Good value

[hpnas]

First time poster and was seeking some guidance if this stone is good value:

GIA certified
1.7 carat
VS1
G
Excellent Cut
Excellent Symmetry
Excellent Polish
No fluorescence
Table %: 57%
Depth %: 62.3%
Measurements: 7.60-7.64x4.75mm

I was quoted a price of $16K which I think is fair but seeking others opinion as I am very new to this process

 

[stone-cold11]

What is the GIA report number?

We will need the crown, pavilion angles, star and lower half numbers.

 

[Lorelei]

Date: 11/4/2009 4:53:06 PM
Author: Stone-cold11
What is the GIA report number?

We will need the crown, pavilion angles, star and lower half numbers.

Ditto

 

[hpnas]

The pavilion angle is 41 dgrees. What are the star star and lower half numbers?

 

[Lorelei]

Date: 11/5/2009 11:05:23 AM
Author: hpnas
The pavilion angle is 41 dgrees. What are the star star and lower half numbers?

You will find those on the grading report on the diamond diagram near where the crown and pavilion angles are. The star percentage will say something like 50% to the top right hand side of the diagram, the lower girdle facet percentages will be towards the bottom of the diamond ( normally something like 75 - 80%).

But more importantly what is the crown angle to go with the pavilion angle please?

 

[hpnas]

Crown angle is 35 degrees. I ran an HCA test and it came out Very Good (as opposed to Excellent), is this cause for concern?

 

[stone-cold11]

Yes it is a concern. Could be over come with a larger lower half or it could be leaky.

 

[hpnas]

What''s the ideal range of crown and pavilion angles to create the most brilliance, scintillation, and fire?

 

[Lorelei]

Date: 11/5/2009 11:30:07 AM
Author: hpnas
What''s the ideal range of crown and pavilion angles to create the most brilliance, scintillation, and fire?

It depends also on the tightness of the cut and other factors, sometimes even longer lower girdle facets won''t save these types of diamonds, images such as Idealscope are essential.

Here is the cheat sheet some of us use in order to find well cut diamonds.

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.

From expert John Pollard.

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).

 

[hpnas]

Thanks this information is helpful. What''s the general consensus on Blue Nile Signature Ideal collection? It seems the BN Sig Ideal proportions are exactly what I''m looking for as the diamonds give off the most fire and brilliance

 

[stone-cold11]

They are generally good, but GCAL did not release any data on how to read their proprietary light performance color map so can''t say anything about that and their images is useless to determine if they are actually H&A as claim.

 

[Lorelei]

Date: 11/5/2009 1:32:00 PM
Author: Stone-cold11
They are generally good, but GCAL did not release any data on how to read their proprietary light performance color map so can't say anything about that and their images is useless to determine if they are actually H&A as claim.

Ditto. If you want a h&a diamond then stick to vendors who can provide images to prove a diamond is h&a.

 

[hpnas]

So I guess if I stick to a table % of 54-57, depth % of 60-62, crown angle of 34.3-34.8, and pavilion angle of 40.6-40.9 that would result in an HCA score of <2 which would maximize my brilliance and fire. I think that should be my baseline approach and then tweak the color and clarity based on my preference and budget

Thoughts?

 

[stone-cold11]

Just note that GIA round the crown numbers to 0.5 degrees step so if you use your criteria, you will be essentially looking at only one crown angle, 34.5 degrees. use the full range and then the HCA to weed out the non-performers.

 

[Lorelei]

Date: 11/5/2009 2:13:22 PM
Author: Stone-cold11
Just note that GIA round the crown numbers to 0.5 degrees step so if you use your criteria, you will be essentially looking at only one crown angle, 34.5 degrees. use the full range and then the HCA to weed out the non-performers.

Yes with GIA proportions are rounded so thats a fly in the ointment there, the Holloway Cut Advisor will be helpful to you, see which score below 2 and go from there with images.

 

[hpnas]

Ok so given my ideal proportions I think I found something very reasonable:

1.7 carats
Excellent Cut
Excellent Symmetry
Excellent Polish
Color: F
Clarity: VS2
Depth %: 61.1
Table %: 57
Girdle: Medium to slightly thick
Crown Angle: 34
Pavilion Angle: 40.8
No fluorescence
Holloway Cut Adviser Score: 1.0 (Excellent)

$16,410 from Blue Nile

 

[stone-cold11]

Yap, looks good.

 

[Lorelei]

Date: 11/5/2009 3:43:29 PM
Author: hpnas
Ok so given my ideal proportions I think I found something very reasonable:

1.7 carats
Excellent Cut
Excellent Symmetry
Excellent Polish
Color: F
Clarity: VS2
Depth %: 61.1
Table %: 57
Girdle: Medium to slightly thick
Crown Angle: 34
Pavilion Angle: 40.8
No fluorescence
Holloway Cut Adviser Score: 1.0 (Excellent)

$16,410 from Blue Nile

Yes, this one has great potential.

 

[diamondsman]

I think its a very nice stone, I would probably go a bit bigger and sacrifice clarity to a VS2 which is still a very nice quality, other than that the stone you are looking at is nice

good luck

 

[hpnas]

So this diamond really looks like it is a good value from BN. I''d appreciate if someone more experienced than me had a look at the inclusions / clarity diagram to make sure there is nothing majorly wrong with it.

 

[hpnas]

Also attaching the proportions

 

[stone-cold11]

Looks good to me, as long as it checks out eye-clean.

 

[Lorelei]

Date: 11/6/2009 3:02:24 PM
Author: hpnas
So this diamond really looks like it is a good value from BN. I''d appreciate if someone more experienced than me had a look at the inclusions / clarity diagram to make sure there is nothing majorly wrong with it.

It looks like an excellent diamond.

 

[diamondsman]

Hi
as an expert in the diamond industry, I like the imperfections to be on the side by the crown facets rather than in the center of the table, I think that if you would go with a vs2 you'd be better off.

by the way the diagram you are showing us is not a vs2 ??

just my opinion

 

[hpnas]

According to the GIA paperwork it is a VS2 diamond. Does the diagram indicate that it is something worse? What is your opinion?

 

[stone-cold11]

No it doesn''t, it just indicate the location and extent of the inclusions not the severity of it. Talk the the vendor about it. If you are still worried, hired a independent appraiser to look at it, no way for any one to tell without the stone in their hand.

 

[diamondsman]

Hi
it might be a vs2 by G.I.A ,as there are many variations of VS2, I prefer the imperfections to be closer to or on the crown facets,and the table cleaner, with a little more research I am sure you could find one before you make a final descision on this stone.

 

[hpnas]

Have one more to add to the mix

GIA certified
1.7 carats
Excellent Cut
Excellent Polish
Excellent Symmetry
G color
VS1 clarity
7.61 x 7.64 x 4.77 mm
62.5% Depth
55% Table
35% Crown Angle
40.8% Pavilion Angle
HCA Score: 1.6 (Excellent)

Only difference between this one and the I am considering is that this is a drop down in color from F to G and the clarity is a grade up from VS2 to VS1

 

[Lorelei]

Date: 11/9/2009 12:18:47 PM
Author: hpnas
Have one more to add to the mix

GIA certified
1.7 carats
Excellent Cut
Excellent Polish
Excellent Symmetry
G color
VS1 clarity
7.61 x 7.64 x 4.77 mm
62.5% Depth
55% Table
35% Crown Angle
40.8% Pavilion Angle
HCA Score: 1.6 (Excellent)

Only difference between this one and the I am considering is that this is a drop down in color from F to G and the clarity is a grade up from VS2 to VS1

Has potential, it is a hair deeper than I prefer but it looks like a well cut diamond, do you have any images such as Idealscope?

 

[hpnas]

These are all from BN, where do I get an Idealscope image?