GIA vs. AGS

[CountryBoy]

Hello everyone,

As part of my quest to get educated on diamonds this past month, I''ve had trouble finding the differences between an AGS diamond and a GIA diamond. My research on this forum has led me to decide against an EGL diamond, but beyond that I am unsure. Most of the diamonds on my wish list (dirt cheap diamond signature round cuts

) have been graded by AGS and not GIA. Should this cause me any concern?

Are there any advantages/disadvantages in going with one over the other? Thank you.

 

[aljdewey]

No cause for concern at all.....AGS and GIA are both top-shelf labs. Both have an excellent reputation. Around here, most of the RB folks actually prefer AGS because their grading reports provide cut grade info. Many find their clarity grading even a little stricter than GIA as of late.

However, as long as you have measurement info from a Sarin or OGI or similar device on GIA stones, no worries.

 

[WinkHPD]

Aljdeway is correct that AGS will give you more information about the cut, and that is even more true since they have come out with their new grading system for cut. It is a proformance based system and it is much harder to get an AGS 0 for cut grade than it was before. Many manufacturers are complaining, but I believe that the public will be cheering.

If you are truly interested in Cut as the most important factor in your decision, you will probably find it easier to get information from an AGS cert than a GIA cert.

Wink

 

[CountryBoy]

Thank you Aljdeway and Wink. I now feel totally confident purchasing an AGS certified diamond. Thanks again!

 

[codex57]

Either one. I''d actually prefer AGS cuz it gives you more info. However, most "reputable" places carry GIA much more cuz that''s what the market expects. Both are perfectly fine.

 

[WinkHPD]

Here is my take on the AGS GIA certs.

With the advent of the new AGS proformance based standards many dealers are going to avoid them like the plague since they are much tighter about what receives and AGS 0 cut grade. If I was selling slightly off AGS 0 makes I would send them to GIA and get them labeled ex ex and be a happy camper. Seeing the new standards that AGS has set will make many of the manufacturers crazy. Some have already called in to say that no one can cut these goods consistently.

The FACT that Paul Antwerp and others are already doing so is a great comfort to those of us who sell such stones, as they are adequate PROOF that indeed the standards can be met.

I forsee the next couple of years being REAL interesting, especially since GIA is apparently not any where near ready to reveal their own research. AGS is going to great lengths to be transparent to the trade, I wish GIA would follow suit.

Wink

 

[Garry H (Cut Nut)]

After spending some time buying diamonds today I have to say how disapointed I am with both GIA and HRD''s SI2 grades.

When we conducted this survey last year http://grading.pricescope.com/ Country boy we found that GIA was balanced or slightly tougher on color than AGS and EGL USA, but that both AGS and EGL USA were stricter on clarity.
Below are some of the Myth and Facts we found in our conclusion:

“Diamonds graded by GIA-GTL have better resale liquidity”. Fact
"GIA is the strictest laboratory in the world" – Myth. According to this survey 8 out of 16 diamonds were graded more strictly by AGS. EGL tended to grade clarity more strictly.
"AGS is very strict" – A fact overall, but AGSL color grades can be softer than GIA-GTL.
"EGL certificates are not worth the paper they are printed on" – Myth. Although in 12 cases out of 17 EGL graded color softer, EGL clarity grading was as strict or stricter as GIA.
"GIA has the strongest international diamond brand" - Fact.
"It is safer to buy a GIA graded diamond" - Myth. Any diamond grading report is an opinion, not a guarantee.
"GIA invented the grading standards and independent reports"- Fact.
"GIA or AGS reports guarantee grading accuracy" – Myth. This survey shows that both labs can grade either softer or more strictly and this affects a diamonds price.
"Consumers should consider an appraisal by a qualified and independent gemologist" – Fact. This can ensure a diamond meets a consumers criteria and to avoid possible switching errors (two occurred in this survey).
"Diamonds with GIA reports trade for higher prices". Myth - AGSL diamonds often trade for more.
"GIA has trained more gemologists world-wide than all the other schools combined" - Fact.
"Excellent / Excellent GIA graded diamonds are more beautiful" – Myth. An Ex / Ex diamond can have poor proportions; symmetry and polish have less effect on diamond beauty than proportions.
"GIA-GTL charges more than other labs" – Fact. This adds to the cost.
"GIA-GTL takes longer to grade a diamond than other labs". Fact - This adds to the cost.
"GIA-GTL provides the least useful cut grading information of any major lab" - Fact
"You can get ripped off buying an EGL USA graded diamond" - Myth. Even if you buy a one higher color EGL graded diamond than you require, GIA-GTL may grade it a color grade lower and the same clarity, but you will probably pay less.
Over time labs may adjust their grading strictness, and new myths and market pricing may evolve. For this reason Pricescope will regularly conduct similar surveys of these and other diamond grading laboratories.

So infact there is no reason not to buy any diamond based on its grading report - even EGL USA - as long as you are comfortable with the diamond itself.

 

[Michael_E]

Date: 6/7/2005 10:02:43 PM
Author: Garry H (Cut Nut)
So infact there is no reason not to buy any diamond based on its grading report - even EGL USA - as long as you are comfortable with the diamond itself.

I find this comment really funny. You wouldn''t be saying that the best buys to be had in diamonds can be those whose certs are from lesser respected labs or even those which have no cert are you, Garry ? Why that''s almost sacrilegious !