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Help me find a perfect engagement diamond

Alixman984

Rough_Rock
Joined
Aug 17, 2016
Messages
4
Hi all,

I'm glad I found this place, I've been researching and studying diamond for about a month and I just seem to get more confused as different jewellers tell me different things and I can only assume it is because they want me to buy what they are selling.

I have spent the last couple of days going through this forum, I'm very grateful for this resource.

Long story short I'm looking to purchase a 1.4-1.5 ct diamond to be placed in a platinum setting. My budget is £8000 (around $10500) for the diamond but if I find something that worth it I probably can extend it another £500-£750.

I have found three different GIA certified loose diamonds from a reputable Hatton Garden, London seller, but before I pop into their shop I'd like to get some more unbiased opinion.

My first option is a Round Brilliant, 1.42 Ct, H colour with a VS1 clarity, Ex cut grade, polish, and symmetry but a strong blue fluorescence.

Certificate details: http://www.gia.edu/UK-EN/report-check?reportno=7223807916

My second option is another Round Brilliant, 1.51 Ct, I colour with VVS2 clarity, Ex cut grade, polish and symmetry and a strong blue fluorescence. - This is so far my favorite, it is reasonably priced and as far as I can see with naked eye, couldn't see the difference between I and H (my option 1).

Certificate details: http://www.gia.edu/UK-EN/report-check?reportno=2226677121

my third option is also Round Brilliant, 1.50 Ct, I colour with VVS1 clarity, V. Good cut grade and Ex. polish and symmetry and no fluorescence. This option is the most expensive, being £500 more expensive than the option 2 and £300 more expensive than the option 1.

Certificate details: http://www.gia.edu/UK-EN/report-check?reportno=7232005375

Now my questions:

1- Does it worth sacrificing the size (1.51 to 1.42) and clarity (VVS1/2 to VS1) to get one grade higher colour (H), bearing in mind both option 1 and option 2 have strong blue fluorescence. I had initially restricted my search to H only, but after seeing an I next to an H diamond I couldn't say the difference but I'm a novice.

2- specifically with option 1 and 2, how does strong blue fluorescence impact the diamond look with the naked eye? I've read on other web sites that with Colour 'I' a medium blue fluorescence is actually a good thing but strong one will make the diamond look hazy (whatever that means).

3- If you had to decide between these three diamonds, which one will you pick? any other suggestions?

apologies for the long post and very much appreciate your assistance. any other question please let me know and I can discuss it with seller and get more information.

Thanks again.
Ali.
 

Gypsy

Super_Ideal_Rock
Joined
Aug 8, 2005
Messages
40,225
None of them. Go for an H Vs2 eyeclean. And HCA score per below with crown of 33.5-35 and depth of 59-62.4, table 60 and above. Pavilion of 40.6-40.9

Okay?
 

Gypsy

Super_Ideal_Rock
Joined
Aug 8, 2005
Messages
40,225
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 as GIA's criteria for EX cut is over broad and includes many stones have compromised light performance, or spread. 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?
http://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.
http://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. http://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.

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.

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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. 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 if you DO NOT KNOW YOUR LADY'S COLOR PREFERENCES.

If you are talking fancy shapes without ideal light return (because there is no 'ideal' for EC's Radiant, etc) it's a bit different.

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 side by side. 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, you only see the contrast because of the proximity. But it's very slight, you could set an F center with G sides and never tell the difference. And even H sides depending on the setting and the size of the sidestones... especially with round brilliants.


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/diamond-clarity
Clarity Vs2 or Si1 and eyeclean is as high as you need to go in a round. So set that as a floor. And verify eyeclean with vendor or images and vendor (best). An Eyeclean SI1 will look just like an IF to the naked eye. So... really anything over VS2 and eyeclean is just because you want higher clarity for some personal or cultural reason (and that's fine of course, just make sure it's an educated decision) or because you are getting a good deal on a stone because higher clarity stones can be harder to move (especially in lower colors). So make sure you don't put a CEILING on your clarity. All you need is a floor. And with rounds, in general that floor is Si1 or Vs2.[/quote]
 

Alixman984

Rough_Rock
Joined
Aug 17, 2016
Messages
4
Thanks Gypsy

I will go through all the information you have kindly provided as soon as possible.

Thanks again for your reply.
 

Gypsy

Super_Ideal_Rock
Joined
Aug 8, 2005
Messages
40,225
:wavey:
 

Alixman984

Rough_Rock
Joined
Aug 17, 2016
Messages
4
Hi Gypsy

Spent the last hour or so reading through your comments (thank you very much again) and I have talked to my Jeweller, within my budget the option 1 I mentioned above had an HCA of 1.8.

I have checked quite a few other H diamonds with VS1 and VS2 clarity and what is advertised as Excellent cut, polish and symmetry and they perform quite poorly with HCA calculator (3-5) and even those are more expensive than the first option I have.

Can I ask how problematic is the strong blue fluorescence? a lot of online resources say it's not the biggest issue.

Nonetheless the search continues, at least for now!

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Gypsy

Super_Ideal_Rock
Joined
Aug 8, 2005
Messages
40,225

Alixman984

Rough_Rock
Joined
Aug 17, 2016
Messages
4
Thanks Gypsy

I think I might have found what I was looking for, just need one final advice before I put the deposit down.

It's a GIA certified Round Brilliant, 1.35 crt (7.03x6.99x4.36), H, VS1. 3xEx. Medium Flu.
Depth. 62.2%, Table 57%, C.A 35.5 deg and P.A 40.6 deg

This gave me an HCA value of 1.4, however since CA is above recommended 35 deg I asked for Idealscope or ASET image, the diamond advisor wasn't sure if he can source it. Is this normal? shouldn't all diamonds come with these imageries?

how much risk of light leakage is there with that C.A?

I very much appreciate your input.
 
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