Blue Fluorescence in Diamonds

[michaelgem]

The short version or a definition is?
Blue White diamond is a blue fluorescent diamond that only has a one grade shift in color when being color graded under a grading light with and without a Lexan filter.
Next question - is D to F and acceptable range before or after the shift?
And would a low D that shifted to a high F still be Blue White?
I am concerned Michael that if people make such claims that there should be a clear and concise definition.

(I would also like to find one for color grading light sorurces - I do not accept the ancient opinions of single people in days with very different knowledge and lighting sources.) Garry Holloway

I see Wade and Bruton not as single people with ancient opinions. Instead, I see them as the diamond experts that they were in their respective eras providing us windows through their writing into diamond industry knowledge, grading and valuation.

As explained by both, the true blue white or Jager stone is a blue fluorescing diamond that still appears white in lighting which does not stimulate fluorescence, whereas the "false white" shows tints of color in the same lighting. That is both a concise definition and the way to test. When the diamond is not fluorescing is it white or tinted?

Since you asked, I would say to be on the safe side take GIA''s teaching that a diamond begins to "draw color" at G.
If a VSB D color diamond stays in the D-F range that GIA calls colorless, it is safe to say it qualifies as a Jager.

If, as the more common VSB diamonds do, the color absent fluorescent stimulation drops three or more grades, the stone clearly does not qualify as a Jager. At some point (you decide) it is the "false color" diamond well known in the diamond trade going back before the turn of the 20th century.

Antoinette''s 3.02 carat cushion is a textbook example of what both diamond experts in Wade''s time and Bruton''s time called Jager or the true "blue-white".

Michael D Cowing

 

[Garry H (Cut Nut)]

Date: 6/29/2009 11:28:09 PM
Author: michaelgem

The short version or a definition is?
Blue White diamond is a blue fluorescent diamond that only has a one grade shift in color when being color graded under a grading light with and without a Lexan filter.
Next question - is D to F and acceptable range before or after the shift?
And would a low D that shifted to a high F still be Blue White?
I am concerned Michael that if people make such claims that there should be a clear and concise definition.

(I would also like to find one for color grading light sorurces - I do not accept the ancient opinions of single people in days with very different knowledge and lighting sources.) Garry Holloway

I see Wade and Bruton not as single people with ancient opinions. Instead, I see them as the diamond experts that they were in their respective eras providing us windows through their writing into diamond industry knowledge, grading and valuation.
Michael D Cowing

I see Bruton as a journalist with good intentions. I have used that as a text for many lectures to GAA diamond students over two decades Michael and you can drive a truck thru the errors that would never have been made by a diamond person.

 

[Garry H (Cut Nut)]

Date: 6/29/2009 11:28:09 PM
Author: michaelgem

The short version or a definition is?
Blue White diamond is a blue fluorescent diamond that only has a one grade shift in color when being color graded under a grading light with and without a Lexan filter.
Next question - is D to F and acceptable range before or after the shift?
And would a low D that shifted to a high F still be Blue White?
I am concerned Michael that if people make such claims that there should be a clear and concise definition.

Since you asked, I would say to be on the safe side take GIA''s teaching that a diamond begins to ''draw color'' at G.
If a VSB D color diamond stays in the D-F range that GIA calls colorless, it is safe to say it qualifies as a Jager.

If, as the more common VSB diamonds do, the color absent fluorescent stimulation drops three or more grades, the stone clearly does not qualify as a Jager. At some point (you decide) it is the ''false color'' diamond well known in the diamond trade going back before the turn of the 20th century.

Michael D Cowing

A Blue White diamond is any blue fluorescent diamond that has a color of F or better when color graded under a grading light with absolutely no long wave Ultra violet light (e.g. with a Lexan filter).

Next question - please define the type of grading light that you would use - must it have a Lexan filter? What color temp? what tube type? What distance etc please Michael? A totally repeatable process please.

This will be very useful to establish a new collectors catagory, and I will include it in the Pricescope tutorial.

 

[diagem]

Date: 6/29/2009 8:31:45 PM
Author: Garry H (Cut Nut)

Date: 6/29/2009 11:49:45 AM
Author: michaelgem

Date: 6/29/2009 9:57:50 AM
Author: Garry H (Cut Nut)

Date: 6/28/2009 12:09:08 PM
Author: michaelgem

one Very Strong Blue in particular, Antoinette''s 3.02ct cushion that turned out to be a true ''blue-white'' or Jager stone.

Michael D. Cowing

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.

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. 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”.

I believe these "false-white" Diamonds were also marketed as "Premier" type Diamonds which as I recall had a slightly yellowish tinted body color with a nice bluish glow face up appearance..., which also commanded a certain value premium.
Like the Jagersfontein (for better whites)..., Premier was known for their tinted material.

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

The short version or a definition is?

A Blue White diamond is a blue fluorescent diamond that only has a one grade shift in color when being color graded under a grading light with and without a Lexan filter.

Next question - is D to F and acceptable range before or after the shift?
And would a low D that shifted to a high F still be Blue White?

I am concerned Michael that if people make such claims that there should be a clear and concise definition.

(I would also like to find one for color grading light sorurces - I do not accept the ancient opinions of single people in days with very different knowledge and lighting sources.)

 

[strmrdr]

I think the term blue-white diamond is best left in the history books.
Any US based retailer who uses the term is walking on hot coals, it is asking to get burned.
Doing a google search brings up many pages where it is called a scam based on its history of abuse.

 

[adamasgem]

16 CFR part 23.14

 

[Garry H (Cut Nut)]

There is nothing in that legislation to stop anyone in USA selling what Michael has defined as Blue White

 

[michaelgem]

Date: 7/3/2009 4:46:25 PM
Author: Garry H (Cut Nut)
There is nothing in that legislation to stop anyone in USA selling what Michael has defined as Blue White

Right Garry,

By grading the "true body color" in grading light that does not stimulate fluorescence, we easily separate the "false white" diamonds, including the extreme example of the Premier, from the true "blue-white" or "Jager". I have not so much defined as explained in current terms how to detect and grade these dissimilar fluorescent diamonds that under current grading standards and industry pricing are being equally discounted. Based upon their relative rarity and beauty diamond''s like Antoinette''s should garner a premium rather than a discount. That beauty and rarity has been lost on the diamond industry perhaps largly due to almost universal grading too close to UV rich fluorescent lighting.

To be fair and in the interest of full disclosure, it should be important to reveal to the consumer what the industry always intended: the diamond''s "true color" grade.

I remember Rapaport saying over 10 years ago: “Unfortunately, the probability of a lab over-grading a fluorescent stone is much greater than a non-fluorescent stone and a large percentage of high colour mistakes turn out to be fluorescent”. He concluded: "Obviously from the market perspective there appears to be a reasonable basis for price discrimination against fluorescence ... The labs are going to have to be very serious about not over-grading the colour of fluorescent stones even though these stones tend to appear whiter than they are."

I wonder if he meant, "then they are" in indoor lighting, which does not cause the diamond to fluoresce. Because that was what in essence Wade said the diamond industry wanted to be graded going back over 100 years.

Michael D. Cowing

 

[Garry H (Cut Nut)]

Date: 7/3/2009 11:08:12 AM
Author: strmrdr
I think the term blue-white diamond is best left in the history books.
Any US based retailer who uses the term is walking on hot coals, it is asking to get burned.
Doing a google search brings up many pages where it is called a scam based on its history of abuse.

Diamonds of the description we have been discussing meet and exceed this legislation:

23.14 Misuse of the term “blue white.”
It is unfair or deceptive to use the term "blue white" or any representation of similar meaning to describe any diamond that under normal, north daylight or its equivalent shows any color or any trace of any color other than blue or bluish.

 

[Garry H (Cut Nut)]

Date: 7/3/2009 11:23:02 PM
Author: michaelgem

Date: 7/3/2009 4:46:25 PM
Author: Garry H (Cut Nut)
There is nothing in that legislation to stop anyone in USA selling what Michael has defined as Blue White

Right Garry,

By grading the ''true body color'' in grading light that does not stimulate fluorescence, we easily separate the ''false white'' diamonds, including the extreme example of the Premier, from the true ''blue-white'' or ''Jager''. I have not so much defined as explained in current terms how to detect and grade these dissimilar fluorescent diamonds that under current grading standards and industry pricing are being equally discounted. Based upon their relative rarity and beauty diamond''s like Antoinette''s should garner a premium rather than a discount. That beauty and rarity has been lost on the diamond industry perhaps largly due to almost universal grading too close to UV rich fluorescent lighting.

To be fair and in the interest of full disclosure, it should be important to reveal to the consumer what the industry always intended: the diamond''s ''true color'' grade.

I remember Rapaport saying over 10 years ago: “Unfortunately, the probability of a lab over-grading a fluorescent stone is much greater than a non-fluorescent stone and a large percentage of high colour mistakes turn out to be fluorescent”. He concluded: ''Obviously from the market perspective there appears to be a reasonable basis for price discrimination against fluorescence ... The labs are going to have to be very serious about not over-grading the colour of fluorescent stones even though these stones tend to appear whiter than they are.''

I wonder if he meant, ''then they are'' in indoor lighting, which does not cause the diamond to fluoresce. Because that was what in essence Wade said the diamond industry wanted to be graded going back over 100 years.

Michael D. Cowing

Thanks Michael, and FYI - my post just after yours was in preperation but I was called away for an hour or 2 - so it came after yours and looks out of place.

I have had a play with a few GIA graded fluoro stones of high color and strong and very strongl blue. One F could be a G when screened with a thick piece of Lexan (and we dropped the color grade to G for sale purposes, even though it will be sold with a gIA report of F), but 3 other D and E stones were still E, E and F. So they should qualify for ''Blue White''.
(There is no such legislation in Australia or to the best of my knowledge, anywhere else in the world.)

If there are any consumers reading this (which I hope there is, but doubt) perhaps we could have an opinion if owning a Blue white diamond would have any appeal to you?

 

[adamasgem]

Date: 7/4/2009 12:08:45 AM
Author: Garry H (Cut Nut)

Date: 7/3/2009 11:08:12 AM
Author: strmrdr
I think the term blue-white diamond is best left in the history books.
Any US based retailer who uses the term is walking on hot coals, it is asking to get burned.
Doing a google search brings up many pages where it is called a scam based on its history of abuse.

Diamonds of the description we have been discussing meet and exceed this legislation:

23.14 Misuse of the term “blue white.”
It is unfair or deceptive to use the term ''blue white'' or any representation of similar meaning to describe any diamond that under normal, north daylight or its equivalent shows any color or any trace of any color other than blue or bluish.

Gee Garry, doesn''t an E or F exhibit a "trace of color" due to nitrogen

 

[michaelgem]

Date: 7/4/2009 12:08:45 AM
Author: Garry H (Cut Nut)

Diamonds of the description we have been discussing meet and exceed this legislation:

23.14 Misuse of the term “blue white.”
It is unfair or deceptive to use the term 'blue white' or any representation of similar meaning to describe any diamond that under normal, north daylight or its equivalent shows any color or any trace of any color other than blue or bluish.

It is a shame that a truckload of "false white" diamonds can be driven through the loopholes in this flawed FTC regulation, because all of them will appear blue or bluish under normal, north daylight.

All it takes is the 150 uW/cm2 in the DiamondLite to elevate the "false white's" three to 4.5 grades.

I've measured blue sky, northern daylight in Maryland, and found it to be 500-600 uW/cm2.

By not requiring a look at the diamond in lighting that does not stimulate fluorescence, the FTC regulation totally misses the point that a diamond is not a blue-white if it has tints of yellow in such lighting.

So, although these diamonds exhibit a trace of color other than blue or bluish in lighting that does not stimulate fluorescence, in north daylight they exhibit blue or bluish and qualify as blue-white according to this FTC regulation.

Michael D. Cowing

 

[michaelgem]

Date: 6/30/2009 1:18:11 AM
Author: Garry H (Cut Nut)

Date: 6/29/2009 11:28:09 PM
Author: michaelgem
Since you asked, I would say to be on the safe side take GIA''s teaching that a diamond begins to ''draw color'' at G.
If a VSB D color diamond stays in the D-F range that GIA calls colorless, it is safe to say it qualifies as a Jager.

If, as the more common VSB diamonds do, the color absent fluorescent stimulation drops three or more grades, the stone clearly does not qualify as a Jager. At some point (you decide) it is the ''false color'' diamond well known in the diamond trade going back before the turn of the 20th century.

Michael D Cowing

A Blue White diamond is any blue fluorescent diamond that has a color of F or better when color graded under a grading light with absolutely no long wave Ultra violet light (e.g. with a Lexan filter).

Next question - please define the type of grading light that you would use - must it have a Lexan filter? What color temp? what tube type? What distance etc please Michael? A totally repeatable process please.

This will be very useful to establish a new collectors catagory, and I will include it in the Pricescope tutorial.

Following is a "straw" conclusion that answers your question about the type of grading light that I would use. The short and clear answer is one in which fluorescence is not stimulated beyond faint, so the "true color" is properly graded.

It is time to solve the problem of over grading blue-fluorescent diamonds. The desired grade for a blue-fluorescent diamond should be reestablished as its “true body colour” defined historically in the diamond trade and affirmed by GIA’s founder Robert Shipley as that colour seen in typical artificial lighting where fluorescence is not stimulated. The “true body colour” of a diamond is seen and can be graded against master diamonds at normal wearing distance from daylight fluorescent overhead illumination (3 to 4 feet distant) where neither the UV nor “Visible Violet” is strong enough to influence the colour grade.

Since lab grading is done from about 2 to 10 inches from fluorescent tubes (rather than 3 to 4 feet away where UV has greatly decreased), the use is recommended of a polycarbonate plastic (Lexan or Makrolan are examples) as an effective and inexpensive filter to remove UV from 400nm down. This polycarbonate filter is designed to only screen out UV, purposefully avoiding noticeably altering the visible spectrum.

The solution to removing excitation from the visible-violet is to attenuate these wavelengths, so they do not stimulate fluorescence. This can be accomplished by keeping the visible light intensity below 400fc with a white plastic diffuser. In addition to lowering the light intensity, such white diffusers were recommended by GIA to reduce spectral reflections and glare from diamonds being graded and to filter UV emissions.

This investigation found that by keeping the light intensity below about 400fc with a white plastic diffuser, and by filtering the UV from fluorescent lighting, even the VST Blue diamonds graded as their "true body colour".

An equally effective solution in concert with the movement to the “green” technology of LED lighting is the use of white LEDs such as the investigation’s Dazor LED desk lamp. It not only provides inherently, UV-free grading light, but is dimmable without change in colour temperature down to 200-400fc (2000-4000lux), so as not to stimulate fluorescence from the LED’s small amount of Visible-Violet.

A return to lighting standards that allow grading of the true body colour would benefit the diamond industry in a variety of ways. First it would remove the distrust and stigma attached to fluorescent diamonds. Second, the rarer blue-fluorescent diamonds that hold their high-white colour absent stimulation of fluorescence would be recognized for their superior beauty and rarity. Thirdly, blue-fluorescent diamonds graded at their “true colour” would be shown to whiten, and sometimes appear blue-white in natural daylight, giving them the edge in marketing over their non-fluorescent counterparts that they used to enjoy.

In the final analysis, it would be as beneficial as it is simple and affordable to correct the problem of over grading blue-fluorescent diamonds. By doing so, we would restore and return to the colour-grading of diamonds based on the traditional diamond industry standard of “true body colour.”

Michael D. Cowing

 

[Garry H (Cut Nut)]

Date: 7/4/2009 12:43:35 AM
Author: adamasgem

Date: 7/4/2009 12:08:45 AM
Author: Garry H (Cut Nut)

Date: 7/3/2009 11:08:12 AM
Author: strmrdr
I think the term blue-white diamond is best left in the history books.
Any US based retailer who uses the term is walking on hot coals, it is asking to get burned.
Doing a google search brings up many pages where it is called a scam based on its history of abuse.

Diamonds of the description we have been discussing meet and exceed this legislation:

23.14 Misuse of the term “blue white.”
It is unfair or deceptive to use the term ''blue white'' or any representation of similar meaning to describe any diamond that under normal, north daylight or its equivalent shows any color or any trace of any color other than blue or bluish.

Gee Garry, doesn''t an E or F exhibit a ''trace of color'' due to nitrogen

Marty I have been trying to glean a definition for "Blue White" - Michaels is that the stone remainds in the D-F range when UV is absent.

If you know of a different definition then please share it.

I find the idea intruiging and would really like to revisit it because in the rest of the world the US prejudice is absent, and as i read the legislation there - it also does not preclude the idea.

 

[Garry H (Cut Nut)]

Date: 7/4/2009 12:51:28 AM
Author: michaelgem

Date: 7/4/2009 12:08:45 AM
Author: Garry H (Cut Nut)


Diamonds of the description we have been discussing meet and exceed this legislation:

23.14 Misuse of the term “blue white.”
It is unfair or deceptive to use the term ''blue white'' or any representation of similar meaning to describe any diamond that under normal, north daylight or its equivalent shows any color or any trace of any color other than blue or bluish.

It is a shame that a truckload of ''false white'' diamonds can be driven through the loopholes in this flawed FTC regulation, because all of them will appear blue or bluish under normal, north daylight.

All it takes is the 150 uW/cm2 in the DiamondLite to elevate the ''false white''s'' three to 4.5 grades.

I''ve measured blue sky, northern daylight in Maryland, and found it to be 500-600 uW/cm2.

By not requiring a look at the diamond in lighting that does not stimulate fluorescence, the FTC regulation totally misses the point that a diamond is not a blue-white if it has tints of yellow in such lighting.

So, although these diamonds exhibit a trace of color other than blue or bluish in lighting that does not stimulate fluorescence, in north daylight they exhibit blue or bluish and qualify as blue-white according to this FTC regulation.

Michael D. Cowing

In other words Michael, you believe many if not most blue fluoro diamonds can be legally called Blue White?

 

[strmrdr]

Date: 7/4/2009 3:51:28 AM
Author: Garry H (Cut Nut)
In other words Michael, you believe many if not most blue fluoro diamonds can be legally called Blue White?

The problem Garry is the wording of the rule/law has little to do with what is legal in the US legal system.
The law is based on case law that interprets the law as written.
In the case of regulations also how the regulatory agencies interpret the rule is given a lot of weight.
So to truly understand what is legal or not would require careful study of when where and why that rule has been enforced.
Then a written opinion should be requested from the agency.

 

[michaelgem]

Date: 7/4/2009 3:51:28 AM
Author: Garry H (Cut Nut)

Date: 7/4/2009 12:51:28 AM
Author: michaelgem

Date: 7/4/2009 12:08:45 AM
Author: Garry H (Cut Nut)





Diamonds of the description we have been discussing meet and exceed this legislation:

23.14 Misuse of the term “blue white.”
It is unfair or deceptive to use the term 'blue white' or any representation of similar meaning to describe any diamond that under normal, north daylight or its equivalent shows any color or any trace of any color other than blue or bluish.

It is a shame that a truckload of 'false white' diamonds can be driven through the loopholes in this flawed FTC regulation, because all of them will appear blue or bluish under normal, north daylight.

All it takes is the 150 uW/cm2 in the DiamondLite to elevate the 'false white's' three to 4.5 grades.

I've measured blue sky, northern daylight in Maryland, and found it to be 500-600 uW/cm2.

By not requiring a look at the diamond in lighting that does not stimulate fluorescence, the FTC regulation totally misses the point that a diamond is not a blue-white if it has tints of yellow in such lighting.

So, although these diamonds exhibit a trace of color other than blue or bluish in lighting that does not stimulate fluorescence, in north daylight they exhibit blue or bluish and qualify as blue-white according to this FTC regulation.

Michael D. Cowing

In other words Michael, you believe many if not most blue fluoro diamonds can be legally called Blue White?

Yes, Garry,

It is crystal clear that who ever worded this regulation was knowingly or unknowingly (I vote for knowingly) allowing for the "false white" diamonds, of which Wade and Bruton spoke, to be called blue-white. It appears that the writers of this regulation, by making the test illumination north daylight, intended to exclude from the blue-white category only those most blatant, off-color diamonds that are still tinted even with the help of over 500 uW/cm2 of UV.

At the time of the introduction of this regulation there was such wide spread misuse of this term, that salesmen were calling almost any diamond blue-white, and that most fraudulent of abuse of the term appears to be all the regulation was designed to stop.

By their wording in this regulation, they have allowed to pass as blue-white all the fluorescent "false white" diamonds that are blueish only under north daylight and revert to their tinted "true color" absent stimulation by Ultra Violet or Visible Violet.

Michael D. Cowing

PS: If you are ever in court over this issue, simply read the jury this regulation. Then invite them all outside under north daylight, show them the diamond along side a faceted colorless quartz crystal (Herkimer diamonds will do just fine), and ask if the diamond is any amount more blueish than the non-fluorescing, perfectly colorless quartz. Case closed.

 

[adamasgem]

Date: 7/4/2009 9:47:06 AM
Author: strmrdr

Date: 7/4/2009 3:51:28 AM
Author: Garry H (Cut Nut)
In other words Michael, you believe many if not most blue fluoro diamonds can be legally called Blue White?

The problem Garry is the wording of the rule/law has little to do with what is legal in the US legal system.
The law is based on case law that interprets the law as written.
In the case of regulations also how the regulatory agencies interpret the rule is given a lot of weight.
So to truly understand what is legal or not would require careful study of when where and why that rule has been enforced.
Then a written opinion should be requested from the agency.

Unfortunately Storm, the FTC is "guidedancce" has been largely influenced by the self serving elements of the industry, GIA and the current JVC, among them, not to mention others, largely absent of individual technical knowledge.

1) North Daylight denotes a general color temperature of about 6500K, where there is sufficient blue in the incident spectrum.

2) The amount of UV in outdoor "North Daylight" depends on where you are in the world and the aspect angle to the primary illumination source. As an example a ruby looks different outdoors in NYC than it does in outdoors Bangkok.

3) DEVOID of ultraviolet, MEANS NONE.

4) Diamonds are graded indoors, and for the greater part of their lives, worn and shown indoors, where there is no or minimal UV.

Blue-white is a largely technicallly ambiguous term, as "defined" by the FTC or others here, and should be banned in its use in the trade.

NIST should be the only one defining it, not the idiots in the trade or those working for the flim flam artists in the trade, or no nothing autocrats at the FTC.

The GIA lab should be stripped of its tax exempt status because of its outright lies, and its "master master stones" confiscated, and analysed technically by others than the current fox guarding the chicken coop to set any "standards".

 

[michaelgem]

Date: 7/4/2009 10:13:41 AM
Author: michaelgem

PS: If you are ever in court over this issue, simply read the jury this regulation. Then invite them all outside under north daylight, show them the diamond along side a faceted colorless quartz crystal (Herkimer diamonds will do just fine), and ask if the diamond is any amount more blueish than the non-fluorescing, perfectly colorless quartz. Case closed.

Here is an interesting bit of diamond industry history.

I just found the use of colorless quartz crystal recommended by Frank Wade in his 1916 book on Diamonds A Study of the Factors That Govern their Value.

Wade says: "Probably the finest white diamonds are those classed as "Rivers." These stones are either snowy white or bluish white in their body colour as well as when faced up. To test the colour of a stone in order to see if it is really in the River class, put it beside a cut piece of purest rock crystal. It should not suffer in the least by the comparison, whereas the best Crystals, or even Wesseltons, will hardly stand the comparison."

Michael D. Cowing

 

[gwendolyn]

Thanks for a very interesting read, Garry. It was very helpful to read the strangely contradictory history of the industry''s (and as a result, the consumer''s) perception of the value or lack thereof of fluorescence (which, for the record, I love).

 

[Garry H (Cut Nut)]

Date: 7/4/2009 11:01:28 AM
Author: adamasgem

Date: 7/4/2009 9:47:06 AM
Author: strmrdr

Date: 7/4/2009 3:51:28 AM
Author: Garry H (Cut Nut)
In other words Michael, you believe many if not most blue fluoro diamonds can be legally called Blue White?

The problem Garry is the wording of the rule/law has little to do with what is legal in the US legal system.
The law is based on case law that interprets the law as written.
In the case of regulations also how the regulatory agencies interpret the rule is given a lot of weight.
So to truly understand what is legal or not would require careful study of when where and why that rule has been enforced.
Then a written opinion should be requested from the agency.

Unfortunately Storm, the FTC is ''guidedancce'' has been largely influenced by the self serving elements of the industry, GIA and the current JVC, among them, not to mention others, largely absent of individual technical knowledge.

1) North Daylight denotes a general color temperature of about 6500K, where there is sufficient blue in the incident spectrum.

2) The amount of UV in outdoor ''North Daylight'' depends on where you are in the world and the aspect angle to the primary illumination source. As an example a ruby looks different outdoors in NYC than it does in outdoors Bangkok.

3) DEVOID of ultraviolet, MEANS NONE.

4) Diamonds are graded indoors, and for the greater part of their lives, worn and shown indoors, where there is no or minimal UV.

Blue-white is a largely technicallly ambiguous term, as ''defined'' by the FTC or others here, and should be banned in its use in the trade.

NIST should be the only one defining it, not the idiots in the trade or those working for the flim flam artists in the trade, or no nothing autocrats at the FTC.

The GIA lab should be stripped of its tax exempt status because of its outright lies, and its ''master master stones'' confiscated, and analysed technically by others than the current fox guarding the chicken coop to set any ''standards''.

Marty would you consider any diamonds to be justifyably "BLUE WHITE"?

If so, what would be the definition they should meet to qualify?

 

[Garry H (Cut Nut)]

Date: 6/30/2009 1:18:11 AM
Author: Garry H (Cut Nut)

Date: 6/29/2009 11:28:09 PM
Author: michaelgem


The short version or a definition is?
Blue White diamond is a blue fluorescent diamond that only has a one grade shift in color when being color graded under a grading light with and without a Lexan filter.
Next question - is D to F and acceptable range before or after the shift?
And would a low D that shifted to a high F still be Blue White?
I am concerned Michael that if people make such claims that there should be a clear and concise definition.

Since you asked, I would say to be on the safe side take GIA''s teaching that a diamond begins to ''draw color'' at G.
If a VSB D color diamond stays in the D-F range that GIA calls colorless, it is safe to say it qualifies as a Jager.

If, as the more common VSB diamonds do, the color absent fluorescent stimulation drops three or more grades, the stone clearly does not qualify as a Jager. At some point (you decide) it is the ''false color'' diamond well known in the diamond trade going back before the turn of the 20th century.

Michael D Cowing

A Blue White diamond is any blue fluorescent diamond that has a color of F or better when color graded under a grading light with absolutely no long wave Ultra violet light (e.g. with a Lexan filter).

Next question - please define the type of grading light that you would use - must it have a Lexan filter? What color temp? what tube type? What distance etc please Michael? A totally repeatable process please.

This will be very useful to establish a new collectors catagory, and I will include it in the Pricescope tutorial.

Michael I just revisted this and it should have an additional qualification - should the Fluorescence be Strong, Very Strong only, or is Medium also acceptable?

 

[adamasgem]

Date: 7/7/2009 8:40:57 AM
Author: Garry H (Cut Nut)
Marty would you consider any diamonds to be justifyably ''BLUE WHITE''?

If so, what would be the definition they should meet to qualify?

1) The FTC guides are entirely ambiguous, even in saying "North Daylight" as they do not specify the strength of the implied UV component of north daylight, which is dependent on location, location, location.

2) The FTC guides say no other color present, which implies, to me, that only a true D would seemingly qualify, because by definition and practice, E''s and F''s SHOW discernable bodycolor. And, of course, there are good D''s and bad D''s, that is, " D" encompasses a range of color.

3) To have blue fluorescence you need N3 centers unbalanced by quenching N2 centers.

Right now, without the answer to 1 above, I''d not use the term "blue white", untill these things are defined in terms of a qualifying CIE coordinate range, but then again, I''m not a merchant.

 

[diagem]

Date: 7/7/2009 3:12:53 PM
Author: adamasgem

Date: 7/7/2009 8:40:57 AM
Author: Garry H (Cut Nut)
Marty would you consider any diamonds to be justifyably ''BLUE WHITE''?

If so, what would be the definition they should meet to qualify?

1) The FTC guides are entirely ambiguous, even in saying ''North Daylight'' as they do not specify the strength of the implied UV component of north daylight, which is dependent on location, location, location.

2) The FTC guides say no other color present, which implies, to me, that only a true D would seemingly qualify, because by definition and practice, E''s and F''s SHOW discernable bodycolor. And, of course, there are good D''s and bad D''s, that is, '' D'' encompasses a range of color.

3) To have blue fluorescence you need N3 centers unbalanced by quenching N2 centers.

Right now, without the answer to 1 above, I''d not use the term ''blue white'', untill these things are defined in terms of a qualifying CIE coordinate range, but then again, I''m not a merchant.

Just a thought...

A natural Type IIa "D" with the correct amount (decided on a case by case basis) of blue fluo. to appear bluish in a variety of lighting environments...

Must possess a bluish glow in combination with the clearest/purest (Historically called First Water) material in all lighting!

No oily/cloudy/hazy appearance in any lighting (including direct sunlight)...

Not so simple to be a systematic grade call you might be looking for..., but based on my experience, it has no chance on becoming a systematic grade call!

In my opinion, a Blue-White should be a Diamond that possesses an appearance that justifies a premium in value!

 

[adamasgem]

Date: 7/7/2009 4:25:32 PM
Author: DiaGem

Date: 7/7/2009 3:12:53 PM
Author: adamasgem

Date: 7/7/2009 8:40:57 AM
Author: Garry H (Cut Nut)
Marty would you consider any diamonds to be justifyably 'BLUE WHITE'?

If so, what would be the definition they should meet to qualify?

1) The FTC guides are entirely ambiguous, even in saying 'North Daylight' as they do not specify the strength of the implied UV component of north daylight, which is dependent on location, location, location.

2) The FTC guides say no other color present, which implies, to me, that only a true D would seemingly qualify, because by definition and practice, E's and F's SHOW discernable bodycolor. And, of course, there are good D's and bad D's, that is, ' D' encompasses a range of color.

3) To have blue fluorescence you need N3 centers unbalanced by quenching N2 centers.

Right now, without the answer to 1 above, I'd not use the term 'blue white', untill these things are defined in terms of a qualifying CIE coordinate range, but then again, I'm not a merchant.

Just a thought...

A natural Type IIa 'D' with the correct amount (decided on a case by case basis) of blue fluo. to appear bluish in a variety of lighting environments...

Must possess a bluish glow in combination with the clearest/purest (Historically called First Water) material in all lighting!

No oily/cloudy/hazy appearance in any lighting (including direct sunlight)...

Not so simple to be a systematic grade call you might be looking for..., but based on my experience, it has no chance on becoming a systematic grade call!

In my opinion, a Blue-White should be a Diamond that possesses an appearance that justifies a premium in value!

Golconda might fit the bill.... see http://www.rwwise.com/tgd2.html

But you have to remember GIA's Clintonesque definition of the word "NONE" when it comes to fluorescence, "none" may mean "some"

 

[diagem]

Date: 7/7/2009 4:40:44 PM
Author: adamasgem

Date: 7/7/2009 4:25:32 PM
Author: DiaGem

Date: 7/7/2009 3:12:53 PM
Author: adamasgem

Date: 7/7/2009 8:40:57 AM
Author: Garry H (Cut Nut)
Marty would you consider any diamonds to be justifyably ''BLUE WHITE''?

If so, what would be the definition they should meet to qualify?

1) The FTC guides are entirely ambiguous, even in saying ''North Daylight'' as they do not specify the strength of the implied UV component of north daylight, which is dependent on location, location, location.

2) The FTC guides say no other color present, which implies, to me, that only a true D would seemingly qualify, because by definition and practice, E''s and F''s SHOW discernable bodycolor. And, of course, there are good D''s and bad D''s, that is, '' D'' encompasses a range of color.

3) To have blue fluorescence you need N3 centers unbalanced by quenching N2 centers.

Right now, without the answer to 1 above, I''d not use the term ''blue white'', untill these things are defined in terms of a qualifying CIE coordinate range, but then again, I''m not a merchant.

Just a thought...

A natural Type IIa ''D'' with the correct amount (decided on a case by case basis) of blue fluo. to appear bluish in a variety of lighting environments...

Must possess a bluish glow in combination with the clearest/purest (Historically called First Water) material in all lighting!

No oily/cloudy/hazy appearance in any lighting (including direct sunlight)...

Not so simple to be a systematic grade call you might be looking for..., but based on my experience, it has no chance on becoming a systematic grade call!

In my opinion, a Blue-White should be a Diamond that possesses an appearance that justifies a premium in value!

Golconda might fit the bill.... see http://www.rwwise.com/tgd2.html

But you have to remember GIA''s Clintonesque definition of the word ''NONE'' when it comes to fluorescence, ''none'' may mean ''some''

Unfortunately these days the magic word "Golconda" is being abused similarly to how "Blue-White''s" became a common description back in the days it was a added value name.

I know its a touchy subject but every Type IIa GIA graded Diamond this days comes with an appendix connecting the graded Diamond to the Golconda region hypothetically.

See attachment...

Another issue is..., from the handful specimens of Historic Golconda''s I studied, I have never once noticed ''blue'' fluorescence..., I did notice "orange" fluorescence as a typical color for Historic Golconda''s...

 

[diagem]

Speak of the devil...

http://www.idexonline.com/portal_FullNews.asp?SID=&id=32605



"GIA Report Explains Fluorescence, Why Some Diamonds Glow

(July 7, ''09, 5:44 IDEX Online Staff Reporter)

In an effort to help educate the public about the little understood phenomenon of ultraviolet fluorescence in diamonds, the Gemological Institute of America (GIA) will include additional information describing fluorescence in every GIA Diamond Grading Report and Diamond Dossier® that carries a diamond fluorescence description of medium or stronger.

The GIA will include an insert that addresses the most frequently asked questions about fluorescence, explains its properties and includes comparison images of diamonds in both natural and UV light to illustrate varying intensities of fluorescence.

“Fluorescence is the emission of visible light by a diamond when it is stimulated by invisible ultraviolet (UV) rays,” said Thomas M. Moses, GIA’s senior vice president of Laboratory and Research. “It is a common characteristic of diamonds. The diamond simply glows under the UV lights, usually a blue color, which most often stops when the energy source causing it is removed.”

The five terms GIA uses to classify the intensity of the fluorescence are None, Faint, Medium, Strong and Very Strong.

“This insert will help the public better understand diamonds in general, which gives them more confidence and knowledge when making a decision about a diamond,” Moses added.

GIA has additional information on fluorescence on its Web site, including a scientific article, “A Contribution to Understanding Blue Fluorescence on the Appearance of Diamonds,” by Moses, Ilene M. Reinitz, Mary L. Johnson, John M. King and James E. Shigley, which appeared in the Winter 1997 issue of GIA’s Gems & Gemology. "

 

[adamasgem]

Date: 7/7/2009 5:09:00 PM
Author: DiaGem
Unfortunately these days the magic word ''Golconda'' is being abused similarly to how ''Blue-White''s'' became a common description back in the days it was a added value name.

I know its a touchy subject but every Type IIa GIA graded Diamond this days comes with an appendix connecting the graded Diamond to the Golconda region hypothetically.

See attachment...

Another issue is..., from the handful specimens of Historic Golconda''s I studied, I have never once noticed ''blue'' fluorescence..., I did notice ''orange'' fluorescence as a typical color for Historic Golconda''s...

I''d expect nothing less from the self proclaimed "world''s Formost Authority", marketing hype with nothing to back it up... It is about time that they identify those stones (IIa or IaB''s ) that could have been decolorized. On the fluorescence issue they are trying to justify 50 years of fraudulant grading, which they eff3ectively admitted to in the W08 G&G.. we always wanted UV... B***S***.


Interesting, I have seen salmon fluor in a natural Ia a few years back, but not in any IIa I have seen. What do you think of Richard Wise''s comments?

 

[adamasgem]

Date: 7/7/2009 5:17:07 PM
Author: DiaGem

Speak of the devil...

http://www.idexonline.com/portal_FullNews.asp?SID=&id=32605



''GIA Report Explains Fluorescence, Why Some Diamonds Glow

(July 7, ''09, 5:44 IDEX Online Staff Reporter)

In an effort to help educate the public about the little understood phenomenon of ultraviolet fluorescence in diamonds, the Gemological Institute of America (GIA) will include additional information describing fluorescence in every GIA Diamond Grading Report and Diamond Dossier® that carries a diamond fluorescence description of medium or stronger.

The GIA will include an insert that addresses the most frequently asked questions about fluorescence, explains its properties and includes comparison images of diamonds in both natural and UV light to illustrate varying intensities of fluorescence.

“Fluorescence is the emission of visible light by a diamond when it is stimulated by invisible ultraviolet (UV) rays,” said Thomas M. Moses, GIA’s senior vice president of Laboratory and Research. “It is a common characteristic of diamonds. The diamond simply glows under the UV lights, usually a blue color, which most often stops when the energy source causing it is removed.”

The five terms GIA uses to classify the intensity of the fluorescence are None, Faint, Medium, Strong and Very Strong.

“This insert will help the public better understand diamonds in general, which gives them more confidence and knowledge when making a decision about a diamond,” Moses added.

GIA has additional information on fluorescence on its Web site, including a scientific article, “A Contribution to Understanding Blue Fluorescence on the Appearance of Diamonds,” by Moses, Ilene M. Reinitz, Mary L. Johnson, John M. King and James E. Shigley, which appeared in the Winter 1997 issue of GIA’s Gems & Gemology. ''

That 97 article was the start of GIA''s backtracking on fluor, at first saying it didn''t have an effect on color grading BS. I wonder how much they effected the value of the DeBeers stockpile.?

 

[ct-appr]

Great article!

Recently I helped my future son-in-law buy a diamond for my daughter. We picked a G color Ideal cut SI2 with slight blue fluorescence. It is a beautiful stone! The combination of the ideal cut and the fluorescence makes it spectacular in daylight.