dimensions of princess cut

[mbn]

I have came across 2 1.52 princess cut; one with premium cut, and the other what I assume good cut diamond. The premium cut has larger dimensions than the good cut with other characteristics equal. I am wondering why the good cut stone has shorter dimensions and where did the extra weight go since both have thin to medium girdles and same depth measurement % ?
I see other diamonds that are 1.52 or less and looks bigger than B diamond below, so I am wondering whether the B diamond below is a good cut diamond?A)
Premium cut
1.52carat
6.65.652x4.49
Depth 68.9%
Table 76%
polish: good
symmetry:good
flourescence: noneB)
Good cut
1.52 carat
6.46x6.30x4.49
Depth 71.3%
Table 76%
polish: very good
symmetry: good
flourescence:faint

 

[pricescope]

Hi Mbn,The appearance of the diamond (spread) depends on total depth, table size, crown and pavilion angles, and girdle of course.Diamond A has less total depth hence better spread.Diamonds with the same depth could have different spread if they have different crown and pavilion angles and table sizes.You can play online with proportions and measurements with any models at
www.cutstudy.com/cut/english/collection.htm To work with princess you'll need a full version of Diamond Calculator: www.cutstudy.com/octonus/english/diamcalc/index.htm Have you checked the cut grades for your princess diamonds at www.gemappraisers.com/chrt4.htm ?To evaluate grade more accurately you'll need crown and pavilion measurements though...

 

[Garry H (Cut Nut)]

Read the tutorial on table depth %

 

[mbn]

What site do you recommend I go to for tutorial on table depth %?

 

[Garry H (Cut Nut)]

Ship them to Dave Atlas, or if you can see them live buy an Ideal-scope.
Garry www.ideal-scope.com

 

[pricescope]

[FONT=Verdana,]quote:[/FONT]
Originally posted by mbn:
Does this mean that the stone w/larger diameter has smaller crown angle and height?

Correct.

[FONT=Verdana,]quote:[/FONT]
What site do you recommend I go to for tutorial on table depth %

www.gemappraisers.com/chrt4.htm you also might find this one useful: www.drostes.com/princess-table.html

 

[mbn]

provided depth measurement is the same in both princess cut stones 4.49, table size is same because both are 76, girdle both thin to medium in both stones, if crown and pavilion angles are different then spread is different. Does this mean that the stone w/larger diameter has smaller crown angle and height?

 

[mbn]

stone w/larger dimensions has smaller table and height, which means less crown is visible, how does this affect dispersion or sparkle of diamond?

 

[pricescope]

There is less knowledge on how fancy cuts proportions affect brilliance and fire of the diamonds comparing to rounds.You can start with AGA grading system and compare diamonds yourself or with the help of a professional.You also can use ideal-scope to see and compare qualitatively how well diamonds return the light.