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Should we discourage or recommend FL stones?

Texas Leaguer

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I’ll just have to say this- as he won’t respond- I don’t believe Bryan was or is a diamond buyer or grader.
That doesn’t invalidate his or your ideas- but for all those reading we need to put this in context.
I am not sure if @Rockdiamond is trying to push my buttons or what. It seems he feels a great need for me to respond to him, even though he has been issuing exactly the same statements for years and I have many times responded to him. I am not intentionally ignoring him but if his statements aren’t additive because of redundancy or other reasons, I no longer feel the need to respond for the sake of responding. That just tends to grow the thread so long that it gets watered down and turns people off.

But for the record, I have been working in the jewelry industry for over 40 years. For almost 30 of those years I was a sole proprietor. The first part of my career was in the colored gem business and I travelled overseas regularly to buy rough and cut gemstones (I have a decent eye for color). My specialties were East African gemstones and unheated sapphires from Sri Lanka. Later in my career I was pulled into the diamond business where again, I bought my own diamonds for my operation. Over the course of my career I also became a GIA Graduate Gemologist and an AGS Certified Gemologist.

In 1999 I was recruited by the first publicly traded, pure play internet seller of luxury goods (Ashford.com) and was Operations Manager of the Diamond Division up until and through the transition of the sale of Ashford to Diamond.com. In the first year or so at Ashford we were buying and stocking all of our diamonds (tens of millions$), a process I was obviously intimately involved in. In the year 2000 the ‘tech bubble’ burst and we had to find a way to sell diamonds without buying and stocking them. We pioneered the concept of virtual inventory, which involved developing the information/ web technology and vendor cooperation necessary to offer tens of thousands of deliverable diamonds on our website. (As an aside, during the early years, Blue Nile was actively trying to get acquired by Ashford.)

After my stint at Ashford I started my own internet company (gemdiamond.com) where I combined my interests in gems, pearls, diamonds and fine jewelry with departments for each product. It just so happened that I was operating out of the same jewelry building as Whiteflash so I knew the principals, and was following their work as they were following mine. Because of the synergies Whiteflash acquired Gemdiamond in 2009 and I joined the leadership team. While we ran both websites initially, it became clear that we had limited bandwidth and decided to focus primarily on our in-house diamond business. For over ten years I have been the senior gemologist here at Whiteflash during which time we have produced and sold hundreds of millions of dollars worth of diamonds.

Sorry for the diversion, but I felt I should correct the record.
 
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Rockdiamond

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Impressive Bryan- I wasn't trying to "push anyone's buttons"- I wasn't aware you had any hands on experience.
In all that time you never saw a single Medium or strong blue diamond that showed a different color face up in daylight.....that in itself is pretty remarkable, and it's why I assumed ( incorrectly) that you didn't have hands on experience- my apologies on that.
 

Texas Leaguer

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Impressive Bryan- I wasn't trying to "push anyone's buttons"- I wasn't aware you had any hands on experience.
In all that time you never saw a single Medium or strong blue diamond that showed a different color face up in daylight.....that in itself is pretty remarkable, and it's why I assumed ( incorrectly) that you didn't have hands on experience- my apologies on that.
Then you shouldn't post about things unless you know about them.

And you should not invent your own 'facts' such the bolded above.
 

Rockdiamond

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SO you have seen whitening? I'm really confused about your stance Bryan.
 

Texas Leaguer

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SO you have seen whitening? I'm really confused about your stance Bryan.
The fact that you are confused is no longer surprising to me. I even put my position in bullet points for you earlier in the thread. But to no avail.

You have succeeded in illustrating why such nonsense is a waste of everyone's time.
 

Rockdiamond

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Bryan - this is so simple and no need to waste anyone's time or have them read over pages and pages to clarify. What I see is a valuable thread- with many views and many people finding value.
Do you agree that certain fluorescent diamonds whiten in daylight?
Real easy. Yes or no. There's three tradespeople participating in this discussion- Garry and I have seen this on countless occasions. Cowing made suppositions Garry disagrees with. Cowing is not participating now....so it's only the three of us.
If we agree on this, please let's move on so the discussion can be profitable for all to read.
 

Rockdiamond

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Hi @Texas Leaguer
So- you're unwilling to answer this extremely simple question due to the fact you've answered in "bullet points"
Can you please point us to the bullet points you speak of?
To be clear- I'm not at all confused at the physical characteristics of fluorescent diamonds. Exactly what your position is on whitening, yes, I'm unclear.
 

Garry H (Cut Nut)

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@sledge - I’m curious as to how you’ve formed your opinions on how to grade the color of a diamond?
I have graded literally thousands of diamonds that did not have GIA reports. In many cases I have graded original productions ( while I was grading for a DeBeers Site Holder) so I estimated the grade prior to GIA submission. I earned a reputation as accurately predicting the GIA grades in a majority of stones.
That’s a small part of the experience which forms my ideas about how to color grade diamonds that I’m bringing to the discussion..
I’ll just have to say this- as he won’t respond- I don’t believe Bryan was or is a diamond buyer or grader.
That doesn’t invalidate his or your ideas- but for all those reading we need to put this in context.
David did you change your procedures when GIA changed theirs? They made a radical transformation 20 years ago.
 

Rockdiamond

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Hi Mate! ( not many know this, but I'm fluent in Australian)
From my perspective, there have been many changes over the years.
I don't adjust my methodology- rather I adjust the output.
IOW- as GIA shifted to where stones that used to get K were getting J more frequently, I started to adjust my grades accordingly. If I felt a stone was borderline J-K, I started leaning towards J.

My position on GIA is more of a practical nature. I have not cared why the changes took place- only noticed them. I never felt there was anything I could do about it anyway...
My participation here has been incredibly enlightening because people like Garry take time to delve into why the changes we see are occurring.
 

sledge

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Thirdly, I think you should read the 2008 article I linked after I posted - so maybe you missed it. The lamp topic has been addressed https://www.gia.edu/doc/Coloring-Grading-D-to-Z-Diamonds-at-the-GIA-Laboratory.pdf
Thank you @Garry H (Cut Nut). I did miss the linked article, but back tracking I see you modified your original post to include a link.

I have downloaded the article and read it, and found it interesting. More comments to follow.

I like your idea :) but I fear accusations of 'vested interest' in making fluor more valuable! lol
Yeah, you are probably right.


A related factoid:
GIA has been doing color grading for some time now by machine. A subset of their stones are no longer graded by human graders. These are mostly small stones but there are other criteria that determine whether a stone is a candidate for machine grading on their proprietary device. Fluoresce is one of those criteria.
The article referenced by Garry, also includes some tidbits about machine grading that I found interesting.


CaptureInstrumentGrading1.PNG

CaptureInstrumentGrading2.PNG
 

Rockdiamond

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blue-fluoresence.JPG
It's really hard to capture with a camera, these two shots show a bit of what I'm talking about. The diamond was graded D color by GIA, Very Strong Blue Fluorescence.
It takes a lot of light to get a close up photo of a diamond, and have it be in focus.
We have large windows- indirect, and reflected sunlight- daylight- allows close up photography.
The lightbox also has lights bright enough to allow close up photography. The LED's in the lightbox seem to lack the particular wavelengths that stimulate the blue.
 

Karl_K

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David, I am not about the read all the bickering but anytime sunlight of any form is present fluorescence being activated is a probability in reactive stones.
I really don't see how that can be denied by anyone.
The question is: how much it is activated in non-sunlight environments and specifically under the gia/ags diamond grading environment?
 

Rockdiamond

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Great summation Karl. My position is that an element of sunlight is a main component of how humans ( those NOT in a gem lab) are able to perceive diamond body color.
Therefore, if one is looking at a fluorescent diamond in an environment contains enough daylight - or sunlight- to visualize the difference between a D and an E ( for example) a color change will be perceptible in a percentage of fluorescent diamonds, compared to observing them in a lab environment without daylight.
There’s conflicting “science” if we can call articles that have been written by Cowing and even those written by GIA “scientific”. Statements about exactly when and where color change take place are oft times conflicting reports other statements.
I don’t need to read anything to understand the color change.
Garry has experienced and explained the color change. Others won’t seem to accept these facts.

The part of the discussion about GIA and how they grade FL diamonds gets completely lost if we can’t agree on the basics.
 

prs

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There is lots of natural variation between humans. I know from wine tastings there are big differences in people's taste buds and how they perceive a wine. We all react differently to allergens in the air around us. I get sun burnt in about ten minutes, my wife just gets browner and browner. etc etc etc.

I think it's quite possible that human eyeballs differ in how they register diamond fluorescence. Some, like David, might be super sensitive to it, and others might not see it at all. This would certainly explain why there is no trade consensus on what should be a relatively simple phenomenon. Everybody sees it different depending on how their genes configured their eyeballs!

This also means that everybody is right on this subject, and nobody is wrong. =)2
 

OoohShiny

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There is lots of natural variation between humans. I know from wine tastings there are big differences in people's taste buds and how they perceive a wine. We all react differently to allergens in the air around us. I get sun burnt in about ten minutes, my wife just gets browner and browner. etc etc etc.

I think it's quite possible that human eyeballs differ in how they register diamond fluorescence. Some, like David, might be super sensitive to it, and others might not see it at all. This would certainly explain why there is no trade consensus on what should be a relatively simple phenomenon. Everybody sees it different depending on how their genes configured their eyeballs!

This also means that everybody is right on this subject, and nobody is wrong. =)2
I think this is an excellent point - I recall seeing a TV program where a tribe had a lot more ability to see the ranges of green over other colours, because that was their environment and they had had little external influence.

This site covers it nicely!


The debate sits at the center of an ongoing war in the world of color research. On the one side stand “universalists,” including the authors of The World Color Survey and their colleagues, who believe in a conformity of human perceptual experience: that all people see and name colors in a somewhat consistent way. On the other side are “relativists,” who believe in a spectrum of experience and who are often offended by the very notion that a Westerner’s sense of color might be imposed on the interpretation of other cultures and languages. Many researchers, like Surrallés, say they stand in the middle: While there are some universals in human perception, Surrallés argues, color terms don’t seem to be among them.
 

Rockdiamond

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There is lots of natural variation between humans. I know from wine tastings there are big differences in people's taste buds and how they perceive a wine. We all react differently to allergens in the air around us. I get sun burnt in about ten minutes, my wife just gets browner and browner. etc etc etc.

I think it's quite possible that human eyeballs differ in how they register diamond fluorescence. Some, like David, might be super sensitive to it, and others might not see it at all. This would certainly explain why there is no trade consensus on what should be a relatively simple phenomenon. Everybody sees it different depending on how their genes configured their eyeballs!

This also means that everybody is right on this subject, and nobody is wrong. =)2
THANK YOU!!!
I have taken inordinate steps to frame the discussion in this light. There’s so many possible reasons some don’t see the color change. No one need be “wrong”
 

coda72

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I know this thread has gone on a long time, and hopefully I can still get a response to my question. Can diamonds show uneven fluorescence, where part of it is fluorescent and part of it isn’t? The new stone I just received seems to show this, and I was wondering if it’s common. Here’s a pic to show what I mean. It’s the center stone, the side stones are evenly fluorescent. 608BEB10-8D31-4C5E-89AE-B6BD0AB09F8D.jpeg
 

TODiamonds

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I know this thread has gone on a long time, and hopefully I can still get a response to my question. Can diamonds show uneven fluorescence, where part of it is fluorescent and part of it isn’t? The new stone I just received seems to show this, and I was wondering if it’s common. Here’s a pic to show what I mean. It’s the center stone, the side stones are evenly fluorescent. 608BEB10-8D31-4C5E-89AE-B6BD0AB09F8D.jpeg
Is it possible that's just reflection from the side stone?
 

coda72

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Both side stones are also blue fluorescent, in fact to a greater degree than the center stone. They are strong blue fluorescent and the center stone is graded as medium blue fluorescent.
 

Garry H (Cut Nut)

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Only slightly related, but the way GIA grades hazy milky is under clarity (which I think is a travesty of consumer protection) .

Here is an example of an E colored diamond that GIA call I2 / Fancy White boundary - it is one of their masters.

1576811222519.png

"The E-color diamond with I2 clarity and whitish internal graining on the right is one of the color master stones in GIA’s Carlsbad lab. It represents the boundary between the D-toZ color scale and those deemed Fancy white."
Page 322 https://www.gia.edu/doc/Fall-2019-Gems-Gemology.pdf
The article is about fancy white and fancy black natural diamonds
 
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Garry H (Cut Nut)

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I know this thread has gone on a long time, and hopefully I can still get a response to my question. Can diamonds show uneven fluorescence, where part of it is fluorescent and part of it isn’t? The new stone I just received seems to show this, and I was wondering if it’s common. Here’s a pic to show what I mean. It’s the center stone, the side stones are evenly fluorescent. 608BEB10-8D31-4C5E-89AE-B6BD0AB09F8D.jpeg
Interesting, could be a collectable! I am not sure I have seen this before!
 

sledge

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Is it possible the angle of the UV light source is causing uneven distribution? If you rotate the UV light around do you have the same active and non-active areas on the stone?

Asking because you mentioned both the side stones are strong yet one is glowing and the other isn't.

After all the hoopla of tech talk, that picture was a pleasant relief. It looks so cool.
 

Texas Leaguer

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I know this thread has gone on a long time, and hopefully I can still get a response to my question. Can diamonds show uneven fluorescence, where part of it is fluorescent and part of it isn’t? The new stone I just received seems to show this, and I was wondering if it’s common. Here’s a pic to show what I mean. It’s the center stone, the side stones are evenly fluorescent. 608BEB10-8D31-4C5E-89AE-B6BD0AB09F8D.jpeg
Yes, diamonds occasionally show uneven fluorescence. They can even show different colors of fluorescecence, although that is very rare.

Fluorescence can be localized within the diamond and directional as well. A good example that came through our operation below.

diamond-fluor.jpg

 

coda72

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Thanks, everyone for your responses. I have owned about 10 fluorescent diamonds, but this is the first one that I have owned that shows fluorescent zones. That made me very curious about it, and I’m glad I was still able to get responses to my question.
 

coda72

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Is it possible the angle of the UV light source is causing uneven distribution? If you rotate the UV light around do you have the same active and non-active areas on the stone?

Asking because you mentioned both the side stones are strong yet one is glowing and the other isn't.

After all the hoopla of tech talk, that picture was a pleasant relief. It looks so cool.
I moved the UV light around and the areas didn’t change. Because of the angle of the side stones to the center stone, I couldn’t get a good pic of all 3 showing fluorescence. However, the side stones are equally fluorescent, they just don’t appear that way in the pic.
 
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