Fluorescence-AGS question

[EvaEvans]

@Texas Leaguer
Where the science and the human perception of what is beautiful shake hands, there is the truth.
But you are right, that between the white and the black there is plenty of shades of gray!
In my personal researches I went to the conclusion, that the fluorescence does not have straight connection with the diamond clearness, sparkle and beauty.
What I'm fighting for is the accurate diamond description made with acceptable precision.
Who knows, may be with the development of the science and changing the standards one day the lab report will be extended and the included data will be much more informative.

 

[Texas Leaguer]

@Texas Leaguer
Where the science and the human perception of what is beautiful shake hands, there is the truth.
But you are right, that between the white and the black there is plenty of shades of gray!
In my personal researches I went to the conclusion, that the fluorescence does not have straight connection with the diamond clearness, sparkle and beauty.
What I'm fighting for is the accurate diamond description made with acceptable precision.
Who knows, may be with the development of the science and changing the standards one day the lab report will be extended and the included data will be much more informative.

@EvaEvans I hear your frustration. As you mention there are different scales and different standards for measuring different things. In gemology most laboratories follow GIA standards to a large extent. That is certainly true of AGS Laboratories -they are sister organizations after all. But they do certain things differently in a number of areas. For instance, they have a different standard for assessing cut quality. Many people prefer AGS reports because they like the more rigorous standard. But many customers do not feel the need to determine light performance to that degree and feel that the GIA standard of EX is sufficient for their needs.
Because AGS elects not have an intermediate category of 'faint' on their reports between Inert and medium fluorescence, one might be tempted to say that the GIA standard is stricter (although that is debatable given some of the evidence you have seen in this thread). However, if you are a customer to whom small levels of fluourescence is important, then you might want more information than is contained on an AGS report of "negligible". Just as you might want to see ASET images on a GIA Ex to be sure that it meets your particular needs. In neither case is one lab necessarily failing. They are pretty clear that their standards are different and what those standards mean. It is for the consumer to determine what information meets their needs, the best lab to use, and what additional testing that they may or may not want to avail themselves to.

 

[Garry H (Cut Nut)]

A lot can be learned of GIA via patents . e.g. about what GIA do to lower costs and reduce the risk of legal action because of inconsistencies in human grading (a fact often mentioned in their patents).
this is the patent that mentions 365nm and 385nm UV used for grading.
If you follow the links at the bottom to others of their patents (including automatic color grading) you can see that in 2004 they mentioned 370nm, and as we know their 2013 research led to the discovery (confirmed by a European source) that closer to 400nm in the just visible spectrum, is where the most emission is generated (and hence color improvement) - I do believe that GIA have or are soon will be using 385nm as the benchmark in digital fluoro grading.
https://patents.google.com/patent/U...signee=Gemological+Institute+Of+America+(Gia)

 

[Diamond_Hawk]

@Diamond_Hawk

It is obvious that you don't understand what "standard" mean and why in the science the standards are so important! There will be NO science without standards! For example, do you know what "standard measurements" mean? Fahrenheit or Celsius is the standard scientific measurement for temperature? Why diamonds are measured in mm, not in inches? Because millimeter is scientific dimension!
Why D-Z color, not other terminology? Why IF-VVS-VS-Si-I clarity? Because they are standards in the diamond industry, right?

Aside from the tone of the reply being condescending, let's examine what you have cited as standards:

Fahrenheit - Objective
Celsius - Objective
mm - Objective (as are inches)

The others are different:

D-Z Color - Subjective
Clarity - Subjective
Fluorescence - Subjective

While the terminology is fairly standardized in the industry no pure scientific standards apply, only subjective judgments. These terms and the above subjective "standards" can vary not only GIA vs. AGS vs. HRD vs. IGI etc. but from grader to grader and lab to lab within the same company.

There is a chance, however, with advancing technology that fluorescence could be scientifically standardized, perhaps that is what you are after.

 

[EvaEvans]

D-Z Color - Subjective
Clarity - Subjective
Fluorescence - Subjective

There is a chance, however, with advancing technology that fluorescence could be scientifically standardized, perhaps that is what you are after.

D-Z color is not subjective, but D-E-F is.
Clarity is subjective, but plot of inclusions is not.
Fluorescence at non specified UV long wave (315-400nm) is subjective, but existence or absence of fluorescence at specific wavelength (365 +_ accuracy of the UV lamp) is objective. Fluorescence level is always subjective.

As diamond industry created and follow the standards of color and clarity, the same way diamond industry has to follow strict rules and terminology with the fluorescence - you understand me absolutely right!

 

[EvaEvans]

@EvaEvans I hear your frustration. As you mention there are different scales and different standards for measuring different things. In gemology most laboratories follow GIA standards to a large extent. That is certainly true of AGS Laboratories -they are sister organizations after all. But they do certain things differently in a number of areas. For instance, they have a different standard for assessing cut quality. Many people prefer AGS reports because they like the more rigorous standard. But many customers do not feel the need to determine light performance to that degree and feel that the GIA standard of EX is sufficient for their needs.
Because AGS elects not have an intermediate category of 'faint' on their reports between Inert and medium fluorescence, one might be tempted to say that the GIA standard is stricter (although that is debatable given some of the evidence you have seen in this thread). However, if you are a customer to whom small levels of fluourescence is important, then you might want more information than is contained on an AGS report of "negligible". Just as you might want to see ASET images on a GIA Ex to be sure that it meets your particular needs. In neither case is one lab necessarily failing. They are pretty clear that their standards are different and what those standards mean. It is for the consumer to determine what information meets their needs, the best lab to use, and what additional testing that they may or may not want to avail themselves to.

I do not put advantage to GIA vs AGS, as you might think. I like more the AGS presentation of cut and diamond measurements. When it is important for me, I double certify my diamond, because AGS gives more detailed information about the cut dimensions, especially in Old cuts. Old cut diamonds are mistreated by GIA, but this is subject for another thread.

 

[kmoro]

I compared my AGS negligible to my GIA none:

AGS:


GIA:


AND, when my AGS fluoresces, it becomes quite hazy. I don’t like it. It even turned a strong blue color when I was outside the other day, looking exactly like a dark blue sapphire.

Trying to love the diamond anyway as it is otherwise stunning.

Not sure how to ensure an upgrade doesn’t have so much fluorescence.

I realize AGS negligible ranges to medium, but I was really hoping my diamond would be in the closer to none part of the scale.

Oh well - first world problems, lol.

 

[Dancing Fire]

My AGS negligible (CBI) stone doesn't glow blue under the UV light. My wife have 4 more AGS negligible stones that I haven't check for flour yet.
Here's my ring under the UV light...



Here is my wife's GIA none and my daughter's AGS med-blue under the UV light.

 

[Dancing Fire]

AND, when my AGS fluoresces, it becomes quite hazy. I don’t like it. It even turned a strong blue color when I was outside the other day, looking exactly like a dark blue sapphire.

Not sure how to ensure an upgrade doesn’t have so much fluorescence.

That is strange, b/c here is my old Octavia AGS VSB under the sun and it is nowhere never a dark blue color.



Here is my daughter's AGS med blue under the sun.

 

[kmoro]

That is strange, b/c here is my old Octavia AGS VSB under the sun and it is nowhere never a dark blue color.



Here is my daughter's AGS med blue under the sun.

Yes, I'm pretty sure mine is right on the borderline ... I'm actually thinking it's hard to believe it wasn't graded medium, as the comparison of mine look pretty much exactly like yours.

I'm on the lookout for a new diamond. I am not saying it's mis-graded at negligible -but it had to be really darn close. I'd really rather put my money on a negligible that is closer to the none end.

I'm surprisingly sad. I really don't like the fluorescence. At least if it was a BGB, it would have been screened for milky/hazy effect ... this one definitely turns to bright glowing blue haze. Boo.

The rich blue effect was also quite a surprise ... I doubt that would have happened if it was not blue fluorescent .... I had some pictures but deleted them because they made me sad - I regret that and will have to get outside around the same time of day to get more photos. It really looked like a deep blue sapphire ... maybe someone else can shed some light on this (ahahaha, sorry I had to make the pun).

 

[Karl_K]

Dark blue sounds more like the reflection of the sky.
I have seen a diamond that showed strong under sunlight but under a gia lamp and on the report had none.
Under a bunch of UV leak detectors it ranged from none to very strong.

 

[Dancing Fire]

Kmoro...did you purchased your stone from an in-house vendor ?

 

[Garry H (Cut Nut)]

Kmoro I think you are looking at your stone in strong sunlight directly from over your shoulder - if the stone is well cut it will appear dark - and it is nothing to do with fluoro. The body shade of a diamond in that situation will be dark because there will be one to tree very very bright blinding flashes that shrink your pupil making everything alse in the diamond appear dark. Turn 90 degrees and the diamond will probably only show a bluish hazyness (which many Pricescopers love).
Less well cut stones and crushed ice cuts do not go dark in direct sunlight.

 

[kmoro]

Kmoro I think you are looking at your stone in strong sunlight directly from over your shoulder - if the stone is well cut it will appear dark - and it is nothing to do with fluoro. The body shade of a diamond in that situation will be dark because there will be one to tree very very bright blinding flashes that shrink your pupil making everything alse in the diamond appear dark. Turn 90 degrees and the diamond will probably only show a bluish hazyness (which many Pricescopers love).
Less well cut stones and crushed ice cuts do not go dark in direct sunlight.

Thank you ... I appreciate that ... but really I’m. not talking about dark, I’m talking rich rich rich blue. It did not look like a diamond at all - it looked like a rich medium/dark blue sapphire.

I did go with a fantastic vendor and I am sure the follow-up will be great ... it’s early in the game

 

[kmoro]

Dark blue sounds more like the reflection of the sky.
I have seen a diamond that showed strong under sunlight but under a gia lamp and on the report had none.
Under a bunch of UV leak detectors it ranged from none to very strong.

Thank you, Karl - your opinion is valued!

I guess I would be more prone to thinking I just had a highly critical (if you allow that description) UV light, but when my other diamonds showed no fluorescence under the same light, I figured it was a fair representation of the fluorescence.

?

I mean - I realize fluorescence is hardly the end of the world, I knew I ran this risk with AGS, I did not ask the vendor to take a look at it for fluorescence level ... I am accountable for that ... but we’re talking about my preference in this case ... and I spent a lot on symbolism for this thing lol ... not a $5000 diamond with the intent of upgrading ... at my personal max size and have the budget for near perfection (somehow I still can’t do the premium for IF on a D color - it’s a crazy increase) so really, in the end, I hope and strongly suspect, that I’ll end up with a diamond with less fluorescence. I hope so. I hate being “that guy” lol

 

[TreeScientist]

Thank you, Karl - your opinion is valued!

I guess I would be more prone to thinking I just had a highly critical (if you allow that description) UV light, but when my other diamonds showed no fluorescence under the same light, I figured it was a fair representation of the fluorescence.

?

I mean - I realize fluorescence is hardly the end of the world, I knew I ran this risk with AGS, I did not ask the vendor to take a look at it for fluorescence level ... I am accountable for that ... but we’re talking about my preference in this case ... and I spent a lot on symbolism for this thing lol ... not a $5000 diamond with the intent of upgrading ... at my personal max size and have the budget for near perfection (somehow I still can’t do the premium for IF on a D color - it’s a crazy increase) so really, in the end, I hope and strongly suspect, that I’ll end up with a diamond with less fluorescence. I hope so. I hate being “that guy” lol

Well, buying from a SuperIdeal vendor means that you have excellent return and upgrade policies, so nothing to worry about. I understand that it can be frustrating to have a diamond in your hand, that you like in every other way, except for the fluor issue. But consider it a lesson learned. If you don't want a stone with fluor in the future and you're buying an AGS-negligible, just be sure to ask the vendor to test it with a cheap UV light prior to committing. A quick 1 minute job on their part, and gives you peace of mind.

As an aside, I know you don't like the way it makes your stone look in sunlight, but I must say, that is one of the prettiest colors of fluor I've ever seen in a diamond! Especially in the third picture. It look pretty close to cyan (one of my favorite colors. ).

 

[Karl_K]

Thank you, Karl - your opinion is valued!

I guess I would be more prone to thinking I just had a highly critical (if you allow that description) UV light, but when my other diamonds showed no fluorescence under the same light, I figured it was a fair representation of the fluorescence.

?

What I was getting at was dark blue sounds really odd too me.
But some diamonds do odd things, the stone I was talking about being one.

If it interferes with your enjoyment of the stone talk to your vendor about a return for a stone they verify has none.

 

[kmoro]

Well, buying from a SuperIdeal vendor means that you have excellent return and upgrade policies, so nothing to worry about. I understand that it can be frustrating to have a diamond in your hand, that you like in every other way, except for the fluor issue. But consider it a lesson learned. If you don't want a stone with fluor in the future and you're buying an AGS-negligible, just be sure to ask the vendor to test it with a cheap UV light prior to committing. A quick 1 minute job on their part, and gives you peace of mind.

As an aside, I know you don't like the way it makes your stone look in sunlight, but I must say, that is one of the prettiest colors of fluor I've ever seen in a diamond! Especially in the third picture. It look pretty close to cyan (one of my favorite colors. ).

Ah thank you so much! I kind of expect thoughtful replies from the kind folk here, but just to let you know ... I really appreciate it! And you are so right - I could honestly see my part in this right away. Believe me, I am not pointing fingers at anyone but me - there is absolutely zero misrepresentation on the part of the lab or the vendor!

I have a great upgrade policy and have no doubt I will end up 100% happy.

 

[kmoro]

What I was getting at was dark blue sounds really odd too me.
But some diamonds do odd things, the stone I was talking about being one.

If it interferes with your enjoyment of the stone talk to your vendor about a return for a stone they verify has none.

I so wish I kept those photos ... arrrrgh. Maybe if I saw some crazy uniqueness to it, my boat would float ... haha. I’ll try to get some repeat pics.

Thanks again!

 

[Stephan]

kmoro, is this your D-VVS diamond? It turns my stomach to see that much fluo in a "negligible" diamond.
Imagine sending to GIA and it comes back as a E with medium fluo...
The vendor should have told you, even if you didn't ask.

 

[kmoro]

kmoro, is this your D-VVS diamond? It turns my stomach to see that much fluo in a "negligible" diamond.
Imagine sending to GIA and it comes back as a E with medium fluo...
The vendor should have told you, even if you didn't ask.

Yes, that is the one. And you actually have described my feelings pretty well. Part of the reason I went with D in AGS is because it may be an E, but the amount of flouro really took me by surprise.

 

[Garry H (Cut Nut)]

It would be great to see some photos of this and your other diamonds in sunlight and shaded light to make a comparison so we might understand what you are seeing Kmoro - and please be sure to show us what the light environment looks like.
A good way is to place a shiny teaspoon back toward you in the same orientation as the diamond - we can then see the light from the diamonds point of view.

 

[kmoro]

It would be great to see some photos of this and your other diamonds in sunlight and shaded light to make a comparison so we might understand what you are seeing Kmoro - and please be sure to show us what the light environment looks like.
A good way is to place a shiny teaspoon back toward you in the same orientation as the diamond - we can then see the light from the diamonds point of view.

For sure I’ll do that ... today is rather cloudy where I am ...

I kept one photo from the blue appearance, but it does not really show all. This was the least blue of all of the images. Imagine the blue that you see extend to the entire diamond, with no hint of colorless, and a darker shade.

I see that the setting band shows blue as well - not sure if that is from the diamond or the light ... but it was sunlight against white background with snow on the ground. Based on the reflection, it looks like blue light is entering the diamond but I’m not sure how that can be from sunlight and snow reflection?

The other pictures here show the fluorescence level, which is the effect I personally don’t like. I’m not sure how I feel about it turning into a blue stone yet, lol.

Also, I really do not blame the vendor. I did not ask them to look at it for me ... next time, I will. Right now their inventory is pretty low on alternatives, so I’ll be patient.

 

[Garry H (Cut Nut)]

For sure I’ll do that ... today is rather cloudy where I am ...

I kept one photo from the blue appearance, but it does not really show all. This was the least blue of all of the images. Imagine the blue that you see extend to the entire diamond, with no hint of colorless, and a darker shade.

I see that the setting band shows blue as well - not sure if that is from the diamond or the light ... but it was sunlight against white background with snow on the ground. Based on the reflection, it looks like blue light is entering the diamond but I’m not sure how that can be from sunlight and snow reflection?

The other pictures here show the fluorescence level, which is the effect I personally don’t like. I’m not sure how I feel about it turning into a blue stone yet, lol.

Also, I really do not blame the vendor. I did not ask them to look at it for me ... next time, I will. Right now their inventory is pretty low on alternatives, so I’ll be patient.

The blue reflected off the loop bale shows it is the sky

 

[kmoro]

The blue reflected off the loop bale shows it is the sky

Ah! Thank you! Very cool

 

[Garry H (Cut Nut)]

Shaded daylight at 11am close to the solstice in Melbourne taken just now on 24th December. The shade is from my body. My hand was vertical and you can see me in the wedding ring and the blue cloudless sky. Its a hot day.

Note in direct sunlight the ideal-cut round diamond is showing blue from the sky and dark because the light from the sun is only lighting up a few facets. The sun is a very small point light source.
The other fancy shapes all have crushed ice effects and are glowing with various reflected light bouncing all around in the stones.

The strongest fluorescence is in one of the cushions and the marquise. Fluoro has nothing to do with how the diamonds appear in daylight (other than improving their colour).

 

[kmoro]

Shaded daylight at 11am close to the solstice in Melbourne taken just now on 24th December. The shade is from my body. My hand was vertical and you can see me in the wedding ring and the blue cloudless sky. Its a hot day.

Note in direct sunlight the ideal-cut round diamond is showing blue from the sky and dark because the light from the sun is only lighting up a few facets. The sun is a very small point light source.
The other fancy shapes all have crushed ice effects and are glowing with various reflected light bouncing all around in the stones.

The strongest fluorescence is in one of the cushions and the marquise. Fluoro has nothing to do with how the diamonds appear in daylight (other than improving their colour).

Hi Gary - saw this in your other thread.

As I mentioned there - I just don’t like the glowing blue floureacensce when it fluoresces- and if I’m going to buy a diamond that has it (which I did as my diamond glows like yours on the left), I would prefer to have a suitable discount in my pocket.

 

[TreeScientist]

Hi Gary - saw this in your other thread.

As I mentioned there - I just don’t like the glowing blue floureacensce when it fluoresces- and if I’m going to buy a diamond that has it (which I did as my diamond glows like yours on the left), I would prefer to have a suitable discount in my pocket.

I don't blame you one bit. It's not that fluor necessarily has a negative effect per-say (although in this case it seems like it is having a negative effect to your eye). The bigger issue is that you should get what you pay for. Like it or not, fluorescent diamonds trade at a discount to non-fluorescent diamonds. As @Stephan said, let's take a hypothetical situation in the distant future where AGS no longer exists, and you needed to have the diamond re-certed by GIA prior to an estate sale. If it came back from GIA as an E with med blue fluor as opposed to a D with no fluor, we're taking about a difference of about $5k in today's dollars for a VVS clarity diamond of this size. Obviously in this hypothetical scenario we're making the assumption that fluor diamonds still trade at a discount in the distant future. But if today's precedent holds, then this would be the case.

If this diamond was sold at the price of a fluor diamond in today's market, then I would say keep it and wear it with pride. As I said, I love the color of the fluor in this diamond. But not getting what you paid for is unacceptable IMO.

Don't feel bad at all about sending it back for a trade-in. It's your diamond. You need to feel happy with what you're getting. I hope for your sake that a suitable replacement will pop up soon.

 

[Garry H (Cut Nut)]

Regarding discounts, its all topsy turvey.
Prior to the debacle in South Korea about 30 years ago strong blues with higher colour were more expensive than non fluoro diamonds.
With the work that is going on by GIA, HRD and OctoNus / Lexus, it is possible that we will revert back to that scenario in years to come. So snap up a bargain while you can.
And if you have a near medium from AGS and no desire to sell it, then please do not panic.
But by all means change it from the vendor if it really worries you.

 

[Dancing Fire]

And if you have a near medium from AGS and no desire to sell it, then please do not panic.

Garry, Is my stone near medium blue? It doesn't glow blue under the UV light.