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Need help choosing GIA G or AGS G

kayi078

kayi078

Rough_Rock
Joined
Mar 12, 2017
Messages
64
Im proposing very soon and need to make a decision today. I took out the F color as mentioned in previous thread because it is way over-budget and now im down to only 2 diamonds.

1.67 Premium Select G VS2 eye clean (Graded by GIA) - $15,500
(currently reserved by me)

or

1.578 ACA G VS1 eye clean (Graded by AGS) - $17,738

I would like to get ACA cut for my fiancee but i have heard that AGS grades color softer than GIA. In the photos it seems like AGS G looks whiter than GIA G but the vendor said they should look the same.

I'm about to pull a trigger on either one of these, which one should i get? Any input would be greatly appreciated. Thanks.

Comparison Chart
https://www.whiteflash.com/loose-diamonds/compare.aspx?idnos=3726902,3801980
 
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Both look good.
Usually, the 35/41 combo of the Premium Select is not my cup of tea, but it looks like the upper halves are slightly painted, so it's great.
 
I think GIA rounded the numbers?
 
Also, I think GIA is a little stricter in color grading than AGS.
 
They both look great. I imagine it would be quite difficult to see a difference between the two in person. If I were deciding for myself, I would go with the one you chose. A bit larger and lower cost. Congrats on your pending engagement!
 
kayi078 said:
I think GIA rounded the numbers?
Click to expand...
Right, and a 41° (even a 40.9°) should round to 43.5 %.
Did you ask them why it didn't make the ACA label?
Is it totally eye-clean?
 
Yes both are totally eye-clean

they didnt make it ACA because the numbers are out of their ACA requirement range. Also the GIA one has a HCA score of 2.3
 
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I would go with the ACA (cut and clarity), but you can't go wrong.
 
I would definitely choose the ACA stone. While there have been instances in color discrepancies from time to time, I don't think that is a generally accepted fact by the diamond experts on this board. I think you would probably be hard pressed to see a color difference in the stones but ask WF to photograph them side by side for you. In this instance I would always choose the better cut parameters of the ACA - they are beautifully cut stones and worth the premium to me.
 
I would pick the premium select.
Top performing GIAx with ideal proportions, backed by all light performance images and full lifetime upgrade and one year buy back coverage at a VIRTUAL INVENTORY PRICE.

Great value imho.
 
I agree with flyingpig...the stone didn't make the ACA line bc it doesn't meet WF's parameters for that line, not bc it isn't a top performer. There are many experts on here that maintain that there are other angle combos that could also result in a gorgeous stone and this is one of them.

You could always take advantage of their generous policies if you want to return or upgrade.
 
Yet one is brighter, guess which one...

Sans titre.png
 
If you are trying to maximize your budget and aren't fussy about cut, the GIA stone might be the way to go. It is their Premium Select grade - not the Expert Selection that is a step down from ACA making it twice removed from ACA. It would be a nice stone but I was inderstanding that you wanted the finest. We all have different criteria for choice and you have to decide which attributes are most important to you. I had an AGS ideal cut stone that was a great stone and decided I still wanted to see a super ideal cut stone. I can tell a significant difference but I had the previous stone for ten years and loved it and knew it inside and out. Even so, this new stone performs like nothing else! I paid the premium, knew I could have made other choices and haven't regretted it for a moment. i am not just starting out though and that makes a big difference in choice as well. I just think you need to hear all points of view so that you can make the most informed decision that you can. The good news here is that you can't go wrong with either so I wish you all the best! Please let us know what you choose and come back with pictures when you get the ring!!
 
Stephan said:
Yet one is brighter, guess which one...

Sans titre.png
Click to expand...
Really? It could also be the effect of photography, as exhibited in this screenshot of 3 ACA's...all I color...and 1 is noticeably dull/brownish/silvery.

IMG_0453.PNG
 
Look at the picture I've posted.
The table of the one on the left looks darker than the edges.
The ACA is bright on its entire surface.

The picture you've posted shows different tinges, but none has a darker table ... except the Expert Selection.
 
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Besides the bit of blue around the inner ring, the ASET would show more blue or green under the table if it was in fact dark...but it's still mostly dark red. I still think it's an effect of photography and can agree to disagree!
 
My pick would be the premium cut (but I would also get WF's honest opinion on real life performance (without magnification, and side by side view).

Firsty, the 35/41 combo may be slightly less bright than the uniform brightness of slightly shallower stones such as in this ACA vs premium, but as mentioned the idealscope images are perfect which trump the certificate numbers. But is this slight reduced brightness (under the table relative to the edge) actually a bad thing? Is it even discernible in RL without this very particular photography set up which is monocular and not stereoscopic?

This thread provides interesting perspective butu stereoscopic vision in these diamonds https://www.pricescope.com/community/threads/simple-science-is-shallow-or-deep-better.44007/
I believe it is serge has expressed before that he likes the steeper end of the diamonds and this contrast witnessed contributes to the brilliance of the diamond.

https://www.pricescope.com/community/threads/a-cut-above-vs-regular-cut.215044/ this thread provides a stimulating discussion that the more light return a diamond has is not always the better diamond.

Secondly (and more academic than anything), with this combination of averaged angles, The diamond proportions stated, the calculated pavilion angle MUST be less than 41 and likely to be 40.9 (using this tool I made to try 'unround' GIA diamonds) source: gmsoft.somee.com. The true crown angle is also likely to be <35. But that is irrelevant because the the scopes are great.
 
I afraid the AGS G will look duller than GIA G and more like a H color

If above statement is true I'm paying extra $2200 to downgrade a color and upgrade the clarity (unnecessary for me) and have a slightly better cut...
 
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I disagree AGSL grades color softer than GIA.
Such practice does not make any sense.

AGSL is used by many premium brands and vendors to market their products. We are talking GOG AVC/AVR/Ascendancy, Brian Gavin Signature/Black, WF ACA, CBI, EmbeeDiamonds (maker of Sirius Star in Canada). And AGSL caters to these vendors, whose customers are serious, knowledgeable and demanding.

Intentional and systemic softer color grading will destroy AGSL's and its partner vendors' reputation.

If what you truly want is the G VS1 ACA, but hesitant because of possible softer color grade by AGS, I say don't worry and get the ACA. If you are really concerned, ask WF for a side-by-side comparison video.
 
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gm89uk, I like the tool you've posted.
But change the culet to 0.2 and the result you'll find will be different.
 
Stephan said:
gm89uk, I like the tool you've posted.
But change the culet to 0.2 and the result you'll find will be different.
Click to expand...

The results are not different, this is based on probabilities, not an exact science due to averaging, and the conclusions are the same, that the overwhelming likelilood is the angle is less than 41.

Additionally the angle of 41 is only possible when the culet >0.3 maybe a bit more.. The program is designed to allow up to roughly 0.౩x culet if you put 0 (or pointed) to account for rounding errors and tiny culets not visible with a loup

By putting the starting culet as 0.2, you are falsely expanding the range as the program will allow up to 0.5x which you may expect GIA to put as very small in a 1.67.
 
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Wow. That is a nice tool you got, gm89uk.
I always found you very analytical. But, this is a whole new level.

I will be play with this.:appl:
 
Go for the ACA. I believe that studies have shown that the difference in grading between GIA and AGS is not substantial. I wouldn't necessarily make inferences about color based on a video. Lighting can make a diamond look great...or not.
 
flyingpig said:
Wow. That is a nice tool you got, gm89uk.
I always found you very analytical. But, this is a whole new level.

I will be play with this.:appl:
Click to expand...
Thanks flyingpig, and you too. It isn't always useful, if there are too many possibilities it's not possible to determine any meaningful results but sometimes it can. With some clever stats I probably could extract more useful data but haven't had the time to incorporate it! I do have a few examples somewhere tested against sarin reports

kayi078 said:
I think i will exchange the GIA G to AGS G color because the AGS G looks whiter in comparison video. I might be wrong but i think the GIA G looks warmer in video.

https://www.whiteflash.com/loose-diamonds/compare.aspx?idnos=3726902,3770047,3801980
Click to expand...

I personally would ask WF to test these blindly side by side if possible (ie you don't already have the premium select stone in hand). The video is not always a standardised testing environment and you may save thousands if they can't notice a difference.
 
I just found out the pricing in James Allen (true heart series) is at least 10% cheaper than Whiteflash (ACA) but i already paid for the U113 ring & premium cut diamond

As an international buyer i dont find the WF's upgrade policy beneficial to me too =[
 
WF has a 30 day return policy in the event you change your mind. Not sure, though, why you couldn't take advantage of their upgrade policy? You could still send your ring back using international shipping in order to upgrade. Many PSers have done this...
 
My fiancee (Asian) is already satisfied with 1.6ct diamond and it looks big on her size 4 finger.
 
What more can you ask for? Congratulations!
 
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