Deciding btw 2 diamonds

[wd564]

Hi all, both are 3EX GIA diamonds:

#1: 1.03ct - I - SI1
61.7 - 56 - 34.5 - 40.8
Dia: 6.47 - 6.50
Medium, faceted, 3.5%
Fluo: none

#2: 1.04ct - I - VS1
62.3 - 56 - 35 - 40.8
Medium to slightly thick, faceted, 3.5%
Fluo: none

Below are more details on clarity: (GIA clarity figures)
http://2.1m.yt/mVZczJD.jpg

Thanks!

 

[Gypsy]

Is the first eyeclean? It has slightly better numbers. But if it's not eyeclean (and the plot doesn't tell me if it is, you would have to ask the vendor and get a picture) then there's no point.

You need an idealscope image for the second if you can get one. It will be eyeclean though, so that's great.

 

[a03b]

Thanks Gypsy, if the 1.03 turns out to be not eye-clean, would you recommend the other one? The dimensions (esp. depth) could be better, I know, but it will perform well anyways right?

 

[diamondseeker2006]

What's the diameter on the second one? It could be as good or better than the first one. But you don't know without the idealscope or ASET. Do you have magnified images of the stones?

 

[a03b]

What's the diameter on the second one? It could be as good or better than the first one. But you don't know without the idealscope or ASET. Do you have magnified images of the stones?

Diameter of #2 is 6.49-6.50. I am leaning towards #2 to be honest, at least I don't have to worry about eye cleanliness.

I will be able to acquire magnified photos of #2, I think. But that won't tell me anything regarding the optics performance, right?

Thanks!

 

[Gypsy]

No we need an idealscope image, ideally. Diameter is great. I agree with DS, you might have a winner there.

Round Diamonds 101:

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. With round diamonds even a GIA triple Excellent is not enough. And you must stick to GIA and AGS only (HPD in Europe is good as well). 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 generally, though you can. In general, AGS0 trumps HCA though as one examines the actual stone and the other does not.
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,BE, 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. Some AGS0's are better than others though, so pay attention to any ASET or IS provided.

In general with rounds, you will want a table 60% or less. A depth between 59 and 62.3. Crown angle 33.5-35. Pavilion Angle: 40.6-40.9 (there is a little give on this). And the crown and pavilion angles must be complimentary which is what the HCA checks for you.

 

[gr8leo87]

I can't comment on specific stones as being from trade but I can give you general tips.

While cut is obviously important and obviously impacts the price, the inclusion pattern also has it's own impact on the prices. If stone has concentrated inclusions on the table especially if those inclusions are colored such stones may trade at slight discounts over table clean stones. Just like ideal proportion stones trade at premium over the common cut ones.

It's a good idea if you keep all of this mind when making a decision.

Spread is also another factor that should be kept in mind when making decisions between two stones.

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