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Blue Fluorescence in Diamonds

sam0415

Rough_Rock
Joined
Jan 26, 2015
Messages
14
Hi Everyone - just wanted to get feedback regarding how you feel about diamond fluorescence in general.
I read many articles about the impact of florescence but remain hesitant about it. Does it really help out in I - Color diamond ? I'm between and H and I but all the articles I read said that if I get an I color diamond with medium fluor. that it will actually appear possible a grade higher or similar to an H.
The diamonds I'm looking at are 1.3-1.5 rounds with excellent cuts/polish/symm. There is obviously a significant price delta when you drop between H and I but I wasn't sure if the medium blue fluo. will make up for the lower color grade.
Anyone with an I diamond that has medium fluo... what are your thoughts?

Thanks :)
 

monipod

Brilliant_Rock
Joined
Jun 25, 2019
Messages
565
I love fluorescence though more for geeky science reasons than what it might do for a lower colour diamond. I think while the jury of experts are still out on the matter, most owners of SBF stones swear that they help make a stone whiter. At HIJK, it wouldn't hurt so I'd certainly get the H or I, but don't buy them expecting them to look like D's. I think H/I stones are pretty colourless as they are and it will only be in certain lighting conditions that the fluor will come into play.
 

autumngems

Brilliant_Rock
Premium
Joined
Jul 24, 2003
Messages
1,696
I LOVE Blue Florescence in diamonds and my K had Medium Blue and you never would have known it was a K. Some can be milky or hazy so please don't buy sight unseen unless someone can attest that it isn't milky or hazy.
 

Roselina

Brilliant_Rock
Joined
Feb 1, 2020
Messages
576
Huge fan here! I love this hidden super power. Science at it‘s best. My I (or J, I forgot) has very strong blue fluorescence and it faces up quite white. In strong sunshine it gets a blue hue.
 

MMtwo

Ideal_Rock
Joined
Sep 20, 2009
Messages
2,024
I love my strongly fluorescent I diamond. No issues with it - looks fine in daylight. I love the "black light" fun of it. I am not color sensitive at this level of color, so lucky for me.
 

Texas Leaguer

Ideal_Rock
Trade
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Jul 27, 2009
Messages
3,311
@sam0415 ,
There are many threads here on fluorescesence, some of them are epic! It is a very interesting phenomena and there are strong views around the impacts of this property.

It is important to understand a couple of basic things in order for you to decide where you come down on the issue. First is that fluoro is MUCH more of an identifying characteristic than a performance characteristic. That is, if two diamonds are very similar in all other respects, knowing their reaction to UV wavelengths can help you separate the two. This is the primary reason fluoro was first noted on laboratory reports.

Secondly, for the fluorescent effect to be stimulated the UV component of the lighting environment must have sufficient intensity. Direct daylight provides such an environment. However, the vast majority of indoor lighting environments do not.

The extent to which a diamond will benefit or suffer from fluorescence is debatable and depends on several factors, but fluorescence will only have the potential to change a diamond's appearance (for good or bad) in those environments capable of triggering the fluorescent effect.

It is wise to base your buying decision primarily on other critical factors that are in play in all lighting environments. It is unwise to make a buy decision based on the assumption that fluorescence will make the diamond look like a higher grade.
 

Rockdiamond

Ideal_Rock
Trade
Joined
Jan 7, 2009
Messages
8,449
I don't have an I, but my OEC is a K with SBF and it always looks bright white. I'd never guess it was a K. I'm really happy with my decision.
Bryan and I have different experiences in this regard.
I've personally experienced what iluvshinythings and others have expressed here.
In many cases, I-J-K stones with MEd or Strong blue appear to be a few shades whiter in virtually any lighting environment bright enough to perceive the subtle color differences.
 

Garry H (Cut Nut)

Super_Ideal_Rock
Trade
Joined
Aug 15, 2000
Messages
15,828
@sam0415 ,

The extent to which a diamond will benefit or suffer from fluorescence is debatable and depends on several factors, but fluorescence will only have the potential to change a diamond's appearance (for good or bad) in those environments capable of triggering the fluorescent effect.
Hi Bryan, I guess you using 'debatable' means I must call you out.
The light that causes a color improvement in a blue fluorescent diamond travels through windows.
The research that says this does not happen is flawed. They assumed shorter wave lengths that gemologists used which produce half the strength of whitening as the long wave from GIA's old testing devices.
Here is a simple test Bryan - please do it.
1. check the fluoro strength of a suitable diamond under your GIA device. Then use a cheap $5 UV torch.
You will find a bluer reaction.
Then hold the cheap torch on the other side of a pane of glass - you will see the UV light passes through the window,

In order to be able to see the color in say a 1ct H diamond set in a ring - you need pretty good lighting. Much brighter than most people are happy to live or work in.
But when you are in a room with windows there is more light coming from the windows then from the lamps in the room.
The test for this is the back of a spoon. Most people are amazed.
An H strong Blue fluorescent diamond will look like a G in such a room.

So many Prosumers here know this Bryan.
and even our resident resurrected Dinosaur, David - he knows it because he sees it all the time sitting near a frosted window in chilly NYC.
 

coda72

Brilliant_Rock
Joined
Mar 1, 2005
Messages
1,648
I love blue fluorescence in diamonds, and mostly purchase diamonds that exhibit it.
 

Rockdiamond

Ideal_Rock
Trade
Joined
Jan 7, 2009
Messages
8,449
Diamondasuarus here!
Putting my money where my mouth is......sometimes I actively seek out I-J-K stones that are MB or SB....
It's by no means a blanket endorsement, as I reject at least 3/4 of these stones. The mere presence of the fluorescence doesn't, in itself make it a great stone.....
I would, for example, not guarantee that an MB J looks like an H in daylight indoors- but there's a good likelihood it will.
But give me a super well cut 3ct J color EC with MB- and many times it does look like an H ( or better)
 

Texas Leaguer

Ideal_Rock
Trade
Joined
Jul 27, 2009
Messages
3,311
I told you @sam0415 , it's debatable. :)

First, as I always need to preface in these discussions, I am not trying to dissuade anyone from buying a diamond with this property. At Whiteflash we sell diamonds with fluorescence up to medium. I also personally think fluorescence in nature is very cool. So, it can add to someone's enjoyment of owning a diamond that fluoresces. I am totally on board with that concept. Especially since the property will not change the performance or appearance of that diamond in any way (positive or negative), in the majority of lighting environments likely to be encountered in real life.

It is easy to demonstrate with inexpensive light meters, how the intensity of UV drops off dramatically with distance from an overhead light source or from a window. And this is the reason for the concern about overgrading of color when making observations at very close range (inches) from a light source that is not filtered for UV wavelengths.

My point is that consumers are not well supported by continuing to perpetuate the notion that strong fluorescesce is a benefit to the appearance of a lower color diamond. It 'may' whiten under a very limited range of lighting conditions. Therefore, my advice is not to predicate a buy decision on this dubious claim.

The biggest observational studies done on diamond fluorescence and appearance ( GIA ) support this position. Participants identified as representing the buying public were unable to notice any difference between inert and fluorescent diamonds.

John King and Tom Moses, two of that study’s authors, discussed the quality of fluorescence as investigated by GIA. “You don’t see the quality of fluorescence with the eye,” King says. “In the overwhelming percent of diamonds, there is no effect on the appearance.” Both inexperienced observers — that is, members of the consuming public — as well as members of the trade did not discern any difference in the color appearance or transparency of stones with and without fluorescence by eye.
 

Rockdiamond

Ideal_Rock
Trade
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Jan 7, 2009
Messages
8,449
Especially since the property will not change the performance or appearance of that diamond in any way (positive or negative), in the majority of lighting environments likely to be encountered in real life.
Bryan, Bryan, Bryan......to quite Ronnie Raygun.....there you go again:)
This has been debunked countless times here on PS.
I'd very much like to see where the (totally off base) quote you posted comes from- and in context, please.
I can spot fl stones frequently, without the use of any specialized lighting. In many cases, the ones that are easy to spot are stones that do have a haziness.
The bad ones absolutely do exist- and they debunk your quote- they're easy to spot.

Secondly, we've sold quite a few MB even SB stones in the I-J-K range, based on the characteristic we're discussing here. Best case examples will look like H color or even better when people view them in lighting bright enough to perceive the color. We've described this phenomenon to the clients.
They've agreed.
This is so basic, it's strange to debate it ( yet again)
 

Texas Leaguer

Ideal_Rock
Trade
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Jul 27, 2009
Messages
3,311
David,
The fact that you pronounce that something has been 'debunked' does not make it so. No matter how many times you do it.


The King quote came from an interview published in Rapaport magazine following the release of the survey results. It is merely a restatement of the conclusions of the study.

This quote is from the study itself:

One interesting aspect of this study was that the nontrade observers could not make meaningful distinctions. For this group,which would be considered most representative of the jewelry-buying public, fluorescence had no overall effect on color appearance or transparency.
 

Rockdiamond

Ideal_Rock
Trade
Joined
Jan 7, 2009
Messages
8,449
Good point Bryan- The word "debunk" wasn't specific enough. I'll rephrase.
This subject has been discussed here - at great length.
The study you were basing your position on ( Cowing) was shown to be defective by Garry- and myself.
And a 24 year old paragraph, based on a defective premise proves nothing either.....so much has changed over that period of time - especially concerning consumer awareness, and participation.
 

Texas Leaguer

Ideal_Rock
Trade
Joined
Jul 27, 2009
Messages
3,311
24 years is a long time for someone to prove the conclusions of the GIA study were defective.

I haven't seen it. You certainly haven't provided it. The sole basis for your arguments here and in all the fluorescence threads on pricescope is your opinion based upon your experience. Which is totally fine. But I have to give the conclusions of the researchers at GIA a bit more weight.
 

Rockdiamond

Ideal_Rock
Trade
Joined
Jan 7, 2009
Messages
8,449
Of course!!! GIA can never be incorrect!!!
And of course, consumer attitudes and experiences are exactly the same as they were in 1997- the internet didn't change one single aspect of consumer awareness or experience buying..

Sorry for the sarcasm, but C'mon man!
Use your own eyes- Garry gave you a great experiment......
From what I can see, there are only three PS vetted trade members discussing this.
Garry, and I ( with thousands of real consumers) explaining why we see whitening, and you're on the other side.
Meanwhile, I'm looking at an amazing emerald cut, J color with Medium blue and that sucker looks white!!
 

Texas Leaguer

Ideal_Rock
Trade
Joined
Jul 27, 2009
Messages
3,311
Thanks David. I think you proved my point about the evidence you present to 'debunk' GIA's conclusions.

Oh, and I do use my own eyes. I have been training them on diamonds and gemstones for perhaps as long as you have. :shock:
 

Rockdiamond

Ideal_Rock
Trade
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Jan 7, 2009
Messages
8,449
See, the problem is- GIA has tons of articles about fluorescence
For example:
GIA uses a standard set of lighting conditions for the color grading of all diamonds. The light source used is designed to simulate natural sunlight, which contains a component of ultraviolet radiation. In rare cases, a diamond can emit strong or very strong blue fluorescence when exposed to ultraviolet radiation—in such instances that fluorescence may temporarily and slightly affect its color appearance.

The word "rare" is not defined. If we took 1000 random diamonds, maybe 10-20 would be I-K color, MB or SB....which could easily be interpreted as "rare".
It does, however, state clearly that UV may affect color and appearance. I'm not suggesting MB or SB I-K colors look whiter in every case- in certain cases they do.

Garry will hopefully provide a more technical explanation of why indoor lighting generally contains UV radiation. And he's already given the suggestion of checking UV through a window- try it!
 

Texas Leaguer

Ideal_Rock
Trade
Joined
Jul 27, 2009
Messages
3,311
Nobody is arguing those points David.

Yes, color whitening does happen in certain conditions and it has a slight affect on appearance.

Yes, there is a UV/VV component in many indoor lighting environments, including some color grading environments.

But when the light source is devoid of fluorescence stimulating wavelengths, or when the intensity of those wavelengths is too weak, the fluorescence will not be triggered and hence it can have no effect on the appearance of the diamond.

The results of the GIA appearance survey are in alignment with the science.
 

Rockdiamond

Ideal_Rock
Trade
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Jan 7, 2009
Messages
8,449
Thank you, Bryan- my apologies if I was argumentative.....
It's been one of those days... years actually:)

I think this discussion is illustrative of how interesting the phenomenon of fluorescence is. I say that because it's the sort of characteristic on which even well meaning experts may disagree.
Even the '97 GIA article- seems ...incorrect on it's face.

John King and Tom Moses, two of that study’s authors, discussed the quality of fluorescence as investigated by GIA. “You don’t see the quality of fluorescence with the eye,” King says. “In the overwhelming percent of diamonds, there is no effect on the appearance.” Both inexperienced observers — that is, members of the consuming public — as well as members of the trade did not discern any difference in the color appearance or transparency of stones with and without fluorescence by eye.
Bryan- I'm sure you've commented on the potential effects of strong fluorescence on transparency. Bad examples of SB stones are bad for precisely that reason. You don't need to be an expert- and you don't even need a specific UV light. The dullness is readily apparent indoors, with any lighting bright enough to allow the eye to focus on an item as small as a diamond.

I'm not writing this to be argumentative- but it does show that it's an issue that is truly not settled. Likely it won't ever.
 

Texas Leaguer

Ideal_Rock
Trade
Joined
Jul 27, 2009
Messages
3,311
It's been my experience that many of those cloudy SB diamonds are cloudy for other reasons such as twinning wisps and graining that can compromise transparency. Some of the same forces that cause those defects in natural diamond also give rise to the atom defects related to blue fluorescence.

If the cloudiness is caused by something other than fluorescence, the stones will look bad in all lighting environments. If the cloudiness is caused only by the fluorescence, the stone will be perfectly transparent in lighting conditions not rich in UV/VV.
 

MamaBee

Ideal_Rock
Joined
Mar 31, 2018
Messages
8,444
This is my antique rectangular step cut diamond with medium blue fluorescence. It looks very white to me...not hazy at all.
4C329703-C06F-4D9B-B8FB-ECBD9EC926F3.jpeg
 

gregchang35

Ideal_Rock
Joined
Sep 11, 2012
Messages
3,029
I have fluoresces in earring- I sought one from BGD, specifically for this feature. my eternity rings and my fancy colour diamonds also have this phenomenon, not all but some . I love this feature.

In my diamonds, flour tends to make the stones more distinct- clear/ crisp.

You will have to look at the stones in person to know if it is for you.
In sunlight, my F colour earring stones, does have a diffenrt appearance- intend to think of it as a slightly blue colour- a highly regarded fancy colour !!! So, a win win.
 

Garry H (Cut Nut)

Super_Ideal_Rock
Trade
Joined
Aug 15, 2000
Messages
15,828
Lets show you Bryan.
To dispel the argument that UV light that causes color whitening in blue fluorescent diamonds does not pass through windows.
This bathroom door is 10mm thick or 0.4 inches! Much thicker than normal windows and probably about the same as many double glazed windows.

The center diamond is GIA Medium Blue. Clearly the diamonds are fluorescing.

What is more, the long wave frequency used for grading fluorescence has around half the effect as these simple cheap torches which work in the near visible range.

It is for this reason that earlier tests (with the wrong light meters) are totally irrelevant. This simple test shows that very long wave UV that is in the just or near visible range does pass through windows.
 

Garry H (Cut Nut)

Super_Ideal_Rock
Trade
Joined
Aug 15, 2000
Messages
15,828
And as a little fun offering - I have done lots of tests in Northern hemisphere ski resorts with this little fun sunscreen cap.
I actually purchased it in Jackson, not Oz - and also tested it in Japan skiing this year - even in the north island - in a ski lift gondola with curved perspex windows the UV on cloudy days turns the cap blue! I do not know for sure that the perspex would have been Lexan - which when thick enough blocks a lot of the light from even cheap LED lights.
 

Rockdiamond

Ideal_Rock
Trade
Joined
Jan 7, 2009
Messages
8,449
It's been my experience that many of those cloudy SB diamonds are cloudy for other reasons such as twinning wisps and graining that can compromise transparency
Not at all my experience. I've seen plenty of VS clarity dull SB stones.
 
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