Should we discourage or recommend FL stones?

[Rockdiamond]

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.

Is Diamond Fluorescence Good or Bad?

What is diamond fluorescence and how does it affect the look and price of the diamond? Find out answers to all this questions with this guide.

www.whiteflash.com

I have nothing against Bryan. If he insists on providing false information to the people going to his site, and reading the link he shared, he has every right to do so. Once it’s shared here , on a thread I started to dispel myths and increase understanding, I need to correct it.
To the statement in red- Bryan refuses to illustrate or discuss/ defend this “recent science”. To claim “science” proves a point, when no such science exists seems extremely misleading.

While I’m sure we can find indoor areas where no daylight exists, most daytime indoor viewing areas DO have an element of daylight. Therefore the statement in blue is easily disproved.
Frustrating that Garry is explaining that VV in indirect sunlight ( daylight) can cause whitening or color change, Bryan refuses to accept it.


However, recent science has demonstrated that the fluorescent effect is diminished dramatically as the distance from the light source is increased. In almost all normal indoor viewing circumstances the distance from the light source is too great to excite the fluorescence effect. Therefore, the idea that the appearance of diamonds in lower colors is improved by fluorescence is largely unfounded. Therefore, in reality it is NEITHER good nor bad

 

[Rockdiamond]

I know of many cases where a piece of rough was sawed prior to cutting and only one piece was fluorescent. So it makes sense that it can happen within one stone.

 

[sledge]

I have nothing against Bryan. If he insists on providing false information to the people going to his site, and reading the link he shared, he has every right to do so. Once it’s shared here , on a thread I started to dispel myths and increase understanding, I need to correct it.
To the statement in red- Bryan refuses to illustrate or discuss/ defend this “recent science”. To claim “science” proves a point, when no such science exists seems extremely misleading.

While I’m sure we can find indoor areas where no daylight exists, most daytime indoor viewing areas DO have an element of daylight. Therefore the statement in blue is easily disproved.
Frustrating that Garry is explaining that VV in indirect sunlight ( daylight) can cause whitening or color change, Bryan refuses to accept it.


However, recent science has demonstrated that the fluorescent effect is diminished dramatically as the distance from the light source is increased. In almost all normal indoor viewing circumstances the distance from the light source is too great to excite the fluorescence effect. Therefore, the idea that the appearance of diamonds in lower colors is improved by fluorescence is largely unfounded. Therefore, in reality it is NEITHER good nor bad

Come on David.

Off topic, but let's talk boxing for a minute. We may all have different ideas of who the best or strongest puncher of the greats are, but one thing we can't really deny is what is called ape index. This is the length of a person's arm reach in comparison to their height.

Obviously when you have a much taller person boxing a much shorter person, the difference can be obvious as evidenced in this picture of Primo Carnera.



Can you imagine being the little guy fighting him? It really wouldn't matter how powerful of a punch you could throw, because unless you unleashed a Mike Tyson bulldog approach you are probably going to go down faster than a hooker on 50 cent night.

While Primo was a big guy at 6'6" (or 78") he had an arm reach of almost 85". Most people's arm spans is roughly their height, so not only was he abnormally tall against opponents in his day who was less than 6' tall but he enjoyed a 85" - 78" = 7" ape index advantage as well. His arm reach was more common for a person of 7' height.

Another more modern day & popular boxer is Lennox Lewis, who has a height of 6'5" (or 77"). His arm reach also measures at 85", so he enjoyed an 8" ape index advantage. When fighting David Tua, there was a total of 15" arm disadvantage for Tua.

While ape index is obviously an advantage, it can be countered. Mike Tyson was known for many things, but in particular was his intensity and speed of immediately attacking using close range punches. This neutralizes ape index reach, but few people can do it as well as Tyson did. And when he fought Lennox, he faced a 13" disadvantage and lost his footing and speed, so Lennox lit him up and ended up winning the fight.

Some other fun facts, getting hit by Mike Tyson is like....

How Hard Could Mike Tyson Really Punch?

About as hard as a big ol' anvil dropped from 5ft.

www.thrillist.com

Getting hit with a 221lb anvil dropped from 5ft.

Or having Simon Cowell crash into you on a Vespa at nine miles per hour.

It'd feel just like a dorm refrigerator filled with three 12-packs of ice cold beer falling out of a second-story window.

Imagine current Tour de France champion Vincenzo Nibali slamming into you on his bike at 15 mph.

If you were on 7ft stilts and fell over, you would know what Mike Tyson's fist felt like.

Say you were wearing a bullet-proof vest, and 13 men shot you with .22s. It'd feel like that.

So what in the hell does boxing have to do with fluor? Within a boxer's arm reach, you are likely to feel quite a bit of pain. However, as you go further away, no matter the strength of the boxer or how long their ape index advantage may be, you aren't going to feel the effects.

I don't think it takes a rocket scientist to figure out that the further you go from a UV source, the less effect it will have on fluor. One of the reports indicated in the lab, going from 2-3" to nearly 7" had an impact. Most people are a good 5' (or 60")+ away from light bulbs above them. Sure, some indoor areas have windows, etc but that UV source gets filtered to as it passes through windows, etc.

My point is obviously distance from the UV (or punching) source makes all the difference in the world.

 

[Karl_K]

but that UV source gets filtered to as it passes through windows, etc.

400nm passes right through modern windows.
Otherwise good post.
Anytime there is sunlight even reflected there is the possibility of a reaction indoors our out.
Other lightimg at typical distance there likely isnt much if any.
In the current grading environment at the labs im not sure either way.
No one here knows what lighting GIA uses in their machines.

 

[Rockdiamond]

I see....interesting diversion.
Sledge, can you show us the "scientific proof" that what I've been seeing for more than 40 years wasn't???
How much do you know about VV?
Distance from bulbs, and how it affects fluorescence is totally irrelevant to this point.
In fact, just today- a half hour ago, I took a video of a green diamond with strong yellow fluorescence.
I did the video in a brightly lit room- daylight- no direct sun.
The effects of the fluorescence on that stone are over the top, plain wacky. And clearly visible.

And while it's lovely of you to come to Bryan's defense....he's the one in the trade making statements which are false. Consumers are clearly in different strata.
Tradespeople are - and should be- held to a higher standard.

 

[sledge]

400nm passes right through modern windows.
Otherwise good post.
Anytime there is sunlight even reflected there is the possibility of a reaction indoors our out.
Other lightimg at typical distance there likely isnt much if any.
In the current grading environment at the labs im not sure either way.
No one here knows what lighting GIA uses in their machines.

Thanks for clarifying @Karl_K.

If a Low-E glass, would it be the same, even for 400nm bandwidth?

I see....interesting diversion.
Sledge, can you show us the "scientific proof" that what I've been seeing for more than 40 years wasn't???
How much do you know about VV?
Distance from bulbs, and how it affects fluorescence is totally irrelevant to this point.
In fact, just today- a half hour ago, I took a video of a green diamond with strong yellow fluorescence.
I did the video in a brightly lit room- daylight- no direct sun.
The effects of the fluorescence on that stone are over the top, plain wacky. And clearly visible.

And while it's lovely of you to come to Bryan's defense....he's the one in the trade making statements which are false. Consumers are clearly in different strata.
Tradespeople are - and should be- held to a higher standard.

LOL, so distance doesn't matter now? Have you heard of the inverse square law for intensity? Are you saying that VV is exempt from it?

Also, it's not my burden to prove your theory. You tell me the reason for your results, how they were precisely controlled. What devices were used to measure them. And how I can duplicate the environment and get the same repeatable result. Make sure to put in a neat type written format so it can be used for decades as reference material and disputed by other diamond nerds like us.

But honestly -- was I disputing what your eyes had seen? My prior point/post was that distance makes a difference. I still believe that.

I am curious why Bryan's statements are false, but yours are accurate? If you can't provide such scientific proof then wouldn't your opinion be just as false as his?

 

[Rockdiamond]

The two videos have NOTHING all to do with the discussion Sledge.
I'm not hiding behind "science" and I have no "theory"
I've been teaching and advising consumers online for 20 years.
I'm speaking of actual life experience.

I don't want to risk putting words in his mouth- but by his position and statements, it seems clear Bryan has never seen whitening or color change take place in daylight. If I'm not stating his position correctly, and he has witnessed it, there's no argument. He's clearly not willing to discuss this.

But a claim that something does not occur, based on "science", when observers are stating, YES IT DOES, seems to call any science related to the claim it's not possible into question.
Thank goodness Garry is here, to add more technical reasons why we see what we see.

 

[Karl_K]

If a Low-E glass, would it be the same, even for 400nm bandwidth?

yep it passes it right through.
They don't care about 400nm as it is not what causes fading and cancer and is very close to being able to be seen by humans.

 

[Texas Leaguer]

yep it passes it right through.
They don't care about 400nm as it is not what causes fading and cancer and is very close to being able to be seen by humans.

But if VV (400ish) and 365 (as well other wavelengths in between) all contribute to fluroescence stimulation, and the sub 400 wavelengths are filtered out, you are still diminishing the potential of the light coming through the window to cause emissions.

 

[Rockdiamond]

See, if someone never saw something, never experienced it, it's difficult to conceive of it.
I get that.
But that does not mean it doesn't exist.
Bryan- if you're willing to answer- is it your belief that other colors of fluorescence are similarly limited from color change in daylight?

 

[Texas Leaguer]

See, if someone never saw something, never experienced it, it's difficult to conceive of it.
I get that.
But that does not mean it doesn't exist.
Bryan- if you're willing to answer- is it your belief that other colors of fluorescence are similarly limited from color change in daylight?

The discussions about fluorescence on this board have largely been focused on N3 centers with their emissions in the range of 450nm (blue). Other defects causing other colors of fluorescence might be differently excited by a different set of wavelengths.

 

[sledge]

@Rockdiamond, why do you feel the videos are not relevant?

If you hold a stone with fluor 1" from the UV source, will it glow or not? Now back up to 24" -- does it glow as quickly, as strongly or even at all? How about at 60"?

On a lighter note, here is one stone that clearly exhibits a blue hue.

 

[Rockdiamond]

The discussions about fluorescence on this board have largely been focused on N3 centers with their emissions in the range of 450nm (blue). Other defects causing other colors of fluorescence might be differently excited by a different set of wavelengths.

If we could speak English, non-techie, that would likely help a lot of readers to grasp this.
That would include me.
So, to translate- you believe that it's possible for yellow fluorescence ( for example) to be triggered under circumstances where blue fluorescence is not?
I've noticed remarkable effects from yellow fluorescence- just today.

I want to reiterate- I'm not trying to "catch you" or argue.
I have a lot of respect for Bryan. I'd love to sit down with a beer and listen to Scarlet Begonias.
This one issue is a sticking point for me precisely because it's important to many diamond lovers-myself included.

 

[Rockdiamond]

If you hold a stone with fluor 1" from the UV source, will it glow or not? Now back up to 24" -- does it glow as quickly, as strongly or even at all? How about at 60"?

This is a great question. Relevant.
It really depends on the lighting environment.
In a dark room, a strong blue will light up even if the UV lamp is three feet away...working on a video now....

 

[Rockdiamond]

Nonscientific display- but it's cool...warning for those at work- I'm speaking in the video.
The UV torch is a very strong one- which definitely affects how much it activates from a distance. But I do get pretty far from the stones.
They are in a lightbox- with the lights switched off. Dim lighting, not total darkness- but dark enough to see the effects.

 

[Karl_K]

But if VV (400ish) and 365 (as well other wavelengths in between) all contribute to fluroescence stimulation, and the sub 400 wavelengths are filtered out, you are still diminishing the potential of the light coming through the window to cause emissions.

300-365 is a target of the coatings so it is blocked more but 400nm causes a strong response in many stones and is passed right through.
I dont get what is so hard to comprehend about anytime sunlight is present the possibility of activation exists.

 

[sledge]

@Rockdiamond thank you for posting that video. I have not seen too many yellow flour stones.

So a few interesting thoughts:

1. Looking at the screen caps of your video below, it appears the stones do exhibit a slightly lower intensity of glowing from 3' away, as opposed to the starting point of 2'. This is what I would expect to see and is exactly why I posted the inverse square law videos above. No real magic, but the further you get from the UV source the weaker it is so the glow/whitening of flour stones lessen.

2. Rather you consciously or subconsciously did it, when testing UV you wanted to filter as much normal light as possible by creating a dark environment to examine UV and fluor together. This makes perfect sense to me as regular light would interfere with your results and make them harder to clearly comprehend.

For the same reasoning you'd want to eliminate regular lighting in this test, is the same reason I think the industry should try to eliminate UV/VV light from color grading. If it's not there, then there is zero chance of it altering a color grade. I actually think this is good for the industry, as consumers could then know a stone is really a G at it's worst case scenario. Any perks from areas with heavy UV/VV radiation and the stone fluorescences then it's a true perk. This would help remove doubt and possibly build consumer confidence and may even effect market pricing on fluor stones.

 

[Karl_K]

The discussions about fluorescence on this board have largely been focused on N3 centers with their emissions in the range of 450nm (blue). Other defects causing other colors of fluorescence might be differently excited by a different set of wavelengths.

That has me thinking. It should be possible for a diamond to have different color florescence in different wavelengths of UV.
I wonder if anyone has ever documented it happening.

 

[sledge]

That has me thinking. It should be possible for a diamond to have different color florescence in different wavelengths of UV.
I wonder if anyone has ever documented it happening.

I was thinking that earlier as well, but thought maybe I was being too simplistic in my views.

If that were to be true, it continues to echo the need for a testing environment that is free of UV for color grading and one that is specialized for various colors of fluor.

 

[Texas Leaguer]

That has me thinking. It should be possible for a diamond to have different color florescence in different wavelengths of UV.
I wonder if anyone has ever documented it happening.

There can be, and often are, multiple defects in a diamond capable of being excited to different results by different wavelengths. For instance if you have a diamond with both an N3 center emitting blue and an H3 center emitting yellow, it will appear as white fluorescence.

But to my understanding, if a defect center is stimulated by the required energy to activate, it will consistently emit at or near a certain wavelength so color will not vary much. At least at normal temperatures.

 

[Texas Leaguer]

300-365 is a target of the coatings so it is blocked more but 400nm causes a strong response in many stones and is passed right through.
I dont get what is so hard to comprehend about anytime sunlight is present the possibility of activation exists.

It's the probability more than the possibility that is at issue.

The possibility exists anytime wavelengths that are capable of causing emissions are present in sufficient intensity. Sunlight contains all the wavelengths (unless some are filtered), and in general is more intense than artificial light (unless the stone is held very close to the source). But the intensity of any sunlight coming into an indoor environment is still critical. So proximity of the stone to the window, whether the sunlight is direct or reflected, whether it's a cloudy day, the kind of glass on the window, and any coatings, all affect that intensity, and thus the probability that any grade whitening might be perceived.

 

[Garry H (Cut Nut)]

A couple of points regarding the recent discussions:
1. when Shipley wrote that, all artificial lights had the whitening UV. The only new
/ change is what is the effect caused by LEDs. In my experiments I am seeing whitening under LED's too which should not be the case as there should be very little radiation below 430nm. But I do not have a way to measure the violet and near visible violet effectively (my instrument is however better at that then the one MC used).
2. All other artificial light does create whitening.
3. regarding inverse law (which is valid David) - as you move away from any light source your ability to detect slight color differences falls away. It becomes Scotopic vision uses only rods to see, meaning that objects are visible, but appear in black and white, whereas photopic vision uses cones and provides colour. - this is why in moonlight we only see black and white.
4. So as the whitening effect drops away, so too does the ability to sense the color. I have just walked around the building with a clients non fluoro 3ct J and in most places unless I have a D beside it, I could never tell the diffence (although with a D fluoro the difference is clear in more places).
5. windows let all the most effective whitening radiation through - even Museum glass only cuts out about half of the below 400nm.

Finally I have asked Jeffery Post to tell me if the Portuguese 1.27ct Smithsonian famous yellow M colored diamond is is hazy overblue in LED lighting - but he is on vacation. It is clearly and well researched as fluorescing under all other types of artificial light. Check for yourself Bryan.

 

[Garry H (Cut Nut)]

Does anyone know how to contact Chip Clark and ask him how he did the yellow photo? What type of lighting?
And please someone ask Michael Cowing how the HELL GIA gave this diamond an M color grade - when I saw it - it was blueish, not yellow. So much for GIA using too much UV in their grading post 2000. Can I rest my case?

like this colour below

 

[Rockdiamond]

The grading issue, from my perspective, has worked itself out fairly well. In my experience GIA is grading at the lower of the perceived color grades on MB/SB colorless diamonds.
Say a SB stone has a body color of J through the pavilion in a UV limited grading scenario. It’s possible that the diamond may face up like a G near a window.
GIA is grading such a stone J and the market is correcting. If the stone does show improvement the sellers get prices at the higher end of the range for the color.
As Garry points out - and I didn’t mean to refute the fact that you need a lot of light to see the difference between a D and J, especially if we’re facing up we’ll cut RBC diamonds.
Most people would walk closer to the window to get a better idea of color.
I’d advise never color grading at night if your money is on the line.

 

[Garry H (Cut Nut)]

Seasons greetings Bryan (I hope that as I keep closing doors on your arguments that you can start 2020 with 20 20 vision).

 

[Garry H (Cut Nut)]

Bump

 

[Rockdiamond]

Sometimes, when people are really “dug into” a position, you’re not going to change their minds with facts. This is the world today. I’ve tried extremely hard to accommodate Bryan’s position- maybe that would allow a bit of movement- a possible exchange of ideas. But he’s not going to give an inch. Which is perfectly fine.

 

[Karl_K]

Garry.
White leds are not using white emitters as they do not exist.
The are either rgb or phosphor based.
Modern phospher based leds emitters are blue which creates spikes of blue wavelenth light.

http://www.photonstartechnology.com/learn/how_leds_produce_white_light

 

[Texas Leaguer]

@Karl_K ,
Thanks for posting that link. It would be interesting to know if the lighting industry is moving in the direction of the ChromaWhite technology. Better color rendition, but also relatively more expensive.

 

[sledge]

@Karl_K ,
Thanks for posting that link. It would be interesting to know if the lighting industry is moving in the direction of the ChromaWhite technology. Better color rendition, but also relatively more expensive.

What is a ballpark figure of more expensive?

How often would the bulbs need replaced and on how many light boxes?

Given the number of reports done in a year, you'd think $5 more each report would cover the costs, if even that much.

I could see it being more of a pain for the independent jeweler that doesn't make profit from grading reports.