HCA Score vs. GemEx Report

[tulip1]

Hi Everyone, looking for some more help in my diamond search.

1. I am interested in this diamond from Good Old Gold:

Round brilliant, F, VS21 1.25 carat, GIA cert
HCA of 2.2
Length: 6.93mm
GIA Cut Grade: Excellent
Table: 56.81%
Depth: 61.83%
Crown: 34.77°
Pavilion: 40.98°
Symmetry: Excellent
Polish: Excellent
Fluorescence: Negligible
Girdle: 1.74%
Culet: None
Lab Report: GIA


The GemEx Report scores were great - everything very high (this was one of the few diamond to score a very high in the white light return category). However, the HCA score was only 2.2 with everything in the very good range. I would have expcected the HCA scores would have been excellent. Should I give more weight to the GemEx Report versus the HCA score with respect to the appearance of this diamond?

2. I am also considering this diamond from a B&M. Should I expect good light return and brilliance with these numbers or more fire? I prefer brilliance over fire, but am looking for a nice balance. What can I expect with the combination of the larger table (59) and the steeper crown (35)?

Round brilliant, F, VS2, 1.25 carat, GIA cert
HCA of 1.4
6.85 x 6.91 x 4.24
Depth 61.6
Table 59
Crown angle 35.0
Pavilion angle 40.6
Polish very good
Symmetry Very good
No culet
Girdle mediim


Thanks for your help!

 

[Regular Guy]

a) Have you heard the old 40s are the new 50s?

Anyway, the old 0-2 is the new 0 - 2.5 or so...meaning you get two thumbs up with the GOG option.

b) re the other, my feeling is that the large table coupled with the big crown angle may get you your balance, but right now it''s only a feeling, so better get some other input.

 

[Ellen]

Hi tulip,

I agree with Ira. Unless you can get an IS image to compare, the GOG stone is the winner.

The HCA is 1. partial to shallower numbers, but is in the process of being revised, and 2. should really only be used when you don''t have any info such as IS or ASET images. It merely gives you an idea on how good a stone may or may not be, then you need more info.

With the GOG stone, you have everything you need to determine how good a stone it is, and it IS a good one.

Isee you enjoying that one very much, it will have a nice mix.

 

[Regular Guy]

Date: 3/12/2007 2:44:20 PM
Author: Ellen

Isee you enjoying that one very much, it will have a nice mix.

Ellen, he didn''t say it was also tested with the ISEE...

 

[Ellen]

Oh, look at that, my keyboard must have stuck.

 

[strmrdr]

The HCA is kicking the first one down because of the pavilion rounding to 41 round it to 40.9 and its a 1.8.
That is one area that in some cases I really dislike the hca, its overly harsh at 41 degrees with stones that walk the line.