shape
carat
color
clarity

How do Table/Depth numbers affect how big a princess cut looks?

Status
Not open for further replies. Please create a new topic or request for this thread to be opened.

AZDiamondShopper

Rough_Rock
Joined
Apr 4, 2003
Messages
22
Hi,
I have been reading on this forum for quite some time. I know that numbers don''t tell the whole story on princess cut diamonds. However, can anyone tell me how the numbers can influence how big a princess cut looks to the eye? I have seen various princess cuts with very good Bscope results, but they vary widely in table and depth percentages. I want to get a princess cut with great Bscope results, but I also would like to know how the numbers affect the visual size appearance of the diamond.
Thanks as always!
 

mdx

Brilliant_Rock
Joined
Mar 1, 2002
Messages
570

Most princess cuts are cut from Octahedrons (They look like two pyramids on top of each other joined at the bases.) and can yield up to 80% recovery from the rough, This is why you will find most princess cuts are very deep (heavy) and with large tables 75% –80%.


The large tables are usually at the expense of crown height thus reducing visual performance. The larger tables do to some extent give the elusion of a bigger stone but at the expense of beauty


/www.pricescope.com/idealbb/images/smilies/3.gif[/img]>/www.pricescope.com/idealbb/images/smilies/3.gif[/img]>


As a simple guideline you, the shallower the depth the larger the visible surface area The smaller the table the better the diamond will look.


/www.pricescope.com/idealbb/images/smilies/3.gif[/img]>/www.pricescope.com/idealbb/images/smilies/3.gif[/img]>


My personal favorite is a depth of 65% and a table of 65% with a crown height of around 10%. But they are not easy to find.


/www.pricescope.com/idealbb/images/smilies/3.gif[/img]>/www.pricescope.com/idealbb/images/smilies/3.gif[/img]>


I would suggest that you use the cut charts of Dave Atlas at www.gemappraisers.com as a guideline.


/www.pricescope.com/idealbb/images/smilies/3.gif[/img]>/www.pricescope.com/idealbb/images/smilies/3.gif[/img]>


Wayne


Melbourne Diamond Exchange ltd (Australia)

 

Giangi

Ideal_Rock
Joined
Jan 23, 2003
Messages
2,530
Stick with a princess w/57-68% table and ~65% depth... Crown higher than 10%... No extremely thin or very thin girdles...
1.gif
 

Rhino

Ideal_Rock
Trade
Joined
Mar 28, 2001
Messages
6,340
My personal experience with princess cuts of those numbers are not that good. Especially with stones where the total depth is 65% and the table is 65-68%. The reason I say this is because if the stone has a total depth of 65% with a 10% crown, you usually have a 3% girdle which leaves a pavilion depth of approx. 50-52% and THAT pavilion is generally too shallow for the 10% crown that it is being coupled to which generally results in too much leakage. I appreciate the attempts at princess cut grading scales but a scale that does not consider the crown/pavilion relationship IMO is useless. I am excited about the upcoming grading scales AGS will be producing which will be based on the optical quality of the stones and not necessarily the numbers.

My .02c

Rhino
 

AZDiamondShopper

Rough_Rock
Joined
Apr 4, 2003
Messages
22
Rhino,
When will these new grading scales be available?
 

oldminer

Ideal_Rock
Trade
Joined
Sep 3, 2000
Messages
6,691
I know what Rhino is talking about and agree that the relationship of certain elements needs to be correct. Looking at separate components of cut may only give a clue as to the end result. I have seen many AGA 1 grade princess cuts that cutters made into excellent and brilliant diamonds. I have seen a few, maybe more than a few, that had a bunch of "correct" parameters, but failed to be pretty or really brilliant.

I, too, await the coming of light return analysis as a key ingredient to grading the best cut and most attractive diamonds.

One thing is certain. A diamond that is overly deep does not show a reasonable amount of size (diameter) for its weight. If you pay for a 1 ct diamoind, it should look like a 1 carat stone, not a 3/4 ct stone... That isn't science, but just common sense.
 
Status
Not open for further replies. Please create a new topic or request for this thread to be opened.
Be a part of the community Get 3 HCA Results
Top