Observation - Round vs. Princess

[Amory]

I was just looking at a friend's princess cut diamond ring on her hand (she wears the same ring size as my intended), and I couldn't help but think that the 2.01 ct stone looked small on her hands. 2 carat rings always seemed larger to me (for that ring size). Then it hit me.

(please correct me if any of my math is wrong - it's possible - even likely!)

representative dimensions for ideal cuts:

2.01 ct ideal cut princess
7.14 x 6.91 x 5.07

2.01 ct ideal round cut
8.05 x 8.12 x 4.99

Since I generally gauge the size of the stone (appearance wise) relative to the width of the finger it's on (two fingers being the same size), the round stones always look bigger. The width of a round stone above is about 8.085 whereas the width of the princess is 7.14 (if the widest part is across the finger) - only 6.91 if the narrowest edge is across the finger.

If the princess stone were turned 45 degrees one way or the other, it would look so much bigger relative to the finger (about 9.93) using the pythagorean theorem (again - if my math is right).

Not only that, but the surface area (table) showing on the princess cut stone is 49.34 whereas the surface area showing on the round stone is 51.31.

Don't get me wrong - I am in no way trying to disparage fancy cuts - everyone should get the cut they like best. But all else being equal (cut quality, color, clarity, polish, symmetry, overall beauty - and I know it would be difficult to get all else equal given two different cuts), but don't round stones generally look larger for the same carat size?

I haven't done the calculus, but fancy cut stones (at least princess cuts) appear to have more depth than round stones meaning that more of the carat weight is below the surface.

Just an observation (I think?). Comments...


ps I'm new here, so if this has been discussed before, please just ignore my post!

 

[prettyinpave]

Rounds always look bigger than equivalent weight princess cuts to me. I don''t know if your math is right, but that has been my observation.

I''ve seen an oval and a round of equivalent weight next to each other, and to my eye, the oval looked larger.

 

[Garry H (Cut Nut)]

There is a thread somewhere from last year with a lot of discussion and some cost / size studies too.

But the hiden factor is that a well cut round returns a lot more light - especially from the edges - so there is also an optical illusion that makes rounds appear bigger.

Ovals and marquise can have the biggest surface spread.