Comparing round diamonds with same diameter

[maconomist]

I'm a newbie when it comes to diamonds. I recently previewed two diamonds set in the same engagement ring style. Both diamonds had the same measurements (diameter and depth) according to their GIA certificates, but one looked substantially bigger. The diamonds were:

Diamond 1:
Carats: 0.74
Measurements: 5.78 - 5.81 x 3.57 mm
Color: G
Clarity: VS2
Cut: Excellent
Table: 57%
Depth: 61.7%
Crown Angle: 36
Pavilion Angle: 40.6

Diamond 2:
Carats: 0.70
Measurements: 5.77 - 5.81 x 3.44 mm
Color: H
Clarity: VVS1
Cut: Excellent
Table: 60%
Depth: 59.4%
Crown Angle: 32
Pavilion Angle: 41

When looking at them in person, Diamond 1 looked noticeably bigger. While Diamond 1 has a larger carat weight (0.74 vs. 0.70), the actual diameter as reported by the certificate is almost the same: "5.78 - 5.81" vs. "5.77 vs 5.81"

My question is: how is it possible that Diamond 1 would look noticeably bigger than Diamond 2? Does it have to do with the angles or something else?

 

[OECsareforLovers]

Were they in the same exact setting? I'm no expert, but they should face up the same size since they have the same measurements.

 

[maconomist]

Yes, they were both in the exact same Ritani halo setting. Any chance the certificates could be wrong? I ended up getting the 0.74, but the size difference is baffling.

 

[Diamond_Hawk]

The way the diamond 'looks' is exactly what the members here on Pricescope love to talk about. The actual cut proportions and light performance can vary dramatically in rings that "face-up" similarly.

If Ring 1, for example, had light return all the way to the edges and Ring 2 did not, the 'edges' on Ring 2 would look smaller even though, physically, they are nearly identical.

What you did was (absent an ASET which would have shown you light return) exactly what you should have done. Look at them both, see which you like better - and pick that one!

 

[maconomist]

Thanks for your reply. They both scored under 2 in the HCA but, admittedly, I did not get an ASET or Idealscope prior to viewing. They both looked stunning in person, but ultimately since the 0.74 just "looked bigger", I ended up picking that one. These are the two diamond's on Ritani's site:

Diamond 1: http://www.ritani.com/diamonds/round-diamond-0-74-Carat-G-color-GIA-certified/D-MRFY2N
Diamond 2: http://www.ritani.com/diamonds/round-diamond-0-70-Carat-H-color-GIA-certified/D-MQSNW3