GIA - what to look for

[timetim]

Hello,

After reading through many posts about problems with GIA and its many scandals, I am a bit confused about it. Do you all still consider it to be reliable?

Say, if a jeweller offered me a diamond with a GIA cert, would I be able to trust it? And could I just take the depth %, table % etc figures, input them into HCA and see how well it is cut?

Also, without Idealscope images etc, would I be able to tell whether there was light leakage etc?

Basically, I want to know whether I could tell sufficiently whether a stone was ideally/excellently cut from just a GIA cert nowadays.

Thank you.Hope someone can help!

 

[Kelli]

I WISH I had posted this question before I bought my stone. I bought a GIA Excellent cut with excellent polish and symmetry thinking I was getting a great stone. It took me a little while, having never owned diamonds before, and also not seeing enough truly well cut ones, but I realized mine''s cut was rather poor. It is now almost done with the re-cutting process, because I just couldn''t stand the fact that it wasn''t right. But anyway.... on to your question. Getting the info and running it through the HCA certainly would help. You have to have the crown and pavilion angles to do this. (Had I known that I would''ve avoided the whole mess and bought a different stone to begin with.) If the score is under two, you may have a very well-performing diamond. I think, and I hope one of the experts will chime in here, that the only problem left is the fact that the GIA rounds numbers in the percentages so they might not be exact. I don''t know how much of a problem that is, but maybe someone will.

So to wrap it up, no you can''t really just go by what the cert says, but that doesn''t mean you can''t find a good GIA stone either. I know for me personally, I will NOT be buying a GIA diamond again, just based on the fact that the AGS does so much of a better job. Good luck, and I hope this was helpful.

 

[timetim]

Thanks very much, Kelli. I would go for an AGS stone too, but the B&M retailer I think I might go with here in New Zealand doesn''t have any AGS stones, only a few GIA stones, and the rest are not graded.

So, you think that just inputting the numbers from the GIA cert into HCA would be able to give me a good idea of how well it is cut compared to those I see online with AGS Ideal Cut 0? I want a stone like that, but it is way too expensive because I am in NZ.

Anyone else could advise too? Thank you.

 

[Skippy123]

Date: 9/19/2008 8:11:53 PM
Author:timetim
Hello,

After reading through many posts about problems with GIA and its many scandals, I am a bit confused about it. Do you all still consider it to be reliable?

Say, if a jeweller offered me a diamond with a GIA cert, would I be able to trust it? And could I just take the depth %, table % etc figures, input them into HCA and see how well it is cut?

Also, without Idealscope images etc, would I be able to tell whether there was light leakage etc?

Basically, I want to know whether I could tell sufficiently whether a stone was ideally/excellently cut from just a GIA cert nowadays.

Thank you.Hope someone can help!

You could buy an idealscope. I would copy the numbers of the cert depth, table, pavilion and crown and input them into the HCA.

 

[arjunajane]

Date: 9/20/2008 12:01:44 AM
Author: timetim
Thanks very much, Kelli. I would go for an AGS stone too, but the B&M retailer I think I might go with here in New Zealand doesn't have any AGS stones, only a few GIA stones, and the rest are not graded.

So, you think that just inputting the numbers from the GIA cert into HCA would be able to give me a good idea of how well it is cut compared to those I see online with AGS Ideal Cut 0? I want a stone like that, but it is way too expensive because I am in NZ.

Anyone else could advise too? Thank you.

A GIA cert is definately preferable to none at all !
Most here regard GIA and AGS as the most reputable, consistent labs. I would second getting the measurements of the cert, than you can always come here and post them. People will be happy to help.
Yes, they have had their scandals, but they are still more reliable for clarity, colour etc.

Does the store have an idealscope? Otherwise, as Skippy suggested, getting your own IS viewer and learning what to look for could be a good idea.

I don't know about NZ, but from my experience in stores in Australia it is rare to find a store with a choice of GIA stones - most have EGL, IGI etc

Good luck and keep us posted !

 

[Kelli]

The HCA will at least help you weed out the ugly steep deep stones like I bought. You should be able to find a beautiful one. The idealscope would definitely be a great idea too!

 

[stone-cold11]

Ditto on all of the above. Maybe ask if you B&M store have a sarin scanner? Those would give you the numbers on the stones you are interested in.

 

[Lorelei]

Date: 9/19/2008 8:11:53 PM
Author:timetim
Hello,

After reading through many posts about problems with GIA and its many scandals, I am a bit confused about it. Do you all still consider it to be reliable?

Say, if a jeweller offered me a diamond with a GIA cert, would I be able to trust it? And could I just take the depth %, table % etc figures, input them into HCA and see how well it is cut?

Also, without Idealscope images etc, would I be able to tell whether there was light leakage etc?

Basically, I want to know whether I could tell sufficiently whether a stone was ideally/excellently cut from just a GIA cert nowadays.

Thank you.Hope someone can help!

That is certainly an approach you could use and if you bought your own Idealscope you should be able to find a lovely diamond using these methods.
http://www.ideal-scope.com/cart_zoom_item.asp?Id=2&ShowAdd=Y