How important is Crown Height?

[rke]

I am curious to get the opinions of those knowledgable with Princess Cuts on how important crown height is. Is there big differences (and if so what) between 7.1% and 8.5% or 8.5% and 10%, assuming the table and depth percentages are in line? What would be too shallow?

I have read through this forum (Pricescope is a great site) and benefited from the commentary.

Thanks!

 

[Garry H (Cut Nut)]

Crown and pavilion angles are important.
%'s mean nothing by themselves.

But trying to buy princess by #'s is not all that efficient in my opinion.

 

[rke]

So, what do you look for? I purchased a stone by the percentages(depth, table, etc), but have nothing to compare it to. On round diamonds it appears much by the numbers. I have tried to follow the chart from Dave Atlas's site, but am uncertain what, if anything, a 1.5% table height would change.

 

[Garry H (Cut Nut)]

Have a look at the www.ideal-scope.com site.

 

[robbe]

dear rke, ideally the crown height % of a princess cut is between 8 & 13 %. the table % should preferably not exceed 75 %. the crown angle cannot be measured very accurately and is not so relevant as 1) there is a break on each crown facet (now you have 2 areas with 2 different angles) and 2) the crown height is usually so little that the crown angle is not able to affect the life in any way. the most important part is (as always) the pav.angle & % however there are 3 areas where one could measure the pav of a princess: 1) the 4 triangular facets at the girdle/pav, 2) the 'fishbone'-facets and 3) the entire pav depth. all these areas play an important role in lightreturn of a princess cut. although 7.1% is too shallow in my opinion, this could still be an attractive stone if the pav is well proportioned. robbe

 

[rke]

Thanks Gary and Robbe! I feel like the saying the "the more I learn, the less I know." Finding a a very square Princess cut in the correct proportions/cut, grade, color, etc. has proven very challenging. For this reason, I do see how this could be a difficult hurdle for those selling online as it does not seem to be as exact as a round brilliant.

Though the stone looks good to me (I have no frame of reference however), I think I will send it to Dave Atlas to get another opinion.

 

[barry]

rke;

You're correct. Finding a Princess Cut that is
a great looker is very difficult.

Crown height is but one variable. More important is
the combination of Crown and Pavillion angle
in conjunction with table % and Pavillion depth.
There are many combinations of these that will result
in great-looking Princess cuts. Since two Princess
Cuts with the same exact specs may differ on
"looks" and light performance, it is important IMO
to get additional information on the stone that
will give you indications on the diamond's
light output and extent of light leakage.

Barry
www.superbcert.com