What are the downsides of very strong blue fluorescence

[agc]

What are the downsides of very strong blue fluorescence provided it does not cause the diamond to be milky/oily? I was considering a AGS000 RB 1.7 ct, H color, SI1 eye clean with very strong blue fluorescence. Is the fluorescence effect different for colorless vs near colorless and faint yellow stone? Thanks.

 

[diamondseeker2006]

This might answer some of your questions:

http://diamonds.pricescope.com/fluor.asp

 

[jewelerman]

From my experiance and study i have found that color and fluorascence affect each other greatly.A diamond of 1/2 carat or under and of J or lower color can be enhanced by having fluorasance that can hides yellow.The high colored stones of D-G will show a negative oily or milky/cloudy look when the stone has a high flouresance.

 

[arjunajane]

Date: 6/3/2008 2:28:59 AM
Author: jewelerman
From my experiance and study i have found that color and fluorascence affect each other greatly.A diamond of 1/2 carat or under and of J or lower color can be enhanced by having fluorasance that can hides yellow.The high colored stones of D-G will show a negative oily or milky/cloudy look when the stone has a high flouresance.

Careful there jewelerman!

- the statement that you have made is not necessarily true
To my knowledge, it is the accepted wisdom that only very few stones with very strong blue will exhibit any milky or cloudy characteristics. I believe when the GIA tried to do a study on this, they couldn''t find enough of these stones to actually correlate a decent sample..
But of course its always advisable for consumers to check these stones to be sure..

 

[WinkHPD]

Date: 6/3/2008 2:28:59 AM
Author: jewelerman
From my experiance and study i have found that color and fluorascence affect each other greatly.A diamond of 1/2 carat or under and of J or lower color can be enhanced by having fluorasance that can hides yellow.The high colored stones of D-G will show a negative oily or milky/cloudy look when the stone has a high flouresance.

I must take exception to this last statement. While some diamonds of any color may display this affect that you speak of (called overblues in the trade) less than one percent of strongly fluorescent diamonds will display a oily/milky/cloudy look according to a study done by the GIA. It is referenced somewhere here on Pricescope by John Pollard in his earlier incarnation as the artist formerly known as John Quixote. I have it bookmarked at the office, but it is only a few minutes to 6 here so it will be hours until I am at the office.

I wish the labs would list overblues on their reports, as perhaps this would lessen the unjustified fear that so many have of fluorescence.

Many of us vendors and many many of our clients actually prefer the beautiful appearance of a strongly fluorescent gem in the sunlight. It can be a gift of additional beauty to any diamond of any color.

Wink

 

[WinkHPD]

Date: 6/3/2008 2:44:05 AM
Author: arjunajane

Date: 6/3/2008 2:28:59 AM

Author: jewelerman

From my experiance and study i have found that color and fluorascence affect each other greatly.A diamond of 1/2 carat or under and of J or lower color can be enhanced by having fluorasance that can hides yellow.The high colored stones of D-G will show a negative oily or milky/cloudy look when the stone has a high flouresance.

Careful there jewelerman!

- the statement that you have made is not necessarily true

To my knowledge, it is the accepted wisdom that only very few stones with very strong blue will exhibit any milky or cloudy characteristics. I believe when the GIA tried to do a study on this, they couldn''t find enough of these stones to actually correlate a decent sample..

But of course its always advisable for consumers to check these stones to be sure..

LOL, this is what happens when I get long winded and also take time to pour myself a cup a Joe before finishing my post.

GIA did do a very nice study on fluorescence, I shall have to hope John sees this thread and posts a link to the study as he did before. It was a very illuminating study...

Wink

 

[agc]

Thanks Wink for you help. Are the very strong blue fluorescent stones still discounted and if so how much?

Andy

 

[strmrdr]

Date: 6/3/2008 8:02:39 AM
Author: Wink

GIA did do a very nice study on fluorescence, I shall have to hope John sees this thread and posts a link to the study as he did before. It was a very illuminating study...


Wink

Im not sir John but here is the link:

http://lgdl.gia.edu/pdfs/W97_fluoresce.pdf

Note worthy is the conclusion:
"Unlike the notion held by many in the trade,
fluorescent diamonds are not as prevalent as nonfluorescent
stones, as the GIA Gem Trade Laboratory
sample data for more than 26,000 diamonds
showed. The present study also challenges the trade
perception that fluorescence usually has a negative
effect on better-color diamonds. Our results show
that the diamond industry would be better served
by considering each individual diamond on its own
visual merits."

 

[WinkHPD]

Date: 6/3/2008 7:31:28 PM
Author: agc
Thanks Wink for you help. Are the very strong blue fluorescent stones still discounted and if so how much?


Andy

It depends on the color, I believe it can be as high as 10% in a D color, but usually it is in the 3-5% in the higher colors and in the lower colors actually brings the premium that it deserves.

Wink

 

[WinkHPD]

Date: 6/3/2008 10:03:05 PM
Author: strmrdr

Date: 6/3/2008 8:02:39 AM

Author: Wink


GIA did do a very nice study on fluorescence, I shall have to hope John sees this thread and posts a link to the study as he did before. It was a very illuminating study...



Wink

Im not sir John but here is the link:


http://lgdl.gia.edu/pdfs/W97_fluoresce.pdf


Note worthy is the conclusion:

''Unlike the notion held by many in the trade,

fluorescent diamonds are not as prevalent as nonfluorescent

stones, as the GIA Gem Trade Laboratory

sample data for more than 26,000 diamonds

showed. The present study also challenges the trade

perception that fluorescence usually has a negative

effect on better-color diamonds. Our results show

that the diamond industry would be better served

by considering each individual diamond on its own

visual merits.''

Perhaps I then shall have to call you Sir Storm. That is indeed the report I was referring to, and I especially agree and appreciate their closing statement.

Thanks.

Wink

 

[diagem]

Date: 6/4/2008 12:25:15 AM
Author: Wink

Date: 6/3/2008 7:31:28 PM
Author: agc
Thanks Wink for you help. Are the very strong blue fluorescent stones still discounted and if so how much?


Andy

It depends on the color, I believe it can be as high as 10% in a D color, but usually it is in the 3-5% in the higher colors and in the lower colors actually brings the premium that it deserves.

Wink

Now you are sounding like Rapaport....

(Systematic....)

I think you meant to start your writing as: "...It depends on the DIAMOND,..."

Unless you started working via the system???

 

[elmo]

To specifically answer your question "What are the downsides of very strong blue fluorescence":

1. Very strong fluoro may make a stone more difficult to resell because of the irrational bad rap that fluorescence has within the trade. Some pros whose opinions I otherwise respect think of fluorescence as almost some sort of curse. H is at the point where it shouldn't affect value one way or the other but it's strange how many otherwise rational folks in the trade think of this. Also, the pros who participate here in PS who confirm that fluoro is usually no problem are an "enlightened" group, but liquidity and resale price are probably affected more by what the "average" jeweler or consumer thinks.

2. There's some chance that the stone's color was overgraded i.e. depending on how you grade, if there is UV in the grading environment, that the stone would grade as I or even J without it. The GIA's standard lighting for color grading has changed over the last several years and there is still debate about the subject. So even if the GIA's current lighting environment is "correct" by nature of GIA's market position, there are thousands of gemologists who were taught by the GIA to grade in UV-free light and may justifiably grade your stone's color lower when it comes time to resell.

3. As others have said, with a *very small* percentage of stones, strong and very strong may cause a milky appearance.

 

[Rhino]

I''d like to just toss my .02c in here and concur with Wink.

A false perception of fluoroescence is generated by a lot of misinformation about it.

When it contributes to the appearance of diamond, it mostly contributes to positive effects and in most instances it is neutral.

With regards to the posters question on *pricing* ...

On commonly cut diamonds we generally find discounts akin to what Strm listed (or similar to rap) because these suppliers will give whatever incentive they can to move the kaka in their inventory. Amongst the cutting factories we do biz with regularly I don''t see these discounts for fluoroescence and I understand since they bear nothing on the optics or beauty of the diamond.

 

[WinkHPD]

Date: 6/4/2008 4:30:51 AM
Author: DiaGem

Date: 6/4/2008 12:25:15 AM
Author: Wink

Date: 6/3/2008 7:31:28 PM
Author: agc
Thanks Wink for you help. Are the very strong blue fluorescent stones still discounted and if so how much?


Andy

It depends on the color, I believe it can be as high as 10% in a D color, but usually it is in the 3-5% in the higher colors and in the lower colors actually brings the premium that it deserves.

Wink

Now you are sounding like Rapaport....

(Systematic....)

I think you meant to start your writing as: ''...It depends on the DIAMOND,...''

Unless you started working via the system???

Sigh, but where else will we find the "guidelines" to the ridicules and undeserved discount for fluorescence? Were it up to me I would return to the days when we rewarded the beauty of fluorescence with a premium that did once indeed depend on the beauty of the gem in sunlight. I used to regularly pay 10% and as much as 20% for a truly magnificent case of VSB.

As much as I wish it were not so, I am not big enough to control the market and must use the tools available to me, including those of the great system lord...

Wink

 

[WinkHPD]

Date: 6/4/2008 10:41:24 AM
Author: elmo
To specifically answer your question ''What are the downsides of very strong blue fluorescence'':

1. Very strong fluoro may make a stone more difficult to resell because of the irrational bad rap that fluorescence has within the trade. Some pros whose opinions I otherwise respect think of fluorescence as almost some sort of curse. H is at the point where it shouldn''t affect value one way or the other but it''s strange how many otherwise rational folks in the trade think of this. Also, the pros who participate here in PS who confirm that fluoro is usually no problem are an ''enlightened'' group, but liquidity and resale price are probably affected more by what the ''average'' jeweler or consumer thinks.

2. There''s some chance that the stone''s color was overgraded i.e. depending on how you grade, if there is UV in the grading environment, that the stone would grade as I or even J without it. The GIA''s standard lighting for color grading has changed over the last several years and there is still debate about the subject. So even if the GIA''s current lighting environment is ''correct'' by nature of GIA''s market position, there are thousands of gemologists who were taught by the GIA to grade in UV-free light and may justifiably grade your stone''s color lower when it comes time to resell.

3. As others have said, with a *very small* percentage of stones, strong and very strong may cause a milky appearance.

If I have a GIA graded stone and some local appraiser wants to grade it lower more power to him. He will never have the credence that a GIA Diamond Grading Report has by virtue of it being a GIA Diamond Grading Report. Whether you love them or hate them they are the current reigning authority in the trade and in the public''s mind.

While I respect people like Marty Haske who rant and rail against the beast, they have not yet had much, if any, affect in changing the system. I sell a diamond for its beauty, not its paper, although the paper does set the price. I have sold several AGS I1''s that would easily have been GIA SI2''s because Infinity grades their diamonds with AGS for the cut grading. All of those stones were priced at I1 prices, regardless of the fact that they could (very probably would) have been GIA SI2''s. This is the nature and fact of the business, the credible paper rules. A local appraiser will NEVER be able to overrule the GIA paper with any consistent credibility in more than a small fraction of the public. They have enough problems convincing people that some of the lesser regarded labs are full of horse poop, even when they clearly are, thus I do not think that worrying about them overriding a respected lab such as GIA or AGS is something I would worry about.

This statement I am in full accord with. It may indeed cause the gem to be more difficult to sell, which is, like the irrational fear of fluorescence, irrational in its own right. Sigh. Say it aint so, Joe. Sorry, I can''t. So if you are buying a diamond for resale and you do not have a clientele that appreciates fluorescence, then it may be a bad thing for you.

If however you are buying the gem for its beauty and enjoyability, then go for it!

Wink

 

[WinkHPD]

Date: 6/4/2008 10:55:52 AM
Author: Rhino
I''d like to just toss my .02c in here and concur with Wink.

A false perception of fluoroescence is generated by a lot of misinformation about it.

When it contributes to the appearance of diamond, it mostly contributes to positive effects and in most instances it is neutral.

With regards to the posters question on *pricing* ...

On commonly cut diamonds we generally find discounts akin to what Strm listed (or similar to rap) because these suppliers will give whatever incentive they can to move the kaka in their inventory. Amongst the cutting factories we do biz with regularly I don''t see these discounts for fluoroescence and I understand since they bear nothing on the optics or beauty of the diamond.

Agreed. Missed you at Vegas this year. Hoping to see you again next year.

Wink

 

[elmo]

Date: 6/4/2008 12:42:59 PM
Author: Wink
If I have a GIA graded stone and some local appraiser wants to grade it lower more power to him. He will never have the credence that a GIA Diamond Grading Report has by virtue of it being a GIA Diamond Grading Report. Whether you love them or hate them they are the current reigning authority in the trade and in the public's mind. While I respect people like Marty Haske who rant and rail against the beast, they have not yet had much, if any, affect in changing the system.

Agreed, GIA sets the direction on this due to their market position. It's not just "some local appraiser" or Marty Haske "ranting" though...Gary Roskin who is highly respected in the industry wrote the following in What GIA’s Fluorescence Study Ignored which is relevant:

What about the actual color grade? Does strong blue fluorescence, whether perceived by a consumer or not, enhance the color grade of a diamond? Having graded diamonds under Verilux lights that were filtered to remove almost all UV, I have seen diamonds with “Strong Blue” and, especially, “Very Strong Blue” fluorescence appear lower in color than when viewed under “normal,” traditional methods. The difference can be quite dramatic, possibly by two or three color grades. For example, an “E”-color diamond that fluoresces “Very Strong Blue” could be graded “G” or “H” under UV filtered light.

There's much other discussion there, including the response from the GIA here. No revelatory answers in this, but good information to be aware of.

p.s. Wink, good comments about Rapaport.