is this round too deep?

[CushionDva]

I was looking at this round brilliant 2 carat. Here are the specs:

depth: 63.3
table:58
polish, symmetry, cut: very good
no flour, no culet
girdle stk-tk
measurements: 7.98-7.74 x 5.04

Its a D color, really eye clean si2.

I am really concerned as to why its measurements arent in the 8''s? I was looking at a triple excellent 1.85, and even that one measured at7.88-7.92x4.84. I feel like the 2 carat is too small for some reason. Is it cut too deep? I was looking at another 2 carat and its measuremnets were in the 8.15''s but it was an si2 and had LOTS of bubbles....couldnt really tell if it was eye clean. The first 2 carat had a flower off to the side that a prong can cover, and another feather off to the side agan, but other than that...had no other inclusions...it was a really good si2...just dont know if it is cut too deep and wont have the best light return! Any suggestions? I''m new to this forum, so thank you in advance for any help or insight you can give.

 

[jet2ks]

Yes, it is too deep and will most likely not perform well as a result. It also makes the diamond appear smaller, as you have already noted. I would suggest dropping color a little and raising the clarity to VS2 or SI1 in order to find a well cut diamond in the same price range. The vast majority of people cannot tell the difference between a D and G, even side by side.


Here is some good guidelines when looking for a well cut round.

depth - 60 - 62%
table - 54- 57%
crown angle - 34- 35 degrees
pavilion angle - 40.6- 41 degrees
girdle - avoid extremes, look for thin to slightly thick, thin to medium etc
polish and symmetry - very good and above

note - with crown and pavilion angles at the shallower ends ( CA 34- PA 40.6) and steeper ( CA 35- PA 41) check to make sure these angles complement in that particular diamond - eyeballs, Idealscope, trusted vendor input - check as appropriate!

As the above implies, configurations depend on each other. A little give here can still work with a little take there.

From expert John Pollard.

With that said, here's a "Cliff's Notes" for staying near Tolkowsky/ideal angles with GIA reports (their numbers are rounded): A crown angle of 34.0, 34.5 or 35.0 is usually safe with a 40.8 pavilion angle. If pavilion angle = 40.6 lean toward a 34.5-35.0 crown. If pavilion angle = 41 lean toward a 34.0-34.5 crown.

GIA "EX" in cut is great at its heart, but it ranges a bit wider than some people prefer, particularly in deep combinations (pavilion > 41 with crown > 35).

 

[Garry H (Cut Nut)]

If the girdle was thick to very thick (and priced accordingly) it might not have steep deep problems.
But as is I think the crown and or pavilion angles will be bad

 

[Lorelei]

I agree with the gentlemen, you can do better.

 

[Todd Gray]

I''d narrow the range down even further:

Total depth: 59 - 61.8%
Table diameter: 53 - 57%
Crown angle between 34.3 - 34.8 degrees
Pavilion angle between 40.6 - 40.9 degrees
Girdle: thin to slightly thick
Culet: GIA none or AGS pointed

And then of course, I''d recommend getting a Sarin / OGI / Helium report indicating the facet-by-facet structure of the stone to verify that the average crown / pavilion angle measurements are based on a tight range and not a wide variance... Followed by ASET, Ideal Scope and H&A images to judge the optical symmetry (cut precision) of the stone.

 

[Rockdiamond]

I agree, it''s too deep.
Let me give you an alternative viewpoint.
I''d look at stones that are slightly "spreadier"
Table size 58-60, depth no greater than 60.5%.
In a well cut stone, these measurements should produce a stone larger than 8mm- and one that looks brighter than the smaller tables recommended by others.
I''d include stones that GIA graded "EX" cut grade, as well as those graded "VG" cut grade.
In many cases people will choose the "VG" cut grade based on appearance- plus you''re likely to save money.

 

[Todd Gray]

Date: 12/21/2009 2:53:57 PM
Author: Rockdiamond
I agree, it''s too deep.
Let me give you an alternative viewpoint.
I''d look at stones that are slightly ''spreadier''
Table size 58-60, depth no greater than 60.5%.
In a well cut stone, these measurements should produce a stone larger than 8mm- and one that looks brighter than the smaller tables recommended by others.
I''d include stones that GIA graded ''EX'' cut grade, as well as those graded ''VG'' cut grade.
In many cases people will choose the ''VG'' cut grade based on appearance- plus you''re likely to save money.

With what combination of crown angle and pavilion angle offset David? Stating a preferred range for total depth and table diameter is only part of the puzzle and opens the lid on Pandora''s box in terms of a myriad of unknown options for consumers without proper insight. The range which you''ve stated can result in an overall proportions rating anywhere from AGS-2 Very Good all the way down to AGS-10 Very Poor!

 

[FB.]

Date: 12/21/2009 12:41:05 PM
Author: Todd Gray
I''d narrow the range down even further:

Total depth: 59 - 61.8%
Table diameter: 53 - 57%
Crown angle between 34.3 - 34.8 degrees
Pavilion angle between 40.6 - 40.9 degrees
Girdle: thin to slightly thick
Culet: GIA none or AGS pointed

And then of course, I''d recommend getting a Sarin / OGI / Helium report indicating the facet-by-facet structure of the stone to verify that the average crown / pavilion angle measurements are based on a tight range and not a wide variance... Followed by ASET, Ideal Scope and H&A images to judge the optical symmetry (cut precision) of the stone.

Agreed, although I think that the best lookers have a 55-57 table. I also dislike more than one grade of variation in girdle thickness.
Setting the maximum acceptable depth at 61.8% (with a 55-57 table) seems to weed-out most of the "steep/deep" stones. Most steep/deep (35.5/41.2) with 55-57 tables, seem to be in the 62.0-62.5% range, with a few borderline stones (35.0/41.0) in the 61.9-62.0 range.

 

[Rockdiamond]

Good question Todd!
Since I buy using my eyes- and recommend others do the same, it is not necessary to know the CA/PA.
If you look at the stone, and there is a problem, you will see it.
Sometimes trying to use too many stats unnecessarily complicates what might be a very intuitive decision.

If one wanted to buy without looking at stones, than using a recommended list of stats to buy will work great. BUT only if the buyer loves the same thing that the person who compiled the list does.

Since there is a lot of money involved, my recommendation was to look at different stones- including GIA VG cut grades to see what the person actually does like.

Todd, I''m sure that using your list will get someone a well cut stone- but it would certainly exclude many combinations that the person might find more attractive looking at the stones.

 

[Todd Gray]

Date: 12/21/2009 3:42:17 PM
Author: Rockdiamond
Good question Todd!
Since I buy using my eyes- and recommend others do the same, it is not necessary to know the CA/PA.
If you look at the stone, and there is a problem, you will see it.
Sometimes trying to use too many stats unnecessarily complicates what might be a very intuitive decision.
If one wanted to buy without looking at stones, than using a recommended list of stats to buy will work great. BUT only if the buyer loves the same thing that the person who compiled the list does.
Since there is a lot of money involved, my recommendation was to look at different stones- including GIA VG cut grades to see what the person actually does like.

Todd, I''m sure that using your list will get someone a well cut stone- but it would certainly exclude many combinations that the person might find more attractive looking at the stones.

I always assume that the average consumer lacks the benefit of having the experience of being able to examine a broad selection of well cut diamonds required to develop actual insight into what the various combinations of proportions are capable of delivering and thus rely on a proven set of measurements which will yield optimum visual performance time and time again - provided that the average crown and pavilion angle measurements are based on a tight range and not a broad variance.

Hopefully customers reading your advice reside in an area where a broad range of diamonds is available to them to evaluate so that they can view 500 - 1000 diamonds in order to find one which might rival a super ideal cut of the proportions recommended. I know that "buying by the numbers" is certainly more economical both in terms of time and money from my perspective - but then again, I also restrict my buying to a select group of cutters - which I''m sure you do as well David, which also enables you to have a higher rate of success when buying with just your experienced eyes - something which the average consumer is probably not capable of doing with any real degree of accuracy beyond the few very, very capable, diamond expert level consumers that provide advice here on PS.

 

[Rockdiamond]

Interesting Todd.
Our views about table size- as well as diamond buying in general are quite different- and I believe illuminating for readers.
500-1000 stones? Maybe if they want to become a grader, but I think it is possible for a consumer to see 5 or 10 diamonds to get a good idea what they are looking at. Provided they are working with a dependable dealer with the ability to show them some different types of makes in different, and representative lighting environments.

I always assume the person wanting to buy a diamond is interested in spending as little as possible, while sacrificing as little as possible- or nothing at all.
Therefore I would not use my idea of "optical performance" to guide them to stones costing quite a bit more than others because I felt they were "better".
Why steer people straight to "Ideal" when they may actually prefer something else?
Especially if the something else is prettier to their eyes, and cost less.

 

[Dancing Fire]

i''d prefer stones with 54-55% table.

 

[Dancing Fire]

Date: 12/21/2009 6:20:51 PM
Author: Rockdiamond
Interesting Todd.
Our views about table size- as well as diamond buying in general are quite different- and I believe illuminating for readers.
500-1000 stones? Maybe if they want to become a grader, but I think it is possible for a consumer to see 5 or 10 diamonds to get a good idea what they are looking at. Provided they are working with a dependable dealer with the ability to show them some different types of makes in different, and representative lighting environments.

I always assume the person wanting to buy a diamond is interested in spending as little as possible, while sacrificing as little as possible- or nothing at all.
Therefore I would not use my idea of 'optical performance' to guide them to stones costing quite a bit more than others because I felt they were 'better'.
Why steer people straight to 'Ideal' when they may actually prefer something else?
Especially if the something else is prettier to their eyes, and cost less.

what you paid is what you'll get.