Any thoughts about this diamond?

[less_confused]

GIA certified
Measurements: 6.60 - 6.63 x 3.94 mm
Carat Weight: 1.06 carat
Color Grade: H
Clarity Grade: VS2
Depth: 59.6%
Table: 58%
Girdle: Medium to Thick, Faceted (4.0%)
Culet: Very Small
Polish: Very Good
Symmetry: Good
Fluorescence: None
Crown Angle: 30.5°
Crown Height: 12.5%
Pavilion Angle: 40.8°
Pavilion Depth: 43.0%
Star length: /td> 55%
Lower Half: 80%/td>
Cut Grade: Good

The HCA is 1.6 Excellent

Why would GIA rate the cut as Good?

What should I consider here?

Thanks in advance....

 

[The Ice Man]

How much are they charging you per carat?

 

[jet2ks]

Date: 8/8/2009 7:50:40 PM
Author:less_confused
GIA certified
Measurements: 6.60 - 6.63 x 3.94 mm
Carat Weight: 1.06 carat
Color Grade: H
Clarity Grade: VS2
Depth: 59.6%
Table: 58%
Girdle: Medium to Thick, Faceted (4.0%)
Culet: Very Small
Polish: Very Good
Symmetry: Good
Fluorescence: None
Crown Angle: 30.5°
Crown Height: 12.5%
Pavilion Angle: 40.8°
Pavilion Depth: 43.0%
Star length: /td> 55%
Lower Half: 80%/td>
Cut Grade: Good

The HCA is 1.6 Excellent

Why would GIA rate the cut as Good?

What should I consider here?

Thanks in advance....

Crown angle is very shallow and girdle is outside of optimum range. The HCA score is good, but if you look a little closer, it is shown as a BIC (Brilliant Ideal Cut) which tends to be very white and bright, but not have much fire--a result of the shallow crown.

 

[Gypsy]

Lorelei’s Round Rule of Thumb-- You can use these as a guide to find a well cut stone.

"depth - 60 - 62% - although my personal preference is to allow up to 62.4%
table - 54- 57%
crown angle - 34- 35 degrees
pavilion angle - 40.6- 41 degrees
girdle - avoid extremes, look for thin to slightly thick, thin to medium etc
polish and symmetry - very good and above

note - with crown and pavilion angles at the shallower ends ( CA 34- PA 40.6) and steeper ( CA 35- PA 41) check to make sure these angles complement in that particular diamond - eyeballs, Idealscope, trusted vendor input - check as appropriate!

As the above implies, configurations depend on each other. A little give here can still work with a little take there.

With that said, here''s a "Cliff''s Notes" for staying near Tolkowsky/ideal angles with GIA reports (their numbers are rounded): A crown angle of 34.0, 34.5 or 35.0 is usually safe with a 40.8 pavilion angle. If pavilion angle = 40.6 lean toward a 34.5-35.0 crown. If pavilion angle = 41 lean toward a 34.0-34.5 crown.

GIA "EX" in cut is great at its heart, but it ranges a bit wider than some people prefer, particularly in deep combinations (pavilion > 41 with crown > 35)."

 

[stone-cold11]

Easy.

Too shallow a crown angle and a thick in the girdle variation.

Cut more for brilliance than fire in this case from the crown angle. The shallow pavilion angle coupled with the crown angle will result in the stone having a black arrow due easier to head shadow. Thick in the variation means a slightly smaller spread compared to a thin-sl thick girdle variation.

 

[Lorelei]

Date: 8/8/2009 7:50:40 PM
Author:less_confused
GIA certified
Measurements: 6.60 - 6.63 x 3.94 mm
Carat Weight: 1.06 carat
Color Grade: H
Clarity Grade: VS2
Depth: 59.6%
Table: 58%
Girdle: Medium to Thick, Faceted (4.0%)
Culet: Very Small
Polish: Very Good
Symmetry: Good
Fluorescence: None
Crown Angle: 30.5°
Crown Height: 12.5%
Pavilion Angle: 40.8°
Pavilion Depth: 43.0%
Star length: /td> 55%
Lower Half: 80%/td>
Cut Grade: Good

The HCA is 1.6 Excellent

Why would GIA rate the cut as Good?

What should I consider here?

Thanks in advance....

Less confused glad you asked that question, the answers aren't obvious to everyone!

In this case it will be because of the crown angle which is shallow and the girdle thickness.

If this diamond is online it is definitely a candidate for an Idealscope image, although no way to tell for sure if this diamond will show obstruction ( darkening of the diamond when examined closely due to head shadow) without IS, also the pavilion angle is not shallow by the way. If the diamond is from James Allen they will be able to provide an IS image in a couple of days.