Does your AGS negligible stone have faint fluorescent ?

[Dancing Fire]

Not that it matters, just wondering. I have 4 stones that I still need to check.
IYO, should AGS separate none and faint like GIA?

 

[CareBear]

AGS's use of 'negligible' is what a lot of B&M stores use as a scare tactic for consumer to buy their lesser quality GIA stones. Some shady jewelry tried to get my friend to return his ACA and buy one of his stones because the ACA was AGS 'negligible', which he claims is not as good as GIA 'None'.
Outside of PS, fluo is VERY BAD!!!
It would be nice if my AGS report had detail information about my stone's fluo. Then I wouldn't be shining random lights on my stones trying to assess how much fluo it has myself.

But you brought up this topic earlier and John P had an excellent explanation for AGS's use of 'negligible'.
https://www.pricescope.com/community/threads/some-of-ags-negligible-fluor-stones-gia-faint.239784/

 

[Wewechew]

Two out of four of my AGS "negligible" have had faint fluorescence. I do wish they would split the two and have "none" and "faint".

 

[Paul-Antwerp]

Would you accept that a GIA None still shows some fluorescence?

Live long,

 

[david b]

Even Faint is negligible to a diamond appearance. GIA made a wide research on this and have come with the conclustion that any Fluor degree does not effect the diamond appearance in 95% of the times:
Some quotes from GIA EDU website:
https://4cs.gia.edu/en-us/blog/diamond-fluorescence-good-bad/
"
6. Is diamond fluorescence good or bad?

Fluorescence is neither good nor bad. A diamond’s beauty is in the eye of the beholder. You may perceive fluorescence, or you may not. You may like it, or you may not.

If you are considering a diamond with bluish fluorescence, take the time to look at it under different kinds of lighting, including natural daylight, and compare it to other diamonds of the same color. See if you notice any difference.

Perhaps diamond fluorescence sparks so much conversation because its effect is so subjective. Opinions range across the spectrum. See if you notice it the next time you’re in a jewelry store – and then decide if it appeals to you. You should love what you end up buying. There’s no hard rule, so let your heart lead the way."

 

[yssie]

Would you accept that a GIA None still shows some fluorescence?

Live long,

I own these stones - a vendor sent me this when he was resetting them. All stones have GIA reports.
One of the largest pair of sidestones has "faint" fluor, the other has "none"; both of the middle pair of sidestones have "none".
365nm

 

[sledge]

I personally prefer GIA's method of none or faint vs negligible. I understand AGS changed this due to inaccuracies in grading equipment, etc. so in a sense AGS may be more accurate in their approach as they are trying to give a realistic answer/test report.

None and faint only work as long as the ability to test at those levels is truly accurate.

Assuming accuracy and trust is in-place, if I were to re-buy I'd prefer a stone with none or faint. I have nothing against fluor personally, and in fact bought my fiancee a BGD Blue stone that has MBF. It doesn't bother me in the least; however, if you are looking solely at value in the market place, potential resale/trade, etc. it would be more advantageous to have a stone with none/faint/negligible than with medium. Not because it makes the stone superior, but because of the majority of the market's perception.

At least with my BGD Blue stone, I received a discount for the MBF which equals out the balance IMO. It might annoy me if I were buying a stone I believed to have none, and then later discovered it did indeed have it.

I am curious -- when buying diamond rough, is the fluor levels known at time of purchase? If so, I'm assuming a true "none" piece of rough might trade slightly higher than a "faint/negligible" piece of rough. Consequently, it would allow the buyer of that rough to take advantage of that price difference for their own gain. Not saying our guys here would do that. But the opportunity would exist.

 

[david b]

The problem is that GIA is not mistakes proof, I have seen it from first hand, a diamond that was strong came back as None.

 

[david b]

Diamond's certificates come as the stone ID, not as a collections of Goods and Bads, fluor came as informative point but later was considered by the mass as the more-the bad.
It is controlling now the diamond's price, medium Fluor diamond is cheaper to buy.

 

[ringbling17]

I wish they did. I have two earrings that are AGS certed and one has faint flourescence and the other has none. They are both listed as negligible on the certs.
I picked these two because they had basically the same exact specs otherwise so it does bother me.

 

[oldminer]

GIA frequently disregards the true meaning of the word "none" and uses the term when there is fluorescence than any gemologist can readily see. AGS was doing a service to the trade and consumers by understanding that the word "none" does not mean "some, but only a little". It never made sense to say none when there was visible some UV fluorescence. If you want none, then when you examine GIA graded diamonds shine your own Long Wave UV source on the diamond and see if YOU see any. If you see fluorescence, there is some, never none.

I have stated for a long time that UV fluorescence can be beneficial to the appearance of some diamonds and often does nothing at all to hurt their appearance. Now the GIA has said it, there is a chance that it will be heard and accepted. It takes patience and you have to live a long time to see such changes become commonly agreed upon. When the big leaders of the trade dictate a change, the sheep follow right along. Overall, this change is for the best. It amazes me how long so few gemologists questioned how "none" actually often meant "some" when it came to GIA and fluorescent strength grading. Since it didn't mean a whole lot anyway, no one made a big fuss over it, but it never was correct. AGSL did it right from early on.

 

[Karl_K]

The problem is that GIA is not mistakes proof, I have seen it from first hand, a diamond that was strong came back as None.

And even when it it is not a a mistake and the diamond has none under gia grading lights, it can be very strong under other uv light sources with different wavelengths.

The entire fluorescence grading situation is a mess.

 

[david b]

I fully agree with OLDMINER.
There is nothing significant in fluorescence at all, I see a medium fluorescence diamond as a chance to purchase a perfect diamond at a nice discount!

 

[sledge]

And even when it it is not a a mistake and the diamond has none under gia grading lights, it can be very strong under other uv light sources with different wavelengths.

The entire fluorescence grading situation is a mess.

Admittedly I'm not well versed in various UV lighting but it seems logical that a test procedure could be written specifying exactly what test methods, test equipments, procedures, etc is required to get a repeatable and reliable result.

ASTM immediately comes to mind, although I am not sure I've seen an ASTM test method referenced when talking diamonds. Odd as it applies to most other material types.

Implementing such standards would equalize labs and make data somewhat more reliable, correct?

I fully agree with OLDMINER.
There is nothing significant in fluorescence at all, I see a medium fluorescence diamond as a chance to purchase a perfect diamond at a nice discount!

I agree fluor isn't necessarily a beauty concern. My earlier statements were in relation to market values. Even if you buy a MBF stone at discount, the risk you run is the discount is not large enough to surpass the stigma the general public has concerning fluor.

As @oldminer noted, until consumers become truly educated and/or the big dogs swing their sticks the right direction to force mass market change of opinions it will continue to be a problem.

So until then, values will be skewed and monetary risk will be present. Personally I'd love to see the market swayed so MBF stones demand a premium. If such a time exists, the fiancee will get an upgrade.

 

[Karl_K]

Admittedly I'm not well versed in various UV lighting but it seems logical that a test procedure could be written specifying exactly what test methods, test equipments, procedures, etc is required to get a repeatable and reliable result.

Actually that is where a lot of the mess comes in to grading.
To understand it you have to understand the history, the system was not made to be just, send it to the lab.
The GIA standards are based on trained by GIA people being able to apply what GIA teaches out in the world not in the lab.
That is why 10x.. it was available. Diamond master sets.. they could make them.
UV tubes for fluorescence grading and white light tubes for color grading that were commercially available and fairly consistent were selected.
The market was to small to have special tubes made so they took what was available and called it the standard.
They did not have the more wavelenth specific leds that are available today.
Even the horrible 5% rounding of the lowers was excused by saying that in the field with a loupe graders could not get more accurate than that.

AGSL on the other hand based their cut grading system on having a scanner and software which is a fairly expensive investment.
That is not the way GIA wants it because a big part of what they are is a school and teaching to grade with fairly common equipment.
That the market has moved to trading on reports from the labs is not what they were based on.

 

[Garry H (Cut Nut)]

I own these stones - a vendor sent me this when he was resetting them. All stones have GIA reports.
One of the largest pair of sidestones has "faint" fluor, the other has "none"; both of the middle pair of sidestones have "none".
365nm

Yssie are you sure that was done in 365nm old fashioned UV?
My bet it was done with a much longer wave around 380-400nm where there is way more effect.

BTW HRD have just reported that J can look like D in 'normal' light. So really, who would want a non fluoro diamond????

 

[yssie]

Yssie are you sure that was done in 365nm old fashioned UV?
My bet it was done with a much longer wave around 380-400nm where there is way more effect.

BTW HRD have just reported that J can look like D in 'normal' light. So really, who would want a non fluoro diamond????

I was told 365. Don’t know if that’s accurate (ie. don’t have confirmation that whatever device used had new/properly calibrated bulbs), but given that this was from a well-respected vendor - I assume so.

 

[Garry H (Cut Nut)]

I was told 365. Don’t know if that’s accurate (ie. don’t have confirmation that whatever device used had new/properly calibrated bulbs), but given that this was from a well-respected vendor - I assume so.

It is the wild west Yssie.

From https://www.gia.edu/gems-gemology/summer-2013-luo-fluorescence-optical-defects
"UV Light Sources.GIA UV Lamp. Gemologists use conventional UV lamps (figure 2A) to observe a stone’s fluorescence color in response to long- or short- wave radiation. The lamps in this study were sold by GIA Instruments until 2009 and are still prevalent in the trade. It is well known that traditional UV lamps do not provide single characteristic 365 nm (LWUV) and 254 nm (SWUV) emission lines (Williams, 2007; Pearson, 2011) due to the variety of materials used in UV filters and the aging of lamps and filters. Rather than a single 365 nm emission peak, LWUV lamps often emit 404 and 435 nm lines and a broad band that extends from the UV to the visible region of the spectrum. Similarly, SWUV lamps always have distinct peaks at 254, 315, and 365 nm instead of a single 254 nm emission. All of these emission lines, as well as several weaker ones, are produced by the mercury lamp inside the units. The filter materials used to remove mercury radiation are not 100% efficient and leak undesired emissions. As the filters age, the leaked emissions become stronger and more prominent.

Examination of two handheld UV lamps manufactured by GIA and used at its laboratory revealed a major peak at 368 nm (FWHM = 17 nm) with LWUV excitation, accompanied by a small peak at 404 nm (figure 4A). In addition to the 252 nm (FWHM = 3 nm) SWUV emission, which shifted 2 nm from typical 254 nm SWUV, there were major peaks at 312, 365, 404, and 435 nm, as well as minor peaks at 296, 302, and 334 nm. Interestingly, the peak intensity at 365 nm (the typical LWUV emission) was more intense than the 252 nm SWUV peak (figure 4B), likely due to filter aging. The existence of this intense 365 nm peak in the excitation may have a pronounced effect on what is observed as SWUV fluorescence. Because most gemologists use UV lamps for many years and never replace the filters, these tests are representative of industry practices."

And it is now well known that near visible UV (that is not blocked by windows - but is by the material "Lexan" that others have proposed, like Michael Cowing, AGS et al) has much more impact on whitening or colour improvement than the historical hysterical 365nm that never really was of any interest when used with diamonds. It is a coloured gem ID tool.

 

[Paul-Antwerp]

It indeed is the Wild West, and I am happy to see so many professionals confirming the same.

The reason I asked is related to consumer-perception. I now know the case of a reputable retailer having sold a GIA-None. The consumer however now rejects it because there is 'some' fluorescence, and will not accept the retailer's education on this.

The retailer has asked me to help him out in sourcing a replacement-stone with absolutely no fluorescence. Cost is not even a limiting factor. But stone after stone, I am stuck, always seeing 'some' fluorescence, never absolutely sure that it is actually none.

In that sense, and in this very particular case, GIA is doing a disservice to the entire diamond-industry by using the word 'None' for something that generally is 'Some'.

Probably comparable to using the terms 'Very Good' or 'Good', while they have a totally different meaning than anything good.

Live long,

 

[Karl_K]

The retailer has asked me to help him out in sourcing a replacement-stone with absolutely no fluorescence. Cost is not even a limiting factor. But stone after stone, I am stuck, always seeing 'some' fluorescence, never absolutely sure that it is actually none.

Has this always been the common case or does today's rough tend more towards having fluorescence than say 15-20 or longer years ago?

 

[TreeScientist]

It indeed is the Wild West, and I am happy to see so many professionals confirming the same.

The reason I asked is related to consumer-perception. I now know the case of a reputable retailer having sold a GIA-None. The consumer however now rejects it because there is 'some' fluorescence, and will not accept the retailer's education on this.

The retailer has asked me to help him out in sourcing a replacement-stone with absolutely no fluorescence. Cost is not even a limiting factor. But stone after stone, I am stuck, always seeing 'some' fluorescence, never absolutely sure that it is actually none.

In that sense, and in this very particular case, GIA is doing a disservice to the entire diamond-industry by using the word 'None' for something that generally is 'Some'.

Probably comparable to using the terms 'Very Good' or 'Good', while they have a totally different meaning than anything good.

Live long,

Couldn't you source a Type IIa diamond for the retailer if cost is not an issue? Since fluorescence is typically caused by nitrogen impurities, the same impurities that cause yellow color (albeit in a slightly different distribution), then I imagine that the only diamond that would be truly free from fluor on both eye-visible and measurable scales would be a Type IIa diamond, as they don't possess any measurable impurities.

 

[Texas Leaguer]

I am curious -- when buying diamond rough, is the fluor levels known at time of purchase? If so, I'm assuming a true "none" piece of rough might trade slightly higher than a "faint/negligible" piece of rough. Consequently, it would allow the buyer of that rough to take advantage of that price difference for their own gain. Not saying our guys here would do that. But the opportunity would exist.

Yes, fluoro levels are generally known when buying rough. However, in some cases fluoro tends to be localized. You could therefore have a rough that would produce mulitple diamonds of different levels of fluoro from none to very strong. Fluoro can also be directional, and this is why AGS grades from the face up direction.

I will agree with @david b and others who say that fluoro is primarily an identification factor, not a quality factor. And i agree with @Karl_K and @sledge that the plethora of different UV sources in use today creates much of the confusion on the consumer level. I also see many people, even professionals, mistaking reflections from the black light tube as fluorescence.

To @TreeScientist I would say that to understand how difficult it would be to have a universal standard one only has to understand that a UV tube will output different wavelengths in different intensities as it ages!

 

[Texas Leaguer]

Couldn't you source a Type IIa diamond for the retailer if cost is not an issue? Since fluorescence is typically caused by nitrogen impurities, the same impurities that cause yellow color (albeit in a slightly different distribution), then I imagine that the only diamond that would be truly free from fluor on both eye-visible and measurable scales would be a Type IIa diamond, as they don't possess any measurable impurities.

Type IIa is rare. It would therefore be MUCH harder to fill the order for a particular size,color,clarity combination, even if you were in control of cut quality and even if price was not a priority issue.

 

[TreeScientist]

Type IIa is rare. It would therefore be MUCH harder to fill the order for a particular size,color,clarity combination, even if you were in control of cut quality and even if price was not a priority issue.

I'm aware that the rough is rare, but it's not impossible to source. For a discerning customer like this, it may be worthwhile.

And Type IIa only come in one color, no? (well, I suppose they could be brown or pink as well due to graining).

 

[Texas Leaguer]

I'm aware that the rough is rare, but it's not impossible to source. For a discerning customer like this, it may be worthwhile.

And Type IIa only come in one color, no? (well, I suppose they could be brown or pink as well due to graining).

It is not impossible to source. But again, the customer has other parameters that also need to be met, compounding the feasibility.
I am not sure that all IIA are all by definition D color. IIa are characterized by a relative lack of Nitrogen but that does not necessarily mean 'none'. More like 'negligible'

And yes, you could get coloring influence from other defects besides nitrogen.

 

[Garry H (Cut Nut)]

Gentle folk with testing equipment - try various stones with traditional mercury tubes and cheap visibly violet cheap UV LEDs.
Many more stones will show up stronger.
If there is a problem here I suspect it will become more common now that so many people have these tools which create way more fluorescence in diamonds.

 

[Karl_K]

I was told 365. Don’t know if that’s accurate (ie. don’t have confirmation that whatever device used had new/properly calibrated bulbs), but given that this was from a well-respected vendor - I assume so.

99.9% of what is advertised as 365 isn't.
In bulk real tightly binned 365nm led is $18-$50 depending on power level and how tight they are binned.
The 380-400 start at $.20 or less in bulk

 

[Dancing Fire]

Gentle folk with testing equipment - try various stones with traditional mercury tubes and cheap visibly violet cheap UV LEDs.
Many more stones will show up stronger.
If there is a problem here I suspect it will become more common now that so many people have these tools which create way more fluorescence in diamonds.

My cheap LED UV flashlight pointing at a GIA none and a AGS MB stone.