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XXX diamond or higher color?

T

Thomas44

Rough_Rock
Joined
Jul 15, 2014
Messages
7
I'm trying to decide on two diamonds, both 1.5 carat. They're round cut. One is a XXX, H color, SI1 and the other is Excellent Cut with polish/symmetry being excellent and the cut being good, but a G color, and SI1. I feel they both look the same in color, but the XXX slightly bigger for some reason. My eyes are bad though and I would think the 2nd option with the G color would be whiter? I feel buying the XXX and going even higher in color may not be cost effective. By the way, the jeweler is selling each diamond at the same exact price. Thanks for your help!
 
Welcome to the forum.

Post up the AGS or GIA numbers so we can work out if they are good stones. :)
 
I don't have the numbers, I just looked at them at the store...
 
Hi Thomas,


A cut (grade) of good is simply not good (enough)- the price bump between G & H is really small change.
The question is whether you're paying to much for the H or how deep the G is discounted.

Comparing these two diamonds is live comparing sparkling wine and champagne, or a Jetta to an Audi.
 
They're both GIA certified..
 
If the XXX looks bigger and you can't tell the difference in color, just get the XXX. H is still white for a GIA graded stone. No one is going to think it's not white.
 
A badly cut stone can look small for its size.
Do not buy a "Good" cut. It needs to
Be "Excellent" or "Ideal" and some of those
Arent that good.

Can you post the depth, table, crown
And Pavilion angles for the H stone
So we can see how well its cut.
 
Hi,


If you have a look at the AG Laboratories cut-grade system, you will have a fair comparison. Stone unseen (and for camparison) the GIA XXX may be comparably to an AGS 1 (with 0 or AGS Triple 0) being the best there is. So you can see the fall/drop from an AGS 1 to a 3 or even 4, is a big one.

https://www.agslab.com/education-diamond-cut-grade.php
 
See if you can get the GIA report numbers, then post them here. You can access the reports online with the number. Then run the table and depth % as well as the crown and pavillion angles through the HCA calculator. You want a value under 2. Then request an idealscope image if they do that.

My guess is that the XXX is better cut, thus it looks larger and whiter. Poor cut can give the illusion of smaller size and darker color.

GIA "good" is pretty poor. It's all about the angles. And even GIA XXX can be not good enough - the excellent cut category is very broad, and some lesser performers do fall through. Thus the HCA to help weed out the poorer performers. An idealscope image will reveal all.
 
One might have a larger table and one a very small table which will make one look larger because diamonds are calculated by weight not mms across. Alternatively as the others have pointed out a better cut diamond can (as an optical trick) appear larger because it has edge to edge brightness across the whole stone.

You need to ask the vendor to email you a copy of the GIA certificates, post them here and then everyone will give you recommendations as to which one to buy. Or if you prefer one visually over the other then that is the winner. Cut has more to do with how much fire a stone has than colour.
 
Here's all the information...

What do you guys think? They're the same price!

_20292.jpg

_20293.jpg
 
the second one performs way better, but is still not great IMO (HCA 3.6 vs. 5-something for the G/SI1).
 
Past on both...way too deep!. the first one is deeper than the Grand Canyon... :eek:
 
What do you suggest? It seems these are the best I've seen... What do you think about uniondiamond.com?
 
Neither is any good. Pass on both.

The entire purpose of faceting a diamond is to reflect light.
How well or how poorly a diamond does this determines how beautiful it is.
How well a diamond performs is determined by the angles and cutting. This is why we say cut is king.
No other factor: not color, not clarity has as much of an impact on the appearance of a diamond as its cut. An ideal H will out white a poorly cut F. And GIA Ex is not enough. And you must stick to GIA and AGS only. EGL is a bad option: [URL='https://www.pricescope.com/community/threads/egl-certification-are-any-of-them-ok.142863/']https://www.pricescope.com/community/threads/egl-certification-are-any-of-them-ok.142863/[/URL]
So how to we ensure that we have the right angles and cutting to get the light performance we want?
https://www.pricescope.com/wiki/diamonds/diamond-cut
Well one method is to start with a GIA Ex, and then apply the HCA to it. YOU DO NOT USE HCA for AGS0 stones.
https://www.pricescope.com/wiki/diamonds/holloway-cut-advisor
The HCA is a rejection tool. Not a selection tool. It uses 4 data points to make a rudimentary call on how the diamond may perform.
If the diamond passes then you know that you are in the right zone in terms of angles for light performance. Under 2 is a pass. Under 2.5-2.1 is a maybe. 2.6 and over is a no. No score 2 and under is better than any other.
Is that enough? Not really.
So what you need is a way to check actual light performance of your actual stone.
That's what an idealscope image does. https://www.pricescope.com/wiki/diamonds/firescope-idealscope
It shows you how and wear your diamond is reflecting light, how well it is going at it, and where you are losing light return. That is why you won't see us recommending Blue Nile, as they do not provide idealscope images for their diamonds. BGD, James Allen, GOG, HPD, ERD and WF do.

The Idealscope is the 'selection tool'. Not the HCA.
So yes, with a GIA stone you need the idealscope images. Or you can buy an idealscope yourself and take it in to the jeweler you are working with to check the stones yourself. Or if you have a good return policy (full refund minimum 7 days) then you can buy the idealscope, buy the stone, and do it at home.


Now if you want to skip all that... stick to AGS0 stones and then all you have to do is pick color and clarity and you know you have a great performing diamond. Because AGS has already done the checking for you. That's why they trade at a premium.
 
I do not have time today to run the numbers, but maybe John Pollard will see this and present his wonderful graphic showing an AGS 000 cut grade and an GIA XXX that both look identical. Then he shows two stones that are GIA XXX and AGS1, and on down the line until you get to AGS 5 and GIA XXX before finally falling to GIA very good and AGS 6.

It is a stunning graphic that he has presented here before that shows really well just how worthless the GIA XXX grade is when you are looking for good cutting.

Now I must go, the river and my kayak are whining for me to show up...

Wink
 
That 'good' cut is :knockout: :knockout:
 
What about this one? GIA 1179468097
 
Better proportions. HCA score = 1.0, TIC, Ex/Ex/Ex/VG
Clarity is VS2. Color is G.
7.34 - 7.37 x 4.54 mm , 1.50ct
Seems promising.
 

Attachments

Wink|1405538928|3714584 said:
I do not have time today to run the numbers, but maybe John Pollard will see this and present his wonderful graphic showing an AGS 000 cut grade and an GIA XXX that both look identical. Then he shows two stones that are GIA XXX and AGS1, and on down the line until you get to AGS 5 and GIA XXX before finally falling to GIA very good and AGS 6.

It is a stunning graphic that he has presented here before that shows really well just how worthless the GIA XXX grade is when you are looking for good cutting.

Now I must go, the river and my kayak are whining for me to show up...

Wink
Click to expand...
That sounds really interesting! (Both the kayaking and graphic!) :)
 
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