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Which GIA Graded Triple ex diamond is 'better' value?

jim_diamonds

Rough_Rock
Joined
May 19, 2016
Messages
12
Hi, this is my first post on this forum.

I am in the process or buying a diamond for a engagement ring and need some advice.

I have mainly been looking on blue nile as they seem to be able to ship to the UK without having to worry about customs holding the diamond for ransom.. anyways I'll get to the point.

I am looking for an (Idea) exellent cut, polish and symmetry diamond around 1 ct and eye clean for around £3000 (the best colour I can find in that price range is a J)

I have looked at what feels like 100's of diamonds and these are the 2 I have narrowed it down to.

The first diamond is priced at approximately £3000 and is a J Si1 1.04ct (strong Blue)
1_452.jpg
This diamond scores very well on HCA and is around a 1.1

My concerns with this diamond are it has a inclusion on table (pictured below) also it has a low crown percentage of 13.5%
si1__j_colour_1.jpg
The inclusion is quite obvious at this magnification but I was assured it is eye clean when looking at from 6 inchs or further.


The second diamond is priced around £3250 and is a J VS2 1.05ct (strong Blue)
gia__1.jpg

This diamond is supose to be good enough to be in blue niles 'sig idea' range but the J colour is why its not in that range.
Saying that its doesnt seem to score well in HCA with a score around 4.1

I have been told it is eye clean (pic below)
1_453.jpg

I know the J colour and the Strong blue fl isnt great but its a compomise in order get the price to around £3k.
I have heard that blue fl can help improve J colours so might not be all that bad. (both have diamonds have been checked for oilyness with no affect from the FL)

so my question is out of the 2 diamonds above which is the better buy? (or are both no good xD)

Any advice would be of great help. If you need anymore info please ask :)
 

Gypsy

Super_Ideal_Rock
Joined
Aug 8, 2005
Messages
40,198
I can't read those reports. See below and evaluate them yourself accordingly. Anything over 2.5 on an HCA is a no. Anything over 2 on the HCA absolutely needs an idealscope image. And most stones under 2 on the HCA do too.

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 62.4. Crown angle 33.5-35. Pavilion Angle: 40.6-40.9 (there is a little give on this). AND (not OR, AND you need both)the crown and pavilion angles must be complimentary which is what the HCA checks for you
.

ON COLOR:

It is important to remember is that color is graded FACE DOWN. Where there is NO light return. Not face up where there is light return and refraction. You wear diamonds set. FACE UP.

Within one color grade, even the labs can't agree on the color grades of stones and something could be a "high" H or a "low" E. So... no. Not really. Within 2 color grades it is hard. Not impossible. But very hard. And it gets harder once set. If you are talking ideal rounds, or any stone with ideal light return and no sharp corners it gets harder still because the ideal light return masks body color.

Generally we say to be conservative stay above H in a round. But MANY people have happily bought white I or even J diamonds when trying to eek out a little more size.

This is how I think of it.

Ever gotten one of those HUGE paint fan decks? Where there are literally 100s of colors of whites? And when they are RIGHT next to each other you can TOTALLY tell that one is bluer/colder and one is a bit warmer and which one is one is TOTALLY warmer. One there's one that's slightly greener. One that's slightly pinker? But really. They are all white?

Then you pick one after agonizing over this white or that white and when it's on the walls and people are like: Oh. You painted again. And it's STILL white. Great.

And you're all... BUT it's BLUE white. Or it's a WARM white now. It used to be ____ white. It's TOTALLY different.

It's like that. You are talking about shades of white. D is colder... J is warmer. But it's all white.

YES. If you have an accurately graded F and an H THAT HAVE THE SAME PERFORMANCE you are going to be able to tell them apart when you compare them. Just like you would be able to tell if you painted your walls a warm white, but painted the crown molding a cold/straight white. But both are STILL white.


I want you notice all the qualifiers thought. I'm talking about stones with the SAME performance. An ideal H will out white an F that has compromised light performance from a poor cut.

NOTHING impacts the appearance of a diamond as much as cut. CUT is king.

You want the shinest whitest and brightest diamond out there: Cut is King. No other factor, not color or clarity or anything else impacts how white bright an shiny a stone is.

ON CLARITY:
http://www.goodoldgold.com/4Cs/Clarity/SI/ and http://www.goodoldgold.com/4Cs/Clarity/VS/ Generally we say that eyeclean SI1 and VS2 are as high as you need to go with round brilliants, have your vendor check the diamond for this. VS1 will always be eyeclean, but they do cost more and an eyeclean SI1 and a VS1 will look the same to the unaided eye.
 

jim_diamonds

Rough_Rock
Joined
May 19, 2016
Messages
12
Thanks for the repy Gypsy, that information was very useful!

I was wondering, on the first diamond the crown percentage is a bit low at 13.5% will this likely have a negative affect ( it scores 1.1 on HCA)

So it would seem that the first diamond 1.04ct would be a better choice based on the HCA score.
I will investige that diamond further, I just wish it didnt have that crystal on the table. But i supose thats why I can afford it xD

Heres a bigger view of the gia certs

1.04ct si1 HCA=1.1
d1_5.jpg

1.05 ct vs2 HCA= 4 (although it is supose to be the 'better' cut diamond acording to blue nile)
d2_14.jpg

heres a close up of the inclusion on the 1.04 ct
d11.jpg
 

Gypsy

Super_Ideal_Rock
Joined
Aug 8, 2005
Messages
40,198
Lower crown angles mean less fire, and if the girdle is thin then they can be chipping risks.

This might be helpful for you: [URL='https://www.pricescope.com/community/threads/how-can-a-hca-2-rock-be-bad.223043/']https://www.pricescope.com/community/threads/how-can-a-hca-2-rock-be-bad.223043/[/URL]

With that crystal on the table I would ABSOLUTELY want to see picture of it before buying or see it in person (if you are shopping in person).

Is it eyeclean and have you seen the stone?

But it's not a bad stone at all. Just set it securely with 6 prongs.

I would not buy the second stone at all. It is WAY too deep. And the angles are NOT complimentary at all, so it will show lots of leakage.
 

jim_diamonds

Rough_Rock
Joined
May 19, 2016
Messages
12
Gypsy|1463782942|4034173 said:
Lower crown angles mean less fire, and if the girdle is thin then they can be chipping risks.

This might be helpful for you: [URL='https://www.pricescope.com/community/threads/how-can-a-hca-2-rock-be-bad.223043/']https://www.pricescope.com/community/threads/how-can-a-hca-2-rock-be-bad.223043/[/URL]

With that crystal on the table I would ABSOLUTELY want to see picture of it before buying or see it in person (if you are shopping in person).

Is it eyeclean and have you seen the stone?

But it's not a bad stone at all. Just set it securely with 6 prongs.

I would not buy the second stone at all. It is WAY too deep. And the angles are NOT complimentary at all, so it will show lots of leakage.
Hey Gypsy.

Thanks alot for your advice!!

The Diamond I have chosen was the first one 1.04ct J SI1 Strong Blue (HCA = 1.1). Girdle is Medium (3.5%)
I was advised that the second diamond was 'better' but I like yourself I though that its cut ratios were not complimentry.


This is a actual picture of the stone (I have been assured it is eye clean at 6-8 inches)
d11.jpg [*]

Regarding the mount, I did end up going with a 4 prong mount, I would have preferred a 6 prong but that was the only option for this style of ring.

This is the ring below (950 Plat with 12x side diamonds 0.25 ct total)

setting_template_main_7.jpg
setting_template_profile_0.jpg
note the above pictures are stock and dont show the diamond I selected.
 
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