AGS fluorescence: negligible… but I see bright blue?

[ValentineBling]

Congratulations on your new purchase.

In a newbie. Can I ask a silly question? I saw someone saying that fluorescence is a good thing in a lower colour diamond (J,KL) because it actually makes the diamond appear whiter. With this in mind (and not knowing your specs) wouldn't this stand to reason that fluorescence is a good thing?

 

[Sprinkles&Stones]

Congratulations on your new purchase.

In a newbie. Can I ask a silly question? I saw someone saying that fluorescence is a good thing in a lower colour diamond (J,KL) because it actually makes the diamond appear whiter. With this in mind (and not knowing your specs) wouldn't this stand to reason that fluorescence is a good thing?

Hi,

I like fluorescence. I have nothing against fluor. I was just perplexed at how my diamond, which glows blue, could be labeled as “negligible”, while it’s twin has no fluor at all but was given the same label as “negligible”.

Also Bryan answered that old wives tale above that fluor does not make a lower colored diamond appear whiter.

I love how my JKL diamonds look. I don’t want them to look whiter. If I did, I would just buy a higher color diamond

 

[Karl_K]

Also Bryan answered that old wives tale above that fluor does not make a lower colored diamond appear whiter.

not really, its more complex than that in lighting with uv and or near uv present and a diamond that strongly reacts to it can certainly make lower colored diamonds appear to have less color.
With diamonds everything comes down to lighting.

 

[LilAlex]

To a large extent the value of natural, Earth-mined diamonds is predicated on rarity. Thus, the grades (at the upper levels especially) are very small increments corresponding to how frequently or how rarely they come out of the ground.

My point was not that small grading increments do not matter. My point was the exact opposite -- that in a world were (often imperceptibly) small increments do matter, it seems silly to lump all low-fluor grades together because "fluorescence in these small ranges have little impact on how the diamond appears face-up." It is the inconsistency that is baffling. And kinda dumb, imo.

 

[MissGotRocks]

GIA rounds its numbers on their reports. Those small increments matter too but they are there every day on a GIA report. Same with fluor I guess!

 

[max1111]

My point was not that small grading increments do not matter. My point was the exact opposite -- that in a world were (often imperceptibly) small increments do matter, it seems silly to lump all low-fluor grades together because "fluorescence in these small ranges have little impact on how the diamond appears face-up." It is the inconsistency that is baffling. And kinda dumb, imo.

And we pay for those small increments whether that is shared with customers or not.

 

[Texas Leaguer]

GIA rounds its numbers on their reports. Those small increments matter too but they are there every day on a GIA report. Same with fluor I guess!

This is a very good point. And germane to the discussion of fluorescence.

 

[Texas Leaguer]

My point was not that small grading increments do not matter. My point was the exact opposite -- that in a world were (often imperceptibly) small increments do matter, it seems silly to lump all low-fluor grades together because "fluorescence in these small ranges have little impact on how the diamond appears face-up." It is the inconsistency that is baffling. And kinda dumb, imo.

The inconsistency can be explained by the fact that a certain wavelength of excitation was chosen by GIA many years ago for the observation of fluorescence in order to achieve consistency in their reporting. Recent science has shown that other wavelengths can stimulate fluoresces as well, in some cases causing an even stronger reaction. And today there is a plethora of inexpensive UV lights on the market today that consumers and trade people are using which have different properties and create a very wide range of reactions, and therefore observations.

Again, the original intent at the lab was to provide an additional data point to help positively identify a diamond by reporting the reaction to a particular wavelength of UV that would be relatively consistent and repeatable.

Interestingly, in terms rarity, fluorescence is more rare in diamonds. So in that very narrow sense, one would think it would add value. However, that is not the case for a variety of rational and irrational reasons, as well as simple personal preference.

 

[Texas Leaguer]

not really, its more complex than that in lighting with uv and or near uv present and a diamond that strongly reacts to it can certainly make lower colored diamonds appear to have less color.
With diamonds everything comes down to lighting.

Right, whitening is a real thing - strong blue fluorescence can 'cancel' some of the yellow appearance in diamonds with yellow body color. But it requires a certain intensity of stimulation to make that happen. Direct sunlight is by far the most common real world lighting environment where this is possible.

Most indoor lighting, even that with a UV component such as fluorescent tubes, do not produce enough intensity to stimulate the fluoro effect, unless you hold the diamond within a few inches of them.

It is also why we don't get a sunburn while working in our offices.

 

[max1111]

The inconsistency can be explained by the fact that a certain wavelength of excitation was chosen by GIA many years ago for the observation of fluorescence in order to achieve consistency in their reporting.

Assuming GIA and AGS use the same wavelengths to grade Fluor, who does it serve grouping multiple established grades together?

 

[Texas Leaguer]

Assuming GIA and AGS use the same wavelengths to grade Fluor, who does it serve grouping multiple established grades together?

I think there were unintended consequences involved. It was impossible for either lab to fully anticipate where the market would go, where the science would go, and the impacts of online shopping on the way lab reports are used.

I guess the answer is that the situation requires consumers looking at certified diamonds to gain an understanding of the vagaries of this particular data point.

Pricescope is great place to do just that. My colleagues in the trade, along with many knowledgeable members in this community, have had robust debates on this topic over the years!

 

[Karl_K]

Assuming GIA and AGS use the same wavelengths to grade Fluor, who does it serve grouping multiple established grades together?

They were not grades when they were created, they were comments.
They still are comments but they get treated as grades.
The entire system was not designed for buying diamonds off a list on the internet it was designed for professionals buying face to face, then using the reports to assure customers who are buying face to face from the professionals.
A lot of the short comings for internet commerce use comes from this history.

 

[LilAlex]

Recent science has shown that other wavelengths can stimulate fluoresces as well, in some cases causing an even stronger reaction. And today there is a plethora of inexpensive UV lights on the market today that consumers and trade people are using which have different properties and create a very wide range of reactions, and therefore observations.

It is very easy to standardize and measure fluorescence. I used to routinely use an instrument that can measure emission from a living cell at any visible wavelength during excitation at any UV-to-visible wavelength. Cells are tiny -- like 1/100th of a mm. Diamonds are big. It's not hard to do this in diamonds.

I assume it is mostly that no one wants to be the lab that more liberally assigns "badness" to a gem; labs survive by courting industry insiders.

 

[Garry H (Cut Nut)]

Assuming GIA and AGS use the same wavelengths to grade Fluor, who does it serve grouping multiple established grades together?

That is a big assumption, actually.
I believe GIA now use 385nm or right on the boundary of visible violet (that actually appears purple to our eyes).
Historically (or hysterically) GIA and other labs used shorter wave 365nm UV because that was all that was available and mainly used to identify other types of gems and treatments.
I doubt AGS has caught up.
But, infact, the cheaper the UV torch the stronger the fluorescence because the visible violet creates a stronger effect. Thats mainly why people are reporting AGS negligible showing stronger fluoro effects!

 

[Garry H (Cut Nut)]

Fluorescence became a bad thing in 1992.
Then we had global jewelers who thought they better not touch fluorescent diamonds.
Then we got the Internet.
Then we got regurgitated gossip that drove discounts deeper and deeper.
Now that GIA have started studying the topic in the past 12 months we will see those discounts and gossip change.
It is happening already.

 

[sugarcloud]

I have alsways loved flourescence so after reading this thread I ran to see if my ACA had any, sadly it doesn't. Maybe when I upgrade I will see if I can ask for one that has some more, its such a cool effect!

 

[nojs]

Fluorescence became a bad thing in 1992.
Then we had global jewelers who thought they better not touch fluorescent diamonds.
Then we got the Internet.
Then we got regurgitated gossip that drove discounts deeper and deeper.
Now that GIA have started studying the topic in the past 12 months we will see those discounts and gossip change.
It is happening already.

Could it also be that since lab stones (white) don’t have blue fluorescence it is becoming a novelty thing? At least that is how I feel.

 

[Stone Hunter]

Congrats!!!! on your new earrings. I hope you've posted more photos of them somewhere.

Interesting discussion. I personally like Fluor, but it would throw me to find two different stones, graded the same, that show so differently.

 

[Garry H (Cut Nut)]

Could it also be that since lab stones (white) don’t have blue fluorescence it is becoming a novelty thing? At least that is how I feel.

99.5% of colorless LGD have no fluorescence effect from daylight!
That is another reason why natural colorless diamonds with fluorescence are safer bets as being natural.

 

[nojs]

99.5% of colorless LGD have no fluorescence effect from daylight!
That is another reason why natural colorless diamonds with fluorescence are safer bets as being natural.

Can the remaining 0.5 % have blue fluorescence? Fascinating!

 

[Garry H (Cut Nut)]

Can the remaining 0.5 % have blue fluorescence? Fascinating!

These are type 1aB and nitrogen atoms are in pairs; these do not affect the diamond's color and to the best of my knowledge do not have the loose electorns that type 1a have that create the N3 fluorescence effect.
So no.

 

[nojs]

I received my first strong blue fluorescence diamond today (D VVS1 cushion) and I was half expecting it to turn blue in direct sunlight but it doesn’t It is just bright white and very sparkly, but I don’t notice any fluorescence effect on it.

I ordered an UV flashlight and I very much look forward to testing my none, faint, medium and strong fluorescence diamonds with it.

 

[nojs]

OMG!!! I got my UV light today and tested all diamonds I have. I got the absolutely coolest results!!!!

Turns out that with the UV Light I have, the (GIA) strong fluorescence one is not that much different from my (GIA) faint. The difference is much greater in the photo than what my eyes pick up.

Both have a very nice blueish turquoise color fluorescence. BUT my GIA faint heart cut seems to have a PINK fluorescence. It is faint and I can’t capture it on camera. Is it possible to have faint PINK fluorescence without the lab specifying so? Can the experts please comment on this @Garry H (Cut Nut) @Karl_K @Texas Leaguer

Also I remember I once read here of someone how was able to “charge” the stones and then see phosphorescence. So I held the torch really close for two minutes and then turned if off. And sure enough the faint cushion has orange phosphorescence and the strong one has white phosphorescence. So very cool!!!


The second picture is taken in total darkness.

In the last photo:
- upper left GIA K faint Fluor
- upper right IGI F lab diamond (for control)
- lower left GIA D strong Fluor
- lower right GIA G None

 

[nojs]

I would also like to ask the experts here if my melee has been “salted” with lab stones since only one (!) of 20 or so melee diamonds has fluorescence. It is against odds, isn’t it?

 

[nojs]

Hi!

I just got my beautiful WF ACA studs. Of course being a PSer, first thing I do is whip out the loupe and my black light.

I noticed one of the diamonds lights up bright blue under my fluorescence black light. I don’t mind it, but when I checked both my AGS reports I see both of the diamonds are listed as “Fluorescence : Negligible”.

My stud seems to light up to the same level as my other GIA diamonds graded with medium and strong fluorescence.

My question is: how strict is the AGS when grading fluorescence? To me, negligible would be barely visible under black light, not bright blue.

Should I be worried that something is amiss? Is this normal for WF ACA diamonds, or normal for AGS to not match?

My “strong” doesn’t come even close to this level of fluorescence

 

[Karl_K]

I would also like to ask the experts here if my melee has been “salted” with lab stones since only one (!) of 20 or so melee diamonds has fluorescence. It is against odds, isn’t it?

no, melee both in rough form and cut form are bought and sold in bunches so stones in the same bunch can often be similar. So 0 or 20 with would not be abnormal but 20 with would be the less common.

 

[Karl_K]

My “strong” doesn’t come even close to this level of fluorescence

You can not judge the fluorescence level with photos even with both in the same photo because of how cameras work and cell phones are worse for it than a camera.

 

[Karl_K]

BUT my GIA faint heart cut seems to have a PINK fluorescence. It is faint and I can’t capture it on camera. Is it possible to have faint PINK fluorescence without the lab specifying so? Can the experts please comment on this @Garry H (Cut Nut) @Karl_K @Texas Leaguer

yes its possible and its also possible the visible violet component of the uv light source is changing the color.

 

[nojs]

yes its possible and its also possible the visible violet component of the uv light source is changing the color.

Excellent info thank you @Karl_K ! I found this excellent explanation regarding on what you said:

What is the Difference Between 365 nm and 395 nm UV LED Lights? | Waveform Lighting

www.waveformlighting.com

 

[Karl_K]

Excellent info thank you @Karl_K ! I found this excellent explanation regarding on what you said:

What is the Difference Between 365 nm and 395 nm UV LED Lights? | Waveform Lighting

www.waveformlighting.com

Diamonds in general respond more to 395-400nm than 365nm they are in the exception mentioned in the article.