Is it true that AGS is less strict on color compared to GIA?

[NicoleNeedsHelp]

I heard a weird statement yesterday from a reputable jeweler and I’m wondering what your thoughts are......is this true in your experience?

Jeweler told me that in their personal experience, AGS is a “bit more lax“ on color than GIA. Specifically, I was told that a GIA I color stone would be a AGS H color stone. I was told if I was going to buy an AGS, that I should buy one color up from where I wanted— for example, if I want an H color, I should buy a G from AGS.

Does anyone have any thoughts or insights about this? I‘m not trying to cause a war between GIA vs. AGS or anything like that- I’m just wondering if anyone has found this to be true In their experience ? Jeweler said a ton of nice stuff about both AGS and GIA— jeweler just found that there was often a difference in the way the 2 companies grade color.

 

[MamaBear]

This has been discussed. Im sorry I don’t know how to link the thread but if you do a search on “AGS color“ you can find info.

 

[Kaycee2018]

If you do a search you will find that this is not an uncommon belief. There are many discussions and debates on this forum on the topic. The general consensus seems to be that AGS is now more consistent in grading color vs. GIA, but perhaps years ago they were a bit more lax.

 

[Bonfire]

AGS color and clarity grading

What are your thoughts on AGS color and clarity gradings? I hear mixed reviews that they tend to be more lenient on color and clarity then GIA and I’m curious if anyone ever sent to double certify have seen anything else. Thanks

www.pricescope.com

 

[NicoleNeedsHelp]

Thank you! I reviewed the threads on this topic and they are so interesting!

 

[oldminer]

If AGSL was "stricter" on grading than GIA the lab would go out of business. Dealers do not need anything more strict than what GIA would grade any diamond. Since the exact borderline of color between the color grades is not a perfectly defined, scientifically standard color, there are borderline calls that can go either way. AGSL does a great job and has consistency. So does GIA. Both labs are money making businesses and want to follow the same set of standards. The few diamonds they might grade differently than one another are not much to worry over, but it just stands to reason that since GIA is the bigger and more powerful entity that AGSL needs to meet GIA grading and not the other way around. There is no way to perfectly grade every diamond identically even though many would prefer it. A lot of color grading is being done with AI now and much more will be done in the future. As that takes hold, I'd expect near total conformity of grading from all the labs which participate in that advancement.

 

[Laila619]

I think AGS is a bit softer on color than GIA, yes. I used to own an AGS graded ‘H’ color diamond, and I swear that bad boy was an I or even a J. It didn’t bother me too much, but when I read on PS that AGS being soft on color was sort of a thing, it made sense.

 

[denverappraiser]

FWIW, I just did a reinspection on a 2010 AGS and sent it to GIA because the client was concerned about exactly this question. AGS 2.60/SI1/H/000. GIA called it 2.60/SI1/H/xxx. One stone is not a study, of course, but it's an interesting anecdote.

 

[nala]

Here’s the thing. I don’t know how many ags owners will actually comment and respond to you even if they suspect that ags grades softer on color. For one thing, they might not have a readily available gia stone to compare to, so they might not realize this is the case. And the same can be said of GIA owners—except that reputation goes a long way. In this forum, no one has a problem calling out EGL or IGI, etc but AGS is a different story given that many beloved vendors only offer such certificates for their branded stones. Just to simplify your life, if you appreciate colorless, err on the side of caution and go up in color...don’t expect unbiased opinions here.

 

[Dancing Fire]

GIA H on the left and AGS H on the right.



GIA H on top AGS H on bootom.

 

[MissGotRocks]

I put more stock in the vendors and appraisers who see lots of diamonds every day Their consensus has always seemed to be that differences are very negligible. It really wouldn't make sense for one lab to be more strict than the other on either color or clarity. You will find individuals with their own experiences and opinions on a diamond or two but the truth - in my opinion - is always more evident in those who deal with many diamonds on a daily basis.

 

[Petalouda]

This is anecdotal but my diamond happened to be graded by both AGS and GIA when I purchased it. Both graded my diamond as a H VS1

 

[Big Fat Facets]

in my personal first hand experience, agsl and gia grade comparatively.

in fact, i have a diamond that was graded 10 years ago by agsl as an f color. this year, it was sent to gia. and it was also graded an f color. essentially, two cross validating reports from both labs, grading it an f color.

i feel it is important to operate on facts and evidence

 

[Karl_K]

don’t expect unbiased opinions here.

I dont really think that is fair.
My answer is I dont know.
Now I have talked to people with a lot of experence with both of them over time and the general opinion is that AGSL tries to track GIA closely and mostly suceeds.
But that and six bucks will buy you a coffee at Starbucks so take it for what its worth.

 

[nala]

I dont really think that is fair.
My answer is I dont know.
Now I have talked to people with a lot of experence with both of them over time and the general opinion is that AGSL tries to track GIA closely and mostly suceeds.
But that and six bucks will buy you a coffee at Starbucks so take it for what its worth.

We all have biases—so that is very fair. Especially vendors who carry AGS—don’t you think they would have a vested interest in claiming there is no difference?

 

[yssie]

My three most "valuable" stones - I got both GIA and AGS reports on. Just because I was interested - I went in with the expectation that the results would had no impact on my enjoyment of the stones, and they have not.
1. E-ring stone, bought with GIA report: 4.01ct. GIA J, AGS J, same on clarity (VS1)
2. Earring stone #1, bought with GIA report: 2.69ct. GIA J, AGS I, same on clarity (SI2)
3. Earring stone #2, bought with AGS report: 2.71ct. AGS J SI1, GIA K VS2.

The Ering stone and Earring stone #2 also happen to have HRD reports. Shrug. The earring is an HRD J. The E-ring is an HRD L. There is no world in which any reasonable individual calls this stone an L. Shrug, again.

 

[MissGotRocks]

We all have biases—so that is very fair. Especially vendors who carry AGS—don’t you think they would have a vested interest in claiming there is no difference?

No, inasmuch as they don't send diamonds to AGS primarily for color grading. They send them to AGS for the light performance analysis. GIA rounds their numbers and does no light performance. The top ideal cut vendors primarily use AGS for that reason. As long as color grading is still done by human eye, there is always some room for discrepancy. If it happened with each and every diamond, there might be a case for bias but that doesn't appear to be the case either. To me, overall numbers count more than random individual stones. We all know there can be ranges in color grades as well. Just my .02.

 

[missy]

Some interesting links for your reading enjoyment.

https://www.gia.edu/doc/Coloring-Grading-D-to-Z-Diamonds-at-the-GIA-Laboratory.pdf

GIA Graded Lab Diamonds: First Results!

Last week I shared the results of AGS’s return to grading lab diamonds, as part of our involvement with the AGS lab diamond pilot program. We are also one of the first to receive full-fidelity GIA grading reports, with 17 diamonds sent to GIA for secondary grading. The results? Unsurprising...

www.pricescope.com

Results of AGS Graded Lab Diamonds vs. IGI & GCAL

We were invited to participate in the pilot phase of AGS's return to grading lab diamonds, and we have the results back from our first few batches graded by AGS. Most of the stones we sent were previously graded by IGI or GCAL so I am sharing the results with the community to address the...

www.pricescope.com

Bottom line is each stone needs to be evaluated on its own merits. There is no foolproof completely objective grading. Yet.

From what I have read on PS and from my own personal experience AGS can occasionally be softer on color but regarding ideal light performance AGS is the way to go.

For peace of mind one can obtain both GIA and AGS certs for the diamond in question. If one really is curious and wants to/needs to know.

 

[kgizo]

I’ve heard that rumor, too. No idea if it is true or not. I once had a vendor recommend AGS for the reasons MissGotRocks mentions above. The concern was that since cut is important to me if I ever lost the stone the insurance company could replace a GIA XXX with another GIA XXX and there is a lot of variance in cut and performance amongst those diamonds but an AGS 000 is going to be much more narrow. The vendor advised to include the AGS report in my insurance docs so that if they tried to sub a lesser stone I could dispute it wasn’t equivalent based on differing crown, pavilion, depth, etc measurements. I’ve never filed a claim so don’t know if this is true or not either.

 

[MissGotRocks]

I’ve heard that rumor, too. No idea if it is true or not. I once had a vendor recommend AGS for the reasons MissGotRocks mentions above. The concern was that since cut is important to me if I ever lost the stone the insurance company could replace a GIA XXX with another GIA XXX and there is a lot of variance in cut and performance amongst those diamonds but an AGS 000 is going to be much more narrow. The vendor advised to include the AGS report in my insurance docs so that if they tried to sub a lesser stone I could dispute it wasn’t equivalent based on differing crown, pavilion, depth, etc measurements. I’ve never filed a claim so don’t know if this is true or not either.

Absolutely - this is me too. The cut grading is far more important to me than the color grading.

 

[CareBear]

AGS - occasionally less strict on color
GIA - occasionally less strict on clarity
AGS - WAYYYY more strict on cut.

For me, I stick with AGS for my MRBs. And anyone that tells you your AGS stone is two grades off, they are wrong.

 

[Texas Leaguer]

AGS color and clarity grading

What are your thoughts on AGS color and clarity gradings? I hear mixed reviews that they tend to be more lenient on color and clarity then GIA and I’m curious if anyone ever sent to double certify have seen anything else. Thanks

www.pricescope.com

For the sake of convenience (for me) and since it was a recent thread, I will simply copy and paste part of my post #50 in the referenced thread above:

This is a regular topic of conversation on pricescope and in all my years here I have never seen any statistically significant evidence sited to demonstrate that one lab is “softer” on either color or clarity than the other. There is only anecdotal evidence of a stone here or there that show grading variance. And that variance almost always falls into the understood and acknowledged (by all labs) tolerance of a one grade differential.

We deal in both AGS and GIA graded diamonds and have extensive experience with both labs. We have never seen any evidence of consistent grading differences. Every dealer has occasion to question a color or clarity grade at the lab from time to time, and re-checks are a very common process in both labs (and a revenue center because they charge for it!). And once in a while a borderline grade is changed by the process of escalating to a more senior grader. This is just more support for that one grade tolerance inherent in human grading.

Automated color grading is now being done by GIA on a subset of diamonds submitted to their labs. Eventually it may be possible to do all color grading by machine, which would eliminate the human factor. But then there will still be instrumentation deviation to consider!

 

[nala]

For the sake of convenience (for me) and since it was a recent thread, I will simply copy and paste part of my post #50 in the referenced thread above:

This is a regular topic of conversation on pricescope and in all my years here I have never seen any statistically significant evidence sited to demonstrate that one lab is “softer” on either color or clarity than the other. There is only anecdotal evidence of a stone here or there that show grading variance. And that variance almost always falls into the understood and acknowledged (by all labs) tolerance of a one grade differential.

We deal in both AGS and GIA graded diamonds and have extensive experience with both labs. We have never seen any evidence of consistent grading differences. Every dealer has occasion to question a color or clarity grade at the lab from time to time, and re-checks are a very common process in both labs (and a revenue center because they charge for it!). And once in a while a borderline grade is changed by the process of escalating to a more senior grader. This is just more support for that one grade tolerance inherent in human grading.

Automated color grading is now being done by GIA on a subset of diamonds submitted to their labs. Eventually it may be possible to do all color grading by machine, which would eliminate the human factor. But then there will still be instrumentation deviation to consider!

I’m curious—does pricing take this one grade differential variance into consideration? Why not certify with both labs to ensure that customers are truly getting what they paying for? Price jumps are so high from one color to the next that it would seem unfair to overpay

 

[Texas Leaguer]

I’m curious—does pricing take this one grade differential variance into consideration? Why not certify with both labs to ensure that customers are truly getting what they paying for? Price jumps are so high from one color to the next that it would seem unfair to overpay

It's a legitimate question, and while on the one hand this seems like a logical solution, in practice it is both expensive and potentially problematic. Again, we must remind ourselves that there is an inherent potential one grade variance between the top labs. Ultimately these are human calls of grades that are themselves small ranges. If there is a difference, we cannot say that the gemologists in one lab are correct and the other gemologists are mistaken. So how do you reconcile those cases where labs disagree, even if it was practical from a price and logistics perspective for merchants to send all of their diamonds to both labs?

Regarding their reputation for consistent and accurate grading, the only survey that I am aware of was one presented by Martin Rapaport in his annual address several years ago at the big trade show in Las Vegas based upon all the diamonds listed on Rapnet. That survey showed a premium for diamonds carrying an AGSL report over GIA. This certainly reflects the fact that those AGSL reports skewed towards the very top in cut quality, but if color and clarity were not also consistent, that premium would be nullified.

 

[Big Fat Facets]

I feel it is also important to mention that diamonds graded in a lab, gia and agsl, are graded by 2 different gemologists. if they agree, then it stops there, however, if the 2 gemologist do not agree, the diamond will be graded by a more senior gemologist.

diamonds are graded in a controlled environment with specialized diamond grading light, against a set of master stones. that is the process and method in which the educated trained experienced professional gemologist at the labs, grade stones

so, if one comes across an individual claiming that "... agsl is at least one if not two color grades off ... " without bothering to provide lab reports to substantiate is nothing but a joke. and potentially, damaging to vendors that sell agsl certed diamonds

i feel, it is beneficial, to understand that slight infrequent variances could come from either labs. and does not mean when these slight infrequent variances occur that agsl will be the lab softer on color.

i have heard that gia will be the lab less strict on color and clarity. but i have observed very little "chatter" about that. yet, way too many repeated, tiresome chatter and rumors ... that if there is to be a variance, it will be agsl being less strict on color.

in the past, i have made it a point, not to repeat that i have heard gia labs being softer on color and clarity, as i do not wish to perpetuate and contribute to rumors without personal first hand experience, furnishing proof and evidence

@yssie thank you for your personal first hand experience of your personally owned diamonds furnishing certificates from both labs.

of the four most valuable diamonds i have in my collection: 3 are agsl 000 certed diamonds. and 2 are gia certed. 1 of which, is double certed

i don't know about anyone else. but i will happily purchase an agsl certed stone any day of the week as i am assured of it's exceptional ideal/super ideal light performance as a result of top of the mark cut quality over a gia xxx . and am undeterred by the premium assessed on these agsl 000 ideal/super ideal diamonds

i would much rather select an agsl oec stone, antique cushion/old mine stone, round brilliant over a gia certed one

as an aside, i am of the personal opinion, that perhaps, the infrequent seldom exceptions in variances between the labs, could more often occur, when the color of the diamond is warmer as the color range is progressively wider, the further down the color scale

 

[LLJsmom]

For MRB, I prefer AGS cause cut matters most to me with an MRB.
For OEC, I prefer GIA because I can judge whether I like the cut with my eyes. I want to err on the side of a more conservative grading with color.

 

[missy]

For MRB, I prefer AGS cause cut matters most to me with an MRB.
For OEC, I prefer GIA because I can judge whether I like the cut with my eyes. I want to err on the side of a more conservative grading with color.

Same.

You and I have seen with our own eyes AGS color discrepancies. But for MRBs you cannot beat their cut grade.

I agree for genuine OECs GIA really is a great way to go.

 

[yssie]

If there is a difference, we cannot say that the gemologists in one lab are correct and the other gemologists are mistaken. So how do you reconcile those cases where labs disagree, even if it was practical from a price and logistics perspective for merchants to send all of their diamonds to both labs?

This is an excellent question. I think the answer depends on what the person doing the questioning is hoping to get from these reports.

If the lab report was purely academic, then the rationales behind acquiring one would also be largely academic, and the one grade tolerance would be a curiosity.
But the report isn’t an academic exercise: A 3.21 G costs more than a 3.21 H, all else the same. When consumers are expected to pay for, but not trust, a single-grade designation, I feel those consumers are justified in questioning the authority behind that designation.

For reasons stated by others earlier in this thread - AGS will never make a habit of being more tight-fisted on colour than GIA. They strive for parity, but any systematic failure to achieve parity will always err toward lenience.
How do systematic trends predict individual anecdotes? Shrug.

In my case, I bought all my stones with one report (GIA or AGS - let’s discount the HRDs) and then had those stones sent to the other lab. For me it really was an academic exercise. I know that if I’d had any of these stones sent back to either lab for recheck, there is some possibility that the same lab would alter its assessment.

There is a fundamental mismatch in the way that vendors and consumers are expected to interpret and use reports, and until that is resolved, I don’t see these sorts of questions going away.

 

[CareBear]

I think I mentioned this in a previous thread. I used to own a 2.1 I VS2 AGS super ideal stone, which was appraised to be borderline J, solid VS1. The appraiser told me it was likely that GIA would have graded it a J. This bothered me for a while and then I got over it. It was a gorgeous stone. 10 years later, I traded the stone, trade-in priced using the 2.1 I VS2 AGS certificate, and I'm certain I got a price higher than I would have, had it been a GIA I VS2.

 

[Rockdiamond]

I see a lot of "lab shopping"
For example, a cutter that generally uses GIA is offering a large stone AGS graded J/SI1.
I'd bet my bottom dollar, GIA had called the stone a K before it went to AGS.
It's not consistent enough to be a guarantee.....but when many thousands of bucks at stake for the slight difference in grade and- and the cost of the report relatively insignificant- it's going to happen.