Part of the satisfaction derived from buying a colored gemstone is trusting in one’s knowledge of precious and semi-precious stones at the time of purchase. When the deal is done, the buyer, certain the proper price has been paid for the stone of choice, demonstrates a confident stride out of the shop. Still, questions of origin and quality loom, steering weary gemstone buyers into the nearest gem testing lab.

For nearly 15 years, the idea of developing a grading system for colored stones has been aimed at changing a time honored method of gem trading: Simply stated, in-depth knowledge of the gem and jewelry industry and dealing with trustworthy people. For those who want to leap into the colored stones trade, this education process is not only difficult, it can be quite lengthy and costly.

Similar to the grading system for diamonds developed by the Gemological Institute of America (GIA) in the 1950s, efforts to create a method of grading colored gemstones, which began 30 years later, also seeks to help the industry by implementing a standardized method for evaluating gemstones to improve methods of buying and trading.

One of the first known systems for grading colored stones was developed by Howard Rubin of New York. His gem dialogue system of grading used long strips of color hues, working from low to high color saturation, used to match against the color of a gem stone to determine color saturation, hues and tones.

During this time frame, the American Gem Lab (AGL) not only created the Color Scan method of grading colored stones, it also developed a grading system using a master set of gemstones. Unlike other labs, the AGL incorporated information from their colored stone grading system into their lab’s identification certificates.

Shortly after the AGL’s color scan came the GIA’s color system, a Colormaster machine which can project images of faceted gems in different shapes, with the operator adjusting the three primary colors (blue, green and red) until a color match is achieved. By 1983, the GIA added colored stone grading to their curriculum, including clarity and cut along with color matching and grading.

Today the GIA uses GemSet plastic master stones to match and grade color in place of the Colormaster. “GemSet is much more practical than the Colormaster, as the color matching is faster, the cost of GemSet is affordable, and it’s portable,” said Chris Keenan, director of GIA Thailand. The GIA has yet, however, to utilize the system in their Gem Trade Laboratory in the form of a colored stone grading report, Keenan added.

The Asian institute of Gemological Sciences (AIGS) is also presently developing its own method of colored stone grading for rubies using master tones, according to AIGS Director Ken Scarratt Similar to the GIA, the AIGS is looking to develop a colored stone grading system for the benefit of the lab’s affiliated school and the industry.

“A lot of effort has to do with teaching. We have to teach people how to evaluate gems in order to buy and trade them. It would be wonderful for our students to enter the industry when it is already using terminology from a grading system developed by the AIGS,” Scarrat said.

GIA Thailand has been teaching colored stone grading since 1993. “The GIA colored stone grading system gives our students an organized way to judge and discuss the quality factors of colored gems. As part of our professional training, it works.”

However, the topical question is whether or not the jewelry industry at large wants a lab report for colored stones. A widely accepted lab report may have a controlling influence on colored stone prices. The challenge is to find methods to judge color with scientific consistency in a lab that both the lab and the jewelry industry are happy with and at the same time helps the consumer,” Keenan said.

Part of the problem is determining if the industry even wants a grading system for colored stones, according to Dr. James Shigley, director of research for the GIA. :developing a grading system for colored stones would be difficult, but it can be done if the trade wants it. We in the research portion of the industry should listen to what the trade wants.

            A while back we went through a lot effort to develop a system that would detect radiation in treated topaz, but the industry didn’t show any real support for this detection equipment. There’s no use in doing something of the industry doesn’t want it. I suspect many traders have their own grading system anyway. How else we can they make money?” Shigley said.

            A survey of gem traders in the Bangkok area revealed that a majority of wholesalers do have in house grading system, but favor the idea of developing a standardized grading system to facilitate and expedite gemstone trading. The likelihood of creating such a system, however, is quite a stretch.

             Some traders cited problems the diamond sector has encountered over the years with its grading system. The GIA grading system for diamonds, the first to be taught internationally, has 23 categories for color and 11 for clarity. Although there are slight variations from one grading category to the next, one letter grade difference can dramatically impact the asking price for a diamond. As a result, gem traders have certificated by a variety of labs, using the most favorable report for the sale.

            “Diamonds benefit from a narrow channel of distribution, mostly through De Beers and from the great amount of marketing and promotion they invest in support of the diamond industry world-wide. The international diamond grading systems developed by the GIA and the HRD do not grade diamonds based on where they came from, but on the quality of each stone,” Keenan said.

            Many traders surveyed also voiced concerns about creating a universal grading system with gemstones coming from so many sources. Which region produces a definitive color and why? Who is to say one source produces a better color or not? With developments in mining technology generating more could make a grading system using master stones obsolete overnight as well.

Nomenclature for a colored stone grading system stemmed from this particular issue with the industry and end users embracing terminology from sources well known for quality gemstones with good color saturation, such as Burmese ruby or Sri Lankan blue sapphire.

The issue of seeing, interpreting and naming color is the major stumbling block for creating an industry-wide universal grading system, according to Shigley.” Almost everyone can agree on a gemstone’s clarity and cut. Color, however, is a very subjective thing. Each of us sees differently,” Shigley said.

The biggest challenge for trading gemstones, with or without a universal grading system, is communicating color. The human eye is capable of discerning over 6 million colors and shades for starters. This fact and the many names for colors are merely a starting points when discussing the subjective nature of evaluating color.

Randy Wagner, president of LamdaSpec Instruments, is one person trying to resolve the array of problems with determining and communicating color for the gem and jewelry industry with his company’s latest imaging spectrophotometer technology.

According to Wagner, the needs of the gem and jewelry industry have been neglected by the scientific community. Although Wagner acknowledges the contributions and merits of the colorimeter and spectrophotometer to the industry thus far, the present technology for determining a gemstone’s color is limited because it does not produce accurate and precise information.

“When discussing the limitations of these instruments you must first understand that an instrument is accurate when it provides measurements that deviate within acceptable limits from a standard, and an instrument is precise if it can provide measurements that are repeatable,” Wagner said.

The methods of grading colored stones have only been in existence for about 15 years. Converting an industry that has enjoyed a long tradition of trading on its own terms will not change easily. Similar to the diamond traders decades ago, today’s colored stone traders have concerns over already narrow profit margins further eroding with an industry-wide grading system in place.

“It seems the industry is moving in this direction. There is really nothing anyone can do about it because the move toward an industry-wide grading system has a lot momentum. All we in the trade can do is cooperate with those that are creating such a grading system, and hope that, if put in place, it will work to benefit those in the trade while building consumer confidence,” said Jeffrey Bergman of Gem Source.

The grading system for diamonds has helped the trade communicate color, clarity and cut. With the advent of matrix pricing, eventually diamonds will be traded on the Internet, in the not so distant future, if the industry can agree on ways of creating an objective standard for evaluating colored stones, modern communication technology may radically change the way all gemstones are traded.

 

New Madagascar Sapphire Source

            Madagascar is quickly becoming one of the most talked about source for colored gemstones in the world. Dr. E J Gübelin, who visited the country in June to assess a new source of sapphire, shared his assessment and studies of the gemstone deposits there during his September trip to Bangkok.

            Gübelin began his lecture with a brief discussion of the area’s geological history and how it played a role in the developing the country’s high grade metamorphic rock, a coarse white marble referred to as scarn, a common host for corundum.

            With a map of Madagascar projected on a screen, Gübelin pointed out a variety of sources where many species of gemstones are being mined. In the south lie concentrations of many species of gemstones including: beryl, corundum, aquamarine, and hibonite. According to Gübelin hibonite was historically thought to be ancient meteor because the mineral was found in a single source. This theory has changed in light of other sources found in India and Tanzania.

            In the mining area of Andranondambo are large networks of shafts and tunnels carved into the scarn on flatlands that precede a mountain region. Here many families and small mining groups are simple mining tools (chisels, crowbars and hammers) to look for alluvial deposits of sapphire, according to Gübelin.

            Similar to other mining operations where corundum is mined from scarn, large pieces are brought from the mines and reduced to smaller pieces with a hammer to search for corundum. “The sapphire from Andranondambo is similar in color to the royal blue color is one characteristic of this source of sapphire. This can be cured with heat treatment,” Gübelin said.

            Each month 100 kilos of gem material is mined, 80 percent of the being of gem-grade quality. According to Gübelin, 90 percent of the gem-grade sapphire produced is shipped to Thailand for heat treatment. This treatment process, however, produces strong color zoning, said Gübelin.

            According to Gübelin, there are three companies with mining operations in Andranondambo-one Swiss firm, a Thai-Japanese joint venture and a Thai company. This would attribute the Andranondamo sapphire’s biggest markets being Switzerland and Thailand.

            The sapphire found here contains trace elements of iron, titanium and manganese. As with any gemstone, the Andranondambo sapphire has its own unique inclusions.

            Calcite is one of the most common mineral inclusions of this species of sapphire. Apatite crystals have also been found in this variety of corundum. Some signature inclusions for this sapphire are the negative inclusions and fluid inclusions which commonly contain carbon dioxide, according to Gübelin. Other internal features include phantom color zones, similar to those found in ruby from Mong Hsu, as well as comet-tail inclusions, he added.

            “You can’t depend on one internal feature to distinguish this species of sapphire from any other found in the world. If you can find three to four types of inclusions most common to this species of sapphire, you can be assured you have an Andranondambo sapphire,” Gübelin said.

            During his June visit to Andranondambo, Gübelin said many locals tried selling him gemstones, ranging in size from 0.5-2.0 carats of low-to medium-grade gem-quality, leading him to believe there is abundance of this material available.

            Although sapphire is found in many colors, the Andranondambo sapphire has only been found in blue. One extraordinary sample of a 23 carat sapphire of fine color was found recently, according to Gübelin.

            “This find is fascinating in many respects. It offers us a new species of precious gemstone to study,” Gübelin said.

 

The Bangkok Gem Market

            A new cat’s-eye opal from Brazil was brought to Bangkok by Eric and Jean-Claude Nydegger, of De Wal Brazil, the brothers mining this new find in the Bahia state in northeastern Brazil. The opal found in this region is mainly green to golden in color and is being mined in three areas with only one site producing the cat’s-eye opal, according to Jean-Claude.

            David Glickman, of Lambert Holding, has borrowed a few samples of the new opal find, called the Imperial Opal, to show potential customers. Glickman referred to the cat’s-eye opal as a “poor man’s” cat’s-eye stimulant, referring to the inclusion phenomenon commonly associated with chrysoberyl.

            A 20 kilo opal from Australia is on consignment to Glickman, who said it may well be one of the largest opals ever found. In his office Glickman has a large cross-section cut of the large find, as well as other large shards.

            A variety of red beryl is being cut by Lambert Holding that has a strong red color to it and is of gem quality. Although red beryl has been found in Australia and Africa, this variety is only found in the Wah Wah Mountains of Utah, in the United States.  “It is so rare that customers are willing to buy even small unattractive pieces,” Glickman said.

            In a general assessment of the market, Glickman said synthetics are becoming more accepted. Some new synthetic arrivals are a blue quartz in a neon color, as well as alexandrite, padparadcha colors of synthetic corundum and chrysoberyl.

            White sapphire, a gemstone that made a comeback for Lambert Holding earlier this year, is now hard to find. “What we are seeing more of lately is white zircon. Cubic zirconium practically drove if off the market, nearly eliminating it to my surprise. Now people are buying them again in 6-8mm diameter sizes. For a while we were able to get white sapphire, now it’s being bought up by people doing diffusion treatments to make them blue. This may account for white zircon’s popularity,” Glickman said.

            Paranya Makhni, of Makhni Enterprises, also said white sapphire is getiing harder to find. White zircon is not selling well compared to blue zircon, according to Paranya. “Blue zircon is selling very well in Germany and the United States because it has a very nice luster,” he said.

            For Lambert Holding the classic gemstones are going strong, with blue sapphire going up in price, demonstrating the most dramatic price movement of the classic colored stones, said Glickman.

            Ravi Lunia, of Fai Dee Gems, who deals in classic gemstones, said prices for all of these goods are high at the moment. “The borders are opening up, letting more goods come in, but prices for these goods are quite high. Quality goods are very expensive. You can get as much commercial goods as you want, but even these goods are expensive right now,” he said.

            Most of Fai Dee Gem’s ruby are coming from Myanmar (Burma) and sapphire from Sri Lanka. The market is good for Fai Dee Gems, but it s difficult to find quality goods, said Ravi.

            “You can always sell quality goods for a good price if you can get them. The boarders are opening up allowing for more goods to come into Thailand. My recent trip Chantaburi was very good. I am quite pleased with the goods I purchased from there. I found rubies in 2-3 carat sizes of good quality, but they were expensive,” Paranya said.