Advice Needed! Selecting Loose diamond

[jellybellies]

I have basically selected Blue Nile as my store of choice.
I did go to some B&M stores just to get some perspective on the differences in color between a F G and G, and clarity between VVS2, VS1, and VS2.

I have gone with the approach to find a F-H color, VVS2 - VS2 clarity, Ideal cut, 1.5 carat diamond.
I did my search and have basically narrowed down the diamonds by using the cut advisor on pricescope. The range for the signature ideal diamonds on Blue Nile (their best ones) is from .6 to 3.0. How accurate is the cut advisor and can I buy soley from that reading (meaning the .6 will be much better than the 1.5 or is there a significant margin of error in the cut advisor)?

Also, I have basically disregarded the differences between F,G and H and VVS2, VS1, and VS2. Im I right to do this? I couldnt tell the difference between these at the store... Any advice on this aspect is also much appreciated.

 

[Skippy123]

If you couldn''t tell the difference in the store then you won''t w/the F-H range. I have a VS2 and I see no inclusions so you can be safe w/that. Just my 2 cents. There are lots of good vendors and if you want a lifetime upgrade BN does not do that; WF and GOG do just an fyi.
Happy Shopping

 

[chrono]

The HCA is basically one tool a lay person can use to weed out bad performing stones. It does not rate the stone. Basically anything under 2.0 is most likely a great looking stone. Sometimes, a HCA 2.5 stone might be all right though, but it depends. So, in short, a 0.6 isn't better than a 1.5

That said, some picky PSers actually prefer a 1.5 over a 0.6 due to something called head obstruction, but it isn't a biggie.

I just call it personal preference. It is always nice to back up the HCA with an Idealscope picture but BN does not provide Idealscope pictures.

If you can't tell the difference between a FGH and a VVS and VS stone, why not save yourself some $$$ and just shop for a H VS2?

 

[Lorelei]

Date: 10/2/2007 12:13:10 PM
Author:jellybellies
I have basically selected Blue Nile as my store of choice.
I did go to some B&M stores just to get some perspective on the differences in color between a F G and G, and clarity between VVS2, VS1, and VS2.

I have gone with the approach to find a F-H color, VVS2 - VS2 clarity, Ideal cut, 1.5 carat diamond.
I did my search and have basically narrowed down the diamonds by using the cut advisor on pricescope. The range for the signature ideal diamonds on Blue Nile (their best ones) is from .6 to 3.0. How accurate is the cut advisor and can I buy soley from that reading (meaning the .6 will be much better than the 1.5 or is there a significant margin of error in the cut advisor)?

Also, I have basically disregarded the differences between F,G and H and VVS2, VS1, and VS2. Im I right to do this? I couldnt tell the difference between these at the store... Any advice on this aspect is also much appreciated.

No - the cut advisor doesn't work that way, it is an elimination tool which helps to weed out diamonds which may not perform so well, a score under 2 is considered cherry, but once you get there you need to evaluate each diamond with your eyes and other cut technologies. It isn't the case that the lower the HCA score, the better the diamond, more that a score under 2 means it is worth further consideration. Find a well cut diamond and a G or H VS should be a good choice.

 

[jellybellies]

It also seems that the grading reports give different values for the table, depth, and the angles. any comments or advice on this? How can the GCAL (BN''s own report) differ from the GIA or AGSL''s reports?

 

[Regular Guy]

Date: 10/2/2007 12:42:26 PM
Author: jellybellies
It also seems that the grading reports give different values for the table, depth, and the angles. any comments or advice on this? How can the GCAL (BN's own report) differ from the GIA or AGSL's reports?

Attribute to measurement error...do you see anything radical? Consider for accuracy...AGS trumps GCAL trumps (?) GIA.

Ideally, if only one gives you HCA you like...be safe & move on. But, as others have said...HCA is recommended for rejection, not selection.

 

[stebbo]

Date: 10/2/2007 12:42:26 PM
Author: jellybellies
It also seems that the grading reports give different values for the table, depth, and the angles. any comments or advice on this? How can the GCAL (BN's own report) differ from the GIA or AGSL's reports?

Also various levels of rounding.

GCAL are similar to AGS, except their table gets rounded to the nearest full percent, like the GIA's (the GCAL report misleadingly writes the figure to one decimal place though).

GIA's - well..... pavilion gets pushed to the closest 0.2 deg boundary and crown 0.5. AGS and GCAL keep them both at 0.1 deg.

Apparently a premise of being a Blue Nile Signature diamond is that the GCAL matches the AGS/GIA report--I'd expect them to be within (some sort) of tolerance.

Also misleadingly, GCAL is an independent report, it's just customized to their clients and looks in-house. You'll find many other vendors have them, including the big Whitehall/Lundstrom chain.