Table

[DiamondSeeker7]

Hi, I have spent a while researching diamonds and two last things that confuses me are "depth" and "table". I have read some tutorials on both, but I am still confused. Can someone tell me what the ideal table and depth percentage ranges would be? Or any other information I should know? Thanks so much!

 

[blingless]

Look here: http://diamonds.pricescope.com/tolk.asp

If you look under the knowledge tab on this site there is so much excellent information its mind boggling. Everything you could ever want to know is right there under that tab. If you search the archives you''ll find a fair amount of discussion about table sizes and the differences they make in performance. Take full advantage of all the work that somebody put into assembling and organizing all of that information. Its is truely an awesome reference source. Cheers!

 

[diamondseeker2006]

I believe an ideal cut stone can have a table between 53 and 58%, but many target 54-57%. Depth on ideal cut usually runs from about 60-62%.

 

[strmrdr]

The new AGS0 ideal cut has an unlimited table range.
As long as it can pass the tests the table % isn't considered.
The cutting guidelines Iv heard go from 47% to 62% but outside of that can pass the tests and get AGS0
Depth is cut off at around 62.8 or so, its based on spread not on depth but around there it gets knocked down

 

[Stone Hunter]

Well it also dependes on what shape your interested in. Fancy shapes change things a bit.

 

[JohnQuixote]

I had occasion to speak with AGSL and was reminded of this thread.

For anyone curious...

The smallest table size to date for a round achieving 0 in light performance has been 50% and the largest has been 61.4%. These represent actual diamonds graded by the lab. It will be interesting to see if those actuals widen in another year or so.

Anyone want to guess the largest table% for an actual princess receiving a 0 in light performance so far?

 

[JohnQuixote]

Date: 2/20/2007 12:53:28 PM
Author: JohnQuixote

Anyone want to guess the largest table% for an actual princess receiving a 0 in light performance so far?

Here''s a clue.

 

[Adylon]

That''s a big table

I''ll guess 81?

 

[JohnQuixote]

Ding ding ding ding!

81.2%

Pretty good Yosef...you''re more accurate than many non-contact scanners.

 

[diagem]

Date: 2/20/2007 5:05:00 PM
Author: JohnQuixote
Ding ding ding ding!

81.2%

Pretty good Yosef...you''re more accurate than many non-contact scanners.

For "0" light performance, right???
I allways wondered why they decided "0" is THE best!?!?

It might be great for light performance..., But I personaly would never touch a 80% table''d GEM!!! But thats only me....

 

[Regular Guy]

Date: 2/17/2007 8:15:42 PM
Author:DiamondSeeker7
Hi, I have spent a while researching diamonds and two last things that confuses me are ''depth'' and ''table''. I have read some tutorials on both, but I am still confused. Can someone tell me what the ideal table and depth percentage ranges would be? Or any other information I should know? Thanks so much!

Diamondseeker...

The advise about broad options for table being possible are current thinking, so far as I know, but the question is raised, I think, because not too long ago, ideal was sometimes only known by table & depth. That the big price infobase here primarily includes this data is premised on that understanding. Better understanding of the specific impact that crown & pavilion angles had on performance, sometimes alluded for historical reasons as 60/60, but more practically 55/60...is described in the tutorial here.

Certs from GIA not very long ago only captured this info, and dealers would reference it to profess "ideal." Contemporary certs include more data, and you''ll want to consider more in your search. Smart guys on this board, mindful of the wisdom of conventions along these lines...do still attend to charts that very much include table & depth, but usually, other data as well.

 

[Adylon]

Woo Hoo! So what''s my prize??? From looking at that pic I knew it was around 80 somewhere, I guessed a hair higher since I knew you were looking for a high number

Personally I wouldn''t want a 80% table princess myself. Will WhiteFlash''s 0 grade or X-Factor include these types of stones or are you going to filter out some AGS0 stones like you do with the ACA round?

 

[JohnQuixote]

Date: 2/20/2007 5:58:58 PM
Author: Adylon
Woo Hoo! So what's my prize??? From looking at that pic I knew it was around 80 somewhere, I guessed a hair higher since I knew you were looking for a high number

Personally I wouldn't want a 80% table princess myself. Will WhiteFlash's 0 grade or X-Factor include these types of stones or are you going to filter out some AGS0 stones like you do with the ACA round?

Yosef, if we were throwing darts I'd be buying this round. Good bullseye.

Brian's prescription for the ACA Princess currently includes up to 73%. X-Factor is limited to 70% right now. The high 70s are larger than I'd recommend for the average consumer seeking my input 'blindly,' but those stones do float some peoples' boats. Tastes vary, and just as some people love small tables and the highest crowns they can get there are others who like brilliance and a big table flashing on and off. As with any extreme I'd want to see what we're talking about in person.

We've carried princess cuts in our regular inventory from the low 60s to the high 70s in the past, but I don't know that we've had anything 80+ pass through. If so I think it would have been a special request.

 

[Adylon]

That''s interesting, I haven''t really read up on your X-factor. So it has tighter tolerances then ACA? Will you be replacing all ACA princess with X-factor in the future? I''m trying to determine numerical "premium cut" figures and combinations myself for round, princess, and asscher. I never would have guessed 81% table for princess could make AGS0. Thanks for the fyi

 

[JohnQuixote]

Actually the tolerances aren’t tighter Yosef.The X-Factor is a clipped corner princess so the table size is a bit smaller at both ends of the range.Even so, there can be some flex depending on configuration.It’s not a replacement for ACA Princess, just a different selection for people who might be attracted to its shape and look.

There is so much give and take in fancy shapes that we don’t try to predict them by the numbers.Even though we have a range of tolerances which suits our fancy (pun intended) we know ours isn’t the only answer.Take the AGS0 princess for example; many different ‘looks’ can acquire the numeric values necessary for their top grade…that unique 81% table-flasher will look far different than one with a 55% table but they may have equally high performance.Hard to say one or the other is ‘right’ or ‘wrong.’

I hear where you’re coming from though.Many gemologists and diamantaires have ‘instincts’ and favored recommendations for fancy shape configurations, gained from years of experience.As we’re exposed to new metrics and measures, some of those old-time instincts about fancy shapes will be right as rain…while others we never even considered are coming to light.

 

[Adylon]

Ah very nice, so it''s like a brilliant asscher, very intersting, I like it (I should read up more on your products) I''m glad you guys limited the table at a max of 73% for ACA princess.

 

[JohnQuixote]

We are currently in R&D for our own square emerald, but this baby is not ours.The photo is a very unconventional configuration - a 41% table according to Wink Jones if I’m not mistaken - cut by an Indian company for Peter Yantzer according to AGSL’s predictive modeling.This is an actual photo; no enhancement. It's been featured in some of their educational materials (photo reproduced with permission). I would love to see it live.