No HCA rating for this stone??

[snoopy]

I came across a stone labelled as 'xx Ideal' with both excellent polish and symmetry, 1.22 carats, F VVS1 and with the following measurements.

Diameter 6.96
Depth 60.7
Table 56.5
Crown Angle % 34.8
Pavilion Angle % 43
Girdle 0.9%

Culet is not mentioned and when I tried to fit it into the HCA, it comes up with the comment that the girdle is dangerously thin or the depth is incorrectly entered. I checked the figures again and I didn't get them wrong. What does this mean?

I have been playing with the cut adviser and this is the only stone that it won't 'accept'.

 

[DiamondOptics]

Hi Snoopy,


I'm sure that Garry will get to the bottom of this.


Stay tuned!



Kirk
www.diamondoptics.com
Exclusive SuperbCert tm Specialists

 

[glocko]

Are the numbers you specified for crown/pavilion "angles" or "%"? You specified both terms but it should be one or the other (i.e. either "angle" or "%").

When I plugged both crown and pavilion as angles, I got the same error you did. However, when I changed the Pavilion to "%" instead of angle, it worked and I got:

.8 = Excellent

Light Return - Excellent
Fire - Excellent
Scintillation - Excellent
Spread or diameter for weight - Very good

I'm kind of new at this too, but just thought that might be what the problem was as I've made the same mistake.

 

[snoopy]

Glocko, I think you are right; went back to the website to check but it does say angle (they prob got it wrong). But this time the pavilion angles are no longer there (??). Thanks for everybody's input!

 

[Garry H (Cut Nut)]

You are correct Glocko

But ask for the pavilion angle because if there is a culet the depth % will not give us an accurate pavilion angle from the conversion between pav depth % to angle.
43% = 40.68 degrees. But if the culet is slightly large - 2.6% then the pavilion angle would actually be 41.43 degrees and the HCA score would be terrible (well - not real good).