Fancy light blue diamond with GIA report of origin listed as "undetermined"

[dvj]

Hello all! First thread I have posted, but I enjoy looking at your pieces all very much!

I am wondering if I could get some opinions from experts on fancy colored diamonds. I found this beautiful fancy light blue diamond with greenish tint on James Allen. Everything looks great, the diamond is natural, the price is surprising low compared to the other blues, but then when I asked for the GIA report --oh no-- I see that the origin is undetermined!

Is it most likely treated in some way? Most likely not treated? If GIA can't say now, when might they be able to? Would this be worth purchasing (making the unlikely possibility of owning a fancy blue diamond a reality) or would I just be setting myself up for disappointment? Maybe no one can really say, and that should be answer enough. Perhaps it is too good to be true.

Link to the diamond: https://www.jamesallen.com/loose-di...ar-shaped/0.43-carat-si1-clarity-sku-14040922

Link to the GIA Report: https://www.gia.edu/report-check?reportno=2376143414

Do you think it is because of the green modifier (which could be irritated) that GIA can't say?

 

[kenny]

In the future GIA may acquire technology/equipment or processes to determine whether the origin of the color is natural or the result of manipulation in a lab.

Should you buy it?
I'm not a gambler so I wouldn't.
If you like to gamble in this way go ahead and buy it.

In the future if GIA determines the color is from lab treatment it will definitely be worth less than you paid.
If GIA determines color is of natural origin then it MAY be worth more than you paid, but maybe not.
It depends how much JA is charging.

It is hard enough to determine a fair price for FCDs that GIA has graded to be fully natural.
With undetermined color origin it's even more difficult/impossible to guess a "proper" "fair" price.

I'd call GIA's FCD grading department in NY or Carlsbad, CA with your technical questions on their grading now and the future.

Good luck.
You'll need it.

 

[Rockdiamond]

Hi @dvj !

Most likely it's the green component causing this "Undetermined" grade. The reason is that the green in diamonds is caused by Radiation.
It's not (currently) possible to ascertain if the radiation was man-made, or natural, hence that damaging "Undetermined" statement.
For the past 10 years or so, since this has become an issue, cutters will submit the diamond to GIA in the rough, at which point, the cause of the radiation can be determined- and in many cases, a small portion of the diamond is left unpolished./

We've seen some really lovely green stones which were tarred by this comment- and they are basically......really tough to sell......
If you like the stone and the price is attractive to you, and you never intend to sell it....
I'd probably value such a stone similarly to a treated, or Lab Grown Diamond

 

[Demon]

Hi @dvj !

Most likely it's the green component causing this "Undetermined" grade. The reason is that the green in diamonds is caused by Radiation.
It's not (currently) possible to ascertain if the radiation was man-made, or natural, hence that damaging "Undetermined" statement.
For the past 10 years or so, since this has become an issue, cutters will submit the diamond to GIA in the rough, at which point, the cause of the radiation can be determined- and in many cases, a small portion of the diamond is left unpolished./

We've seen some really lovely green stones which were tarred by this comment- and they are basically......really tough to sell......
If you like the stone and the price is attractive to you, and you never intend to sell it....
I'd probably value such a stone similarly to a treated, or Lab Grown Diamond

I just read that 90% of (natural) blue diamonds have no observable fluorescence. Would you say that's true or not from your experience?

Fluorescence and Color Diamonds

Often times, fluorescence is misunderstood as a negative attribute that compromises the quality of a diamond, but in most of the cases, that is far from the truth. Here are some questions and answers to clarify some murky issues concerning misconceived characteristics of fluorescence. What is...

www.langerman-diamonds.com

 

[Rockdiamond]

At least 75% of percentages used in cases like this are pulled out the authors butt

Seriously …. I’ve not done a study on it. Plus there’s so many variables. What about blue stones with modifiers ?
So, I don’t doubt it- but nor do I endorse the statement.

 

[Demon]

At least 75% of percentages used in cases like this are pulled out the authors butt

Seriously …. I’ve not done a study on it. Plus there’s so many variables. What about blue stones with modifiers ?
So, I don’t doubt it- but nor do I endorse the statement.

Lol, thanks. That's why I asked.

 

[oncrutchesrightnow]

If you go to their selection of green diamonds, you will notice a lot of the blue-ish green ones have asterixes next to the color description. So if you only want a blue diamond if is natural and untreated, maybe pass. If you just want a pretty blue green diamond and don’t care if the color is natural, then before you buy it, assess whether it is fairly priced compared to diamonds known to be color treated.

 

[dvj]

In the future GIA may acquire technology/equipment or processes to determine whether the origin of the color is natural or the result of manipulation in a lab.

Should you buy it?
I'm not a gambler so I wouldn't.
If you like to gamble in this way go ahead and buy it.

In the future if GIA determines the color is from lab treatment it will definitely be worth less than you paid.
If GIA determines color is of natural origin then it MAY be worth more than you paid, but maybe not.
It depends how much JA is charging.

It is hard enough to determine a fair price for FCDs that GIA has graded to be fully natural.
With undetermined color origin it's even more difficult/impossible to guess a "proper" "fair" price.

I'd call GIA's FCD grading department in NY or Carlsbad, CA with your technical questions on their grading now and the future.

Good luck.
You'll need it.

Thank you so much for responding to me, Kenny. I took your advice and contacted the GIA in Carlsbad over the phone. I spoke with someone about the report, but she was not an expert in Fancy Coloured Diamonds. She took my information, and my questions, and promised that someone from FCD would get back to me. They did! What they could say was that most likely if the diamond was graded again today it would come up as UD. So a gamble, as you suggested.

 

[dvj]

Hi @dvj !

Most likely it's the green component causing this "Undetermined" grade. The reason is that the green in diamonds is caused by Radiation.
It's not (currently) possible to ascertain if the radiation was man-made, or natural, hence that damaging "Undetermined" statement.
For the past 10 years or so, since this has become an issue, cutters will submit the diamond to GIA in the rough, at which point, the cause of the radiation can be determined- and in many cases, a small portion of the diamond is left unpolished./

We've seen some really lovely green stones which were tarred by this comment- and they are basically......really tough to sell......
If you like the stone and the price is attractive to you, and you never intend to sell it....
I'd probably value such a stone similarly to a treated, or Lab Grown Diamond

Hi David! I really appreciate your response. I like the stone, but if compared to a land-grown blue diamond I have seen prettier ones for much less. This one was very well priced if it could be proved to be all natural. If treated or lab-grown it was a terrible deal. I was so excited to think I might be able to afford a natural blue diamond, and maybe the gamble could have been worth it (I thought about never checking if it was natural or not and living life in a hopeful mystery) but I am too curious of a person. It wouldn't have worked.

 

[Rockdiamond]

Hi David! I really appreciate your response.

You're very welcome!!
I remember a green stone we had a few years back- also GIA Undetermined.....
If it had been natural, it would have been worth about $200k.
IIRC, the guy was asking $15k for it........

 

[dvj]

I just read that 90% of (natural) blue diamonds have no observable fluorescence. Would you say that's true or not from your experience?

Fluorescence and Color Diamonds

Often times, fluorescence is misunderstood as a negative attribute that compromises the quality of a diamond, but in most of the cases, that is far from the truth. Here are some questions and answers to clarify some murky issues concerning misconceived characteristics of fluorescence. What is...

www.langerman-diamonds.com

Hi Demon! Thanks for your comment and for linking the article. It got me searching more, and it seems that most pure blue diamonds without modifiers do not have fluorescence. I did a simple albeit biased study by looking at fancy blue diamonds on Leibish. Most did not have fluorescence or only faint. But the ones that did, had green or greenish as an overtone. This was sometimes strong, and it was always blue. The sample size really is too small to say that the fluorescence from green will always be blue, but it seem not to be uncommon. I then went on to check out fluorescence of fancy green diamonds with blue or bluish overtone on Leibish (they have 15 diamonds currently with specs) and 3 of the 15 had medium blue fluorescence. Again, the sample size is too small to measure any kind of statistical significance, but I couldn't find a chart that shows a break down of different fluorescence frequencies for different overtones in fancy colored diamonds or even fancy coloured diamonds.

As an aside this led me down a path of checking out programs on the GIA website and imagining going back to school! I think this stuff is so cool! But, I love my job and don't see this happening anytime soon. I will read some books instead first and keep dreaming.

Anyway, thanks again for commenting. I love the electric color of the diamond in your avatar.

 

[dvj]

You're very welcome!!
I remember a green stone we had a few years back- also GIA Undetermined.....
If it had been natural, it would have been worth about $200k.
IIRC, the guy was asking $15k for it........

If you could afford to gamble every day then it might be worth it... but most of us can't. I really wonder if they would ever publish results on how many diamonds that were originally marked "undetermined" for origin were later found to have an origin. How long that took, and how many of the "undetermined" went to treated vs natural. I guess there must be so many different ways to treat diamonds--reminds me of crime cartels that create counterfeit money--that knowing the percentage that came back later as "natural" might not help in making a decision. Unless of course, the answer was ZERO and they were all treated.

 

[dvj]

If you go to their selection of green diamonds, you will notice a lot of the blue-ish green ones have asterixes next to the color description. So if you only want a blue diamond if is natural and untreated, maybe pass. If you just want a pretty blue green diamond and don’t care if the color is natural, then before you buy it, assess whether it is fairly priced compared to diamonds known to be color treated.

Thanks oncrutchesrightnow! I checked it out and the price of this diamond compared to a lab or a treated diamond was way high. So I passed. Maybe sometime in the future I will have the chance to own a nancy fancy colored diamond that hasn't been treated.

 

[Rockdiamond]

I really wonder if they would ever publish results on how many diamonds that were originally marked "undetermined" for origin were later found to have an origin.

Based on my experience....some cutters re-submit repeatedly to challenge an undetermined comment. Sometimes shipping the stone across the globe to submit to a different GIA branch....
I don't recall a case of GIA reversing an "UNdetermined"...of course, it may have happened regardless...

Regarding Natural Blue Diamonds and fluorescence:
Based on a much larger sample size.
Of 80 diamonds graded Fancy Light Blue, Fancy Blue, and Fancy Intense Blue by GIA, only one stone -a Fancy Light Blue- had Stong Blue. Three of the stones had "Faint" fluorescence. So I guess I have to eat my words

Blue stones with modifiers, different story.
Strong Blue is common in Green, or Greenish blue diamonds, for example.
Gray-Blue Diamonds also exhibit fluorescence more commonly.
of the stones graded "Fancy Blue" had any fluorescence.

 

[Demon]

Hi Demon! Thanks for your comment and for linking the article. It got me searching more, and it seems that most pure blue diamonds without modifiers do not have fluorescence. I did a simple albeit biased study by looking at fancy blue diamonds on Leibish. Most did not have fluorescence or only faint. But the ones that did, had green or greenish as an overtone. This was sometimes strong, and it was always blue. The sample size really is too small to say that the fluorescence from green will always be blue, but it seem not to be uncommon. I then went on to check out fluorescence of fancy green diamonds with blue or bluish overtone on Leibish (they have 15 diamonds currently with specs) and 3 of the 15 had medium blue fluorescence. Again, the sample size is too small to measure any kind of statistical significance, but I couldn't find a chart that shows a break down of different fluorescence frequencies for different overtones in fancy colored diamonds or even fancy coloured diamonds.

As an aside this led me down a path of checking out programs on the GIA website and imagining going back to school! I think this stuff is so cool! But, I love my job and don't see this happening anytime soon. I will read some books instead first and keep dreaming.

Anyway, thanks again for commenting. I love the electric color of the diamond in your avatar.

I thought I remembered the Hope diamond fluoresces red, so I looked it up. The article say this: "Most blue diamonds produce a bluish-white phosphorescence if exposed to ultraviolet light."

So now I'm more confused than I was before because I would think in order to show phosphorescence they would have fluorescence also? But its all very interesting.

Bombarded with ultraviolet light, the blue Hope Diamond glows red

Smithsonian geologist investigates the mysterious red phosphorescent glow the stone emits when exposed to ultraviolet light.

www.si.edu

 

[Demon]

of the stones graded "Fancy Blue" had any fluorescence.

Would that be None of the stones graded "fancy blue"?

 

[Garry H (Cut Nut)]

Based on my experience....some cutters re-submit repeatedly to challenge an undetermined comment. Sometimes shipping the stone across the globe to submit to a different GIA branch....
I don't recall a case of GIA reversing an "UNdetermined"...of course, it may have happened regardless...

Regarding Natural Blue Diamonds and fluorescence:
Based on a much larger sample size.
Of 80 diamonds graded Fancy Light Blue, Fancy Blue, and Fancy Intense Blue by GIA, only one stone -a Fancy Light Blue- had Stong Blue. Three of the stones had "Faint" fluorescence. So I guess I have to eat my words

Blue stones with modifiers, different story.
Strong Blue is common in Green, or Greenish blue diamonds, for example.
Gray-Blue Diamonds also exhibit fluorescence more commonly.
of the stones graded "Fancy Blue" had any fluorescence.

GIA have the most sophisticated methods to ID diamonds they have seen before. So resubmitting is money for jam for GIA.

 

[dvj]

Based on my experience....some cutters re-submit repeatedly to challenge an undetermined comment. Sometimes shipping the stone across the globe to submit to a different GIA branch....
I don't recall a case of GIA reversing an "UNdetermined"...of course, it may have happened regardless...

Regarding Natural Blue Diamonds and fluorescence:
Based on a much larger sample size.
Of 80 diamonds graded Fancy Light Blue, Fancy Blue, and Fancy Intense Blue by GIA, only one stone -a Fancy Light Blue- had Stong Blue. Three of the stones had "Faint" fluorescence. So I guess I have to eat my words

Blue stones with modifiers, different story.
Strong Blue is common in Green, or Greenish blue diamonds, for example.
Gray-Blue Diamonds also exhibit fluorescence more commonly.
of the stones graded "Fancy Blue" had any fluorescence.

I misspoke David. NONE of the pure fancy blue diamonds (so without any overtones) I checker had fluorescence. A few fancy blue diamonds with green or greenish overtone had blue fluorescence. So you shouldn’t eat your words!

 

[dvj]

I thought I remembered the Hope diamond fluoresces red, so I looked it up. The article say this: "Most blue diamonds produce a bluish-white phosphorescence if exposed to ultraviolet light."

So now I'm more confused than I was before because I would think in order to show phosphorescence they would have fluorescence also? But its all very interesting.

Bombarded with ultraviolet light, the blue Hope Diamond glows red

Smithsonian geologist investigates the mysterious red phosphorescent glow the stone emits when exposed to ultraviolet light.

www.si.edu

I am interested too. Thanks for posting the article. What is the relationship between fluorescence and phosphorescence in general, and that FCD in particular?

 

[Demon]

I am interested too. Thanks for posting the article. What is the relationship between fluorescence and phosphorescence in general, and that FCD in particular?

I have no clue on that, and hope someone does. In my very limited experience, every diamond I have that shows phosphorescence has fluorescence, so I suspect there's a connection. But its not like I have hundreds, lol.

 

[Demon]

I am interested too. Thanks for posting the article. What is the relationship between fluorescence and phosphorescence in general, and that FCD in particular?

This article is wayyyyy more in depth than I was looking for, but it did have this:

"Fluorescence is the emission of electromagnetic radiation light by a substance that has absorbed radiation of a different wavelength. Phosphorescence is a specific type of photoluminescence related to fluorescence."

4.5: Photoluminescence, Phosphorescence, and Fluorescence Spectroscopy

Photoluminescence spectroscopy is a contactless, nondestructive method of probing the electronic structure of materials. Light is directed onto a sample, where it is absorbed and imparts excess …

chem.libretexts.org

 

[Garry H (Cut Nut)]

I believe all Argyle blues fluoresce

 

[rockysalamander]

I can't speak to definitions used in diamonds, but in biology, fluorescence occurs immediately after excitation of the substance and is short-lived. Phosphoresce is a long-lived light after the excitation of the substance has ended.

So, all phosphoresce has fluoresce, while the opposite is not true. {had to discuss this in my defense ages ago!}

 

[dvj]

I can't speak to definitions used in diamonds, but in biology, fluorescence occurs immediately after excitation of the substance and is short-lived. Phosphoresce is a long-lived light after the excitation of the substance has ended.

So, all phosphoresce has fluoresce, while the opposite is not true. {had to discuss this in my defense ages ago!}

Thank you for the explanation.

 

[Demon]

So, all phosphoresce has fluoresce, while the opposite is not true. {had to discuss this in my defense ages ago!}

Thanks. That's the only thing that makes sense to me with diamonds, as well.

 

[Texas Leaguer]

Here's an article you fancy color nerds will enjoy

Hope Diamond's Fiery Red Phosphorescence Key To Fingerprinting

Shine a white light on the Hope Diamond and it will dazzle you with the brilliance of an amazing blue diamond. Shine an ultraviolet light on the Hope Diamond and the gem will glow red-orange for about five minutes. This phosphorescent property of blue diamonds can distinguish synthetic and...

www.sciencedaily.com

 

[Demon]

Here's an article you fancy color nerds will enjoy

Hope Diamond's Fiery Red Phosphorescence Key To Fingerprinting

Shine a white light on the Hope Diamond and it will dazzle you with the brilliance of an amazing blue diamond. Shine an ultraviolet light on the Hope Diamond and the gem will glow red-orange for about five minutes. This phosphorescent property of blue diamonds can distinguish synthetic and...

www.sciencedaily.com

I have to argue with this part though: "Other colors of diamonds do not phosphoresce, but fluoresce, emitting visible light only as long as they are stimulated with ultraviolet radiation."

I have a fancy green yellow with strong blue fluorescence, and it phosphoresces for several minutes.

And of course chameleons phosphoresce.

 

[Karl_K]

You're very welcome!!
I remember a green stone we had a few years back- also GIA Undetermined.....
If it had been natural, it would have been worth about $200k.
IIRC, the guy was asking $15k for it........

I remember that stone it was up less than 30 minutes before someone bought it.
We were discussing it when you said I will call you back and when you called me back said you had explained everything about it to the buyer and it was sold.

 

[Demon]

I believe all Argyle blues fluoresce

I noticed in another thread you said Argyle pinks fluoresce blue....what color do Argyle blues fluoresce?

 

[Garry H (Cut Nut)]

I noticed in another thread you said Argyle pinks fluoresce blue....what color do Argyle blues fluoresce?

From John Chapman (Argyle's Ex Scientist)
Yes Argyle and Boron blues do fluoresce differently. Argyle’s yellowy-blue and boron weak red and also red phosphorescence. CVD blue fluoresce strong blue. Well I think they do, certainly the HPHT ones do.
I checked several listed on PS and most were CVD IIa so not blue as grown - post treated and they had none.