DBL... genuinely curious.

[Gypsy]

David, I was browsing on your site today and ran across this pair of diamonds and was genuinely bcurious about the listing http://rockdiamond.com/index.php/jewelry/loose-diamond-matching-pair-of-gia-gray-diamonds-that-look-black-with-sparkle-r3210

I had no idea there was a 'fancy dark' catagory for GIA diamonds... it makes sense when I think about it... but I was wondering about it just the same. Are these diamonds that would normally be irradiated to change their color? Or is there really a market for these? I know your listing says that they look black, but they kinda look cement colored to me (grayish-green?)... what would they look like next to a white diamond? Can you take a pic? They aren't to my personal taste, but I do wonder if they would look interesting haloed.

Also, we normally think of grade setting clouds as a bad thing... is that not the case with fancy dark diamonds? In some of the pics the diamonds look foggy, and in others a bit glassy with their large tables.

I also noticed that they are radiants. So they were cut to retain color? To appear darker so that tells me that the darkness is a desireable thing. And yet most black diamonds I've seen a really affordable. So where is the line between fancy dark and inexpensive onyx-like black?

I appreciate any illumination

.

 

[Gypsy]

Oh, anyone else can feel free to reply as well.

 

[Lurchie]

I''m curious too! What an interesting pair. Very goth! Someone will love those...although that someone will not necessarily be me.

 

[Rockdiamond]

Hi Gypsy,
Thanks for asking!
I'll admit these stones seemed so....different, I felt compelled to add them to the site. They are an "almost pair" so we've considered splitting them us- and a halo would be very cool

You've asked some great questions, so let's go over a few points:
Many people are familiar with the more commonly seen color intensities.
For example lets consider yellow diamonds: Fancy Light Yellow is slightly lighter than Fancy Yellow, which is slightly lighter than Fancy Intense Yellow, which is slightly lighter than Fancy Vivid Yellow.
The "wildcard" grades would be Fancy Deep, or Fancy Dark which can be as deeply saturated as Vivid, but generally lack the brightness.

IN terms of why they were cut to radiant....I suspect it was a practical decision. The cutter is massive-one of the world's largest in fancy colors, so I'm sure they considered many factors when they decided to cut these into radiant cuts. As the color is so unusual, color retention may not have been as high on the list as yield, and producing brilliant, saleable stones

A large percentage of black diamonds on the market are irradiated- such stones are opaque and usually cost far less than "normal" diamonds.
Personally I feel the grade setting clouds in these stones are what give them their personality- and makes them look black to me.
They do have a greenish cast at times, depending on the lighting source. They can look foggy under the loupe, but it's not all that noticeable without the loupe.

I'm not an expert on irradiation, so I would not know if these are good candidates. I also have no idea if there's a market for them....time will tell!

It would be interesting to see them next to colorless stones- however I believe forum rules prohibit me from posting photos.

I will see how they look next to colorless stones and report back

 

[Mrs Mitchell]

I find them strangely compelling and rather intriguing.

I think they would make an incredible pair of cufflinks, if they're a good enough match. Or a tie pin. Something about them looks rather masculine to me, although I'd happily take one set in a pendant with a halo. Or like this ring (which I hope the owner doesn't mind me posting a pic of, it's in my inspiration folder.)

ETA sorry for the tiny pic - it's a stunning DBL sapphire ring.

 

[Gypsy]

Hi David, thanks for taking the time to answer some of my questions. I''m hoping someone else will chime in as well to talk about irradiation candidates, I am curious what irradiation would do to diamonds of this color.

Strangely compelling and intriguing is a good way to put it Mrs.M-- it certainly fits with David''s reputation of running an orphanage for unique stones that most vendors would pass by.

I think the cufflink idea is a interesting one actually. The measurements are a big off from a pair, but it would be a good use for them.

David, I''m not sure if it is a violation to post a pic just as an educational resource in response to a querry by a consumer. If possible though seeing a pic of them next to some white diamonds would be interesting.

They are slightly goth aren''t they?

Certainly an aquired taste. But then that is what David is famous for on here.

 

[decodelighted]

I watched the video & the clouds sort of look like zoning, which I don''t really care for. If the clouds weren''t in there I''d like them a lot better I guess. Interesting stones!

 

[Tom Gelb]

I can say a little about irradiation, and these diamonds are likely not great candidates unless one is looking to create black diamonds from them. The irradiation process cannot lighten a color, it can simple add a particular color and thus mask an underlying color. Most commonly green or yellow is the added color. In the case of these diamonds since they are already so dark the treatment would be less effective than in the more commonly treated top light brown color range.

As an aside might I add that most treated black diamonds on the market today are heat treated and not irradiated.

 

[Mrs Mitchell]

Date: 3/27/2010 3:29:51 PM
Author: Gypsy
Hi David, thanks for taking the time to answer some of my questions. I''m hoping someone else will chime in as well to talk about irradiation candidates, I am curious what irradiation would do to diamonds of this color.

Strangely compelling and intriguing is a good way to put it Mrs.M-- it certainly fits with David''s reputation of running an orphanage for unique stones that most vendors would pass by.

I think the cufflink idea is a interesting one actually. The measurements are a big off from a pair, but it would be a good use for them.

David, I''m not sure if it is a violation to post a pic just as an educational resource in response to a querry by a consumer. If possible though seeing a pic of them next to some white diamonds would be interesting.

They are slightly goth aren''t they?

Certainly an aquired taste. But then that is what David is famous for on here.

An orphanage

That sort of implies that they''d be free to a good home! I wish.

I''ve adopted a few diamonds from David. This pair is a little different from the norm though. I do find them interesting and yes, slightly goth. It''s good to see something beyond the mainstream popping up occasionally.

 

[Gypsy]

HAHA Mrs. M! I''m sure if vendors starting giving away diamonds we''d all be mobbing to get in line. I can''t say that even free, I''d be in line for these but they are interesting from an academic perspective and I do want to learn more about color diamonds.

David, I just noticed that you mention that the diamonds are "relatively inclusion free"... Since they are estimated at I''s with grade setting clouds that seem to make them foggy, what are you defining their clarity relative to?

Hi Tom, thanks so much for the information.. It must be naive of me but I didn''t realize that diamonds were heat treated for color conversion. I have a lot to learn. Since you know more than the average bear, care to share some more information? I''d love to know.

 

[Tom Gelb]

Date: 3/27/2010 6:28:45 PM
Author: Gypsy
HAHA Mrs. M! I''m sure if vendors starting giving away diamonds we''d all be mobbing to get in line. I can''t say that even free, I''d be in line for these but they are interesting from an academic perspective and I do want to learn more about color diamonds.


David, I just noticed that you mention that the diamonds are ''relatively inclusion free''... Since they are estimated at I''s with grade setting clouds that seem to make them foggy, what are you defining their clarity relative to?


Hi Tom, thanks so much for the information.. It must be naive of me but I didn''t realize that diamonds were heat treated for color conversion. I have a lot to learn. Since you know more than the average bear, care to share some more information? I''d love to know.

I am happy to share what I know. The heat treatment of diamonds comes in a few forms, I will try to outline them briefly. The most well known is high pressure/high temperature (HPHT) treatment which has been discussed on this forum and in the gemological literature for a while. I can answer your questions about it, but there are many resources that could do it better. Another common heat treatment is high temperature annealing which is done in conjunction with irradiation treatment. Basically diamonds are first irradiated to turn them green and then subsequently heat treated to change he color (ususally to yellow). Finally there is a low pressure/high temperature treatment which can change diamonds (especially heavily included ones) to black. This type of treatment heats up a diamond to cause fractures (internal or surface reaching) to grow graphite within them. Graphite is black and thus the diamond mimics natrually black diamonds which are colored by their inclusions. This type of treatment is much more common than irradiating diamonds to make them black due to it''s very low cost and avoidance of the potential for residual radioactivity which can occur in irradiated black diamonds. If you have more questions please let me know.

 

[whatmeworry]

Date: 3/28/2010 1:22:41 PM
Author: Tom Gelb



I am happy to share what I know. The heat treatment of diamonds comes in a few forms, I will try to outline them briefly. The most well known is high pressure/high temperature (HPHT) treatment which has been discussed on this forum and in the gemological literature for a while. I can answer your questions about it, but there are many resources that could do it better. Another common heat treatment is high temperature annealing which is done in conjunction with irradiation treatment. Basically diamonds are first irradiated to turn them green and then subsequently heat treated to change he color (ususally to yellow). Finally there is a low pressure/high temperature treatment which can change diamonds (especially heavily included ones) to black. This type of treatment heats up a diamond to cause fractures (internal or surface reaching) to grow graphite within them. Graphite is black and thus the diamond mimics natrually black diamonds which are colored by their inclusions. This type of treatment is much more common than irradiating diamonds to make them black due to it''s very low cost and avoidance of the potential for residual radioactivity which can occur in irradiated black diamonds. If you have more questions please let me know.

Hi Tom, thanks for sharing I wonder if you can comment on
1) what to look for in a grading report that signifies heat treatment or irradiation of black diamonds.
2) The toughness or fragility of these heat treated black diamonds compared with other diamonds.
3) How can a consumer tell the difference between these treated black diamonds and a natural black diamonds?

 

[Rockdiamond]

Date: 3/28/2010 1:50:28 PM
Author: whatmeworry

Hi Tom, thanks for sharing I wonder if you can comment on

1) what to look for in a grading report that signifies heat treatment or irradiation of black diamonds.

2) The toughness or fragility of these heat treated black diamonds compared with other diamonds.

3) How can a consumer tell the difference between these treated black diamonds and a natural black diamonds?

Hi What- I hope you don''t me answering....
1) GIA will note if a diamond has been irradiated, or HPHT ( heated)
2) I''ll leave that one to Tom!
3) If there''s no GIA report on a black diamond, you can safely assume it''s been treated

I''m at the office today- and I admit it Gypsy- you peaked my curiosity.
I''ll put the the stones near some other colored diamonds ( including white) to see what they look like.

 

[Dancing Fire]

i''m more curious about how cutters/vendors come up with a price on these type of stones,just pick the #''s out of a hat? throw darts at #s?

 

[Rockdiamond]

Great question DF!

Pricing fancy colored stones is a totally different ballgame than traditional round brilliant cuts.
For one thing, there''s no "list"
Then there''s the relative rarity. There''s a whole lot more "traditional" stones on the market, which gives dealers and cutters more of a pattern to follow.

When it comes to the more "standard" colors- such as Fancy Intense Yellow- there can be huge differences in value between two ostensibly identical stones- Ostensibly means if we only look at the report, not the diamond.
But that''s still at least some sort of ballpark range.
With unique one of a kind stones, it''s a lot more intuitive for me.

 

[Tom Gelb]

Date: 3/28/2010 1:56:40 PM
Author: Rockdiamond

Date: 3/28/2010 1:50:28 PM

Author: whatmeworry


Hi Tom, thanks for sharing I wonder if you can comment on


1) what to look for in a grading report that signifies heat treatment or irradiation of black diamonds.


2) The toughness or fragility of these heat treated black diamonds compared with other diamonds.


3) How can a consumer tell the difference between these treated black diamonds and a natural black diamonds?

Hi What- I hope you don''t me answering....

1) GIA will note if a diamond has been irradiated, or HPHT ( heated)

2) I''ll leave that one to Tom!

3) If there''s no GIA report on a black diamond, you can safely assume it''s been treated


I''m at the office today- and I admit it Gypsy- you peaked my curiosity.

I''ll put the the stones near some other colored diamonds ( including white) to see what they look like.

Sure David, leave me the one question that I am unsure of! If I had to guess (and this is a guess, because I haven''t heard of or seen any study on it), I would say that there is probably little, if any, difference between natural and heat treated black diamonds in terms of durability. They will likely both have a lot of surface reaching inclusions that may affect their durability, so anyone should be a bit more careful with these diamonds than others. In terms of whether heat treated diamonds are less durable than non-heat treated ones I haven''t heard any evidence, even anecdotal, to suggest this is true.

To add a little to what David had written, I believe that right now the GIA would call heat treated black diamonds simply treated color, rather than heat treated, but it has been a while so it may be worth a call to the Identification department

For question three I would agree with David simply because it takes a good deal of knowledge to distinguish between natural and heat treated black diamonds. If it has a report then you are OK, otherwise be wary. But remember that natural black diamonds are not very expensive and many dealers would not want to spend money on a report (at least before it is sold), so you may have a harder time finding them. Any reputable dealer should offer to send it in for you.

I hope this helps, and good luck.

 

[diagem]

Date: 3/29/2010 7:57:46 AM
Author: Tom Gelb

Date: 3/28/2010 1:56:40 PM
Author: Rockdiamond

Date: 3/28/2010 1:50:28 PM

Author: whatmeworry


Hi Tom, thanks for sharing I wonder if you can comment on


1) what to look for in a grading report that signifies heat treatment or irradiation of black diamonds.


2) The toughness or fragility of these heat treated black diamonds compared with other diamonds.


3) How can a consumer tell the difference between these treated black diamonds and a natural black diamonds?

Hi What- I hope you don''t me answering....

1) GIA will note if a diamond has been irradiated, or HPHT ( heated)

2) I''ll leave that one to Tom!

3) If there''s no GIA report on a black diamond, you can safely assume it''s been treated


I''m at the office today- and I admit it Gypsy- you peaked my curiosity.

I''ll put the the stones near some other colored diamonds ( including white) to see what they look like.

Sure David, leave me the one question that I am unsure of! If I had to guess (and this is a guess, because I haven''t heard of or seen any study on it), I would say that there is probably little, if any, difference between natural and heat treated black diamonds in terms of durability. They will likely both have a lot of surface reaching inclusions that may affect their durability, so anyone should be a bit more careful with these diamonds than others. In terms of whether heat treated diamonds are less durable than non-heat treated ones I haven''t heard any evidence, even anecdotal, to suggest this is true.

To add a little to what David had written, I believe that right now the GIA would call heat treated black diamonds simply treated color, rather than heat treated, but it has been a while so it may be worth a call to the Identification department

For question three I would agree with David simply because it takes a good deal of knowledge to distinguish between natural and heat treated black diamonds. If it has a report then you are OK, otherwise be wary. But remember that natural black diamonds are not very expensive and many dealers would not want to spend money on a report (at least before it is sold), so you may have a harder time finding them. Any reputable dealer should offer to send it in for you.

I hope this helps, and good luck.

Sometimes Natural Black Diamonds can be very valuable...
Not all black diamonds are dark because of inclusions..., rarely one can find a type of transparency in Fancy Black material that doesnt resemble the majority of black Diamonds out on the market...

Some examples:

The Amsterdam Diamond.
The Orloff Black Diamond
The Gruosi (Grisogono) Diamond. (I am not certain its was transparent).
And there are more...
I just heard of a new Guinness record issued to a black Diamond cut in Antwerp which weighs 555.55cts and possess 55 facets...

.

 

[Mrs Mitchell]

I had to google the famous black diamonds Diagem mentioned, just out of curiosity. Orlov black diamond (in the most incredible setting), for interest / eyecandy:

 

[Rockdiamond]

Cool photo Jen!!!


I have to agree that natural black diamonds are very expensive.
In fact, I don''t recall recall seeing even one.
And I''ve seen almost every imaginable color in natural diamonds.

 

[Tom Gelb]

Date: 3/29/2010 9:26:06 AM
Author: DiaGem

Date: 3/29/2010 7:57:46 AM

Author: Tom Gelb

Date: 3/28/2010 1:56:40 PM

Author: Rockdiamond

Date: 3/28/2010 1:50:28 PM


Author: whatmeworry



Hi Tom, thanks for sharing I wonder if you can comment on



1) what to look for in a grading report that signifies heat treatment or irradiation of black diamonds.



2) The toughness or fragility of these heat treated black diamonds compared with other diamonds.



3) How can a consumer tell the difference between these treated black diamonds and a natural black diamonds?

Hi What- I hope you don''t me answering....


1) GIA will note if a diamond has been irradiated, or HPHT ( heated)


2) I''ll leave that one to Tom!


3) If there''s no GIA report on a black diamond, you can safely assume it''s been treated



I''m at the office today- and I admit it Gypsy- you peaked my curiosity.


I''ll put the the stones near some other colored diamonds ( including white) to see what they look like.

Sure David, leave me the one question that I am unsure of! If I had to guess (and this is a guess, because I haven''t heard of or seen any study on it), I would say that there is probably little, if any, difference between natural and heat treated black diamonds in terms of durability. They will likely both have a lot of surface reaching inclusions that may affect their durability, so anyone should be a bit more careful with these diamonds than others. In terms of whether heat treated diamonds are less durable than non-heat treated ones I haven''t heard any evidence, even anecdotal, to suggest this is true.


To add a little to what David had written, I believe that right now the GIA would call heat treated black diamonds simply treated color, rather than heat treated, but it has been a while so it may be worth a call to the Identification department


For question three I would agree with David simply because it takes a good deal of knowledge to distinguish between natural and heat treated black diamonds. If it has a report then you are OK, otherwise be wary. But remember that natural black diamonds are not very expensive and many dealers would not want to spend money on a report (at least before it is sold), so you may have a harder time finding them. Any reputable dealer should offer to send it in for you.


I hope this helps, and good luck.

Sometimes Natural Black Diamonds can be very valuable...

Not all black diamonds are dark because of inclusions..., rarely one can find a type of transparency in Fancy Black material that doesnt resemble the majority of black Diamonds out on the market...


Some examples:


The Amsterdam Diamond.

The Orloff Black Diamond

The Gruosi (Grisogono) Diamond. (I am not certain its was transparent).

And there are more...

I just heard of a new Guinness record issued to a black Diamond cut in Antwerp which weighs 555.55cts and possess 55 facets...

.

I stand corrected, there are certainly a few very valuable black diamonds out there. David, my understanding is that most natural black diamonds on the market are on par in terms of price per carat as Fancy Brown diamonds. While I am not an expert on the pricing of colored diamonds, this category is relatively inexpensive. If this is incorrect please let me know.

Yoram, I am curious, what could cause a diamond to be black if not inclusions? I am pretty sure that I graded the Black Orloff and if memory serves it was black due to inclusions. Sometimes these inclusions are surface reaching feathers, in other cases it is dark inclusions, in most cases it is both. In rare cases I have seen some black diamonds where there are paths through the inclusions to the pavilion, and thus these diamonds have some life, but they were certainly black due their inclusions. In thinking through the database (my brain) I remember a heavily doped type IIb synthetic diamond that appeared black because of the extreme levels of boron in the crystal lattice. And certainly I have seen some artificially irradiated black diamonds, but I cannot remember a natural black diamond not colored by inclusions. Can you please shed some light?

Thanks.

 

[Rockdiamond]

Date: 3/29/2010 8:35:48 PM
Author: Tom Gelb

Date: 3/29/2010 9:26:06 AM
Author: DiaGem

Date: 3/29/2010 7:57:46 AM

Author: Tom Gelb

Date: 3/28/2010 1:56:40 PM

Author: Rockdiamond

Date: 3/28/2010 1:50:28 PM


Author: whatmeworry



Hi Tom, thanks for sharing I wonder if you can comment on



1) what to look for in a grading report that signifies heat treatment or irradiation of black diamonds.



2) The toughness or fragility of these heat treated black diamonds compared with other diamonds.



3) How can a consumer tell the difference between these treated black diamonds and a natural black diamonds?

Hi What- I hope you don''t me answering....


1) GIA will note if a diamond has been irradiated, or HPHT ( heated)


2) I''ll leave that one to Tom!


3) If there''s no GIA report on a black diamond, you can safely assume it''s been treated



I''m at the office today- and I admit it Gypsy- you peaked my curiosity.


I''ll put the the stones near some other colored diamonds ( including white) to see what they look like.

Sure David, leave me the one question that I am unsure of! If I had to guess (and this is a guess, because I haven''t heard of or seen any study on it), I would say that there is probably little, if any, difference between natural and heat treated black diamonds in terms of durability. They will likely both have a lot of surface reaching inclusions that may affect their durability, so anyone should be a bit more careful with these diamonds than others. In terms of whether heat treated diamonds are less durable than non-heat treated ones I haven''t heard any evidence, even anecdotal, to suggest this is true.


To add a little to what David had written, I believe that right now the GIA would call heat treated black diamonds simply treated color, rather than heat treated, but it has been a while so it may be worth a call to the Identification department


For question three I would agree with David simply because it takes a good deal of knowledge to distinguish between natural and heat treated black diamonds. If it has a report then you are OK, otherwise be wary. But remember that natural black diamonds are not very expensive and many dealers would not want to spend money on a report (at least before it is sold), so you may have a harder time finding them. Any reputable dealer should offer to send it in for you.


I hope this helps, and good luck.

Sometimes Natural Black Diamonds can be very valuable...

Not all black diamonds are dark because of inclusions..., rarely one can find a type of transparency in Fancy Black material that doesnt resemble the majority of black Diamonds out on the market...


Some examples:


The Amsterdam Diamond.

The Orloff Black Diamond

The Gruosi (Grisogono) Diamond. (I am not certain its was transparent).

And there are more...

I just heard of a new Guinness record issued to a black Diamond cut in Antwerp which weighs 555.55cts and possess 55 facets...

.

I stand corrected, there are certainly a few very valuable black diamonds out there. David, my understanding is that most natural black diamonds on the market are on par in terms of price per carat as Fancy Brown diamonds. While I am not an expert on the pricing of colored diamonds, this category is relatively inexpensive. If this is incorrect please let me know.

Yoram, I am curious, what could cause a diamond to be black if not inclusions? I am pretty sure that I graded the Black Orloff and if memory serves it was black due to inclusions. Sometimes these inclusions are surface reaching feathers, in other cases it is dark inclusions, in most cases it is both. In rare cases I have seen some black diamonds where there are paths through the inclusions to the pavilion, and thus these diamonds have some life, but they were certainly black due their inclusions. In thinking through the database (my brain) I remember a heavily doped type IIb synthetic diamond that appeared black because of the extreme levels of boron in the crystal lattice. And certainly I have seen some artificially irradiated black diamonds, but I cannot remember a natural black diamond not colored by inclusions. Can you please shed some light?

Thanks.

Hi Tom,
I''d have to say that statement is false.
Fancy Brown diamonds are not all that hard to find- natural black diamonds are so rare that the price would necessarily be higher- although as I mentioned above, I have not seen them on the market.

I did see a 60 something carat black diamond a few years ago- treated. It was about $2000 per carat- which is VERY cheap for a stone that size.
If it was natural it probably would have been exponentially more costly.