Picking the right diamond

[stoneface]

Hi,

I am after a bit of help.
I have seen a really nice diamond in person that seems to sparkle really nice it is a D VS2 very good excellent excellent. The problem is I'm not sure if going for a D/E SI1 xxx would be a better option than the current one selected and sparkle even better. The carat that I am looking for is 0.90

When I check the dimension for the VS2 using the HCA tool, it doesn't give me good results and therefore this is what is giving me the worry. Thanks

ROUND BRILLIANT
Measurements
6.10 -6.13 x 3.84 mm
Carat Weight
.90 carat
Color Grade
D
Clarity Grade
VS2
Cut Grade
Very Good
PROPORTIONS
Depth
62.8%
Table
62 %
Crown Angle
32.5°
Crown Height
12.0%
Pavilion Angle
42.2°
Pavilion Depth
45.0%
Star Length
50%
Lower Half
80%
Girdle
STK to THK, Faceted, 5.5%
Culet
None
Polish
Excellent
Symmetry
Excellent
Fluorescence
Faint

 

[tyty333]

This stone is not well cut...its table is too big and its too deep so you are losing face up size.

Find a well cut eye-clean SI1. If you need help, let us know what specs you are looking for and your budget. D color is also very
high. You might look in the DEF range. G/H are considered pretty white by most people's standards unless very color sensitive.

 

[stoneface]

Thank you very much for your reply.
I think I will look out for a SI1 xxx within the proportion guidelines or if lucky maybe a VS2 xxx
Thank you again for your reply it conformed my research

 

[OoohShiny]

The usual recommended parameters on this forum are something like this:

Table 54-58%
Depth 60-62.4%
Pavilion Angle 40.6 - 40.9 degrees
Crown Angle 34-35 degrees (up to 35.5 degrees with 40.6 Pavilion Angle)

If Crown Angle increases, Pavilion Angle should decrease - e.g. 34c/40.8p but 35c/40.6p.

The HCA tool will help ensure that no matter which combination you go for, the angles work together.

 

[lovedogs]

The usual recommended parameters on this forum are something like this:

Table 54-58%
Depth 60-62.4%
Pavilion Angle 40.6 - 40.9 degrees
Crown Angle 34-35 degrees (up to 35.5 degrees with 40.6 Pavilion Angle)

If Crown Angle increases, Pavilion Angle should decrease - e.g. 34c/40.8p but 35c/40.6p.

The HCA tool will help ensure that no matter which combination you go for, the angles work together.

Definitely use this as a guide along with the HCA.

 

[stoneface]

Thanks guys for all your help, much appreciated. I have found another stone that I think is much better it falls within the guidelines and gets a really good score on the HCA tool. My only question is with it has Twinning Wisp, Crystal will this be a better pick than the first diamond?

Round Brilliant
Measurements
6.14 - 6.18 x 3.83 mm

Carat Weight
0.90 carat

Color Grade
E

Clarity Grade
SI1

Cut Grade
Excellent

Proportions Depth
62.2 %
Table
56 %
Crown Angle
36.0°
Crown Height
16.0%
Pavilion Angle
40.6°
Pavilion Depth
43.0%
Star Length
50%
Lower Half
80%
Girdle
Medium
Faceted, 3.5%
Culet
None

Polish
Excellent
Symmetry
Excellent
Fluorescence
None

clarity characteristics
Twinning Wisp, Crystal

 

[OoohShiny]

Crown angle is slightly outside PS-recommended parameters but if the HCA score is under 2 the pavilion angle should work with it.

Twinning wisps are some of the better inclusions to have - you will have to review the video to see if they have any impact on light performance or if they are visible to the naked eye.

 

[stoneface]

Thank you for your reply.
Would the second stone be more shiny then the first as the dimensions are better or will that be dependent on whether the inclusions impact the performance?

 

[Dancing Fire]

The first stone is horrible...cut too deep, flat top with a large table.

 

[OoohShiny]

Thank you for your reply.
Would the second stone be more shiny then the first as the dimensions are better or will that be dependent on whether the inclusions impact the performance?

Of the 4Cs, it is Cut that really determines a stone's performance. A piece of window glass is colourless and has no inclusions, but it does not sparkle!

If the second stone has a better HCA score than the first (and it is under 2) then the angles will work better together.

The good angles are what the light needs to bounce around the stone and come back out the crown to your eyes, rather than leaking straight through or coming out the sides.


Twinning wisps are usually transparent and hard to see at distance (as I understand it) so are 'good' inclusions, but need assessing to make sure they don't affect light performance.

The crystal may be dark and/or large, which might be why it's an SI1 - pictures/videos would help assess it, as well as the twinning wisps.

An ASETscope image would help evidence cut accuracy and any leakage.

 

[stoneface]

Thank you all for your help it's much appreciated.