Are brown diamonds ever irradiated?

[Indylady]

Are brown diamonds ever irradiated or heated for color?

I thought diamonds are usually irradiated to yellow, blue, black and sometimes pink--but are they ever heated to brown?

Its good to be back!

 

[kenny]

I don't know, but brown is the cheapest of the natural colors.
Seems like spending money to irradiate anything to become brown could only lower its value.

Perhaps it could make it a more attractive brown.

 

[chrono]

I don't know why it would be done unless it makes it a prettier and better valued champagne FCD?

 

[Indylady]

Thanks Kenny and Chrono!

That's along the lines of what I was thinking. But, I haven't been on the boards or up to date with latest treatments, and didn't know if any new techniques/treatments/etc. had appeared recently.

So, collectively, has no one heard of irradiating diamonds to become brown?

 

[Dioptase]

I recall reading some article on G&G about brown / brownish orange diamonds obtained by irradiation / HPHT.

 

[LD]

I was certain they weren't BUT I recently saw something where somebody stated that browns COULD be irradiated. I'm not sure why they would do this because nature gives us quite a lot of browns and it must be expensive to irradiate - so why bother!?

 

[Rockdiamond]

Generally speaking irradiated blue diamonds started out as brown- so in that regard, yes, brown diamonds are frequently irradiated
Light brown diamonds are used for HPHT
Ive never encountered diamonds irradiated to look brown- but I suppose it's possible- but it does not sound too smart

 

[Indylady]

Thank you Dioptase, LD, and Rockdiamond! You all are awesome!

D--Do you remember the source of the article? I'd love to check it out, but no need to track it down if you don't remember!

LD--Ditto! Do you remember the source?

Rockdiamond--I did mean diamonds that are irritated to look brown. Thanks for the clarification!

 

[LD]

Indy I've been racking my brains but couldn't find anything so decided to do an internet search. I've found an article by GIA that confirms a 1.49ct fancy deep brown orange diamond submitted to them for examination showed irradiation. The paper was written at the end of 2010 so I guess we can't be positive when buying browns any more that they're natural and untreated. Note the last sentence as to what they put on the lab report.

http://www.gia.edu/research-resources/news-from-research/irradiated-brown-orange-diamond.pdf

 

[Rockdiamond]

Great article LD- thanks for posting it!!!

Looking at what I wrote earlier, I can see I was wrong about it not being "too smart" to irradiate browns.
There's ample financial incentive for unscrupulous sellers to irradiate undesirably brown diamonds to make them look like more orangy colored- and pricier browns.
Adds another brick to GIA's wall- unless one does not care if a stone is irradiated a GIA report is essential. This is especially true for the costlier shades of brown.

 

[chrono]

Thanks for the link LD. Seems like no single colour FCD is safe from treatment, except perhaps black?

 

[kenny]

Thanks for the link LD. Seems like no single colour FCD is safe from treatment, except perhaps black?

Actually black is often treated.
If fact, assume a black diamond has been treated unless it has a GIA report stating the black is of natural origin.

The only reason I know this is Leibish used to carry blacks that had no reports and they were very affordable.
I discussed this with them and they told me that they had recently switched to only natural blacks, with reports to they can state that they sell only FCDs with color of natural origin.

 

[chrono]

Kenny,
What methods of treatment yields black FCDs? What colour diamond is used to make it black?

 

[LD]

Chrono the majority of black diamonds are irradiated. Natural ones are few and far between. I have no idea what colour they start with to get black but would assume it's a yucky dark colour of some description

 

[chrono]

I suppose they wouldn't use brown because those cost more than black diamonds, right?

 

[kenny]

I suppose they wouldn't use brown because those cost more than black diamonds, right?

I don't know which diamonds are selected to become black.
Perhaps industrial grade or those with blotchy massive dark inclusions, just a guess.

Black is not just black.
It has a unique property.
It is the only "hue" that's opaque so it will hide everything ugly in the diamond.

 

[Rockdiamond]

If we're talking about the irradiated black diamonds......they choose material that's far too poor to be used for "gem" quality diamonds.
And I'm using the "gem" word very loosely. Like maybe stones worse than I3
We're seen these treated black stones going for a few hundred dollars a carat- even in large sizes. That's really cheap.
We can extrapolate who cruddy the material is- as once it's nuked, it turns opaque.
I think the starting diamonds are either horribly imperfect, or totally dull- or both.
They probably try to eliminate stones with large imperfections that break the surface......

 

[chrono]

Urgh....industrial crap. Well, at least they are put to good use with treatment.

 

[Rockdiamond]

We've never offered any treated diamonds on the site, or at our offices- and never will- but here's what a 5ct (iirc) irradiated black looks like.

 

[T L]

I have an old Modern Jeweler article about irradiated diamonds, and they show off some irradiated brown ones. Therefore, I assume they can be.

 

[LD]

We've never offered any treated diamonds on the site, or at our offices- and never will- but here's what a 5ct (iirc) irradiated black looks like.

The problem is non-irradiated look exactly the same David!

 

[Rockdiamond]

I agree LD!
I've never been a fan of fancy white, or fancy black diamonds.