How is this stone? 1.4 HCA

[Equator]

Hi ! I am considering this stone. It''s GIA graded JVS2 and costs a little under USD1,500.

Here are the specs:
77pts JVS2 Good Grade, Good Polish, Good Symetry, No Fluorescence.
Total Depth 58.6%. Table Size 55%.
Crown Angle 32.4 (in degrees)
Pavilion Angle 40.1
Star Length 55%
Lower Half 80%
Girdle Very thin to Medium (2.7%)

You might notice the 58.6%, and I''m worried about fish-eye. I think the bare minimum is 58.5%, and I am interested in this one, because obviously I''d get the biggest (widest) diamond for the least carat that is still in the acceptable range.

Is this a good stone ? Should I be worried about fish-eye effect ? Is it a good deal ?

Would appreciate your opinion. Thanks

 

[JulieN]

I think it would be rather unattractive.

 

[kcoursolle]

I''d pass...

Check out this one, similar size and price and much better cut. I was considering it and it will become available any day now, feel free to contact JA because I no longer have it reserved (unless someone else has it reserved currently). http://www.jamesallen.com/diamonds/I-I1-Ideal-Cut-Round-Diamond-1213284.asp

 

[Lorelei]

It is shallow proportioned and will very likely show obstruction. Obstruction is where a diamond can go dark face up when viewed closely as the viewer's head/ body blocks the light from the stone. That is why these types of stones are better suited for pendants or earrings as the normal viewing conditions don't apply.

See this video to watch obstruction in action, lower right of the same title by Garry Holloway.

http://diamondscope.pricescope.com/

 

[Ellen]

I will just add to the good advice you''ve been given, that it''s best to stick with Very Good and up on cut, sym, and polish.

 

[Equator]

Hi !

Thanks JulieN, short, honest and accurate.

kcoursolle, your stone is still not available. And it''s an I clarity. I think I might want to stick to Si2 if possible.

I ended up watching all the videos in the link you gave me, Lorelei. Thank you. What I don''t understand is why it would score very good and excellent in HCA ? I know how it shouldn''t be the final decision making score, but if we stay within the GIA and/or AGS box, would we be safe ? This stone is not, btw. It is still in the red-orange bit, though.

Thanks everyone

 

[Equator]

Hi, Ellen.

Thanks for taking the time to give me a good advice.

What I also want to know is the minimum depth I should limit myself to avoid that dark obstruction effect ?

 

[girlie-girl]

Date: 5/9/2009 10:57:49 AM
Author: Equator
Hi, Ellen.

Thanks for taking the time to give me a good advice.

What I also want to know is the minimum depth I should limit myself to avoid that dark obstruction effect ?

Hello Equator. Here is a little cheat sheet that Lorelei posts up for people when they ask this question:

depth - 60 - 62% - (Lorelei personally likes 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




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).

Hope that helps.

 

[Ellen]

Date: 5/9/2009 10:57:49 AM
Author: Equator
Hi, Ellen.

Thanks for taking the time to give me a good advice.

What I also want to know is the minimum depth I should limit myself to avoid that dark obstruction effect ?

You''re welcome!

girlie gave you a great list we use to help people out. It''s not the last word, but it can definitely help.

 

[Lorelei]

Thanks GG!

Equator, if you follow the proportions suggested above that should help, also if you can get ASET or Idealscope images for any diamonds you are interested in, that would be very useful.