu became a full subsidiary in 2011.  Zlotowski’s Diamond Cutting Works (Proprietary) Ltd., located in Johannesburg, South Africa, also became a subsidiary in 2011.

Chow Tai Fook has secured multiple sources of rough diamonds to supply their cutting factories and retail stores. In 1993, the company qualified as a Diamond Trading Company (DTC) sightholder, which gave them the right to source rough diamonds directly from the DTC. The addition of Zlotowski’s, already a DTC sightholder at the time, strengthened that position. In 2009, Chow Tai Fook became a Select Diamantaire of Rio Tinto Diamonds. In 2012, they entered into a strategic two-year agreement with Alrosa of Russia for procuring supplies of its rough diamonds.

Rio Tinto has also partnered with Chow Tai Fook to promote its Argyle mine diamonds in their stores. Rio Tinto’s new underground mining operation at Argyle has the potential to produce substantial quantities of small diamonds for the jewelry needs of the Chinese middle class.

	Like all diamond manufacturers, Chow Tai Fook needed to secure a constant supply of rough for their manufacturing needs in a tight global market. Photo by Eric Welch, © GIA, courtesy of Chow Tai Fook, Yueshun Fook Jewellery and Diamond Co.
In 1998, Chow Tai Fook opened the company’s first retail store in mainland China, located in Beijing. In 2003 they centralized their mainland operations with headquarters in Shenzhen. By 2010 they had 1,000 retail outlets in mainland China (including franchisees and their own outlets). Chow Tai Fook’s retail network now includes over 1,800 outlets in more than 400 cities in Greater China, Singapore, and Malaysia. It also has a growing e-commerce presence. Chow Tai Fook has plans to open 2,000 chain stores in mainland China by the year 2020.

In June of 2013, during an extensive trip through China, GIA representatives visited the Chow Tai Fook diamond-cutting factory in Foshan. The team was given a highly informative guided tour of the factory, with detailed explanations of each manufacturing area and process.

	At the Chow Tai Fook factory, the GIA team extensively documented the operation of each department involved in the company’s diamond manufacturing business. Photo by Eric Welch, © GIA, courtesy of Chow Tai Fook, Yueshun Fook Jewellery and Diamond Co.

	Sorting, Planning, and Marking
The tour began in the sorting, planning, and marking room. All incoming rough diamonds come to this room to be sorted by shape, size, clarity, and color. After sorting, the rough diamonds’ cuts are planned and the rough is marked. The process makes use of instrumentation that includes the Helium M Box, Sarin Galaxy 1000, and other Sarin optical measuring and marking instruments, as well as traditional hand marking.

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	Today, optical instruments play a critical role in planning a diamond’s cut.
The instruments can mark the rough with more precision than is possible by hand, and the line is typically straighter and more accurately placed. Even a difference of one degree, causing a weight difference of one percent, can make a substantial difference in value. This is highly important considering the tight profit margins of diamonds today and the large volumes of diamonds coming through a modern factory.

Rough that requires a lot of care in the planning stages due to inclusions often goes into the Helium M Box so the planner can use a microscope to closely examine the inclusions’ nature. Included rough can also be efficiently analyzed with the Sarin Galaxy 1000, which can plan the placement of the cut stone within the rough and eliminate many of the inclusions.

The Sarin DiaMark-Z is the factory’s most commonly used optical planning and marking instrument and is used for “normal goods,” meaning stones with SI1 to IF clarity and standard sawable shapes.

The GIA team watched a planner use the DiaMark-Z to analyze and mark diamond rough for sawing. The first step was for the planner to decide what diamond shape would result in the best yield and value, based on the shape of the rough. If the rough is long, the shape of the cut stone would most likely be something like a pear or marquise.

After the cut stone’s shape is selected, the best combination of cut stone sizes is determined. For most octahedral rough, the stone is sawn off-center so one cut stone will be larger than the other. The best shape and cutting style from octahedral rough is usually the round brilliant. Some rough that is more rounded in shape might best be sawn to produce two equal-size diamonds.

The Sarin DiaMark-Z quickly displays all the potential combinations for two round brilliant cut stones, and value calculations are built into the software. A simple instrument called a polariscope uses polarized light to determine if the rough crystal contains potentially damaging strain.

	In a simple instrument called a polariscope, these diamonds are being checked for strain that could cause breakage. Photo by Eric Welch, © GIA, courtesy of Chow Tai Fook, Yueshun Fook Jewellery and Diamond Co.
The Sarin Galaxy 1000 is an accurate, automated system for mapping out inclusions in more challenging, highly included stones. This machine scans a rough diamond’s exterior and records its dimensions. Mapping of inclusions takes place inside the machine, in some cases making it difficult to see them clearly. This is especially true with the edges of very fine feathers. However, the Galaxy 1000 is much faster than the Helium M Box, which is often used for larger stones.

	The Sarin Galaxy 1000 is a fast and efficient system for mapping a rough diamond’s inclusions. Photo by Eric Welch, © GIA, courtesy of Chow Tai Fook, Yueshun Fook Jewellery and Diamond Co.
The GIA team watched the planning of a challenging piece of rough using the Sarin Galaxy 1000 System. The instrument plotted all the inclusions and showed where round brilliants could be cut from the stone, eliminating most of the inclusions and producing higher-clarity, higher-value diamonds. The instrument identified three stones that could be cut from the rough while eliminating I1 to I3 clarity-grade inclusions. The instrument identified all the inclusions in the rough and then brought up a computer model for planning.

	This complicated piece of rough was analyzed by the Sarin Galaxy 1000. Results showed that it could yield three diamonds while avoiding inclusions that would substantially lower value. Photo by Pedro Padua, © GIA, courtesy of Chow Tai Fook, Yueshun Fook Jewellery and Diamond Co.
Inside the Galaxy 1000, the rough diamond is immersed in a liquid, making it more transparent and allowing more accurate identification and mapping of inclusions. The rough diamond appears white and the inclusions stand out as dark, making their locations and shapes easy to see. After the scanning is complete, the files are transferred to the computer for plotting of all the inclusions onto a 3D model. The model is saved into the company’s server so the diamond markers can open the file and plan the diamond cut.

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	The Sarin Galaxy 1000 helps prepare rough by mapping its inclusions.
The Helium M Box works along with a scanner and a microscope. First, the scanner performs normal mapping of the rough’s outline. Next, the rough is put under the microscope and the inclusions are plotted and input through the computer. At that point, the system can plan the cut, taking into consideration the inclusions and the potential clarity grades of the cut stones.

The microscope’s magnification level can reach to over 150X. The process is time consuming—one stone takes two to three hours—but the advantage is that the powerful microscope makes it very accurate, allowing for more options and the ability to improve the clarity, and ultimately the value, of the cut stones. The team watched this instrument map out a five-carat round brilliant and a four-carat round brilliant from a piece of rough, allowing for removal of a feather to improve the clarity grade of one of the cut stones.

	The Helium M Box uses a powerful microscope along with a scanner to locate and map inclusions. Photo by Eric Welch, © GIA, courtesy of Chow Tai Fook, Yueshun Fook Jewellery and Diamond Co.
The Helium M Box utilizes its very powerful microscope to map out the rough’s inclusions in great detail. This makes even difficult to map inclusions like fine feathers and pinpoints easier to detect. The Helium M Box is often used for analyzing larger stones. The Galaxy 1000 and the Helium M Box often work as a team. Important stones are placed in the Galaxy 1000 for initial mapping. The final mapping is done with the microscope and the Helium M Box.

	The technician used the Helium M Box and the microscope to plot a rough diamond’s surface-reaching feather, which is marked in green. Photo by Pedro Padua, © GIA, courtesy of Chow Tai Fook, Yueshun Fook Jewellery and Diamond Co.
At the end of the tour of the planning and marking area, the group’s expert guide, Simon, reviewed the machines being utilized: the Sarin DiaMark-Z, the Sarin Galaxy 1000, and the Helium M Box system. The Sarin DiaMark-Z is fast, easy to use, and accurate. It’s generally used for rough in SI1 and higher clarity grades. This instrument is not as capable as the other instruments at handling more-included rough, mapping out inclusions, or determining the cutting options for challenging rough.

After sorting, planning, and marking, the information for the rough is input into Chow Tai Fook’s proprietary software system, which tracks the rough and all decisions made throughout the manufacturing process. The first information recorded is the weight of the rough and the planned weight of the cut stones. The papers holding the rough are barcoded for scanning, and have areas where all the information can be recorded as it travels through the manufacturing process. After the information is input, the rough is ready to move on to the next stage—sawing.

	After planning and marking, it is critical to input data for tracking purposes. Photo by Pedro Padua, © GIA, courtesy of Chow Tai Fook, Yueshun Fook Jewellery and Diamond Co.
Chow Tai Fook’s software system can also track worker productivity and quality control. At every production stage, each worker’s production capacity—how many stones they can do in a day and in a week—is recorded. This information is then compiled into a graph. If any worker is not able to meet production standards, a management team works with them to determine how to raise their productivity. The tracking system is linked to the Sarin system. Salaries are linked directly to productivity.

	Sawing the Rough
Next, the GIA team witnessed the rough diamond sawing process. The first sawing system the team observed was the LMJ Laser Water Microjet. This advanced laser sawing process incorporates a continuous flow of water that keeps the rough diamond surface cool, helping to prevent breakage from heat. The laser beam is focused and guided into a hair-thin, low-pressure water jet to precisely target the material being sawn. The laser actually goes through the water to the diamond. This is considered an important advantage over more traditional dry lasers.

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	The factory uses laser technology for sawing and bruting.
Most lasers saw diamonds in a “V” shaped laser pattern. The Laser Water Microjet system uses an “I” shaped pattern with a 40-micron opening. This results in less weight loss than with the “V” shaped pattern: less than 1% for diamond rough over 1.5 carats. Simon estimated the speed of the LMJ laser to be twice that of older green-laser models, with 50% less weight loss. The “I” shaped laser pattern results in a uniform opening from the top of the cut to the bottom. The hot carbon vapor typically associated with laser diamond cutting is evacuated with the flow of water, resulting in a cleaner and smoother surface

Chow Tai Fook also makes use of green lasers for sawing diamonds. The green lasers are probably the most common lasers for sawing diamonds. They’re respected for low weight loss, minimal breakage, and production of smooth sawn surfaces. The green laser sawing machines are programmed during the day to saw multiple diamonds held in cassettes, operating all night without any employees present.

To set up the process, the technician aligns cross hairs on the sawing marks for all the diamonds in the cassette via a screen. Then the diamonds’ dimensions are programmed into the instrument’s computer, which can then saw the diamonds automatically.

Diamond sawing with both systems occurs during the normal 6-to-6 work shift. Then the green lasers are programmed to saw multiple diamonds through the night and into the next morning, when technicians pair up the sawn-off pieces and place them in the proper parcel papers.

Chow Tai Fook also uses lasers to cut the outlines of most of their fancy-shape diamonds. This process is much faster and more efficient for fancy shapes than traditional bruting methods.

	Bruting and Coning
Next stop on the tour was the bruting department, where round stone shapes are created after sawing. In the bruting machine, the diamond is rotated at high speed while it’s being rubbed against a flat-surfaced wheel charged with diamond grit and water. The water keeps the heat from the friction down and lessens the chance of damage to the diamond. A one-carat stone takes about ten minutes to form, with its girdle bruted and polished. The process takes about 6 to 7 minutes for a 0.50-carat diamond and 12 to 13 minutes for a two-carat diamond.

	Round brilliant diamonds are bruted against spinning wheels coated with diamond grit and flowing water. Photo by Eric Welch, © GIA, courtesy of Chow Tai Fook, Yueshun Fook Jewellery and Diamond Co.
While lasers are efficient for forming fancy shapes, Chow Tai Fook does not use them for bruting round-brilliant cut diamonds. The speed is about the same for laser bruting as for bruting with diamond grit, but with laser bruting there’s more risk of stone damage.

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	Bruting and coning form the basic shapes of the girdle and pavilion.
After bruting forms the round shape, the next stop is the so-called coning department, where a similar process is used to create the pavilion. This process is much faster than traditional blocking.

The desired pavilion angle is drawn with a red line. During the bruting of the pavilion, diamond rough is polished away until the red line is reached. This method shapes the pavilion in about 15 minutes compared to 3 hours for traditional blocking. The time needed to shape the pavilion is highly dependent upon the shape of the rough. Pavilions of fancy shapes are still blocked with a polishing wheel.

	Pre-polishing Quality Control
Next, the team visited the quality control department, where the diamonds are inspected after each manufacturing stage to make sure there are no errors before continuing. This is especially important before the labor-intensive last polishing step.

The different colors of the parcel papers are used to identify the suppliers, such as blue for DTC or purple for Alrosa, and also to create a visual management system. Here, the GIA team witnessed a diamond with an already-polished pavilion being checked for polish and symmetry while still in the dop.

	Parcel papers are color-coded to identify the supplier. Photo by Pedro Padua, © GIA, courtesy of Chow Tai Fook, Yueshun Fook Jewellery and Diamond Co.

	The quality of the pavilion’s polish and symmetry is carefully checked at this stage. Photo by Eric Welch, © GIA, courtesy of Chow Tai Fook, Yueshun Fook Jewellery and Diamond Co.

	Polishing
In the diamond-polishing area of the factory, the team could not help but notice the polishers’ intense concentration levels. Visits to diamond-cutting factories around the world have never revealed a higher degree and intensity of focus among polishers.

Demonstrating a high degree of skill and precision, the polishers constantly checked the polish and facet placement with a loupe. Throughout the polishing process, they repeatedly touched the diamond to the scaife and then quickly lifted it to check it with the loupe. For polishing the pavilion, the tang has clicks related to the pavilion facets. Each time one facet’s polish is complete, the polisher clicks to another pavilion facet. A knob on the tang allows for fine tuning of the angle. The polisher adjusts this knob constantly while checking the polish and facet placement.

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	The final polishing stage is a long, careful process.
The polishing speed depends on several factors, including the shape of the rough, the presence of surface graining, clarity considerations, and the shape of the finished stone. For typical octahedral, sawable rough with no complications, it takes about two hours of total polishing time—about one hour for the pavilion and about one hour for the crown—to produce a one-carat round brilliant.

	Final Quality Control
After polishing, all the diamonds go to the grading department for the final quality-control step. Cut is the first quality factor to be graded. Stones 30 points and above are all graded with the microscope. Stones of this size are sent to a gemological laboratory for grading reports, so it is imperative that the polish and symmetry be checked carefully before they leave the factory. Chow Tai Fook wants to make sure the cut grades they receive on reports are up to their standards and their customers’ requirements.

	Diamonds 30 points and above are cut-graded with a microscope. For stones under 30 points, graders use a loupe. Photo by Eric Welch, © GIA, courtesy of Chow Tai Fook, Yueshun Fook Jewellery and Diamond Co.
For smaller stones, grading is done with a loupe. The grader uses a typical overhead daylight-equivalent fluorescent light and a white pad. They separate diamonds into piles based on their quality or to indicate specific re-works such as scratches on the table, polish lines, etc.

After cut grading, the diamonds are color graded. Graders use daylight equivalent fluorescent overhead light, a white folded card, and masterstones. Chow Tai Fook prefers the accuracy of their graders’ eyes over any color-grading machines. By far, most of the graders are women. Chow Tai Fook has found that women tend to be more patient, focused, detail oriented, and accurate when it comes to grading.

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	After polishing, all diamonds go to the grading department.
The final grading step is for clarity. Like cut grading, stones 30 points and above are clarity graded with a microscope. Smaller stones are graded with a loupe. For stones under 30 points, the clarity-grading classifications are broader and not as fine. They grade these diamonds into VVS, VS, SI, and I grades without further classifying them as VVS1 or VVS2, etc. Clarity grading is very fast for these stones, with the grader grabbing a stone in the tweezers girdle to girdle for a quick look through the crown facets and then the pavilion.

	Conclusion
The Panyu, China, area, which includes Foshan, is known around the world as a gem cutting and jewelry manufacturing center, and with good reason. Several factors contribute to the success of the area’s industry. China markets the high quality of the country’s cutting factories in a campaign called China Cut.

While labor costs are lower than in areas like Antwerp and Belgium, Chow Tai Fook reports that their polishers earn 45 percent more than those in Surat, India, and that their labor costs increase about 15 percent a year. Chow Tai Fook maintains high standards of cut quality and markets top-quality cuts globally.

With such a careful process and so many dedicated and skilled workers, it’s no wonder Chow Tai Fook is well known globally for its diamond-cutting expertise. Source: GIA @topic:8


Title: The Ellendale Diamond Field: Exploration History, Discovery, Geology, and Mining Abstract: The Ellendale diamond field in West Kimberley is one of only three hard-rock diamond mine locations in Australia. Though not the first Australian diamond mine, Ellendale was the country’s first hard-rock deposit. It holds a special place in world diamond history as it led in November 1976 to the recognition of a new host-rock for diamond, olivine lamproite. Up until that time, commercial-sized diamonds were considered to be sourced only from kimberlite. The Ellendale lamproites are geologically very young, only 22 Ma (million of years) old. Within several years of the initial discovery, some 46 lamproite pipes were found at Ellendale. By 1980, 38 of these pipes had been assessed for their diamond content.

	More than two decades later, geologists from the Kimberley Diamond Company (KDC) recognized eluvial diamond enrichment over these pipes. After a lengthy legal battle, they wrested the Ellendale mining lease from the Ashton Joint Venture and commenced mining there in May 2002. Ellendale is recognized as a source of high-value fancy yellow diamonds. These high priced stones have been marketed through a special deal with Tiffany & Co since 2009. But the future of mining there is tenuous. Ellendale 4 was closed in 2009, and the high Australian dollar, combined with dwindling reserves, may jeopardize the survival of Ellendale 9.

Abstracted by Guy Lalous Source: GIA @topic:7


Title: Book Review: Handbook of Spectral Lines in Diamond, Volume 1: Tables and Interpretations Abstract: The author has documented both published and unpublished results of more than 2,500 entries assigned to more than 400 optical centers. He includes information on spectral lines for natural diamonds, both treated and untreated, as well as synthetic diamonds, HPHT and CVD. He also explores a variety of impurity defects in diamond: nitrogen, boron, hydrogen, and silicon, among others.

The collection of data is presented in 203 tables, in which the author provides an interpretation and analysis of spectra and the assignment of structures to the optical centers. Tables in the appendices include historical, existing, and new names of defect centers or lines in diamond.

Reviewed by GIA Library Staff
Carlsbad, California Source: GIA @topic:4


Title: Type Ib Diamond Formation and Preservation in the West African Lithospheric Mantle: Re–Os Age Constraints from Sulphide Inclusions in Zimmi Diamonds Abstract: This article was published in Precambrian Research 286, 152-166.

	Abstract
Ten sulphide inclusions in three diamonds from the Zimmi (West Africa) alluvial diamond locality were analysed for their bulk Fe–Cu–Ni–Co contents and Re–Os isotopic compositions. The host diamonds are exceptionally rare, Ib types that still preserve isolated nitrogen (C centres), rather than more common nitrogen pairs (A centres) and nitrogen aggregates (B centres). C centres in Zimmi diamonds require that they did not experience temperatures above 850 °C for any extended period. Such diamonds make up less than 0.1 % of natural gem diamonds and have never before been dated. The sulphides are pyrrhotite-rich, have low Ni and Os contents, and radiogenic 187Os/188Os, all features characteristic of eclogitic sulphides. Each diamond has 3–4 individual inclusions. 187Re/188Os and 187Os/188Os data fall along three individual ~650 Ma age arrays that represent essentially 3-point or 4-point mineral isochrons for each diamond – unambiguously dating the time of diamond formation. The ~650 Ma age correlates with the timing of Neoproterozoic assembly of Gondwana, recorded in the Rokelide orogen along the SW margin of the West African craton. The initial 187Os/188Os of the three age arrays fall between 1.6 and 2.2 and are highly radiogenic compared to chondritic mantle at 650 Ma. Along with low Re/Os ratios, these data suggests that sulphides were not derived from Neoproterozoic subducting slabs, but rather from older eclogitic material already present in the West African lithospheric mantle. The age of the diamonds and their nitrogen substitutional characteristics, along with their residence in a lithospheric mantle with a normal cratonic geotherm (determined here from Koidu clinopyroxene xenocrysts) suggests that after diamond formation they were rapidly exhumed to shallower depths in the lithosphere. This likely occurred through tectonic uplift following Neoproterozoic continental collision.

Purchase the full article.

aGemological Institute of America, 50 West 47th Street, New York City, NY 10036, USA

bDepartment of Terrestrial Magnetism, Carnegie Institution for Science, 5241 Broad Branch Road NW, Washington, DC 20015, USA Source: GIA @topic:7


Title: Winter 2010 G&G Book Reviews Abstract: “Blood on the Stone: Greed, Corruption, and War in the Global Diamond Trade”
By Ian Smillie, 252 pp., publ. by Anthem Press [www.anthempress.com], London, 2010. US$29.95

“Jewellery in the Age of Queen Victoria: A Mirror to the World”
By Charlotte Gere and Judy Rudoe, 552 pp., illus., publ. by The British Museum Press [www.britishmuseumshoponline.org], London, 2010. £50.00

“Amethyst Uruguay”
By Reinhard Balzer, 304 pp., illus., publ. by Christian Weise Verlag [www.lapis.de], Munich, 2009. US$65

“The Fancy Color Diamond Book: Facts & Secrets of Trading in Rarities”
By Eden Rachminov, 231 pp., illus., publ. by Diamond Odyssey [www.diamondodyssey.org], Tel Aviv, 2009. US$215.00

“Agates and Jaspers”
By Ron Gibbs, 239 pp., illus., publ. by theimage.com [www.theimagebooks.com], Wedington, NC, 2009, US$40.00

“Minerals & Precious Stones of Brazil”
By Carlos Cornejo and Andrea Bartorelli, 704 pp., illus., publ. by Solaris [www.solariseditora.com.br], São Paulo, Brazil, 2010, R$148.00

To view the full section, download the PDF above. Source: GIA @topic:10


Title: “Decorated” Jadeite Jade in the Chinese Market Abstract: Figure 1. A light-colored off-white jadeite pendant decorated with small green and brown jadeite attachments. Photo by Fen Liu.

Jadeite jade has long been popular in China, where it has profound cultural connotations. Fine-quality jadeite has the highest market value, especially the colorful and near-transparent pieces. Bright color zoning on a piece of jadeite will enhance its value; therefore, color-enhanced jadeite is available in the market. Filling and dyeing have been used for decades to modify jadeite’s color, but these methods can damage the texture of jadeite and reduce its value. A new method, cementing small colored jadeite attachments on the surface of jadeite ornaments, recently appeared in the Chinese jade market. Because the method does little or no damage to the main jadeite’s texture, we consider this an assembled stone.

Figure 1 shows three jadeite pendants decorated with small green and brown jadeite plates. These pendants were submitted to the Gem Testing Center of China University of Geosciences (Wuhan) for identification of species and treatment. They were tested by observation under microscope and ultraviolet lamp, infrared (IR) spectroscopy, and ultraviolet/visible (UV-Vis) absorption spectroscopy.

The background color and texture quality of the small plate attachments was similar to those of the main jadeite body, creating a harmonious overall appearance (again, see figure 1). The green color appeared to be floating on the surface and seemed to be detached from the base (figure 2, left), whereas the natural color zone of jadeite always changes gradually. Resin with accompanying bubbles was found in the space between the green attachments and the jadeite body (figure 2, right). Under the long-wave UV lamp, the resin in the contact region emitted strong blue-white fluorescence while the body did not fluoresce (figure 3).

Figure 2. Left: The green color on this jadeite appears to float on the surface and has a clear boundary. Field of view 5.50 mm. Right: Resin with bubbles fills the space in the contact area. Field of view 16.8 mm. Photomicrographs by Shufang Nie.

Figure 3. The resin in the contact region emits strong blue-white fluorescence under a
long-wave ultraviolet lamp. Photo by Fen Liu.

The IR reflection spectra of the green attachments showed typical jadeite features (figure 4, left). However, the IR transmission spectrum of the contact zone revealed peaks at 3058 and 3037 cm–1, indicating the stretching vibration of the benzene ring in resin (figure 4, right), which was used to attach the decoration. The blue trace in figure 4 is typical for jadeite without any treatment.

Figure 4. Left: The IR reflection spectrum of the jadeite decorations matches the typical spectrum for jadeite. Right: IR transmission spectra of the jadeite body (blue trace) and the green attachment zone (red trace). The blue trace is typical for natural jadeite without filling, while the 3058 and 3037 cm–1 peaks on the red trace are characteristic for resin, which was used to attach the colored jadeite plates.

The attachments all had a typical fibrous-granulous crystalloblastic texture without loosening or slagging. This implied they were natural jadeite that had not been subjected to acid washing or filling. The green color of the attachments was also natural, as shown by the UV-Vis absorption spectrum, which showed the 690 and 660 nm peaks induced by Cr3+. Source: GIA @topic:12


Title: Gem Olivine and Calcite Mineralization Precipitated from Subduction-Derived Fluids in the Kohistan Arc-Mantle (Pakistan) Abstract: Geochemical data in this study suggests that remobilized CO2 and H2O from a subducted island arc helped form the calcite + olivine-bearing veins in Kohsitan, Pakistan. The authors provide details on the geologic setting, mineralogy, and geochemistry of the vein assemblages, which can yield gem-quality olivine (peridot). The CO2 and H2O from island arc magmas and carbonates mixed with mantle fluids rich in Bo (as evidenced by ludwigite-vonsenite needlelike inclusions in olivine) as well as La, Ce, Ta, Cu, and Zn (from trace-element analysis). Fluid origin and emplacement are discussed at length, with emphasis on macro-geophysical mechanisms within the earth. Gem olivine production data and characterization of the rough were not provided.

Abstracted by Keith A. Mychaluk Source: GIA @topic:1


Title: M.D. Hohenstine’s Gem Displays: The Process of Creating Popular Window Art with Loose Gemstones Abstract: M.D. Hohenstine frequently paid homage to the local theater and dance scene in his gemstone displays. This 1974 design honors the VaudVillities, a still-active Columbus group that bills itself as “the longest-running music and dance spectacular in the nation.” Photo by M.D. Hohenstine/Courtesy of Judith Allen Hall

Editor’s Note: Jeweler M.D. Hohenstine’s spectacular window displays  were a beloved tradition in downtown Columbus, Ohio from the 1920s until his death in 1976. The displays, consisting of hundreds of loose, natural gemstones arranged into a variety of shapes, patterns and figures, were changed every other week. Hohenstine photographed each of the 2,000-plus displays and turned them into slides that he used to educate fellow jewelers and gemologists. He gifted dozens of the slides to former employee and longtime family friend Judith Allen Hall when she began teaching. Hall donated the slides to GIA’s Richard T. Liddicoat Gemological Library and Information Center in 2016.

Here, she remembers the remarkable process Hohenstine followed to create fresh window art for his store for decades.

Mr. Hohenstine made a dozen opaque glass plates with matte surfaces and gilded wood frames. Each was about 10-12 inches in diameter. Some were round, others square; some were white, others were pale green. A couple of them had a small hole drilled in the plate. Under the plate was some sort of a small motor, and on top of the plate was a post that held the 10-ct. diamond upright so that it rotated and glittered.

He would begin by drawing the design on the plate with a soft pencil, and then open the desk drawer full of loose gemstones. With tweezers and an optivisor, he would painstakingly start putting the gems in place. The tables of brilliant cuts would be turned in certain directions to give the illusion of depth. All of the gems were simply laid on the plate – there was nothing to secure them.

It took six or more hours to complete the design, depending on its complexity. Customers could look in the curved window in front of the diamond room window to watch him work.

Hohenstine’s displays – including this bird’s nest scene with 202 diamonds, 238 garnets, 286 hessonites, 92 rubies, 11 pearls and one onyx – were a marvel of craftsmanship and logistics. None of the hundreds of gems on each design was secured to the display boards. Photo by M.D. Hohenstine/Courtesy of Judith Allen Hall
He was very inventive and created a way to photograph every design. A camera was mounted facing downward in a cabinet behind his desk in the diamond room, and it was exactly the right height to put the completed gem design in focus. All you had to do was slide the glass plate on the shelf, push the camera button, and it was done. Each slide contained the number of the design and the number and type of gems included in the design.

Once the design was completed and photographed, it was ready for Tuesday night window trim after the store closed. The left front window was about 90 to 100 feet from the diamond room, which seemed like a mile if you were carrying the plate – which was ever-so-slightly tilted, with the unsecured gems in place.

The left window had one-inch thick, bulletproof glass and a huge I-beam under it, so that street and foot traffic would not jar the design. The back glass lifted up when unlocked to give access to the window. The old design was very, very carefully removed and put on the showcase behind the window. Care was taken so that if there was any calamity getting the new one in place, the old one could be put back in the window.

When the new design was in place, Mr. Hohenstine would put on his optivisor and pick up tweezers and move any gem that might have been displaced. Then the frame was put in place, along with a little typed sign that would read something like: “This is the 1543rd design and contains 200 rubies and 56 emeralds.”

The old design was then carefully carried back to the diamond room, and the next day he would take it apart and put all the little gems back in their respective envelopes. Source: GIA @topic:10


Title: Book Review: Arts of the Hellenized East: Precious Metalwork and Gems of the Pre-Islamic Era Abstract: By Martha L. Carter, Prudence O. Harper, and Pieter Meyers, 424 pp., hardcover, publ. by Thames and Hudson, London, 2015, $75.00.

	The Hellenistic period refers to the era between the death of Alexander the Great in 323 BC and the rise of ancient Rome circa 30 BC. The spread of Greek culture through Alexander’s invasion of eastern lands, from the Mediterranean basin to modern-day Pakistan, influenced many indigenous cultures of these regions and left a significant mark on the region’s history, arts, science, and literature.

	The al-Sabah Collection in Kuwait contains western and central Asian artifacts from the Bronze Age through late antiquity, including the Hellenistic period. Martha Carter concentrated her research on the Hellenistic silverwork and wrote Arts of the Hellenized East: Precious Metalwork and Gems of the Pre-Islamic Era, the sixth volume in the al-Sabah Collection series, with contributions from Prudence O. Harper and Pieter Meyers. The authors provide detailed descriptions for each item within the cultural and historical context of the era and the regions. The 400-page publication is further enhanced by 350 color images illustrating the objects. It is noteworthy that quite a few rare and important objects in the collection are documented for the first time.

	There are more than 400 objects of Hellenistic silverwork in the collection. These include bowls, drinking vessels, and dishes made out of precious metals, mainly gilded silver. Of the hundreds of objects in the catalogue, only nine items contain gemstones, four of which are royal seals and intaglios carved out of carnelian, chalcedony, and garnet. Two bowls and two small cups, both of gilded silver, are inlaid with red garnets. A Buddhist gold reliquary set with red garnets and a blue sapphire is created from sheets of gold. There are two garnets remaining in their original bezel setting along with another unidentified stone (recorded as coral or glass); however, the author indicates that the blue sapphire bead on the lid of the casket was a later addition. Nevertheless, the object stands out as unusual piece from a gemological point of view.

	This volume starts with a brief account of the ancient cultures of the region given within the context of their art traditions and perception of silverware at the time. Objects made from precious metals were favored for both their monetary value and their utility. The value of silverware was simply measured by its silver coin weight. Some researchers suggest that this was an important feature, as use of coinage was not extensive and silverware might have served as large denominational banknotes. The introduction concludes with a summary of the socio-political setting for eastern Hellenistic metalwork.

	The catalogue is followed by a chapter on technical examination of some of the silver objects in the catalogue by Dr. Meyer. In the acknowledgment, Dr. Carter conveys her efforts to authenticate the provenance of certain objects in the collection, as most are from politically unstable regions such as Afghanistan, where systematic excavations are almost impossible. She combines her stylistic expertise with Dr. Meyer’s metallographic analyses to verify the origin of objects found by individuals rather than experts. His scientific insight to the ancient silver sources, production, and the metal’s importance as a commodity is a wonderful source to the reader. The chapter gives a clear explanation on modern analytical techniques to determine method of manufacture, condition, ancient and modern repairs, and authenticity in the collection.

	The last chapter on ancient silver cleaning and conservation is an informative piece to the ancient art collectors, as it reveals the importance of stopping decay on ancient metalwork, especially while on display.

	Ancient art collectors, art historians, appraisers, and jewelers alike would highly benefit from this volume. Arts of the Hellenized East: Precious Metalwork and Gems of the Pre-Islamic Era is a masterfully written, rare catalogue full of informative chapters on Hellenistic art and metal work technology. Source: GIA @topic:10


Title: Gem-Quality Cuprian-Elbaite Tourmalines from São José Da Batalha, Paraíba, Brazil Abstract: Unusually vivid tourmalines from the state of Paraiba, in north eastern Brazil, have attracted great interest since they first appeared on the international gem market in 1989. This article describes what is known of the locality at this time, but focuses on the most striking characteristic of the se gem tourmalines: the unusual colors in which they occur. Quantitative chemical analyses revealed that these elbaite tourmalines contain surprisingly high concentrations of copper, up to 1.92. wt. % Cu (or 2.38 wt. % CuO). Their colors are due to Cu2 + or a combination of Cu2 +, Mn3 +, and other causes. Some colors can be produced by heat treatment, but most also occur naturally. Source: GIA @topic:1


Title: An Update on Color in Gems. Part 3: Colors Caused by Band Gaps and Physical Phenomena Abstract: The previous two articles in this series described the origins of color in gems that derive from isolated structures of atomic dimensions—an atom (chromium in emerald), a small molecule (the carbonate group in Maxixe beryl), or particular groupings of atoms (Fe2 +-0-Fe3 + units in cordierite). The final part of this series is concerned with colors explained by band theory, such as canary yellow diamonds, or by physical optics, such as play-of-color in opal. In the case of band theory, the color-causing entity is the very structure of the entire crystal; in the case of physical phenomena, it is of microscopic dimension, but considerably larger than the clusters of a few atoms previously discussed. Source: GIA @topic:3


Title: An Update on Color in Gems. Part 1: Introduction and Colors Caused by Dispersed Metal Ions Abstract: Studies concerning the origin of color in gem materials have grown in sophistication in recent years, so that much new information is now available about natural color and its possible modification by various treatment processes. This three-part series of articles reviews our current understanding of gemstone coloration. The first part summarizes the factors that govern the perception of color, from the source of light to the human eye, and then examines in detail the role of one color-causing agent, dispersed metal ions, in the coloration of many gem materials, including ruby and emerald. The second part will explore charge-transfer phenomena and color centers as the cause of color in gems such as blue sapphire and Maxixe beryl. The series will conclude with colors that can be explained using band theory and physical optics, such as the play-of-color in opal and the blue sheen of moonstone feldspars. Source: GIA @topic:3


Title: Gem Olivine and Calcite Mineralization Precipitated from Subduction-Derived Fluids in the Kohistan Arc-Mantle (Pakistan) Abstract: Geochemical data presented suggests remobilized CO2 and H2O from a subducted island arc helped form the calcite + olivine-bearing veins in Kohistan, Pakistan. The authors provide details on the geologic setting, mineralogy and geochemistry of the vein assemblages, which can yield gem-quality olivine (peridot). The CO2 and H2O from island arc magmas and carbonates mixed with mantle fluids rich in Bo (evidenced by ludwigite-vonsenite needle-like inclusions in olivine) as well as La, Ce, Ta, Cu, and Zn (from trace element analysis). Fluid origin and emplacement are discussed at length with emphasis on macro-geophysical mechanisms within the earth. Gem olivine production data and characterization of the rough was not provided.

Abstracted by Keith A. Mychaluk Source: GIA @topic:1


Title: Fall 2004 G&G Book Reviews Abstract: “Blood from Stones: The Secret Financial Network of Terror”
By Douglas Farah, 225 pp., publ. by Broadway Books, New York, 2004. US$24.95

“Starting to Collect Antique Jewellery”
By John Benjamin, 191 pp., illus., publ. by Antique Collectors’ Club, Woodbridge, England, 2003. US$25.00

“Starting to Collect Antique Silver”
By Ian Pickford, 192 pp., illus., publ. by Antique Collectors’ Club, Woodbridge, England, 2003. US$25.00

“Within the Stone”
By Bill Atkinson, 180 pp., illus., publ. by Browntrout Publishers, San Francisco, CA, 2004. US$39.95

“Gems and Jewels: A Connoisseur’s Guide”
By Benjamin Zucker, 248 pp., illus., publ. by Overlook Press, New York, NY, 2003. US$60.00

“The Tourmaline”
By A. C. Hamlin, 107 pp., illus., originally publ. by James R. Osgood & Co., Boston, MA, 1873; republished by Rubellite Press, New Orleans, LA, 2004, US$75.00

“The History of Mount Mica”
By A. C. Hamlin, 123 pp., illus., originally publ. by Augustus Choate Hamlin, M.D., 1895; republished by Rubellite Press, New Orleans, LA, 2004, US$85.00

To view the full section, download the PDF above. Source: GIA @topic:6


Title: Winter 2003 G&G Book Reviews Abstract: “Tiffany Flora & Fauna”
By John Loring, 256 pp., two vols., illus., publ. by Harry N. Abrams, New York, 2003. US$50.00

“Burma Ruby: A History of Mogok’s Rubies from Antiquity to the Present”
By S. K. Samuels, 254 pp., illus., publ. by S.K.S. Enterprises, Tucson, AZ, 2003. US$45.00

“Gems from the East and West: The Doris Duke Jewelry Collection”
By Janet Zapata, Ulysses Dietz, and Zette Emmons, 120 pp., illus., publ. by the Doris Duke Charitable Foundation, New York, 2003. US$27.50

“The Rings Book”
By Ole Johnsen, 439 pp., illus., publ. by Princeton University Press, Princeton, NJ, 2002. US$49.50

“Cultured Pearl: Charm of the Pearl”
By Shigeru Akamatsu, 179 pp., illus., publ. by Shinju Shinnbun Co., Tokyo, 2003 (in Japanese). 3,800¥

To view the full section, download the PDF above. Source: GIA @topic:6


Title: Spring 2000 G&G Book Reviews Abstract: “Romance of the Golcondra Diamonds”
By Omar Khalidi, 127 pp., illus., publ. by Grantha Corp., Middleton, NJ, 1999. $39.95

“Ruby, Sapphire and Emerald Buying Guide”
By Renee Newman, 164 pp., illus., publ. by International Jewelry Publications, Los Angeles, CA, 2000. US$19.95

“Rough Diamonds: A Practical Guide”
By Nizam Peters, 172 pp., illus., publ. by the American Institute of Diamond Cutting, Deerfield Beach, FL, 1997. US$89.00

“Crystal Enchantments: A Complete Guide to Stones and their Magical Properties.”
By D. J. Conway, 343 pp., publ. by the Crossing Press, Freedom, CA, 1999. US$18.95

“Diamonds and Precious Stones”
by Patrick Voillot, 127 pp., illus., publ. by Harry N. Abrams, New York, 1998, US$12.95

To view the full section, download the PDF above. Source: GIA @topic:6


Title: An Archive of Excellence: The Richard T. Liddicoat Gemological Library Celebrates 25 Years Abstract: The Richard T. Liddicoat Gemological Library and Information Center at GIA's world headquarters, The Robert Mouawad Campus, in Carlsbad, California. Photo by GIA

                      700+ periodicals
1,800+ videos
57,000+ books
150,000+ photographs

The sheer magnitude of print, video and image resources available through the Richard T. Liddicoat Library and Information Center is astounding. From 31 different editions of philosopher Pliny's “Natural History” – including a copy published in 1496 – to George Frederick Kunz’s “Gems and Precious Stones of North America,” one of the most important works on gems, the library houses some of the rarest and most highly regarded books in gemological and jewelry history. What started humbly as a single bookcase has become the largest, most complete repository of its kind in the world and the first point of reference for those studying gems and jewelry.

GIA’s original library consisted of a handful of publications that GIA founder Robert Shipley loaned to students and staff. Over the years, the collection grew to include important books about gems and jewelry, trade journals and the latest gemological research, totaling 2,500 informally cataloged and stored volumes by 1980.

Richard T. Liddicoat, then-president of GIA, recognized the need and benefit of more professional attention to the Institute’s growing collection. He appointed Dona Dirlam, a diamond grader and former geology teacher, as librarian. Dirlam embarked on a decades-long effort to develop the library into the resource it is today. She began by opening the library to students and staff without an appointment, reorganizing and cataloguing the collection, and expanding the physical space and the staff.

“We needed more staff by the mid-1980s just to handle the growing number of phone calls requesting information,” said Dirlam. “The more you help people, the more they call back for help, and then tell other people.”

As more and more people outside the Institute learned about the indispensable resources available, the library continued to grow, and so did the importance of amassing a comprehensive collection.

GIA acquired the Sinkankas collection, which contains nearly every major work related to the study of gems and jewelry, in January 1988. Accumulated over 40 years by noted author and lapidary John Sinkankas and his wife, Marge, the collection added nearly 6,000 articles and 10,000 books, including works dating back to 1511 A.D., rare volumes and numerous editions in different languages. With the addition of the Sinkankas collection, the library became a resource unlike any other.

GIA held an inaugural celebration in August 1989 to formally dedicate the library to Liddicoat, the ‘Father of Modern Gemology,’ and to officially unveil the Sinkankas collection.

Nearly 300 guests attended the event, described by George Schuster in his 2003 book “Legacy of Leadership: A History of the Gemological Institute of America:”

August 21, 1989. It was a glittering summer night of champagne, laughter and honors, a black-tie evening of men in tuxedos and women in elegant gowns. It was a night important enough to attract hundreds of leading gem and jewelry industry figures to the Gemological Institute of America.

It was the night of the formal dedication of the Richard T. Liddicoat Gemological Library and Information Center, including the newly acquired, world-renowned Sinkankas collection.

It was the night of the official unveiling of what one writer called “the greatest collection of gemological literature ever assembled.”
…

During the official opening ceremony, guests heard firsthand accounts from Dirlam, Liddicoat, and Boyajian on the acquisition of the Sinkankas collection and what it meant to GIA and the gemological community. Another highlight was Sinkankas’s off-the-cuff comments on how he and Marge had created their personal library, including book-buying adventures in Europe, the Howes acquisition and his longtime relationship with GIA. Mayor James Conn presented [then-president] Bill Boyajian with a letter of commendation from the city of Santa Monica acknowledging GIA’s contribution to education in the community. At the end of the night, departing guests were handed reprints of Gems & Gemology’s Spring 1989 article on the Sinkankas collection.

Now, 25 years later, GIA’s library continues to grow and offer resources to the gem and jewelry industry, gem enthusiasts, students and the public. Library staff assisted more than 10,000 visitors, students and staff in 2013. It’s open to the public Monday through Friday, but you don’t have to be in California to take advantage of its resources. Experienced librarians also answer questions and offer reference for gem- and jewelry-related questions by email, mail, phone and fax, responding to more than 1,000 queries each year. You can also search the library catalog online and access all 80 years of Gems & Gemology, GIA's quarterly research journal, on the website.

For Dirlam, the goal of the library is simple.

“We want to make this library the archive of the international jewelry industry, and an important part of our mission to ensure the public trust in gems and jewelry.” Source: GIA @topic:10


Title: A Red Herring in a Red Garnet Abstract: Gas bubbles hide just beneath natural crystal inclusions in this garnet and glass doublet. Photomicrograph by Emily Jones; field of view 1.58 mm.
At first glance, a 2.54 ct round mixed-cut stone examined by the author presented itself as a natural red garnet. Microscopic inspection revealed a host of transparent crystals and widespread epitaxial needles, both typical inclusions for garnet. Upon closer inspection, however, some of the apparent “crystals” were recognized as gas bubbles, betrayed by their smooth spherical forms (see above). This distinction can be easily missed without careful examination under high magnification. Additional observations and testing conclusively identified the material as pyrope-almandine garnet fused with manufactured glass. As with most garnet-topped doublets, the garnet portion was cut to occupy the crown while the glass made up most of the pavilion so that the natural inclusions of the garnet top masked the telltale signs of manufactured glass beneath. Source: GIA @topic:3


Title: An Opal-Calcite Composite Abstract: Figure 1. This 8.54 ct cabochon was a composite of brown opal and white calcite. Photo by G. Choudhary.

              Composites assembled from opaque to translucent gem materials such as turquoise, chalcedony, and chrysocolla have become quite popular in recent years, as evidenced by the number of samples received for identification at the Gem Testing Laboratory in Jaipur, India. We recently examined a white-brown, translucent to opaque oval cabochon (figure 1) that turned out to be a composite featuring an unusual combination of gem materials.

The specimen weighed 8.54 ct and measured 18.03 × 13.12 × 4.63 mm. At first glance, it appeared to be a rock consisting of some brown and white mineral, but the presence of golden veins ruled out such a possibility, suggesting instead a manmade product. Closer inspection of the cabochon from all sides revealed four distinct areas—a colorless polymer, golden veins and patches, a brown mineral, and a white mineral—all showing a different surface luster (figure 2, left). At the base of the cabochon, individual grains of a white mineral were embedded in the colorless polymer, as well as golden areas comprised of fine flakes, composed of zinc (figure 2, right). These features were consistent with those observed in a composite material (e.g., G. Choudhary, “A new type of composite turquoise,” Summer 2010 G&G, pp. 106–113).

	Figure 2. Under reflected light, the cabochon’s luster varied across four distinct portions (left). Note the polymer vein at the center of the image and the parallel planes and cloudy inclusions at the top of the white portion. Some of the golden areas were comprised of fine flakes embedded in polymer (right). Photomicrographs by G. Choudhary; magnified 24× (left) and 48× (right).
Although the cabochon was recognized as a composite, its components had yet to be identified. Spot RIs of 1.56 and 1.45 were obtained from the white and brown portions, respectively. The white portion also displayed a large birefringence blink, typically associated with carbonate minerals such as calcite, while no blink was observed on the brown portion. Under long- and short-wave UV radiation, the cabochon remained largely inert, except for a weak whitish glow observed on the white portions. Furthermore, magnification of the white portion revealed cleavage planes, liquid films, white cloudy inclusions, and doubling, while the brown portion was milky with fine flaky inclusions.

Spot RIs and magnification identified the white portion as calcite and the brown portion as opal, but these tests were not sufficient to prove their identity. Raman spectroscopy of the white portion in the 200–2000 cm–1 range (using 532 nm laser) displayed many sharp peaks at 281, 482, 712, 1086 (the strongest), 1435, and 1749 cm–1; these  peaks are associated with calcite. Raman spectra of the brown portion displayed broad absorptions at around 400–500, 800, and 1000 cm–1; these did not display sharp absorption features other than a peak at 487 cm–1. These absorptions are associated with amorphous materials such as opal (opal-A), and the 487 cm–1 peak is associated with Si-O vibrations (e.g., C.J. Brinker et al., “NMR confirmation of strained ‘defects’ in amorphous silica,” Journal of Non-Crystalline Solids, Vol. 99, 1988, pp. 418–428).

Identification of this cabochon as a composite was straightforward, but the components were more difficult to detect. Although Raman spectroscopy identified the materials present, the use of these two substances for making a composite remains unclear. Source: GIA @topic:2


Title: In Memoriam: Jean Claude Michelou Abstract: Colored stone industry veteran Jean Claude Michelou was founder and longtime editor-in-chief of ICA’s quarterly, InColor. Photo by Vincent Pardieu.

The colored stone industry lost one of its true leaders with the passing of Jean Claude Michelou (see above) on May 3 at the age of 72. Mr. Michelou graduated from the London School of International Business and began selling emeralds in Colombia in 1977. The business he later established, Imperial Colors Ltd., specializes in rough buying, grading, and cutting of emerald, tourmaline, beryl, and sapphire. He relocated the company to Bangkok in 2018.
Mr. Michelou was active with the International Colored Gemstone Association (ICA), serving as a board member for 18 years and as vice president for 10 years. In 2004, he founded ICA’s quarterly magazine, InColor, and was its editor-in-chief until his retirement earlier this year. He was also a consultant for the United States Agency for International Development (USAID), the World Bank, and other agencies on developing standards for the colored stone industry. In addition, he served on the advisory board for the University of Delaware’s Gemstones and Sustainable Development Knowledge Hub and organized the World Emerald Symposiums held in Bogotá since 2015.
For more than a decade before his passing, Mr. Michelou had been deeply involved in several beneficiation projects in source countries, including the Swat Valley emerald deposits of Pakistan and a Nigerian sapphire mining venture. He shared his insights on supply chain transparency and beneficiation with G&G in the Spring 2018 issue (Gem News International, pp. 93–94). Over the years, Mr. Michelou was a valuable source of knowledge for this journal and a mentor to many young industry professionals. We extend our condolences to his family and friends. Source: GIA @topic:7


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

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

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

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

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

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

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

Don’t miss this chance to learn more valuable and exciting information from GIA’s top experts. Find out more about GIA’s Continuing Education Recognition Program. You can also contact the GIA Alumni Association at +1 760 603 4145 or email alumni@gia.edu. Source: GIA @topic:7


Title: Echoes of the Edwardian Era Abstract: Diamonds, silver, gold, and tortoise shell sparkle in this period tiara. Courtesy of a Private Collection

                      Diamonds. Pearls. Platinum. Symmetry. This defined Edwardian Era jewelry – and it’s still is extremely popular with modern designers.

Take a step back in time to the Edwardian Era (1900 – 1915). The sun never set on the British Empire. England was flush with power and wealth. Tastemaker Edward VII was king. For the landed gentry, the Edwardian Era was a period of prosperity and privilege. Perhaps the Titanic, the most luxurious and largest ocean-liner of its time, best captured the spirit of the age with her First, Second, and Third Class cabins. The arts in Great Britain served a definite purpose during the Edwardian Era; they were frequently used to reinforce the class system. Architecture, for example, was symmetrical and orderly, which evoked power, stability, and status.

	Class divisions were everywhere – even at bath houses. The Victoria Baths in Manchester had separate entrances for first class males, second class males, and females.

		Jewelry was a preferred way to show one’s rank in society. Only the upper classes could afford it, and they advertised their wealth and position by wearing exquisite works.

		Robert Ackermann, Jewelry Manufacturing Arts instructor, Carlsbad, GIA.

	Platinum, diamonds, and pearls were the materials of choice. Garlands and triumphal laurel wreaths belonging to a conqueror’s crown were common themes. These regal materials and motifs spoke of the might of the British Empire and the importance of the wearer. Stately tiaras, pendants, necklaces, and chokers were not only the style of the day but also carried symbolic weight. For example, it was rude for a lady to wear taller tiara in the presence of a woman of higher rank. Diamonds were abundant in Edwardian jewelry due to the discovery of mines in South Africa in the 1880s. A ready supply of the gem was now available, and Britain’s aristocracy quickly fell in love with the glittering stone.

	Pearls dangle from this diamond and cat’s eye alexandrite cabochon pendant.
Pearls were also popular during the Edwardian Era, and were often showcased in a piece of jewelry. Drop a pearl in a bed of diamonds or set it in platinum, and Edwardians thought this blazingly white-hot combination to be the height of sophistication and elegance. Although many of the customs of the Edwardian Era may seem to be a part of the distant past, the international success of Downton Abbey, the television drama whose first season was set in Edwardian England, proves that we are still fascinated by the time. And if you look around a jewelry store, you’ll see that Edwardian jewelry continues to influence contemporary designers. Source: GIA @topic:6


Title: Natural Type Ia Diamond with Green-Yellow Color Due to Ni-Related Defects Abstract: Commonly seen in HPHT-grown synthetic diamonds with a green component, nickel-related defects were identified for the first time in a type Ia natural diamond with a strong green component. The 1.75 ct Fancy green-yellow diamond showed a strong peak at 1332 cm−1 in the IR absorption spectrum, strong absorption from the 1.40 eV center and the associated ~685 nm band in the Vis-NIR spectrum, and extremely strong emissions from Ni-related defects in the photoluminescence spectra—all of which proved that nickel was the primary cause of the green color. Source: GIA @topic:4


Title: The Discovery of Davemaoite, the CaSiO3 Perovskite, in a Diamond from Earth’s Lower Mantle Abstract: Figure 1. A typical coated diamond from Orapa. This is not the stone studied, but rather one from the same batch and locality with approximately the same color and size. Photo by George Rossman.
Common silicate minerals such as olivine and garnet convert to other phases when brought to great depths in the planet, where they are subjected to extreme pressures. It has long been thought that two of the most common phases at depth in Earth have the perovskite structure. They have long been known from experimental studies in which they have been called magnesium silicate perovskite (MgSiO3) and calcium silicate perovskite (CaSiO3). Only recently has the magnesium silicate perovskite been found in nature, in a meteorite, where it was characterized and named bridgmanite (O. Tschauner et al., “Discovery of bridgmanite, the most abundant mineral in Earth, in a shocked meteorite,” Science, Vol. 346, 2014, pp. 1100–1102). More recently, the calcium silicate perovskite has been found in a diamond and sufficiently characterized to be given a mineral species name (O. Tschauner et al., “Discovery of davemaoite, CaSiO3-perovskite, as a mineral from the lower mantle,” Science, Vol. 374, 2021, pp. 891–894).
Diamonds are one of the few minerals that bring us samples of the minerals found in the deep earth. Diamonds serve as chemically inert and nearly volume-conserving hosts for these minerals, thereby allowing them to retain their composition and in some cases even their original structure. The examination of the inclusions in an 81 mg (~0.405 ct) octahedral diamond from Orapa, Botswana, has resulted in the discovery of the high-pressure form of CaSiO3 in the perovskite structure occurring as a natural mineral in the diamond (figure 1). This phase has been approved by the International Mineralogical Association with the name davemaoite, named in honor of Dave (Ho-kwang) Mao, for his contributions to understanding the deep-mantle geophysics and petrology of our planet.
Experimental studies in the laboratory have indicated that CaSiO3 assumes the perovskite structure at depths between 420 and ~2700 km. This phase, first synthesized in 1975 (L. Liu and T. Ringwood, “Synthesis of a perovskite-type polymorph of CaSiO3,” Earth and Planetary Science Letters, Vol. 28, 1975, pp. 209–211), is only thermodynamically stable at pressures greater than 200,000 atmospheres (20 GPa). Furthermore, the rate of back-conversion to low-pressure polymorphs is rapid if the pressure is lowered. Consequently, the natural mineral is unlikely to survive transport from the deep earth to the surface.

Figure 2. The polished slab of the diamond containing davemaoite showing the round spots where the grains were excavated for LA-ICP-MS analysis. Photo by Aaron Celestian.
Davemaoite was first identified and characterized within a diamond studied at the Advanced Photon Source at Argonne National Laboratory in Illinois, where an X-ray beam was focused to a 0.5 × 0.5 μm spot. Calcium-rich inclusions in the diamond were first located. Two inclusions, 4 × 6 μm and 4 × 16 μm in size, were examined with X-ray diffraction. They both produced a perovskite pattern. Their identity was further confirmed by infrared spectroscopy. Theoretically, a cubic perovskite has no Raman pattern, and none was obtained from these inclusions. The inclusions were next excavated from the surrounding diamond and analyzed with laser ablation–inductively coupled plasma–mass spectrometry (LA-ICP-MS) (figure 2). Their composition corresponded to the calcium silicate perovskite.
Davemaoite is significant in Earth’s deep mantle because it acts as a host to many elements that are incompatible with upper-mantle minerals, fulfilling a role that garnet plays in the upper mantle. Davemaoite may be the most geochemically important phase in the lower mantle because it will act as a repository in which the radioactive, heat-generating elements thorium and uranium become concentrated. Calculations suggested that davemaoite was entrapped in the host diamond at pressures of at least 290,000 atmospheres and temperatures of at least 1400 K. These diamonds from Orapa are also noteworthy because in addition to davemaoite, a high-pressure form of ice was found as a solid inclusion within them where the diamond’s internal pressure was great enough to maintain the ice in the solid form, allowing it to be characterized as the new mineral species ice-VII (O. Tschauner et al., “Ice-VII inclusions in diamonds: Evidence for aqueous fluid in Earth’s deep mantle,” Science, Vol. 359, 2018, No. 6380, pp. 1136–1139). Source: GIA @topic:4


Title: Colorless to Near-Colorless Diamonds, Emeralds from Pakistan, a History of European Royal Jewel Sales, and More… Abstract: Welcome to the Fall Gems & Gemology! This issue offers an exciting glimpse into the world of D-to-Z diamonds, characterizes the inclusion features and chemical composition of emeralds from Swat Valley, and details the acquisition and auction of crown jewels by European royalty.
“An exciting glimpse into the world of D-to-Z diamonds…”
In the lead article, a GIA team led by Sally Eaton-Magaña and Christopher M. Breeding examines colorless to light yellow/brown diamonds with a “D-to-Z” color grade, which make up the vast majority of the world’s gem diamond trade. Because this group of mostly type Ia diamonds has not been subjected to HPHT decolorizing treatment or laboratory growth, researchers usually investigate their more rare diamond type counterparts. This study evaluates diamond type properties and grading quality factors of D-to-Z diamonds submitted to GIA in 2017 and sheds light on their unique geological formation story.
The second article comes from a team led by Hongshu Guo, a student at the School of Gemology, China University of Geosciences in Beijing. The authors present the gemological and geochemical details of emeralds (including trapiche emeralds) from Swat Valley in Pakistan.
In the third article, Russell Shor examines how European royal families acquired their crown jewels, which were later sold at important auctions. The most recent of these was Sotheby’s historic Bourbon-Parma auction in 2018, in which 10 of the lots once belonged to Marie Antoinette.
Next, Ling Liu and colleagues from the Gemmological Institute, China University of Geosciences in Wuhan characterize turquoise from China’s Hubei Province with a rare surface pattern of spots resembling raindrops. They identify the color origin and formation mechanism of this distinctive pattern.
The final article is a field report from Hạ Long Bay in northern Vietnam, where in late 2019 Nicholas Sturman and coauthors visited a shell nucleus manufacturing factory and two pearl farms, all managed by Orient Pearls (Bangkok) Ltd. The team observed how high-quality bead nuclei are fabricated and used to produce Vietnamese bead cultured pearls suitable for fine jewelry on a commercial scale.
Our regular features continue to highlight interesting gemological findings from around the world. In Lab Notes, discover how gem cutters cleverly use color zoning in alexandrite and closely spaced needles in diaspore to showcase phenomena, and how areas of dramatic fluorescence correspond to diamond defects and produce a “lightsaber” effect. Curiosities abound in the Micro-World section: epigenetic residue mimicking a fried egg, metal sulfide inclusions resembling trees, and ferrocolumbite posing as star cruisers. Gem News International reports on bead cultured pearls with embedded electronic devices and Maxixe beryl with an unusual violet color, among other exciting topics.
This issue also contains the list of winners from this year’s G&G Challenge quiz. Congratulations, and our special thanks to everyone who participated! Source: GIA @topic:1


Title: Round CVD Synthetic Diamond Over 1 Ct Identified in Hong Kong Lab Abstract: Figure 1. Left: This 1.20 ct CVD synthetic round brilliant had a color grade of L, a clarity grade of SI2, and a cut grade of Very Good. Right: The 6.7 mm specimen contained a few black inclusions with irregular shapes. Photos by Ping Yu Poon.

In the past ten years, CVD synthetic diamonds have showed significant improvements in quality and size (Martineau et al., Spring 2004 G&G, pp. 2–25; Wang et al., Winter 2003 G&G, pp. 268–283; Wang et al., Summer 2012 G&G, pp. 80–97). Their color and clarity can be comparable with top natural counterparts, but for the most part they are still small. CVD gem-quality synthetic diamonds over 1 ct are occasionally reported in the trade, usually in fancy shapes with limited depth.

Recently, a round-brilliant specimen, identified as a CVD synthetic diamond, was submitted to the Hong Kong laboratory for grading service. It weighed 1.20 ct (6.70 × 6.72 × 4.30 mm), with a color grade of L, a clarity grade of SI2, and a cut grade of Very Good. This specimen resembled well-cut natural round diamonds (figure 1, left), with a few black inclusions of irregular shape clearly observable under the microscope (figure 1, right).

Figure 2. The CVD synthetic diamond’s infrared absorption spectrum showed a weak peak at 1344 cm–1. This feature, attributed to the isolated nitrogen impurity, was responsible for the L color grade.
Infrared absorption spectroscopy identified it as type IIa. A very weak absorption at 1344 cm–1 was attributed to isolated nitrogen in the diamond lattice (figure 2). Based on the absorption intensity (0.014 cm–1) of this peak, the total concentration of isolated nitrogen was well below 1 ppm. Occurrence of trace isolated nitrogen was the major optical center responsible for the L color observed. No hydrogen-related absorption was observed at either 3107 or 3123 cm–1 using infrared absorption spectroscopy. Photoluminescence (PL) spectra at liquid nitrogen temperature with 532 nm laser excitation showed the [Si-V]– doublet emissions at 736.6 and 736.9 nm (figure 3), a characteristic feature of CVD synthetic diamond. Weak emissions from N-V centers at 575.0 nm and 637.0 nm were also recorded. Fluorescence images collected using the DiamondView showed green fluorescence with characteristic CVD growth striations (figure 4). All these gemological and spectroscopic observations, very similar to those of Gemesis specimens (Wang et al., 2012), confirmed this was a CVD synthetic diamond. It was annealed at high pressure and high temperature (HPHT) to improve its color appearance.

Figure 3. A photoluminescence spectrum collected at liquid nitrogen temperature using 532 nm laser excitation revealed a strong emission doublet at 735.6 and 735.9 nm, indicating a [Si-V]– optical center.

Figure 4. Observed in the DiamondView, the 6.7 mm synthetic diamond showed typical striations indicative of CVD growth. Image by Carmen Lo.
As this sample shows, CVD technology has reached a new milestone, with the growth of crystals thick enough to consistently cut well-proportioned round brilliants. It is highly likely that we will see more gem-quality CVD synthetic diamonds over 1 ct in the trade. Source: GIA @topic:4