AGTA gem ID report - how to interpret?

[Art Nouveau]

In a AGTA color stone ID report, what does it mean when the stone is identified as natural, but under "comments" there is a sentence that says "A fluid is present in fissures"? Does it mean the stone is clarity enhanced or can the fluid be natural? Under "Enhancement" it says "see reverse". The reverse page is just some generic info about enhancement and does not indicate if any of the possible enhancements are applicable to the stone in the report. Hope some of the experts here can help with this question.

Thanks.

AN

 

[chrono]

It is normal for a gemstone to have a liquid filled bubble inclusion. In this case, it sounds like it is a natural occurance.

 

[MakingTheGrade]

Can we ask what kind of stone it is?
Here's a kind of neat picture of liquid films on emerald:
http://www.agta-gtc.org/malysheva-emeralds.htm

 

[Art Nouveau]

The stone is a moderately included Brazilian paraiba tourmaline. The cert does say natural elbaite tourmaline, copper and maganese bearing, origin Brazil. I am not sure, but I think the ''liquid in fissures'' is not referring to liquid 3-phase inclusions. It sounds like there is liquid in the feathers. If the stone is enhanced, then I wouldn''t want be interested.

AN

 

[Richard Sherwood]

It''s fairly common for surface reaching fissures in moderately included Paraiba tourmaline to be clarity enhanced with either oil or resin.

That sounds like what it''s referring to.

 

[chrono]

It does not sound like a natural; more like it has been oiled. I have not heard of paraiba tourmalines being oiled to improve the appearance of the clarity though.

Richard, it this a generally accepted practice in gemstones other than emeralds? I would consider this as enhanced treatment. Wouldn''t the lab cert state it as oiled?

 

[Art Nouveau]

Hi Richard,

Thanks for your response. I was not aware that paraiba tourmalines are oiled or resin filled. Is this an accepted practice like for emeralds? Is it temporary or permanent? Should the price be much lower due to such treatment. I am surprised the cert does not give more details and there are no remarks under ''enhancement''.

AN

 

[Lady_Disdain]

My feeling would be some sort of oil or resin treatment as well. I would think a resin such as Opticon to be most likely.

I would also read it to mean: keep out of sonic cleaners, as it may shatter. As a general piece of advice, no coloured stones in sonic cleaners, but specially any that might have liquid in fractures.

 

[Richard Sherwood]

Date: 6/23/2009 6:23:22 PM
Author: Art Nouveau
I was not aware that paraiba tourmalines are oiled or resin filled. Is this an accepted practice like for emeralds?

The oiling of emeralds has been around for a century, and has become accepted as standard. When resin was introduced a couple decades ago, it first it was regarded as a "pariah" of emerald treatments. But the truth was that the resin treatment did a better job than oil and was more stable. So now it has become much more accepted in the clarity enhancement of emeralds.

That acceptance has creeped over into the area of paraiba tourmaline. It''s all the same region (Brazil, Colombia) with many of the same practices. In truth, I''ve never seen an oiled paraiba, but I have seen plenty of resin treated paraibas. It is not as accepted yet as the treatment of emeralds, but it does not have the stigma of say, clarity enhanced diamonds. It''s like everybody accepts that colored stones (especially commercial qualities) need all the help they can get, although I have occasionly seen it in finer qualities as well.

The qualifier is that the treatment should be disclosed and the material should be priced accordingly.

Date: 6/23/2009 6:23:22 PM
Author: Art Nouveau
Is it temporary or permanent?

Oiling is not permanent, and can be lost in situations like cleaning in a hot ultrasonic. A stone can always be re-oiled though.

Resin treatment is much more stable, and seems to hang on under most conditiions. Heat from a torch can cause a stone to lose its resin treatment, but you shouldn''t be using a torch on the majority of colored stones any way.

Date: 6/23/2009 6:23:22 PM
Author: Art Nouveau
Should the price be much lower due to such treatment.

I find that most stones on the market are usually priced accordingly. A Paraiba with moderate resin enhancement is usually never priced at the same level as a Paraiba with the same visual presentation and no enhancement.

If you take a commercial quality Paraiba that has a "fair" visual presentation though and then clarity enhance it to a Pariaba with a "good" visual presentation, it will usually sell for more money than it would have as an untreated stone, which only makes sense. A better looking stone brings better money.

Date: 6/23/2009 6:23:22 PM
Author: Art Nouveau
I am surprised the cert does not give more details and there are no remarks under ''enhancement''.

Yeah, I''m a little surprised about that as well. Possibly it is a simplistic report which doesn''t cost as much, and doesn''t give as much information.

Usually I would expect an indication as to the type of treatment (oil versus resin), whether it enhances the color or clarity (or both), and the level of treatment (I use the scale of minor, moderate, noticeable and significant).

But I know that a lot of labs these days are tailoring their reports to the amount of money the client wants to spend. Could be this is the cheapo version.

 

[Richard Sherwood]

Date: 6/23/2009 3:04:00 PM
Author: Chrono
It does not sound like a natural; more like it has been oiled. I have not heard of paraiba tourmalines being oiled to improve the appearance of the clarity though.

Richard, it this a generally accepted practice in gemstones other than emeralds? I would consider this as enhanced treatment. Wouldn''t the lab cert state it as oiled?

Hi Chrono. I have only personally seen Paraiba''s that have had resin treatment, but I have read that both treatments have been used (oil and resin), usually on commercial quality Paraiba.

I would not say it is "generally accepted" like it has become in emeralds, but I wouldn''t be surprised if it were to become so over a period of time (5-10 years maybe? 20 on the outside?).

Yes, ordinarily I would expect a lab to designate it as "oiled", or "resin treated". As I mentioned above, it could be that the report ordered was not as extensive (or expensive) as a detailed report. I''d be curious myself.

 

[Richard Sherwood]

I was just researching the AGTA website and found that they charge extra to identify the type of filler:

_______________

Filler Identification

For an additional fee, clients can request identification of the filler substance, which is indicated in the comments section of the report as follows:

The identity of the enhancement substance was determined to be an… [oil/wax/resin]
_______________

 

[chrono]

Thank you, Richard. This is a new one to me. At this point, I cannot accept resin filled or oiled paraibas but maybe as they become more scarce, I might relent.

 

[Art Nouveau]

Hi Richard,

Thank you very much for your detailed explanation. I have left a message with AGTA, but no one has called me back yet. I am a bit disappointed with AGTA. I am under the impression that they are the most reputable lab for color stones reports. If I missed the sentence "A fluid is present in fissures", which is in fine print buried in a long paragraph, I would have thought the stone is an untreated natural Brazilian paraiba tourmaline. It should have at lease said some where in the report that testing for treatment was not requested or something like that. The dealer trying to sell me this stone has not disclosed anything about clarity enhancement, so unless he is willing to drastically reduce the price, I will pass on it. I am a bit tempted because the stone is super neon and glows much more than the best of African paraibas that I have seen.

AN

 

[T L]

I would also want to know if the fluid was colored as is sometimes the case with emeralds. Sometimes colored resin is used instead of clear resin, and that's more unscrupulous treatment.

As for the resin filling, it may also discolor over time I would imagine. Richard can clarify further.

I imagine they would also resin fill African paraiba as well.

 

[chrono]

This is very terrible news to my ears. It''s as though by keeping silent, the vendor is not disclosing the treatment unless asked.

I hope that''s not the case here.

 

[T L]

AN,
I am sorry you have to deal with this, but thank you for letting us know about it. If anyone is considering a Paraiba of any origin, especially a pricey one, they should always check for fracture filling.