The AGS-0 versus GIA Ex Cut Price Premium. Ouch!! Advice?

[diamondjim]

I've been searching this forum and found a number of articles on AGS-0 versus GIA Excellent cut. Seems that the consensus is that AGS-0 is a tighter standard (especially in terms of light performance).

I've also read that a GIA Excellent cut which is Excellent/Excellent (Sym/Pol) and HCA <2.0 would virtually be the equivalent to AGS-0, or at least the bases would be covered.

Am I buying into the hype with AGS-0 over GIA Excellent? Reason I ask is that a 1 CT round VS2, I color with HCA score <2.0 is almost a 50% premium in price!!!

http://www.eternitybyyoni.com/diamond_detail.php?id=748583&ref=pricescope which is $4.6k...

http://www.whiteflash.com/loose-diamonds/round-cut-loose-diamond-2787734.htm which is the same but $7.1k (yes, 1.01CT instead of 1.00CT on the first diamond, but all else I think is the same aside of the AGS-0 distinction on this one).

I could go to 1.25 CT GIA EX/EX VS2 I color for $7.1k.

Thoughts??

 

[madelise]

Re: The AGS-0 versus GIA Ex Cut Price Premium. Ouch!! Advi

The reason why there's this price discrepancy is exactly what you stated: AGS 0 is more stringent than GIA EX. There are plenty of GIA EX that will be just as good, but not all of them are. You have to put in some footwork to find one "worthy".

Run the #'s through HCA to weed out any that are 2.0+.
Then ask the vendors for IdealScope images.



Have you gone through James Allen's inventory? They have images of the diamond up already, so you can see yourself which ones are more "perfect" than the others. You can then request them to give you ideal scopes for up to 3 diamonds, so you can choose which would be the best fit.

HTH.

 

[yssie]

Re: The AGS-0 versus GIA Ex Cut Price Premium. Ouch!! Advi

There's a lot more to that comparison than just AGS0/GIA EX.


The first stone is an ACA. That means

1. Precision cutting to exhibit perfect hearts and arrows patterning. The ED isn't labelled as H&A and GIA doesn't grade optical symmetry (actually neither GIA nor AGSL consider optical symmetry in grading cut at all)

2. It's a branded stone. Branded stones carry brand premiums. WF's ACA brand also comes with generous upgrade/buyback/trade-in guarantees which you're paying for in that brand premium. ED's policies are less generous but they don't charge the premium. They may or may not be worth the extra cost to you.

3. The ACA's proportions fall in highly valued ranges - they'll yield a stone with a certain characteristic "look and feel" that many people like, and that other grading schemes value. The GIA's proportions are outside that range, though they still qualify for GIA's EX grade - the stone will look and perform differently (assuming decent optical symmetry) it's not necessarily a bad thing - just different.

4. The ED is sold - do you know when? Prices can change (ie go up ) overnight, so if it was sold even a few weeks ago it might not be a fair comparison even ignoring all the other differences..

 

[yssie]

Re: The AGS-0 versus GIA Ex Cut Price Premium. Ouch!! Advi

I've also read that a GIA Excellent cut which is Excellent/Excellent (Sym/Pol) and HCA <2.0 would virtually be the equivalent to AGS-0, or at least the bases would be covered.

ETA: don't know where you read that but I hope there's some misunderstanding because that's definitely not the case.

GIA EX, HCA, AGSL's cut grade - to you, the consumer, they're all just different tools that help you decide on the right stone for *you*. GIA EX + HCA <2 is a quick and dirty to find stones that are very likely to be nice (neither considers optical symmetry so there's still a possibility of running into something strange but the probability is low). GIA EX + HCA tells you NOTHING about what AGSL would say - or, rather, what their DQD w/ Light performance would say, and that's the prestigious report that carries the premium. The "light performance" part involves a ray tracing programme (PGS) and what cut grade they assign ultimately depends on PGS output, not what the proportions charts say.

AGS0 on the DQD doesn't promise perfection either, btw, if you define perfection as the "PS Ideal". I've seen AGS0s I wouldn't want - but they're few and far between.

 

[diamondjim]

Re: The AGS-0 versus GIA Ex Cut Price Premium. Ouch!! Advi

Thank you both very much! These are exactly the answers I was seeking.

The ED sold probably because I put it up as a link and someone came along and scooped it in the 20 minutes since I posted this to the forum?

No matter, plenty of stones available that was just an example.

I use the PS search and always have HCA < 2.0 specified.

I'd also like to say that the Diamond Guide was extremely helpful. I took the time to read through the basic and more advanced material. This site is really an asset to prospective buyers like myself. My sincerest thanks to all of you that bring such valuable info to newbies like myself.

Will definitely ask them for the idealscope if I go with ED. I also look at the GIA certificate to ensure that VS2 is not one which includes too many inclusions in the wrong places.

Best regards!

 

[diamondseeker2006]

Re: The AGS-0 versus GIA Ex Cut Price Premium. Ouch!! Advi

Those two stones were likely not equivalent in cut quality regardless of who graded them. One is a hearts and arrows super-ideal cut and the other we have no idea since there is not even an idealscope image posted. And I wouldn't buy a stone with a 32.5 crown, either. There are far more stones graded by GIA, so if you do your homework, you can find plenty of GIA Ex graded stones that are equal to an AGS ideal cut stone. For example, some of Good Old Gold's signature stones are GIA graded and have been tested to have ideal light performance according to AGS standards. So as always, a stone has to be evaluated according to it's own merits, and just because it has been graded by a certain lab, it isn't necessarily better or worse because of that.

 

[diamondjim]

Re: The AGS-0 versus GIA Ex Cut Price Premium. Ouch!! Advi

Those two stones were likely not equivalent in cut quality regardless of who graded them. One is a hearts and arrows super-ideal cut and the other we have no idea since there is not even an idealscope image posted. And I wouldn't buy a stone with a 32.5 crown, either. There are far more stones graded by GIA, so if you do your homework, you can find plenty of GIA Ex graded stones that are equal to an AGS ideal cut stone. For example, some of Good Old Gold's signature stones are GIA graded and have been tested to have ideal light performance according to AGS standards. So as always, a stone has to be evaluated according to it's own merits, and just because it has been graded by a certain lab, it isn't necessarily better or worse because of that.

Thanks diamondseeker2006, so you would prefer a crown closer to the 34.5 degree Tolkowsky ideal cut?

If I go with ED, I'll definitely ask for an idealscope which should give me some info on brilliance and optical symmetry.

 

[oldminer]

Re: The AGS-0 versus GIA Ex Cut Price Premium. Ouch!! Advi

To a novice diamond owner, wearer, or casual admirer, no visual difference, or only a very slight visual difference exists to be seen between nearly any GIA XXX and nearly any AGS000. The HCA may help to equate between such stones but the stone you select should simply be one you like at a price that makes sense to you and your budget. Asking about a single parameter, such as crown angle, without reference to all the accompanying angles of a particular diamond, is not a sound or recommened method for selecting any stone over another. Such advice, if provided, is close to asking which is better, Green mint chocolate ship or White mint chocolate chip ice cream. It would be totally a matter of informal opinion, and not factual. WHile a standard Tolkowsky cut has a 24.5 degree crown angle, that is not the only crown angle that is highly effective so long as other angles around the diamond are adjusted accordingly.

Vendors are entitled to ask what they feel the market will bear for their regular and premium products. Truthfully, most consumers who are buying jewelry buy them at chain stores and buy a rather ordinary level of cut quality yet pay far more than what vendors of high cut quality diamonds charge on-line. The small percentage of those willing to pay a really large premium for a superbly cut stone will consider a premium price part of the deal for a truly superior product, even if the actual difference is hardly visible but more to do with the time spent in perfecting the cut regardless of the cost consideration. Those that want the very finest tend to actually want to pay that premium to get exactly the product their taste demands. It isn't a "value" issue, but how vendors choose to market luxury and uber-luxury items.