EU would be a much better target to get to implement a standard than the US.
A vivid grade on a GIA document makes the diamond important and a vivid color diamond with such a document is worth more than a lesser stone with a "mistaken" or "lucky" GIA document. I refer to values between knowledgeable dealers. The retail asking prices have more to do with the documents than with the actual vivid color. There is no single answer.
The certifigate thing is only representative of the mess our legal system is in. How the rich and powerful often avoid consequences. No matter what, I remain positive about possibilities of change for the better. I have seen little benefit to becoming angry over these revelations.
Maybe if enough people got angry, those who deserve to would vacaction at club Fed.
or one could say that badly cut stones are just overpriced.
I agree that badly cut stones may be overpriced. It is the same deduction, basically.
Excellent article Garry. It and these resulting important discussions have covered much of the issue of blue fluorescenct diamond over-grading.
Just finished reading it all after Garry emailed me about his article and resulting discussions. Although it is late in this thread there are a few things to add.
After Stan''s talk in Feb 08, I began work on a series of three articles, the second one revisiting with new findings the over-grading of blue fluorescent diamonds.
The concern in 97 and now is that after teaching for over 60 years the importance of grading a diamond''s "true body color" in a UV free lighting that did not stimulate fluorescence, GIA suddenly in 97 comes out with a fluorescence article with the "revisionist history" idea stated in the winter 2008 G&G that "since 1974, GIA has promoted using a daylight-equivalent fluorescent lamp with a non- negligible amount of emitted UV" and that "the lamp should emit long-wave UV."
GIA should disclose that in regard to fluorescent diamond grading, since the 60''s they have been grading outside the accepted trade practice that Shipley instituted at GIA. That practice was to grade for "true body color" not the fluorescence enhanced "false color" spoken of by Bruton in Diamonds And Frank Wade in his book in 1916.
Both GIA and AGS are using the DiamondDock as their standard grading instrument, the GIA since 2000. It is important to understand that those still grading in the GIA DiamondLite or GIA microscope light are now grading outside the current GIA dictated standard lighting for color grading. This is due to the fact that the UV component is greatly reduced in going from a 2" distance in the Diamondlite to a 7" distance in the DiamondDock.
The investigation demonstrates that users of the DiamondLite can be grading the most common Very Strong Blue diamonds two grades higher than GIA''s and AGS'' current grading in the DiamondDock, which is in turn up to two grades higher than the "true body color" absent stimulation of fluorescence.
Tom Tashey was the one who started the knowledge base of the issue in actuality with his article in the Professional Gemologist and his use of a film type UV filter in the mid 90''s, with a rather nasty reply from Moses, the mouthpiece for GIA.
It was an oversight, I want to quickly correct, not to have mentioned the continuing contributions of AGA Task Force member Thomas Tashey.
When I stated: "Tom Tashey, I and several others had published articles about this issue ten years earlier after GIA''s article on fluorescence in 97.", it would have been a good time to mention that Tom continues at the forefront of this issue especially in light of his professionalism and credibility as former GIA Assistant Laboratory Director, Co-Founder of Professional Gem Sciences Inc, and advisor to the Israel Diamond Institute (IDI).
In the Gemmological Association article, I note the following at the beginning of the Proof section:
The Proof
How do you define a ''true blue white Jager diamond'' Michael?
I go by the historical definition. The earliest definition to be found in works about diamonds is in Frank Wade''s 1916 book, Diamonds, A Study of the Factors That Govern their Value.
. Bruton noted that the term blue-white “has been much abused,” and speculated that 99% of the diamonds sold as blue-white were not only not blue-white, but had tinted yellow body colour. He called the colour of these diamonds “false white”.
The short version or a definition is?Date: 6/29/2009 11:49:45 AM
Author: michaelgem
I go by the historical definition. The earliest definition to be found in works about diamonds is in Frank Wade''s 1916 book, Diamonds, A Study of the Factors That Govern their Value.
Wade says:
''Jagers'', named after the Jagersfontein mine, which yielded some especially fine stones, are bluish white stones. ... there is really very little difference between some blue-white Rivers and some fine Jagers, and values are closely similar and very high for either class.
In the Gemmological Association article, I address this true ''blue-white'' diamond versus the ''false color'' diamond at the beginning of the Problem section:
The Problem
The light yellowish tints in a Type Ia diamond combine with the various amounts of blue fluorescence, stimulated by daylight and other illumination containing Ultra Violet energy, to give blue-fluorescent diamonds a whiter, “perceived colour“, than its “true body colour” seen in lighting where fluorescence is not stimulated.
Diamond Colour ¯ “True” or “False”
Going back over 100 years, there was concern in the diamond trade for this fluorescence-improved, “perceived colour”, which was viewed as a “false colour”. The rare, true blue-white (also called Jager after the Jagersfontein Mine) is a term historically reserved for “a particular type of white stone … that is very slightly bluish, usually owing to its strong blue fluorescence” (Bruton, 197
Evidence is found of concern for this fluorescence-improved, “false colour“ going back to at least the turn of the 20th century. In his book “Diamonds A study of the factors that govern their value” (1916), Frank B. Wade warned dealers to be “on their guard against them”. He said that few bluish appearing diamonds are really blue in body colour. “Most of them owe their blueness to a bluish fluorescence which becomes more marked the stronger the light. ... Some of these stones are inferior in beauty to pure white stones when viewed under a light which does not cause them to fluoresce.”
So a followup question is how do I know Antoinette Matlin''s 3.02 cushion cut is a true ''blue white''? The answer is found by grading both the fluorescence improved ''false color'' obtained by grading in the GIA DiamondLite and comparing it to the ''true body color'' obtained in lighting that does not stimulate fluorescence.
The data base contained five Very Strong Blue''s including Antoinette''s. The other four VS blues dropped four up to almost 5 grades in color. These are the much more common ''false color'' diamonds referred to by Wade and Bruton. Antoinette''s blue-white went from D to E, an imperceptable change proving it to be the much more rare ''true color'' Jager stone.
Michael D. Cowing
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