HCA Help

[SCARLETTE]

I am looking to upgrade to a 4 carat stone. I have found something that is within budget but concerned that it's not a "triple" excellent stone. If anyone has access to the HCA tool here, if you can run the numbers for me, I'd be so grateful. Many thanks in advance!

Measurements ........................... 10.00 - 10.08 x 6.32 mm
Carat Weight ......................................................... 4.00 carat
Color Grade ........................................K
Clarity Grade ..................................................................... VS2
Cut Grade ............................................................... Excellent
Polish ...................................................................... Excellent
Symmetry ............................................................. Very Good
Fluorescence ................................................................. Faint

 

[Kaycee2018]

Scores a very high HCA of 5.7, which is not surprising. 62.9 is rather deep and a 36 crown angle does not pair well with a 41 pavilion angle. Table is on the large size as well. This would be a hard pass for me. ETA: The HCA is actually 6 based on the symmetry grade of Very Good (I ran it as "Excellent" the first time). I would run from this stone..

Cut Advisor Score 6
Factor Grade Light Return: Fair Fire: Fair Scintillation: Fair Spread: Very Good HCA Score : 6 - Fair

Probably appears dull, although it looks bigger than usual for its carat weight.

 

[SCARLETTE]

Kaycee, thank you so much! I'll keep looking

 

[Garry H (Cut Nut)]

Also it will appear multi colored - the area just inside the table will be much yellower than the rest of the diamond

 

[new-beginning]

you can eliminate diamonds that are not within the following:
table: 54-57
Depth: 60-62.4
Crown angle 34-35
Pavillion angle40.6-40.9
or at least reasonably close
as you can see, the diamond you posted doesn't have any of the desirable dimensions

 

[Garry H (Cut Nut)]

you can eliminate diamonds that are not within the following:
table: 54-57
Depth: 60-62.4
Crown angle 34-35
Pavillion angle40.6-40.9
or at least reasonably close
as you can see, the diamond you posted doesn't have any of the desirable dimensions

So they sa, and we do not know who "they" are.
So 33.5 x 41 is out?
I kindly ask people to stop with such narrow ranges meaning that the search - especially in such a large size - becomes too narrow.

 

[lovedogs]

Table can reasonably go up to 60 (for a 60/60 style diamond), and pavillion angle can be 41 if crown is lower (34). Conversely, crown can sometimes be 35.5 if pavillion is 40.6.

 

[Garry H (Cut Nut)]

Table can reasonably go up to 60 (for a 60/60 style diamond), and pavillion angle can be 41 if crown is lower (34). Conversely, crown can sometimes be 35.5 if pavillion is 40.6.

I disagree LD.
The table should get smaller as diamonds get larger.
(and work well larger in smaller diamonds.)
e.g. in +1ct my limit is 59% and +2ct 58%.
A Tolkowsky equivalent for 41 pavilion is 33.25 degrees.
The rule of thumb is divide or multiply by 5 from the magic Mr T 34.5 40.75. The range extends quite a long way - much further than the "Experts" advice (that I do not think anyone can remeber who invented it.)

 

[lovedogs]

I disagree LD.
The table should get smaller as diamonds get larger.
(and work well larger in smaller diamonds.)
e.g. in +1ct my limit is 59% and +2ct 58%.
A Tolkowsky equivalent for 41 pavilion is 33.25 degrees.
The rule of thumb is divide or multiply by 5 from the magic Mr T 34.5 40.75. The range extends quite a long way - much further than the "Experts" advice (that I do not think anyone can remeber who invented it.)

You are definitely more of an expert than I am, so I'll default to you! But if someone wanted a 60/60 style in a 4ct size, couldn't they still find a good one (in theory)?

 

[Garry H (Cut Nut)]

You are definitely more of an expert than I am, so I'll default to you! But if someone wanted a 60/60 style in a 4ct size, couldn't they still find a good one (in theory)?

The larger diamond can make the table area particularly appear empty and lacking scintillation and bang bang. Sort of boring. The trouble with the consumer diamond videos is all the stones are shown at a standardised size.

 

[parsonsjnyc]

I disagree LD.
The table should get smaller as diamonds get larger.
(and work well larger in smaller diamonds.)
e.g. in +1ct my limit is 59% and +2ct 58%.
A Tolkowsky equivalent for 41 pavilion is 33.25 degrees.
The rule of thumb is divide or multiply by 5 from the magic Mr T 34.5 40.75. The range extends quite a long way - much further than the "Experts" advice (that I do not think anyone can remeber who invented it.)

Hi Gary H

I am new to this forum and have been reading your posts and am very impressed with your knowledge. Would you kindly review the following specs of a stone that I am considering purchasing? I would love a super ideal but find it prohibitively expensive to have one custom cut for me by either Whiteflash or Brian Gavin. And since it is a high carat weight I am not finding many options.

I am most concerned with the larger 58 table wishing it were 55 or 56:

Here are the specs:

E VVS2 4.01 carat GIA triple Ex
Faint Fluorescence
Depth % 61.8%
Table % 58.0%
Crown Angle 35%
Pavilion: 40.8

GIA comments that additional clouds not shown however since the clarity is VVS2 I am not too concerned.

I am not able to get an ideal scope before purchasing but the HCA score is 1.7 and the diamond is returnable.

I would greatly appreciate all of your feedback on the specs of this diamond and how far away it might be from a super ideal / hearts and arrows type of diamond.

Thanks so much in advance!!

 

[parsonsjnyc]

The larger diamond can make the table area particularly appear empty and lacking scintillation and bang bang. Sort of boring. The trouble with the consumer diamond videos is all the stones are shown at a standardised size.

Oh sorry! Here is the image

 

[Garry H (Cut Nut)]

I can not comment on individual diamonds.
And GIA rounded data it useless in this case.
but 58% is fine

 

[parsonsjnyc]

I can not comment on individual diamonds.
And GIA rounded data it useless in this case.
but 58% is fine

I understand completely. I will be bringing the diamond in for detailed analysis. Thank you for your feedback!

 

[Garry H (Cut Nut)]

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