natural black diamonds?

[Buena Girl]

I have read that diamonds can be irradiated to become a black color (or actually a very, very dark green). What about the natural black diamonds? How does this occur in nature? Is this due to large inclusions in the diamond? On a hypothetical chart, would a black diamond be shown kind of in between something that would be considered coal and something that would be considered a less flawed diamond? What about fancy dark gray diamonds?

thanks

 

[DiamondExpert]

Yes, black diamonds to occur naturally, and those with deep, uniform black color without secondary colors, AND have no cracks reaching the surface are collectors'' items and quite rare.

The color results from graphite-like inclusions and light absorption.

Then there are less desirable black diamonds, which have almost a "sintered" appearance with many surface reaching inclusions, and don''t have that great adamantaine luster...almost like polished bort, or carbonado, which is polycrystalline.

 

[diamondsbylauren]

Interesting-
From what I know, the black diamonds on the market are irradiated.
I''ve seen a few such stones- they are not very......pretty (?)

.
Gary- have you seen a diamond with a color grade of " Natural Black" ( or something like it) from GIA?

 

[DiamondExpert]

Hi David: No, never have. I''m sure they are quite rare. The best looking pic I have seen is in Hofer''s book.

Except for a quite large one which used to be on CherryPicked, the others you see sprinkled around the internet look like bort to me, and not very interesting.

Do you have any in your private collection David?

 

[Garry H (Cut Nut)]

I played around with them a couple of years ago. I even have 1 about 2ct in a project for me as the body of a spider pin.
They are more of a graphite lead pencil grey black.
But - they are rather fragile, and we had some workshop breakages.
In the future i would not use them in other than earings and none easily damaged settings.
They do tend to have many surface cracks. (Rocdoc i think they have considerable stress

)

 

[diamondsbylauren]

Gary- Does the Hoefer specifically state it's a natural color?

Cool Garry- I'd be quite interested to see a GIA report on one of those!

 

[diamondsbylauren]

Gary- not only don't I NOT have one- I've heard there's no natural ones on the market.
Of course this is no hard fact- jsut something I've heard- I'd be really interested in seeing a GIA report with a color of Natural Black.

As has been said here by Garry- The black ones I've seen were quite easy to damage to to crevaces and heavy graing which does not allow a totally smooth polish.

 

[Buena Girl]

thanks for the info!

Does anyone know what causes this? More compression when they are being formed??

 

[Garry H (Cut Nut)]

the cost of the stones probably precludes them from certification

 

[diamondsbylauren]

Buena Girl- the ones I''ve seen had so much imperfection ( Off thre clarity scale- like P3 or something) that the stone was opaque to start out with before the nuke-ing.

Come to think of it-
I''ve seen black melee- it''s used in rings - the "black and white" look.
I understand ALL these stones are irradited- the fact that they are inexpensive reinforces the theory they are irradiated.

 

[mkb]

I am having one in production allready for 10 years, it is pre-bruted, managed to block some facets managed a little of the table, but will never get the facets smoothed. Next time I have the guts to touch it I''ll laser the table, and laser block. It currently still weighs 9 carats, and has some coated left in the girdle. The hardest ston I ever had on a scaife.

br
luc

 

[Madam Bijoux]

Hello! I once saw a famous natural black diamond named The Black Orlov in an exhibit. It was interesting to look at, but not something I would want for myself. Here is a link to some information about black diamonds: http://www.jewelinfo4u.com/Black_Diamond_Jewelry.aspx

 

[diamondsbylauren]

The linked to site was interesting- but still, there''s no definitive answer as to the fqact that black diamonds are irradiated.
If GIA has graded a diamond "Fancy Black" or someting like it, then that will be concrete proof of the existance of such a stone.

I certainly would NOT trust anyone about this because of the doubt in my mind- having never seen such a GIA report- again- HAS ANYONE SEEN A GIA REPORT OF FANCY BLACK????

 

[Garry H (Cut Nut)]

David it is very easy to tell the difference between natrual and irradiated.

 

[diamondsbylauren]

Garry........I.........AGREE

Any of the "normal" irradiated diamonds I''ve seen looked nothing like a natrural fancy colored diamond.
BUT, I''ve seen many natural green, yellow blue etc diamonds, all with GIA reports.


As I''ve said- I''ve never seen a GIA report calling a diamond Black ( Fancy Color)

All the black diamonds I''ve seen were inexpensive- like, 1/10 the price of even an inexpensive fancy color- all were purported by the sellers to be irradiated.

Add to this the fact that someone , somewhere ( you know , one of those things you heard, but can''t really remember where) metioned all pure black diamonds were irradiated.
I''m not saying natural blacks don''t exist- but rather that if they are valuable, why haven''t we seen a GIA report on one?

I called one of our cutters and they have a 20 carat black diamond, and they say it''s natural- and that you can tell by looking at it.
I asked my first question- but, NO GIA.
I will have it here tomorrow and report back......

 

[valeria101]

Not GIA, but Gubelin yes.

And they also revised this dude

 

[diamondsbylauren]

Interesting Ana- but in reality, this does nothng at all to confirm or deny the question.
The Gubelin Report is NOT published, and ,well, who is Gublin?

From the article

It is the largest natural black diamond which the GGL laboratory has ever tested.

The term " Natural Black Diamond" does not preclude irradiation.
A Natural Fancy Color Diamond- as described by GIA, may NOT be irradiated.


Again- I''m NOT saying there are no natural Fancy Black Diamonds- but I am saying that until we see a GIA report indicating such, I am dubious.

 

[RockDoc]

Here''s link for the Black Orlov

http://famousdiamonds.tripod.com/blackorlovdiamond.html

Interesting to see the sale prices for it....

Rockdoc

 

[diamondsbylauren]

Very cool RockDoc- based on the age and pedigree, it sure sounds like a natural color- but we still we have no GIA report to validate anything.
With a stone that large and important, wouldn''t that be essential?

 

[RockDoc]

Date: 7/27/2005 8:24:36 PM
Author: diamondsbylauren
Very cool RockDoc- based on the age and pedigree, it sure sounds like a natural color- but we still we have no GIA report to validate anything.
With a stone that large and important, wouldn''t that be essential?

Hey David

I''d almost bet ( I did say almost) that in the auction listing for the last sale, a gemological grading report, as well as a possible authentication document was provided with the sale.

Probably if we dig far enough on the research of this stone on the net, we''d possibly find there was mention of a lab report. But I sort of doubt there is an actual image of it. Pretty much everyone knows the Taylor Burton had a GIA report, but I doubt any one saw a copy of it on the net.


I only posted the link, because the one that Bijoux posted didn''t have any photos, and thought plenty of gem junkies ( like me - would want to see it).

I saw another black diamond ring, that a customer had. It was pretty much the "gemmy" type. But I really wouldn''t call them rare, probably uncommon is a better choice of words.

Rockdoc

 

[RockDoc]

Treatment for Black Diamonds

There is another treatment that works.

In the 80''s I was working with a company who made rocket nose cones. They had a very highly sophisticated "oven", where atmospheres could be introduced and very intricately controlled. Most of their interest was in treating rubies and saphs.

But they also were interested in treated diamonds, sort of a pre-research project for changing color of them without irradiation.

So we did have a piece of diamond rough, that for the fun of it we electocuted with some enormous amount of voltage.
It turned black. ( Previously it was an ugly brownish color. )

I still have the stone.. really neat looking. I even named it. It''s one of Rockdoc''s Pet Rocks.


Rockdoc

 

[valeria101]

Date: 7/27/2005 8:14:11 PM
Author: diamondsbylauren
Interesting Ana- but in reality, this does nothng at all to confirm or deny the question.
The Gubelin Report is NOT published, and ,well, who is Gublin?

'Goblin?'

No, this does nothing to answer the Q if any black diamonds come with GIA certs of non-treated status. Just trying to approximate by finding evidence that some get certified by other mainstream labs. I'll try to produce a copy of such report, if of interest.

 

[diamondsbylauren]

Date: 7/27/2005 8:48:42 PM
Author: valeria101

Date: 7/27/2005 8:14:11 PM
Author: diamondsbylauren
Interesting Ana- but in reality, this does nothng at all to confirm or deny the question.
The Gubelin Report is NOT published, and ,well, who is Gublin?

''Goblin?''

No, this does nothing to answer the Q if any black diamonds come with GIA certs of non-treated status. Just trying to approximate by finding evidence that some get certified by other mainstream labs. I''ll try to produce a copy of such report, if of interest.

Yes- I''d love to see it!

 

[denverappraiser]

Date: 7/27/2005 8:14:11 PM
Author: diamondsbylauren

The Gubelin Report is NOT published, and ,well, who is Gublin?

Gueblin lab is a Swiss based company with a superb track record of grading major stones. They don’t have the broad commercial distribution that is enjoyed by some of the others (like GIA, AGS and HRD) but they are every bit as respectable. They concentrate on major stones and are primarily involved with gemstones other than diamonds.

If the stone is indeed accompanied by a GGL report that indicates natural color origin, this would be sufficient evidence to convince me that this is the case.
I would love to be half as skilled as Dr. Gueblin when I grow up.

Dr. Gueblin passed away earlier this year and it was a great loss to the gemological community. The lab continues in his absence and I have little doubt that continue to do excellent work.
Neil Beaty
GG(GIA) ISA NAJA
Independent Appraisals in Denver

 

[RockDoc]

Date: 7/27/2005 9:00:03 PM
Author: denverappraiser

Date: 7/27/2005 8:14:11 PM
Author: diamondsbylauren

The Gubelin Report is NOT published, and ,well, who is Gublin?

Gueblin lab is a Swiss based company with a superb track record of grading major stones. They don’t have the broad commercial distribution that is enjoyed by some of the others (like GIA, AGS and HRD) but they are every bit as respectable. They concentrate on major stones and are primarily involved with gemstones other than diamonds.

If the stone is indeed accompanied by a GGL report that indicates natural color origin, this would be sufficient evidence to convince me that this is the case.

I would love to be half as skilled as Dr. Gueblin when I grow up.

Dr. Gueblin passed away earlier this year and it was a great loss to the gemological community. The lab continues in his absence and I have little doubt that continue to do excellent work.

Neil Beaty
GG(GIA) ISA NAJA
Independent Appraisals in Denver

Gueblin is certainly a legend in our little group of pet rock junkies.

But personally, Neil, I''d give the Gueblin Lab more creedence than the GIA.

Rockdoc

 

[diamondsbylauren]

Cool Guys! It''s great to learn, even for stubborn rockheads like....me!

Speaking of which- I do not mean to take away anything from The Gueblin lab.
Obviously they have a greeat reputaion among gemologists.
Still wouldn''t you guys agree, that in the US, the Gueblin lab report is nowhere near as well known or accepted as a GIA report?
I''ve never seen anybody offering a diamond with such a report.

Again- I don''t mean to say the report won''t be accurate- just that outdside samll circles, Gueblin lab is unknown.

BTW- My experience with HRD puts them in the same league as EGL- not AGS and GIA.

 

[denverappraiser]

For the sorts of things that they examine and amongst peope who buy and sell this sort of merchandise, GGL very well known. Check the Sotheby sales for gemstones, especially non-diamonds, over $500,000 and you'll see them with every stone. Obviously this is a terribly specialized sort of marketplace. They don't do very many diamonds but then, the Orlov is hardly your typical diamond.

I listed HRD because they commercially very successful in Europe which leads to them being well known. As you correctly point out, well known is not the same as highly skilled. GGL does not do booths at trade shows, magazine advertisements and all of the other nonsense that leads to notoriety and this leaves them little known outside their specialized niche.

On a more commercial level, I will agree that a GIA report is what is called for and I too have never seen one for a 'fancy black'. I wonder if the Orlov would be considered 'vivid' or merely 'intense'.

Neil Beaty
GG(GIA) ISA NAJA
Independent Appraisals in Denver

 

[diamondsbylauren]

Date: 7/27/2005 9:56:58 PM
Author: denverappraiser
For the sorts of things that they examine and amongst peope who buy and sell this sort of merchandise, GGL very well known. Check the Sotheby sales for gemstones, especially non-diamonds, over $500,000 and you''ll see them with every stone. Obviously this is a terribly specialized sort of marketplace. They don''t do very many diamonds but then, the Orlov is hardly your typical diamond.

I listed HRD because they commercially very successful in Europe which leads to them being well known. As you correctly point out, well known is not the same as highly skilled. GGL does not do booths at trade shows, magazine advertisements and all of the other nonsense that leads to notoriety and this leaves them little known outside their specialized niche.

On a more commercial level, I will agree that a GIA report is what is called for and I too have never seen one for a ''fancy black''. I wonder if the Orlov would be considered ''vivid'' or merely ''intense''.

Neil Beaty
GG(GIA) ISA NAJA
Independent Appraisals in Denver

Great point Neil- I would imagine a lot of the most valuable jewelry items ( espeically mega high dollar colored stone or antique) would need far more than a GIA report- for example the item''s history might play a huge role in it''s value- I don''t knwo that GIA could really handle such assesments.

As far as "vivid black"- how could black be less than the maximum grade- I really would love to see a GIA report!!!

 

[widget]

Stupid question, maybe: Couldn''t someone write the GIA and ask them if they''ve ever graded a fancy black diamond? Are there GIA archives somewhere?

Just wondering
widget

 

[strmrdr]

Date: 7/27/2005 10:43:59 PM
Author: widget
Stupid question, maybe: Couldn''t someone write the GIA and ask them if they''ve ever graded a fancy black diamond? Are there GIA archives somewhere?


Just wondering

widget

Then they wouldnt have anything to argue about and what fun would that be?