Help! I''''m so confused

[Diamondpursuit]

I''m trying to decide between two very different diamonds and keep flip-flopping. The first is a RB 2.3 cts with an ideal cut. The second diamond is significantly larger (in my eyes) at around 2.75 cts. Everything looks good on the first diamond except that it''s smaller and one color lower than the second one. Both diamonds have the same clarity grade and are supposed to be eye-clean, but the inclusions on the first diamond is a bit better (no feathers, only pinpoints). The price difference between the two diamonds is $7000. I really like the size of the second diamond, but I''m concerned by the H&A pictures (see below). Please help! What do you think of these pictures?

 

[Diamondpursuit]

Hmm...I can''t upload the second picture.

 

[Diamondpursuit]

Ahh...here''s the second picture!

 

[JohnQuixote]

1. I assume it's the same diamond in the two photos (?)
2. If so, any idea why they switched the colors in the H&A viewer between pavilion and crown views?
3. Is this being sold as a Hearts & Arrows diamond?

 

[Diamondpursuit]

The two pictures of the same diamond (the larger one) and I have no idea why the H&A views were switched. This diamond is not being sold as an H&A stone, but I am told that it performs beautifully. That''s what I''m really concerned about - the performance of this diamond. Even though the numbers look good on paper, these pictures really concern me...and that''s why I can''t decide between the smaller H&A, diamond and this one.

 

[JohnQuixote]

DP - That is helpful information.

These photos show the patterning and physical symmetry of the diamond, but don't indicate overall light performance like an ideal-scope, ASET or other reflector image does. It would be helpful if you can post proportions (table %, depth %, crown angle, pavilion angle, girdle thickness and culet details), and even better if you can post an ideal-scope image. I remain curious about why the different colors for the same diamond.

I would have been surprised if this was being sold as H&A, as this is very pedestrian patterning. Not terrible, but not near the kind of physical symmetry one would expect in a H&A or near H&A diamond. I can tell you some things about overall construction based on these views if you'd like to hear them.

 

[Diamondpursuit]

John, any insight you can give me would be much appreciated! Here are the proportions:

Table: 57%
Depth: 59.8%
Crown Angle: 34.2
Pavilion Angle: 40.8
Girdle: Thin - Med.
Culet: None.

Thank you!

 

[JohnQuixote]

Date: 6/19/2005 9:50:22 PM
Author: Diamondpursuit
John, any insight you can give me would be much appreciated! Here are the proportions:

Table: 57%
Depth: 59.8%
Crown Angle: 34.2
Pavilion Angle: 40.8
Girdle: Thin - Med.
Culet: None.

Thank you!

DP - Based on those proportions it is likely to be a wonderful performer. I would, again, request an ideal-scope image from the vendor to confirm the light return but these numbers are a very good indicator.

Now - and only since you asked - I'll get pickier.

Construction details: You're looking at a diamond with very long lower girdle facets, meaning that the pavilion mains (the mirrors that drive the engine of light return) are thin. This does two things (1) It lessens contrast through obscuration - meaning the sharp on/off quality in scintillation won't be as dramatic as it would be with larger mains and (2) reduces light return in lower light conditions - if the mains had more area the diamond would return more available light. On the other hand, thin mains do focus abundant light intensely in direct lighting conditions (sunlight/halogen lamps, etc), so it will perform dynamically there.

Getting very picky, there are pronounced elements of facet yaw that reduce effective return like one would see in a well patterned diamond (H&A or near-H&A). Simplistically, yaw is 'twist' to the facet that throws the light somewhere other than it should go were the diamond patterned well. You can see this particularly in the pavilion (hearts) view. With optimum alignment of the facets and no elements of yaw those 'hearts' would be more symmetrical (example attached). Logically, when facet alignment/interaction is not optimized, the diamond does not effectively return the maximum amount of available light in diffuse and soft lighting conditions. Many diamonda looks great under halogens - it's lower light conditions where great design and craftsmanship stands apart.

All of that said - you may not be seeking a diamond with H&A type patterning. If the price is right I am sure this is a nice diamond, and given those proportions it's better than a predicted 95% of diamonds out there.

I hope this helps.