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Best/Worst gemstone certifying labs?

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Ideal_Rock
Joined
Aug 15, 2004
Messages
5,537
There have been a couple of threads lately that talk about the different gemstone certifying labs. I know different people have different views, but I'd love to have these shared in one thread that is easily searched for those looking for info, especially on the out of country labs. Thanks!
 

T L

Super_Ideal_Rock
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Joined
Sep 20, 2008
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23,283
Well labs really don't certify anything. They give a report on the opinion of the gemologist who is evaluating the gem stone.

The problem with labs is that not all opinions are equal.

As for out of the country labs, you don't know the expertise of the gemologist in question, and that is a bit disconcerting.

AGL is a premier lab, and I have confidence in Christopher Smith, the owner, to ensure the integrity of his lab.

GIA is also high reputable, but they provide very limited information on colored stones. Diamonds and FCD's are their forte.

I can't speak for the European labs as I have never used them, but I will say that I don't think any of them come close to AGL as far as providing scientific information on the actual QUALITY of the gem. They side track that, and I think that's because they want to cater to vendors if you ask me. I'm sure others may disagree.
 

Upgradable

Ideal_Rock
Joined
Aug 15, 2004
Messages
5,537
You're right, TL. I really meant Gemstone Report.

We pretty much know that AGL is the premier lab. However, given the Asian labs: GIT, AIGS, BGL, and some of the others. Who gives the most reliable info. Or do they have different strengths/weaknesses with certain stones or treatments?
 

T L

Super_Ideal_Rock
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23,283
Upgradable|1314804739|3006351 said:
You're right, TL. I really meant Gemstone Report.

We pretty much know that AGL is the premier lab. However, given the Asian labs: GIT, AIGS, and some of the others. Who gives the most reliable info. Or do they have different strengths/weaknesses with certain stones or treatments?
GIT has the ability to test for diffusion I believe, and they are highly reputable in Thailand, although their memos are pathetic looking (no photo and cheap paper).

AIGS has switched management so much and so often that I really feel it has affected their integrity. They have dodged some of my legitimate questions before, and someone here reported that they stated a sapphire was unheated, but when he sent the same sapphire to GIA, it came back as heated. To me, that is a BIG deal as it affects value on the sapphire significantly. I have very little confidence in them these days, although they do provide a cute little memo card with a hologram and a photo. I also cannot find their online report verification anymore. I wonder if they took it down from their website, and if so, why?????

Burapha and others have limited resources and equipment, but I would trust them with identifying a gemstone that is easy to id, and have very little synthesis and/or treatment (garnets, for example).

The European gem labs like GRS and SSEF both have the ability to test for diffusion, but again, for the price they charge, their lab reports don't provide much on the actual quality of the stone. Flowery descriptions don't do it for me, sorry.

AGL can send gems out for diffusion testing and they also give you a lot for your money when you do purchase their top quality lab report, so I highly recommend them. If you're buying a very expensive gem and you want to know that you got what you paid for, then AGL to me, is above and beyond the rest of the various labs throughout the world.

GIA is the lab of choice for diamonds and FCD's, but I wouldn't send expensive colored stones to them. I rather get an AGL prestige report.

I also do not trust labs that also put appraisal information on their reports. Again, these cater to the vendor, not the consumer.
 

Arkteia

Ideal_Rock
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Nov 3, 2009
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7,565
Let me put it so - Xrays or CTs use the best and most reliable equipment but these are people who read them, and people make mistakes even when they are highly trained. Same with certification of gems. I think LD opened a good thread about how the memos from different labs should look like (which is important too, because certs can be forged). I shall try to find it.

Gubelin, I know, is excellent, but it is hard to send stones there. I know that Switzerland is not what you were asking for, but I just decided to mention it, still...

[URL='https://www.pricescope.com/community/threads/laboratory-certificates.135806/']https://www.pricescope.com/community/threads/laboratory-certificates.135806/[/URL]

Personally, I would be wary of certs without photos because stones may be switched. I bought two spinels from an online vendor and his certs looked paltry. I am going to check the stones with my appraiser.
 

T L

Super_Ideal_Rock
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Pandora II

Ideal_Rock
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Aug 3, 2006
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If you are based in the USA, then I would recommend using AGL and then GIA for coloured stones.

If you are based in the UK or the rest of Europe then I would say that SSEF and Gubelin are on a par with AGL - and far easier to ship to.

Gem-A in London have a receiving system for stones to be sent to GIA - but not to AGL. There are also other shippers who do weekly drops to SSEF and Gubelin. Always much safer than just sticking a rock in the post internationally.

If I was in Thailand I would use AIGS, and if in Colombo there is a French guy who runs a small lab. I have taken stones to him and he's extremely competent - although can't do the big tests like LA-ICP-MS - and I rate him because I have sat and watched him work.

Otherwise the State Gem Corporation out there will do basic tests for free for foreigners. I've also sat with them while they tested a load of stones for me and I give them the thumbs up. Both of these last will issue reports for a fee.
 
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