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is this knot inclusion will be problematic?

royalfalcon

Rough_Rock
Joined
Aug 19, 2016
Messages
6
Hello community, yesterday I bought a loose diamond for my fiance ring:

H color, SI2, Triple Ex, 1.02 ct

I paid attention to every aspect of diamond, the inclusions on the table were not visible to naked eye. However, when I got home I noticed that one of the inclusions is a knot on the pavilion. The knot is visible to the naked eye when you look at the pavilion but I don't care since it is not gonna be visible when the diamond placed on the setting. However, my only concern is that the knot fells off and the value of the diamond drops dramatically. Is this something that I should be worry about? Would you please share your professional comments on this. much appreciated.

untitled_48.jpg
 

ac117

Ideal_Rock
Premium
Joined
Apr 28, 2014
Messages
3,693
First and foremost, can you return it? I hope so...besides the knot, it's a poorly cut diamond and is likely not a great performer. The angles are not complimentary at all and it is on the deep side so it faces up smaller than well cut diamonds of the same weight. All diamonds look great under jewelry store lighting. Let us help you find a better one!
 

John Pollard

Ideal_Rock
Trade
Joined
May 1, 2008
Messages
3,558
royalfalcon|1471619466|4067671 said:
However, my only concern is that the knot fells off and the value of the diamond drops dramatically. Is this something that I should be worry about? Would you please share your professional comments on this. much appreciated.
If the crystal were to fall out on its own the inclusion would simply become a cavity. No change to the clarity grade. If you're concerned about the diamond knocking against something hard enough to dislodge the knot, be aware that all diamonds have cleavage planes. Enough trauma in any one place can cause damage or chipping, even to diamonds with Flawless clarity. For any diamond it's prudent to offset the possibility of damage or theft with a good insurance policy.

The angles are not complimentary at all and it is on the deep side so it faces up smaller than well cut diamonds of the same weight.
This is valid. In technical terms those proportions would make it a candidate for AGS 3-4 in performance. I'd also suggest comparing its mm measurements for diameter to standards for properly-cut 1.02 carat diamonds.
 

royalfalcon

Rough_Rock
Joined
Aug 19, 2016
Messages
6
Thanks for the response, I do not understand though, when the cut, symmetry and polish is all Excellent on the GIA report, how is it possible that the cut be poor?!!
 

royalfalcon

Rough_Rock
Joined
Aug 19, 2016
Messages
6
ac117|1471623262|4067698 said:
First and foremost, can you return it? I hope so...besides the knot, it's a poorly cut diamond and is likely not a great performer. The angles are not complimentary at all and it is on the deep side so it faces up smaller than well cut diamonds of the same weight. All diamonds look great under jewelry store lighting. Let us help you find a better one!

Thanks for the response, I do not understand though, when the cut, syemmetry and polish is all Excellent on the GIA report, how is it possible that the cut be poor?!!
 

royalfalcon

Rough_Rock
Joined
Aug 19, 2016
Messages
6
The angles are not complimentary at all and it is on the deep side so it faces up smaller than well cut diamonds of the same weight.
This is valid. In technical terms those proportions would make it a candidate for AGS 3-4 in performance. I'd also suggest comparing its mm measurements for diameter to standards for properly-cut 1.02 carat diamonds.[/quote]

Thank you John for the response. So just to confirm this, in case the knot falls out, the clarity would not change, right? in other words, a cavity is not worse than a knot?

Moreover, I am a bit confused, when the cut, symmetry and polish are all Excellent on the GIA report, how is it possible that the cut be poor?!! I checked the proportions (table, depth, angles,....) against bluenile and lumeradiamond charts and they all happen to be on Excellent and very good portions!!!

http://www.lumeradiamonds.com/diamond-education/round-diamonds
 

ac117

Ideal_Rock
Premium
Joined
Apr 28, 2014
Messages
3,693
You need to do some more reading here on PS (see below)! GIA Excellent category is VERY broad, which is why we recommend sticking within a certain set of parameters so know you have a well performing stone.

These are measurements to help you stay in ideal cut territory with a GIA excellent cut stone.

table: 54-58
depth: 60-62.3
crown angle: 34-35.0
pavilion angle: 40.6-40.9 (sometimes 41.0 if the crown angle is close to 34)

Gypsy, a very seasoned member here on PS, always posts the following for our novice users:
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.
 

royalfalcon

Rough_Rock
Joined
Aug 19, 2016
Messages
6
ac117|1471629980|4067758 said:
You need to do some more reading here on PS (see below)! GIA Excellent category is VERY broad, which is why we recommend sticking within a certain set of parameters so know you have a well performing stone.

These are measurements to help you stay in ideal cut territory with a GIA excellent cut stone.

table: 54-58
depth: 60-62.3
crown angle: 34-35.0
pavilion angle: 40.6-40.9 (sometimes 41.0 if the crown angle is close to 34)

Gypsy, a very seasoned member here on PS, always posts the following for our novice users:
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.
Thank you providing the info, it is the first time I am hearing about AGS, however, the proportions of this diamond is in the range (except the crown angel, which is off by 1 deg.) , anyway since I assume you are a diamond seller how much do you think this diamond worth?
 

ac117

Ideal_Rock
Premium
Joined
Apr 28, 2014
Messages
3,693
Please re-read what was written - it's not only about having angles that fall within those parameters, but about how the angles work WITH each other. 36 is a high crown angle and if it were paired with a 40.6 pavilion angle, we'd say it COULD work, but we need an IS/ASET to confirm no leakage. But your 36 crown angle is paired with a steep 41 pavilion angle (which specifically says below would generally only work with crown angles closer to 34). "One degree" actually makes a world of a difference. Your diamond scores a 5.5 on the HCA (see photo). The region within the dotted line are GIA triple excellent stones, which as you can see, is very large. The region within the solid white line are AGS ideal stones, already vetted for light performance.

I'm not a seller, I'm a consumer just like you. But I advise you to do your homework before you make such a large purchase. Just by doing a quick search on the diamond search above reveals triple excellent 1-1.05 ct H, SI2 stones going for anywhere from $3500-$6500. Not even filtering by excellent HCA score, which we always recommend.

If you tell us your budget, we could recommend stones for you.

h_si2_hca.png
 

PintoBean

Ideal_Rock
Premium
Joined
Jul 27, 2011
Messages
6,377
Hi royalfalcon,

I am going to guess that you wouldn't be here unless you had reservations about your purchase. Now that a few helpful folks have chimed in that the diamond you purchased recently is not only problematic because of the knot, but not the best bang for the buck in general, I strongly recommend you returning the diamond and start from scratch with help from our fellow PSers.
 
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