Excellent or Very Good Cut

[pinkrose]

is there much difference in an excellent vs. a very good cut GIA cert. diamond?

 

[JulieN]

Too many different looks, also girdle, finish issues. Simply, GIA EX and HCA<2

 

[Rhino]

Hi Julie,

Just curious ... have you ever compared a GIA Ex with 41 - 41.2 pavilion angles that gets over a 2 HCA to compare to a stone that gets under a 2 on the HCA ... say with 40.8 angles?

Regards,

 

[belle]

yes, there can be big differences. i have a gia ''very good'' that looks better than some ''excellent''s'' (yes, you read that right)
if you have a chance to compare these diamonds in person, take full advantage of doing so. if not, keep reading and learning as much as you can (wise to do anyway) and you will be able to make an informed purchase.
best of luck to you!

i would feel remiss if i did not post this https://www.pricescope.com/community/threads/gia-ex-let-the-buyer-beware.41371/

 

[Rhino]

And on the other hand there are GIA Ex steep/deeps with VG polish/symmetry that are brighter than some AGS ideals. If you''re going with a GIA stone the best bet is to see and compare a GIA Ex alongside a GIA Vg for yourself. There are 4 general characteristics that contribute to a diamond getting the VG grade.

a. shallow angled combos
b. steep angled combos
c. digging of the upper/lower girdle facets
d. painting of the upper/lower girdle facets

Each of these variations contributes to a difference in appearance that causes the VG grade and what most observers in GIA''s observation study chose as not being a brighter stone.

You may choose differently but you never know until you see for yourself.

Peace,

 

[pinkrose]

Thanks for all the quick replies! That link was very helpful Belle, really informative. Rhino what does the following mean:
c. digging of the upper/lower girdle facets
d. painting of the upper/lower girdle facets

 

[belle]

you''re welcome pinkrose.
i know the link was terribly long but i just wanted to give you some information on the gia system and what to expect.
here''s one on painting/digging. https://www.pricescope.com/community/threads/girdle-treatments-cheated-girdles-tweaked-girdles-digging-painting.36102/

 

[JohnQuixote]

Date: 10/7/2006 9:22:31 AM
Author: belle
you're welcome pinkrose.
i know the link was terribly long but i just wanted to give you some information on the gia system and what to expect.
here's one on painting/digging. https://www.pricescope.com/community/threads/girdle-treatments-cheated-girdles-tweaked-girdles-digging-painting.36102/

Hi Belle.

GIA cut grading, introduced after that thread was written, handles categorization in the lab differently. This overview by GIA has definitions which may be more in-line with this thread.

Painting & digging may be used to either (1) retain commercially important weight (2) improve a verbal description of girdle thickness/‘chase out’ inclusions or (3) acquire desirable visual properties. #3 is the least-used application globally, but it may be found in ‘superideal’ diamonds and brands discussed on PS. This article in the PS journal is specific to such diamonds (here is forums discussion).

Pinkrose, the short story is this: If you work with a reputable vendor, diamonds with any shortcomings caused by painting or digging should be screened out for clients - in the same way good sellers screen out diamonds with a level of fluorescence that would cause an adverse appearance.

 

[JohnQuixote]

Date: 10/7/2006 1:04:05 AM
Author: Rhino

There are 4 general characteristics that contribute to a diamond getting the VG grade.

a. shallow angled combos
b. steep angled combos
c. digging of the upper/lower girdle facets
d. painting of the upper/lower girdle facets

Actually Rhino, did you know less than 2% of all round diamonds graded by GIA have a grade influenced by painting or digging?

Steep and shallow angles top our list too; in both frequency and significance. I would add that in our experience the diamond's table size, polish & symmetry marks, girdle thickness & girdle range are notable general characteristics which contribute to the diamond's cut grade.

 

[Rhino]

Hi John,

Hope you''re having a good weekend.

Date: 10/7/2006 12:17:10 PM
Author: JohnQuixote

Date: 10/7/2006 1:04:05 AM
Author: Rhino

There are 4 general characteristics that contribute to a diamond getting the VG grade.

a. shallow angled combos
b. steep angled combos
c. digging of the upper/lower girdle facets
d. painting of the upper/lower girdle facets

Actually Rhino, did you know less than 2% of all round diamonds graded by GIA have a grade influenced by painting or digging?

Yep. I still see em though. Particularly on the older GIA reports (which are still in abundance) and on AGS Reports both old and new (not necessarily with digging but with painting that is notable that is making the ID grade).

Steep and shallow angles top our list too; in both frequency and significance. I would add that in our experience the diamond''s table size, polish & symmetry marks, girdle thickness & girdle range are notable general characteristics which contribute to the diamond''s cut grade.

Thanks for pointing that out. I didn''t mean to imply that the 4 characteristics I listed were the only characteristics that contribute to a VG grade. I meant to imply the 4 features that GIA has found in their observation testing which would contribute to a decrease in optical properties causing the VG grade. Sorry if there was any confusion.

Regards,

 

[Garry H (Cut Nut)]

Date: 10/6/2006 5:35:36 PM
Author:pinkrose
is there much difference in an excellent vs. a very good cut GIA cert. diamond?

GIA Very Goods that have just missed their Excellent grade because they are a little shallow are possibly cheaper and quite probably as good or better looking than the majority of the Excellent range.

Cutters get attracted to producing the slightly steeper and deeper and smaller spreading leaky dirt showing stones because they get better retention or yield from the rough. This is especially true on diamonds that just squeeze into the critical weight''s like 1.000000ct, 1.500000ct, 2.00000000000000000000ct etc