2007: Still there are no international standards for colored stone grading. Much work remains to be done.
(via Gemological Digest, Vol.2, No.3, 1998) Richard Hughes writes:
To mention the subject of colored stone grading to many gem dealers is to tell a Jew that Hitler was a great humanitarian—they immediately begin to foam at the mouth, snarling and growling in your general direction. A touchy subject? Not at all. Just don’t drop in into your conversation upwind of an ICA congress. Well, at the risk of getting bitten, I would still like to say a few words on the subject of colored stone grading.
The idea of grading gemstones is as old as the gem business itself. Learning to separate gems into different quality categories is one of the first things learned by most gem dealers and, in fact, their success in business rides to a large degree on their ability to do just that. However, idea of gem labs grading colored gemstones for the trade and public was first realized only in the late 1970s. This coincided with a general boom in the colored market. All booms, though, are usually followed by busts, at least in business. When this occurred in the early to mid 1980s, many dealers pointed at colored stone grading by labs as the major culprit. I do not believe that this is entirely a fair assessment. The issuance of grading reports by labs may have been responsible for part of the downturn, but they were certainly not the major cause.
Early attempts at laboratory grading were (and still are) crude, at best. This is true in the development of anything that is new. If you were to look back at first airplanes you would see that they were hardly satisfactory. Clumsy and dangerous, they often crashed and killed their occupants. Even today crashes occur. Airplanes remain far from perfect and probably never will be. Few people today would argue against their use on that score, but in the beginning many did. ‘Man should not attempt to fly. It is against God’s will. If man were meant to fly, God would have given him wings.’ I guess if man were meant to drive, he should have been born with wheels and horn, too.
Due to the primitive state of colored stone grading today, many dealers have stated that this subject is beyond the ability of humans to resolve (I must confess that I too once held this opinion because of the many difficulties involved). The grading of colored stones is so complex that it can never be summarized on a short report, they claim. When I hear this argument I am reminded of some of the books written on opal prior to 1965. Certain authors (Eyles, W.C., 1964), in discussing the play of color effect seen in opal, stated that it was a mystery that would probably never be solved by humans. For this reason, they claimed opal would never be synthesized. In 1965, however, scientists did discover the cause of this play of color and only six months later these same scientists had produced the first synthetic opal. The lesson here is not to just say no, to paraphrase Nancy Reagan, but instead, to never say never. What is needed is to less science, but more decent science.
I will be the first to admit that colored stone grading (and diamond grading) as practiced today is extremely unreliable and, in my opinion, not reproducible within a reasonable degree of error. I do not believe that any of the labs issuing these reports today (for anyone else, myself included, for that matter) have a firm enough grasp of the subject to do a good job of it. Colored stone grading today is comparable to the airplanes of 1910. Crashes occur far too frequently, and anyone who is offered a ride should definitely be warned of the considerable risks involved. Labs (and appraisers) which do not warn their customers of these risks are guilty of negligence, pure and simple. Too often these risks are swept under the carpet. Of course, you may argue that one does not learn to fly by remaining on the ground, and this is perfectly true. But it seems rash to be taking on passengers, unless they are properly informed of the risks. By risks, I refer to the degree of reproducibility of the grades. This should be clearly stated on the document, both for colored stone grading and diamond grading reports. If the risks are clearly described, however, I see nothing wrong with issuing these reports.
I must confess that the organization I work for, AIGS, also issued colored stone grading reports at one time. We no longer to so, mostly for the reason stated above—lack of a reasonable degree of reproducibility of the grades. We believe that there is still much to be learned about colored stone grading.
The trade’s inability to produce a high standard colored stone grading today does not mean that it should abandon the idea altogether. That would be akin to throwing out the baby with the bath water. The benefits of accurate grading system are too great to quit at the first sign of problems. Instead, we must keep working to develop and refine the grading techniques so that they can be made more reproducible.
Change inevitably brings about certain uneasiness in people, particularly as they age. Some feel this more than others. Many colored stone dealers have considered the changes in the business wrought by the introduction of diamond and colored stone grading reports and have deplored them. Some of the major criticisms leveled against colored stone grading by labs were discussed in 1985 by Reuven Sadkiel (Gemwatch, Feb, 1986), the President of the Israel Precious Stones and Diamonds Exchange. In his 1985 address to the Second European Precious Stones Congress in Antwerp, Sadkiel described colored stone grading by labs in the following terms:
1. It takes the factor of color appreciation and preference away from human taste and senses and replaces it with the judgment of a technical device.
2. It brings us to an artificial and unreal rating of what are supposedly the preferred color ranges.
3. It may bring about a stepped-up demand for certain colors, which are considered preferred when their availability in nature is rather rare.
4. It is absolutely unrealistic to impose a scientific conclusive scale of color preferences when in practice the desirability of color is a matter of personal taste and the natural daylight conditions in different geographic regions greatly influence the perception of color. The same stone has a different color appearance in different regions.
5. Grading and rating systems will cancel the element of illusion which is familiar to all of us, the all important subjective beauty and attraction of a specific rough or cut stone. An appreciation of the stone based on the skills, experiences and professionalism gained by the dealers over many years will become irrelevant the moment a mechanical device establishes a rating and value for the stone.
6. And, perhaps most disturbingly, the trade will de facto transfer the responsibility of setting the value of the goods we deal in to outside gemologists, laboratories, and their devices.
In conclusion, I want to restate unequivocally that it is impossible to allow the trade to accept color grading systems, even if they may seem helpful or practical. These grades will lead to value ratings and preference scales—which totally contradict the market realities which characterize our trade. It will lead first to trading with certificates and eventually to trading in certificates. It will eliminate the special role of dealers in the precious stone business. It will transfer the decision as to prices and preferences from the markets to the laboratories. It will destroy the norms and principles under which the business has flourished for many generations. It will take away the element of illusion, one of the most beautiful aspects of the trade. It will lead our business into chaos. It is up to us to avoid all this by saying ‘no’ to color rating systems.
After reading the above, one may wonder whether, in the opinion of Mr Sadkiel, colored stone grading might also cause hair to grow on the palms of one’s hand. Seriously, I do believe that a number of Mr Sadkiel’s criticisms have a certain amount of truth to them. But at the same time they do not tell the whole story.
Colored stone dealers today often see themselves as the last of the great adventurers, considering that they are among the first travelers to make the journey East since the time of Marco Polo. American dealer, Ray Zajicek, summed up this attitude when he said, “The colored stone dealer must go all over the world to seek his gems, sometimes imperiling his life in distant places such as Africa, South America and Southeast Asia.” (Everhart, 1987). Traveling to foreign lands to obtain the goods, they often visit areas which ordinary tourists shun. And similar to the European travelers of the Middle Ages, they often exaggerate the dangers of such travels. During the Middle Ages, European travelers to Asia often returned with fanciful accounts of their journeys. Dragons, mountains that spit fire, yetis, etc., were said to be the dangers of Asian travel during these times. Today these have replaced by smuggling, difficult access to mining areas, local wars, and simple culture shock at that. The purpose of such stories, I believe, is two fold. First, they tend to discourage any would be competitors, by representing the journeys as being much more hazardous than they actually are. Secondly, they lend a certain romance, or illusion, if you will, to the profession. Many gem dealers believe that colored stone grading would somehow remove this aspect of the trade, but this is not necessarily so.
The important thing to remember about colored stone grading is that it is a creation of humans, and so can be made to be anything that we want it to be. It is not, and should not be, a static entity created in a vacuum. A useable colored stone grading language can only be created by combining the scientific expertise of gemologists and other scientists with the practical expertise of the dealers. If the experts (i.e., dealers) believe the romance factor to be important and essential to the business, then there is no reason why it could not be incorporated into the grading. An additional romance grade could be added to the report. Perhaps gems mined or purchased in countries where a guerilla war is currently underway could be given five bonus points. Are their bandits along the access roads to mines? That would certainly worth a few extra points. Mines located above 4000 meters elevation might fetch ten extra points. Is there a language problem or do the taxi drivers overcharge you in the place where the gems are bought? Separate categories could be created for each of these (of course, a negative scale might also be needed. Male buyers making their purchase in Bangkok, famous for its active nightlife, generally enjoy themselves quite a bit while there, and so, logically, would be penalized. This, however, would not apply to female buyers, at least in Bangkok). The bottom line is that colored stone grading can incorporate anything that we want in to.
Similarly, the idea of different lighting conditions in different parts of the world can also be addressed. Studies can be undertaken to discern exactly what these differences are, or if, in fact, they exist at all. I, myself, as with most dealers, believe that these differences do exist, but until the problem is studied in more detail it would seem somewhat rash to say absolutely that they are detectable (let us not forget that, up until recently, most experts believed the world to be flat). If these differences are found to be important, they can then be incorporated into the report. Regional reports can be made for individual areas where the stone is going to be sold. However, to state that these differences will never be quantifiable is, in my opinion, shortsighted.
One of the biggest problems that we at AIGS have found in developing an effective colored stone grading language is that many experts (i.e. dealers) do not understand color terminology, as used by color scientists in other fields. An example of this is given by common dealer descriptions of rubies. If one asks an average dealer what the difference is between Burmese and Thai rubies, most will tell you that Thai ruby is too purple in terms of its hue positions. In fact, we have found that most Burmese rubies are more purple than their Thai counterparts.
The real difference between a fine ruby and a poor one is the saturation (intensity) of the hue rather than a shift in the hue position itself. We have found this to be the case with most colored stones. Too often dealers tend to refer to differences in color between one gem and another solely in terms of hue position, when saturation differences are the crucial factor. Certainly, an important factor in developing an effective colored stone grading language will be reaching agreement among both dealers and gemologists as to the proper vocabulary to be used in describing the appearance of the stones. And it is the overall appearance of the stone that is the crux of the issue here, not just the gem’s color.
As to market tastes in different countries, most dealers state that appreciation of color varies from one country to another. Colored stone grading reports, it is claimed, would dictate to the market which color is best, rather than the market making this decision. This is not necessarily so. True, certain markets tend to purchase certain colors over others, but I’ve observed that there is general agreement among connoisseurs as to what constitutes the best or better colors. Consequently, these better colors consistently fetch the highest prices in the market. As for the lower grades, yes, certain colors are purchased more for certain markets than for others. Rather than being a disagreement as to what is best, however, it is more a function of the buying power of the customers in that market. For example, Swiss buyers of corundum consistently purchase the better (i.e. more expensive) grades because their customers are generally more wealthy and so can afford to buy the best. In contrast, buyers from England must sell to customers in a market where the economy is depressed, and so are forced to settle for stones of lower quality. This is not to say that the people in England prefer to buy the lower grades. They just do not have enough money to purchase the best. The point here, and it is an important one, is that buyers will purchase the qualities which are most easily saleable in their home markets. Some may say that the English prefer darker rubies, while the Japanese prefer more pinkish stones. It is not that the Japanese and English buyers cannot agree upon what is best. They can. If given an unlimited amount of money to spend and if offered to a broad selection of rubies where side by side comparisons can be made, virtually all experienced buyers will choose the same stone almost every time. That is why these top quality stones fetch the highest prices in the Bangkok market.
One of Mr Sadkiel’s major objections to colored stone grading by labs was that it might bring about a stepped up demand for certain colors which are considered preferred when their availability in nature is rather rare. I fail completely to see the logic in this argument. Should we avoid telling people that Picasso and Van Gogh were great artists simply because they didn’t produce enough paintings to put one in everybody’s home? I think not.
It is interesting to note that the highest prices for the very best qualities are usually paid in the producing country itself. This is because the dealers in the country where the gem is found almost always have the most experience in buying that stone. They know the full range of qualities possible for that stone and so are better able to recognize the very top quality when it is shown to them. This may seem to contradict what I have just said about all experienced dealers agreeing on what is the best quality. The problem here is that the color memory of humans is extremely poor. Given side by side comparisons, humans are able to differentiate literally millions of colors. This ability shrinks very quickly, however, if the colors are examined one at a time. With colored gemstones, it is often not possible to make side by side comparisons—especially for the best qualities, due to their great rarity. Thus, dealers are forced to rely upon their memories when making a decision as to just where a particular stone lies within the color quality spectrum (many dealers carry with them reference stones for this purpose, because human color memory is so unreliable). Dealers in the producing countries have the most experience in judging that particular variety, and so are better able to place an individual stone in its proper rank within the spectrum. Were side-by-side comparisons are possible, dealers in the producing countries would not necessarily have such an advantage. Again, in side-by-side comparisons, my experience is that there is agreement as to which stone has the best color, even among dealers from many different countries.
The lesson to be learned here for those involved in colored stone grading is that, since side-by-side comparisons for the very rare top grades are not often possible, it will be necessary to come up with some other calibrated references (such as the GIA’s ColorMaster), as well as to consult with the most experienced dealers to determine just what constitutes the best for each individual variety. These dealers will generally not be found in the consuming countries, but instead, in the producing countries themselves.
True understanding of all colored stones is much too complex for this knowledge to be gathered into the head of a single person. Instead, I believe that increasing specialization will be required. It we want to learn and define what is best in corundum, we must go to Thailand, Burma, Sri Lanka, India, Australia and East Africa. If we want to learn what is best in emerald, we must seek out experts in Colombia, Zambia, Israel, Brazil, India, Pakistan and Afghanistan. If we want to learn what is best in Jade, we must seek out experts in Burma, China, Thailand, Hong Kong and Taiwan. These are the experts who are most qualified to judge what is best, because it is they who have the most experience in examining that particular type of stone.
Because of the tremendous difficulties involved in assimilating all of this expertise from such widely ranging sources, great mistakes in grading have occurred in the past. Many dealers are familiar with the mistakes in grading rubies made by AGL (American Gemological Laboratories) in New York during the early 1980s. Their grading of rubies was based mainly upon the hue position of the stone, in part because of the incorrect terminology used by dealers in describing such stones. As I stated earlier, dealers often describe color differences solely in terms of hue position when saturation is actually the key. Burmese rubies are said to be more red, while Thai rubies are described as being too purple. Actually, the reverse is true. The result of this lack of a properly defined color vocabulary was that AGL awarded its highest color grades to the dark Thai rubies which were the purest red in hue position (AIGS Type D, daeng dum). Burmese rubies, which have traditionally fetched the highest prices in the market (due largely to their higher saturation of color), were given lower grades because they were more purple in hue position.
Dealers quickly picked up on this discrepancy and began buying up these dark red rubies in Thailand where they were relatively cheap compared with Burmese stones, because they were graded highest in New York at AGL. Eventually AGL realized its mistake and corrected the situation, but not before considerable damage was done. To reiterate, for an effective colored stone grading language to be developed, it will require both scientific expertise as well as dealer expertise. And the dealer expertise is generally greatest at source, not just in the consuming countries.
Assimilating the knowledge from experts at the source is certainly one of the most difficult tasks facing the trade in the development of an effective colored stone grading system. There does appear, however, to be some promise for the future. Specifically what I am referring to is the establishment of gemological institutes and journals in the producing nations. The first such institute in a major producing country was the founding of AIGS in Bangkok ten years ago. Its success should provide a model for similar institutes in other producing nations.
During the nineteenth century the British were able to glean and distribute a tremendous amount of information about Asian countries and their cultures by establishing Asiatic Societies and their associated journals in a number of Asian nations. These societies provided the framework for a direct exchange of information pertaining to Asia and the rest of the world. Similarly, AIGS and this journal will also allow information about Asian gems to be distributed from the source to the rest of the world. What is needed now are similar institutes and associated publications in other major producing and trading centers. India and Sri Lanka have recently founded gemological journals which provide both fascinating and useful information about their markets. The Sauer family and others are presently working to establish an institute along the lines of AIGS in Brazil. We need institutes and journals in Burma, Colombia, China, Kenya, Tanzania, Zambia, Pakistan, Afghanistan, Nigeria, Mexico, in all the places where gems are produced. This is the only way in which the rest of the world can tap into that special knowledge and expertise that is available at the source. I am not trying to discount the importance of the work done by GIA, AGL, AGMS, DgemG, GAGB, GAA, CGA, SSEF, GAAJ, AFG, Gubelin, and others in the consuming nations. These organizations will continue to be essential in the future development of colored stone grading, particularly with regard to new and improved technologies. Today, however, very little information is being disseminated from the producing nations themselves. We must find a way to tap into the expertise at the source. Establishment of institutes and journals in the producing nations offers the most viable means of accomplishing this goal.
In summary, it is clear that much remains to be learned about colored stone grading, much work remains to be done. This will require cooperation among dealers and gemologists. Each has something to learn. Rather than looking upon one another as adversaries, let us look upon each other as colleagues, sharing in the development of something exciting, something new. Rather than looking wishfully back at the past, let us look forward to the future. Colored stone grading is here to stay, no matter how much some people might wish otherwise, because the consumers want it. And our trade exists for the consumers. They are the ones who buy our product. A great adventure awaits us. Colored stone grading can be anything that we make it. Let us work together, dealers and gemologists, to make it right.
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