Confusion over a HCA score of 2.6 (angle) and 1.5 (%)

[DiaBuyer]

Hi All,

Was wondering if anyone here could help me (hope this is the right area of the forum!)

Found a Diamond locally (GIA 5136350084) with the following spec:

Carat Weight 1.14 carat
Color Grade E
Clarity Grade VVS1
Cut Grade Excellent

Depth 62.7 %
Table 56 %
Crown Angle 35.5°
Crown Height 15.5%
Pavilion Angle 40.8°
Pavilion Depth 43.0%
Girdle Medium to Slightly Thick, Faceted, 3.5%
Culet None

Plugging the spec into the HCA gives 2.6 when using the Angles and 1.5 when using the % for Crown and Pavilion values.
I realise this is just a guide and the Angles value is the more accurate but it is quite a big difference.
Can anyone shed some light on this? Any opinions on the numbers as given?

Happy enough with the price and visually looks good. I've asked the dealer for Ideal-Scope images but they aren't normal here (Dubai).

Thanks in advance for any help.

 

[DiaBuyer]

Anyone have any thoughts on this HCA discrepancy between angle and %?

Reading through the posts here I see that the depth of 62.7% is more that the recommended 62% max.
Does this coupled with the HCA of 2.6 mean I should move on from this one?

 

[Niel]

the HCA score is a soft exclusion tool, its not definitive. 2-3 scores could still be a good stone, especially if youre getting under 2 too. (i dont know why your getting different numbers, sorry )

Is there a reason you want such a high color and clarity?

 

[diamondseeker2006]

The depth may affect the face-up size of the stone. Always list the diameter measurements. A stone that weight should be in the 6.7-6.8mm diameter range. If it is not, I would eliminate it.

 

[Christina...]

I haven't seen an HCA score differ this much just by changing the angles and percentages. Interesting, I hope that there is an answer for you and that someone will chime in and explain it. I've seen very small changes before, but again nothing this large.

The dimensions are 6.62x6.69, so it's slightly deep and will appear slightly smaller than other well cut stones.

 

[yssie]

Hi All,

Was wondering if anyone here could help me (hope this is the right area of the forum!)

Found a Diamond locally (GIA 5136350084) with the following spec:

Carat Weight 1.14 carat
Color Grade E
Clarity Grade VVS1
Cut Grade Excellent

Depth 62.7 %
Table 56 %
Crown Angle 35.5°
Crown Height 15.5%
Pavilion Angle 40.8°
Pavilion Depth 43.0%
Girdle Medium to Slightly Thick, Faceted, 3.5%
Culet None

Plugging the spec into the HCA gives 2.6 when using the Angles and 1.5 when using the % for Crown and Pavilion values.
I realise this is just a guide and the Angles value is the more accurate but it is quite a big difference.
Can anyone shed some light on this? Any opinions on the numbers as given?

Happy enough with the price and visually looks good. I've asked the dealer for Ideal-Scope images but they aren't normal here (Dubai).

Thanks in advance for any help.

GIA rounds crown/pav percent to the nearest 0.5%, crown to the nearest 0.5deg, pav *up* to the nearest 0.2deg (40.8 stays 40.8, 40.9 is rounded to 41).
There is a range of angles that can round to a given half-percent, and since GIA rounds the angles on the report as well you really can't do or die by HCA - you can play around with the GIA facetware tool here http://facetware.gia.edu/