Opinion on HCA score & stone please

[Cleo]

Posted pics of my engagement ring in "Show me the ring" and wondered if I could get some advice please.

My diamond was from DiamondsonWeb.com, stats as follows:

AGS Cert: 0008362010 (inscribed on girdle)
Round Brilliant
6.49 x 6.52 x 3.92 mm
Cut Grade: AGS Ideal 0
Polish: Ideal
Symmetry: Ideal
Proportions: Ideal
Colour Grade: F
Clarity Grade: VS2
Carat Weight: 1.001 cts
Fluorescence: negligible

Depth: 60.2%
Table: 56.7%
Crown angle: 33.8%
Pavilion angle: 40.8%
Pointed culet
OK, so I discovered the HCA after we bought the stone.

Put all my stats in the HCA and got a score of 0.9 - Excellent.

The bit I am confused by is the fact the X plotted on the graph seems to be outside the area marked by the solid white line, which represents the AGS Ideal stones.

My stone has an AGS cert saying it''s Ideal for cut, AGS0... so how come it''s not within this region of the graph?!?

*confused*

Oh yes, the date on my cert. is 31st May 2007.

Would appreciate feedback on diamond stats from the expert PSers here - you can be honest, it''s ok! LOL

Karen x x x

 

[JulieN]

the white outline is the guideline for cutters. basically means that those proportions are expected to get a 0. however, you can be outside of the guidelines and get a 0. obviously, your stone is beautiful.

 

[strmrdr]

Date: 1/31/2008 5:18:31 PM
Author: JulieN
the white outline is the guideline for cutters. basically means that those proportions are expected to get a 0. however, you can be outside of the guidelines and get a 0. obviously, your stone is beautiful.

yep
The guidelines are conservative to allow for normal tolerances in cutting and still be able too get the score.
The actual score is done by computer modeling a 3d sarin scan that takes every facet into account and has its own margin of error.
That is why the guidelines are kept very conservative.

 

[Cleo]

That''s very interesting - thank you both for replying.

I really enjoyed reading the explanation given of the scores on the webpage, but it didn''t explain the basis of the position of the white lines on the graph, or that Ideal AGS0 stones can still fall outside of the ''Ideal Zone''.

I was starting to think we''d bought a mutant diamond.... (much as I love it)

Thankyou!

x x x