Has anyone heard of Chanthaburi gemological lab

[userangl28212003]

I am eyeing a ruby stone that came with a Chanthaburi Gemological Laboratory (CGL) certificate, and I was wondering if anyone knows if its legit or had experience with this lab?

 

[Sunshine219]

Never heard of them but their eBay store has some awful reviews. Has good too though. I'm not sure if I would buy. Maybe someone else can chime in their experience

 

[LoversKites]

I believe that only big labs have the ability and expensive equipment to test for heavier treatments. Rubies are especially risky.

 

[userangl28212003]

They offer that u can get it certified through AIGS or GIA too through them. I assume if you can do that, then they are not trying to scam people. Any thoughts on this?

 

[T L]

They seem legit, and have a website where you can authenticate reports. I wouldn't trust sapphires, rubies and emeralds with them, but spinels, garnets and gems that have little to no treatment, are probably okay to send there.

http://www.glclab.com/

The lab I don't trust, and I don't even know if it exists, or if it is real, is SLP gem lab.

 

[LoversKites]

I would not assume. Not with rubies, at least.

As TL said I would be ok with gems that have little to no treatment (sphene, not well known collector's stones, garnet, etc).

What are the disclosed treatments on the ruby? If they say it's untreated or heat only I would request a AIGS brief report. It's $45 and will provide info on treatment which would be my main concern.

 

[DLeigh]

I am also looking at a gemstone certified by Chanthaburi Geomological Laboratory. It is offered by Colorgemstore on ebay. This sapphire is exactly the color (deep, rich blue) and size I am looking for and is untreated, like I want. The seller has 100% positive feed back, but this seems too good to be true. Any advise on this lab or seller?

http://www.ebay.com/itm/CERTIFIED-UNHEATED-1-78CT-Perfect-Round-7MM-Natural-Deep-Royal-Blue-Sapphire-/321321659756?pt=Loose_Gemstones_1&hash=item4ad0436d6c

 

[userangl28212003]

Hi. its for a untreated/unheated ruby. I know its not the best quality one as I am well aware.

 

[userangl28212003]

The GLC report also says no indication of heating.

 

[cm366]

I am also looking at a gemstone certified by Chanthaburi Geomological Laboratory. It is offered by Colorgemstore on ebay. This sapphire is exactly the color (deep, rich blue) and size I am looking for and is untreated, like I want. The seller has 100% positive feed back, but this seems too good to be true. Any advise on this lab or seller?

http://www.ebay.com/itm/CERTIFIED-UNHEATED-1-78CT-Perfect-Round-7MM-Natural-Deep-Royal-Blue-Sapphire-/321321659756?pt=Loose_Gemstones_1&hash=item4ad0436d6c

It's not too good to be true, it's just too dark to be blue

Look at the video, and realize that it's shot under strong lighting and the stone will be darker than that in almost any situation. Ignore the still photos - there's a floodlight or reflector in back of the stone.

 

[MollyMalone]

They offer that u can get it certified through AIGS or GIA too through them. I assume if you can do that, then they are not trying to scam people. Any thoughts on this?

There have been reports on other web site forums (and maybe here on PS too) that some Thai vendors will say this in order to lull you into a sense of security -- but when people have actually asked for, e.g., a GIA report, the vendor never follows through; instead, the vendor tells the prospective buyer something like "Oops, that stone has already been sold."

I have no idea if that's happened with the vendor offering the ruby you are considering, but I wanted to let you know that the offer to obtain a report from an internationally-known, independent lab may not be a genuine, good faith gesture.

 

[userangl28212003]

Thank you for your concern I much appriciate it. But there are reviews of people that actually bought the extra gem reports and left good reviews on it, and I came with a GLC report that i verified online.

 

[LoversKites]

Yep, that's happened to me Molly, only they said 'we will get back to you' and never did!

OP, if you're spending 50 or so bucks there is obviously no point in spending 45 on a report. If you're spending a couple hundred or more an AIGS report will will give you peace of mind that you got something as advertised. Its up to you. I would request a report even with positive feedback.

About the sapphire a different user linked, as cm said, it will probably be near black irl. You can even see the metal tweezers are all shining in the video - meaning a light is being directed at the stone. I wouldn't call the colour (even in the still shots) a 'rich blue' like you said but rather a dark blue. Its easy to get saturation and tone mixed up.

good luck to both of you

 

[MollyMalone]

Note that CGL's web site provides no description of the diagnostic equipment they use -- and compare that with, e.g., AIGS Thailand
http://www.aigsthailand.com/Gemlab-Equipment.aspx
whose web site is overall far more comprehensive:
http://www.aigsthailand.com/

I'm also seeing that AJS Gems, a Bangkok-based company that's included in the respected vendors "sticky" on the Colored Stones forum index page
https://www.pricescope.com/communit...s-vendors.169561/page-5#post-3606743#p3606743
does not use CGL for any stone when a customer requests an outside lab report:
http://www.ajsgem.com/articles/gem-certification.html

 

[T L]

CGL is probably a standard lab with very basic equipment. They're probably good at detecting some synthetics, or simulants, or basic/minor treatment. They're also very inexpensive, so that's why some Thai dealers probably use them. If you get a valuable stone, I probably would go with a more well known lab.

 

[userangl28212003]

From what I read online and in threads that it seems like all treatments on rubies, the ruby id heated in some way. So if this lab was able to say it was unheated, would I have to worry about other treatments not being found?

 

[T L]

From what I read online and in threads that it seems like all treatments on rubies, the ruby id heated in some way. So if this lab was able to say it was unheated, would I have to worry about other treatments not being found?

You still have to worry about convincing synthetics. Sometimes as well, many labs think a ruby or sapphire is unheated, when it really is heated. Corundum is very particular when it comes to the myriad of treatments. For an expensive ruby or sapphire, I would go with AGL.

 

[michellechan2211]

Pasting a thread on a convincing synthetic ruby purchased by a PSer and sent to AGL:

[URL='https://www.pricescope.com/community/threads/how-to-get-an-agl-certificate.189205/']https://www.pricescope.com/community/threads/how-to-get-an-agl-certificate.189205/[/URL]

 

[userangl28212003]

So If I buy it and ask for a AIGS report, that should be alright as long as the report comes back as unheated?

 

[LoversKites]

So If I buy it and ask for a AIGS report, that should be alright as long as the report comes back as unheated?

Yes since that is how it was advertised. If the report says diffused/filled that's a problem. Make sure they have a good return policy just in case.

 

[chrono]

When it comes to rubies, my top lab choice in the US is AGL. If in Asia, I prefer GIA over AIGS. Other labs have found sapphires AIGS deemed as unheated to be heated.

 

[userangl28212003]

I was able to order a AIGS report with my ruby. Hopefully it will come back as advertised. Thank you all for your opinion.

 

[Deborah Jeaan]

I am eyeing a ruby stone that came with a Chanthaburi Gemological Laboratory (CGL) certificate, and I was wondering if anyone knows if its legit or had experience with this lab?

I have purchased several gems since 2017 with the certificate provided by Chanthaburi Gemological Laboratory. Until recently, all were correct.

I had purchased a 1+ct blue sapphire with a CGL Report which stated it was "heated."

I sent the gemstone to GIA. The GIA Report stated the gemstone was Beryllium Treated (See FTC Rules).

I would not rely on any report by CGL.

As far as a ruby, I would send any corundum to GIA Laboratory before setting or selling it.

 

[arkieb1]

I use Lotus Lab in Thailand, owned by Richard Hughes and his daughter Billie as my go to lab for rubies (it also helps it's on my side of the world) I've had rubies bought from one of the largest ruby sellers at the big Hong Kong gem show claim were heat only come back with heat and minor flux residues, so really you need a decent lab or they can and do get it wrong in other places....

 

[T L]

I use Lotus Lab in Thailand, owned by Richard Hughes and his daughter Billie as my go to lab for rubies (it also helps it's on my side of the world) I've had rubies bought from one of the largest ruby sellers at the big Hong Kong gem show claim were heat only come back with heat and minor flux residues, so really you need a decent lab or they can and do get it wrong in other places....

Do they have access to a mass spectrometer?

 

[T L]

I have purchased several gems since 2017 with the certificate provided by Chanthaburi Gemological Laboratory. Until recently, all were correct.

I had purchased a 1+ct blue sapphire with a CGL Report which stated it was "heated."

I sent the gemstone to GIA. The GIA Report stated the gemstone was Beryllium Treated (See FTC Rules).

I would not rely on any report by CGL.

As far as a ruby, I would send any corundum to GIA Laboratory before setting or selling it.

This is a perfect example of why you should get gems, in particular corundum, fully tested. CGL was right, the stone was heated, but many smaller labs do not have access to the expensive equipment which is sometimes necessary to detect chemical enhancement. A lab report shouldn’t say “heated” for corundum, but something like “heated with no additional treatment.”

 

[arkieb1]

Do they have access to a mass spectrometer?

I honestly don't know but Richard Hughes is the guy that wrote many of the textbooks and articles and photographs labs like GIA and AGL use as references, I consider him the "father" of knowledge about sapphires, rubies, jade and spinels he tours the world lecturing on them;

https://www.lotusgemology.com/index.php/about/news

They have written a few reports for me and none of them have ever been wrong. I'd actually rate them as more accurate for things like origin than GIA is....

 

[T L]

I honestly don't know but Richard Hughes is the guy that wrote many of the textbooks and articles and photographs labs like GIA and AGL use as references, I consider him the "father" of knowledge about sapphires, rubies, jade and spinels he tours the world lecturing on them;

https://www.lotusgemology.com/index.php/about/news

They have written a few reports for me and none of them have ever been wrong. I'd actually rate them as more accurate for things like origin than GIA is....

I understand that, and I know of Richard Hughes, but it’s still really important for any lab grading corundum to have access to a mass spectrometer. I would not recommend Lotus unless I knew for sure.

 

[T L]

Here is the list of enhancement codes that Lotus uses:

https://www.lotusgemology.com/index.php/lab/enhancements

In some cases, diffusion can be determined with standard gemological equipment, but not always. AGL, for example will charge an extra fee to test with a mass spectrometer or LA-ICP-MS (more accurate than a LIBS), and if not, they will say, something like additional testing wasn’t requested, but they just won’t say ”heat.” If the stone is determined to be heat only, the report will also state there were no additional enhancements, heat only. Lotus seems vague on this. Does “H” mean that they performed all possible tests on the stone to rule out diffusion??

I’m not dissing Lotus or Mr. Hughes. I understand he is highly respected. I’m just asking questions.

 

[arkieb1]

Here is the list of enhancement codes that Lotus uses:

https://www.lotusgemology.com/index.php/lab/enhancements

In some cases, diffusion can be determined with standard gemological equipment, but not always. AGL, for example will charge an extra fee to test with a mass spectrometer or LA-ICP-MS (more accurate than a LIBS), and if not, they will say, something like additional testing wasn’t requested, but they just won’t say ”heat.” If the stone is determined to be heat only, the report will also state there were no additional enhancements, heat only. Lotus seems vague on this. Does “H” mean that they performed all possible tests on the stone to rule out diffusion??

I’m not dissing Lotus or Mr. Hughes. I understand he is highly respected. I’m just asking questions.

Email them and ask they are usually fairly prompt at getting back to anyone..... if you don't get anywhere let me know I'll email Billie she runs the show these days, while her father travels.