GIA EX/EX- Always good performers?

[E B]

Just out of curiosity...

...if a stone is graded EX/EX by GIA (but the cert is older and lacks crown, pav numbers), can it be assumed it''s a good performer? Or are the angle numbers absolutely necessary?

 

[Paul-Antwerp]

First question: ABSOLUTELY NOT.

Second question: Definitely

Live long

 

[Upside Down Man]

I was actually told by someone whose advice I trust that there is really little difference at all, in terms of light performance to the naked eye, between ex/ex, vg/vg or some combination of ex/vg.

But as far as predicting if any of the above combinations would perform well, you'd need the crown and pavillion angles to know, as well as the table and depth precentages.

 

[Rhino]

I would certainly ditto Paul on both accounts.

Date: 11/3/2006 4:29:31 PM
Author: Upside Down Man
I was actually told by someone whose advice I trust that there is really little difference at all, in terms of light performance to the naked eye, between ex/ex, vg/vg or some combination of ex/vg.

But as far as predicting if any of the above combinations would perform well, you''d need the crown and pavillion angles to know, as well as the table and depth precentages.

In regards to your points UDM, it is true that light performance isn''t really impacted between Ex and VG grades for finish. Some in the trade feel that stones attaining the AGS "0" cut grade should include the 2nd grades down (AGS Excellents in polish/symmetry) as it doesn''t impact diamond beauty and light performance.

Peace,

 

[Garry H (Cut Nut)]

Date: 11/3/2006 4:29:31 PM
Author: Upside Down Man
I was actually told by someone whose advice I trust that there is really little difference at all, in terms of light performance to the naked eye, between ex/ex, vg/vg or some combination of ex/vg.

But as far as predicting if any of the above combinations would perform well, you''d need the crown and pavillion angles to know, as well as the table and depth precentages.

Extend that to certain types of sym and polish downgrades for Good and Fair will also not degrade optical performance.

 

[Rhino]

btw Ebree I love the pic in your avatar.

I have 2 pugs too.

Mojo & Wilbur.

 

[WinkHPD]

Date: 11/3/2006 3:57:06 PM
Author:EBree
Just out of curiosity...

...if a stone is graded EX/EX by GIA (but the cert is older and lacks crown, pav numbers), can it be assumed it''s a good performer? Or are the angle numbers absolutely necessary?

Ex Ex has NOTHING to do with the light performance of the stone. It''s the angles that tell the story...

Wink

 

[jayreneepea]

In what way does polish and symmetry affect a stone? What differences will you see in an ex/ex and a gd/gd?

 

[Upside Down Man]

Date: 11/3/2006 6:07:31 PM
Author: Wink

Ex Ex has NOTHING to do with the light performance of the stone. It''s the angles that tell the story...

Wink

Which invites the obvious questions, what do polish/symmetry influence and why are grades of ex/ex (as opposed to vg/vg) important?

 

[E B]

Thank you all so much!

I have all but one of the major numbers needed (for the HCA, anyway...right?). Depth is 61.3, table is 59, no culet and crown is 33. Do these numbers reveal anything?

p.s. It's always good to meet another pug lover! My little girl is named Sally, and she's smashed up against me as I type, snoozing.

 

[E B]

Oh, and girdle is thin to medium, if it matters.

 

[E B]

Date: 11/3/2006 6:16:46 PM
Author: jayrenay9
In what way does polish and symmetry affect a stone? What differences will you see in an ex/ex and a gd/gd?

I''m curious about this as well. If EX/EX doesn''t insure at least a very good stone, then what''s the point in looking for it?

 

[Garry H (Cut Nut)]

Sounds like it will get a great HCA score. Probably a pavilion angle below 40.75 though - so from very close up the center will go dark.

Re sym and polish grading - common sense is not common

 

[E B]

Date: 11/3/2006 8:57:56 PM
Author: Garry H (Cut Nut)
Sounds like it will get a great HCA score. Probably a pavilion angle below 40.75 though - so from very close up the center will go dark.


Re sym and polish grading - common sense is not common

Gary,

You think so? From the numbers I gave? That's what I was curious about...if, knowing how diamonds are usually cut, using the depth, table and crown to estimate the pavilion and overall cut.

 

[Rhino]

Date: 11/3/2006 8:57:56 PM
Author: Garry H (Cut Nut)
Sounds like it will get a great HCA score. Probably a pavilion angle below 40.75 though - so from very close up the center will go dark.

Re sym and polish grading - common sense is not common

And even from a distance if its painted/dug out enough.

 

[Garry H (Cut Nut)]

digging a little would probably improve it

 

[Rhino]

Date: 11/3/2006 6:17:53 PM
Author: EBree
Thank you all so much!

I have all but one of the major numbers needed (for the HCA, anyway...right?). Depth is 61.3, table is 59, no culet and crown is 33. Do these numbers reveal anything?

p.s. It''s always good to meet another pug lover! My little girl is named Sally, and she''s smashed up against me as I type, snoozing.

Oh they love coming in the computer room and playing.

Here''s a recent shot. Wilbur resting his head on mama''s arms and Mojo looking seemingly interested in my camera.

On subject ... with the likely angle combos I''d suggest looking at this and comparing to stones of known better proportion combo''s (like a current GIA Ex cut grade) before pulling the trigger Ebree and making the comparison in a common lighting environment.

Kind regards,

 

[E B]

Date: 11/3/2006 9:49:10 PM
Author: Rhino

Date: 11/3/2006 8:57:56 PM

Author: Garry H (Cut Nut)

Sounds like it will get a great HCA score. Probably a pavilion angle below 40.75 though - so from very close up the center will go dark.



Re sym and polish grading - common sense is not common

And even from a distance if its painted/dug out enough.

So you wouldn''t recommend it period, or if it has a pav. angle below 40.75?

Rhino, your pugs are PRECIOUS. Such smooshy faces.

Here''s my little girl, looking smug. Isn''t it funny how they sit?

 

[Garry H (Cut Nut)]

Date: 11/3/2006 6:16:46 PM
Author: jayrenay9
In what way does polish and symmetry affect a stone? What differences will you see in an ex/ex and a gd/gd?

You may see a difference if for instance a polish line runs across the top of the table.
But if a facet meet point does not meet it might need 10x un an unset diamond pavilion to see it. There is more here
http://www.gemology.ru/cut/english/symmetry/

It will require abit of common sense to understand the differences

 

[Lorelei]

PUG HEAVEN!! You know I always love new pics of Sally Ebree and your babies are adorable Jon!

 

[diamondseeker2006]

Ebree, I think the thing we need to look for on a GIA cert is excellent for the cut. It''s really just a bonus to get excellent for polish and symmetry. It''s okay to have very good on those two. Even within the excellent cut category, there are still better performers than others, which is why we still even need to post those numbers if you''re getting diamonds from a local jeweler or from a virtual database where the diamonds are not being pre-screened for you like a few of the vendors here do.

(Those pugs are adorable! That''s really why I wanted to post here!

)

 

[Rhino]

Date: 11/4/2006 4:15:34 AM
Author: Lorelei
PUG HEAVEN!! You know I always love new pics of Sally Ebree and your babies are adorable Jon!

Doh! I didn''t mean to hijack this thread. I"m gonna blame it on Sally cause she''s so darn cute!

What a cute pic Ebree! Thanks for sharing. She still looks so small! How old is Sally?

Thanks so much Lorelei for your comments on Mojo and Wilbur. After our kids got to their teens my wife wanted a couple of new babies but a little easier to take care of.

Now they are the babies.

Its so funny how they have their own personalities and dispositions. I love em.

Peace,

 

[Rhino]

Date: 11/4/2006 9:38:00 AM
Author: diamondseeker2006

(Those pugs are adorable! That''s really why I wanted to post here!

)

Haha! They are aren''t they?!? Back around 2 years ago when we first got Mojo it was between him and an English Bulldog. I LOVE ENGLISH BULLDOGS TOO! But at that time they were around 3x the cost (and probably still is) and Mojo was just as cute. About 5-6 months later we went to drop Mojo off as we were going on vacation and when we came to pick him up there was a fresh litter and we found Wilbur.

My wife doesn''t know it but I still want to get an English Bulldog.

 

[diamondseeker2006]

Date: 11/4/2006 11:26:16 AM
Author: Rhino

Date: 11/4/2006 9:38:00 AM
Author: diamondseeker2006

(Those pugs are adorable! That''s really why I wanted to post here!

)

Haha! They are aren''t they?!? Back around 2 years ago when we first got Mojo it was between him and an English Bulldog. I LOVE ENGLISH BULLDOGS TOO! But at that time they were around 3x the cost (and probably still is) and Mojo was just as cute. About 5-6 months later we went to drop Mojo off as we were going on vacation and when we came to pick him up there was a fresh litter and we found Wilbur.

My wife doesn''t know it but I still want to get an English Bulldog.

Gosh, you and my husband would get along well! We''re on our second English bulldog! I''ll see if I can get a picture of him! I''d personally rather have the pug since you can hold them in your lap!

 

[Cehrabehra]

Date: 11/4/2006 9:38:00 AM
Author: diamondseeker2006
(Those pugs are adorable! That''s really why I wanted to post here!

)

me too! this is my in ROFL!! wilbur has the most wrinkly face ever it''s so cute!! they''re all cute!! my inlaws are pugger people - they''re quite characters!!!

 

[denverappraiser]

People are anxious to decide if a stone will look good based on data from the lab reports. This is especially true with internet sales but it’s increasingly so at the stores as well. By and large, it doesn’t work very well. The most common questions people ask about diamond grading are:

Is it eye clean?
Does it face up white?
Is it pretty?
Is it priced right for what it is?

None of these things are addressed by the labs and the relevant information is not contained on their reports. Excellent polish and symmetry are both good things and are worth noticing but, for most customers, they don’t address the key issues and they are only a component to the question of quality of craftsmanship.

Why do people look at them? Because the information is usually available and it’s usually free. It’s the same reason they look at table/depth percentage ratios.

Neil Beaty
GG(GIA) ICGA(AGS) NAJA
Professional Appraisals in Denver

 

[Garry H (Cut Nut)]

Date: 11/4/2006 12:33:45 PM
Author: denverappraiser

People are anxious to decide if a stone will look good based on data from the lab reports. This is especially true with internet sales but it’s increasingly so at the stores as well. By and large, it doesn’t work very well. The most common questions people ask about diamond grading are:

Is it eye clean?
Does it face up white?
Is it pretty?
Is it priced right for what it is?

None of these things are addressed by the labs and the relevant information is not contained on their reports. Excellent polish and symmetry are both good things and are worth noticing but, for most customers, they don’t address the key issues and they are only a component to the question of quality of craftsmanship.

Why do people look at them? Because the information is usually available and it’s usually free. It’s the same reason they look at table/depth percentage ratios.

Neil Beaty
GG(GIA) ICGA(AGS) NAJA
Professional Appraisals in Denver

= common sense is not common

Wuld be great to be able to offer diamond buying Joe some better way Neil.

Reports add a lot to the stone cost, and little real value

 

[Paul-Antwerp]

Hey Garry,

Ancient wisdom: ''For those going on a crusade, it is important to focus on Jerusalem.''

Live long,

 

[strmrdr]

Date: 11/4/2006 2:19:40 PM
Author: Garry H (Cut Nut)

http://www.gemlab.us/

= common sense is not common

Wuld be great to be able to offer diamond buying Joe some better way Neil.

Reports add a lot to the stone cost, and little real value

Lets hang all the vendors that arent 100% honest 100% of the time and put the ones not capable of precision grading out of business then we can discuss doing away with the labs.