How important is it to view IS picture before buying

[crease123]

With respect to the question, I''m referring to purchasing from Bluenile. As you know, they do not provide pictures of Idealscope of their diamonds. What are the chances of us purchasing a diamond that is rated below 2 on the HCA, yet turn in a dissapointing IS picture?

 

[Lorelei]

Date: 1/27/2009 11:32:11 AM
Author:crease123
With respect to the question, I'm referring to purchasing from Bluenile. As you know, they do not provide pictures of Idealscope of their diamonds. What are the chances of us purchasing a diamond that is rated below 2 on the HCA, yet turn in a dissapointing IS picture?

It depends on the proportions crease, some may be combos which are harder to call such as shallower/ steeper diamonds - hence the advice that the HCA is used for elimination and not selection - even with so called ' safe' numbers really we are only estimating that a diamond should be a good looker and performer without images -although it might be a fair bet with certain combos that they will result in a great diamond. Personally I don't like to assume anything as I have been here long enough to learn there can be exceptions to many rules!!

 

[crease123]

Thanks Lorelei. In response to that, is it safe to assume that those that pass the HCA would, at the very least, be a above-average/decent stone?

 

[Lorelei]

Date: 1/27/2009 11:39:22 AM
Author: crease123
Thanks Lorelei. In response to that, is it safe to assume that those that pass the HCA would, at the very least, be a above-average/decent stone?

Most welcome! I would say in a guarded fashion that diamonds which score between 1 and 2 might be good diamonds ( but like I say I don''t assume as I have been proven wrong too many times!), under 1 generally means a shallower combo which needs evaluation from IS.

 

[crease123]

Thanks Lorelei, you are truly the best and an asset to this wonderful forum

 

[Ellen]

If you can find a stone that has the x fall in the overlap of the AGS/GIA boxes, that''s about as safe as you can get without pics.

 

[Lorelei]

Date: 1/27/2009 11:44:16 AM
Author: crease123
Thanks Lorelei, you are truly the best and an asset to this wonderful forum

You are so kind, thank you very much for your sweet words, it truly means a lot to me!!

 

[Lorelei]

Date: 1/27/2009 11:44:54 AM
Author: Ellen
If you can find a stone that has the x fall in the overlap of the AGS/GIA boxes, that''s about as safe as you can get without pics.

And that is an excellent point from Miss Madame above!!

 

[Ellen]

Date: 1/27/2009 11:45:58 AM
Author: Lorelei

Date: 1/27/2009 11:44:54 AM
Author: Ellen
If you can find a stone that has the x fall in the overlap of the AGS/GIA boxes, that''s about as safe as you can get without pics.

And that is an excellent point from Miss Madame above!!

Why fank you.

 

[stone-cold11]

Buy AGS0 stone?

If not, try and stay away from the edge of the HCA = 2 line. GIA round the pavilion angles in steps 0.2 degree and that is an average of 8 pavilions so whatever pav value that is on the report, look at what kind of score it will get if it +- 0.1 degree. Crown angle is worse, 0.5 degree step.

 

[Lorelei]

Date: 1/27/2009 12:07:38 PM
Author: Stone-cold11
Buy AGS0 stone?

If not, try and stay away from the edge of the HCA = 2 line. GIA round the pavilion angles in steps 0.2 degree and that is an average of 8 pavilions so whatever pav value that is on the report, look at what kind of score it will get if it +- 0.1 degree. Crown angle is worse, 0.5 degree step.

But then that excludes the many well cut GIA diamonds that are available, and I saw distinct leakage on IS from a couple of AGS0 diamonds only recently, so like I say it is best to not assume anything - AGS may narrow the target but it is always best to evaluate each diamond carefully.

 

[Regular Guy]

Stone's idea of buying an diamond earning 0 for light performance from AGS does solve that problem, albeit at some premium. The AGS score means no rounding issue, a closer measurement at that, and a system that's more rigorous for earning it's top grade.

But...

Date: 1/27/2009 11:44:16 AM
Author: crease123
Thanks Lorelei, you are truly the best and an asset to this wonderful forum

...to call Lorelei an asset minimizes her help here. Not that there's anything wrong with an ASET.

(edited to add...)..hmmm...."I saw distinct leakage on an IS from an AGS0 diamond only recently," go figure. I wonder what would account for that?

 

[crease123]

Yeah, the stone that I''m eyeing is an AGS 0 with a HCA rating between 1 and 2. But I would agree, nothing is confirm until a reading by IS.

 

[Regular Guy]

Date: 1/27/2009 1:37:49 PM
Author: crease123
Yeah, the stone that I'm eyeing is an AGS 0 with a HCA rating between 1 and 2. But I would agree, nothing is confirm until a reading by IS.

Well...no...I think I disagree with this.

You could take the position that you cannot buy without seeing.

Short of that...let's just say you'd like to recognize what the most conservative set of procedures is for identifying....what shall we call it...an attractive diamond?

Remember...just with respect to the limitations of an IS delivering a reflection of what the eye can see...a) it is a cyclops view, perhaps consistent with that, b) leakage showing emphasizes leakage seen.

That said...if you were seeking the more conservative choice, and could choose, sight unseen, and not knowing any more about the diamonds cut performance than either of these two things for each of two diamonds:

a) AGS0, between 1 - 2 on the HCA
b) a nice honking red IS

Is it clear which you'd pick?

I'd be interested to hear more opinions. But, just knowing these two aspects, I think I'd go for the first.

Further...if I did NOT see a honking red IS...where the IS view was available, but got the AGS0...and I was not lead to think the 0 was miscalculated (i.e., it's proportions comport to O otherwise)...again...I think I'd choose the AGS.

You?

 

[Todd Gray]

Date: 1/27/2009 11:32:11 AM
Author:crease123
What are the chances of us purchasing a diamond that is rated below 2 on the HCA, yet turn in a disappointing IS picture?

The HCA provides insight into the potential visual performance of a diamond based on the total depth and table diameter measurements and the "average" measurements stated for the crown and pavilion angle measurements - the average of eight measurements per section, not the potential visual performance taking all eight measurements per section into consideration. Thus if you''re looking at a diamond with an average crown angle of 34.5 degrees and an average pavilion angle of 40.8 degrees, the average crown angle of 34.5 degrees could be based on a high of 35.5 degrees and a low of 33.5 degrees or perhaps something tighter like a high of 34.6 degrees and a low of 34.4 degrees (obviously better) and the same concept holds true for the average pavilion angle measurement... The HCA has no way of knowing the spread between the high and low measurements that result in the crown and pavilion angle measurements which is why you should use the HCA to sort out the diamonds with potential from the potential dogs that might reside on your list - then get a more detailed view of the facet-by-facet structure of the diamond by requesting a Sarin / OGI / Helium computerized proportions analysis on the diamonds remaining on the list after sorting them out by way of the HCA.

I''m with Regular Guy on this, I''m a BIG FAN of the AGS Visual Performance rating! What a wonderful asset to consumers, is sure has taken a lot of the guesswork out of the equation that existed only a few years ago! Ideal Scope images are helpful, they can provide insight but keep in mind that what is seen by each person viewing the same diamond through an Ideal Scope / Fire Scope / SymmetriScope / whatever will vary depending on the exact angle that each person views the diamond from, the distance between the light source, the type of light source, the angle that the diamond is aligned to the scope, etc.

 

[Rockdiamond]

Just an alternative viewpoint ...
If you are already here- there are some gret sources for diamonds that score well on HCA- and have IS images from some of the vendors here.....

NO question Blue Nie is a trustworthy company...but the questions you ask lead me to believe you''d get value by choosing a vendor who can provide you with all the things you''re looking for....

If given the choice, I''d really rather see a photo.....

 

[strmrdr]

Date: 1/27/2009 2:19:54 PM
Author: Regular Guy

Date: 1/27/2009 1:37:49 PM

Author: crease123

Yeah, the stone that I'm eyeing is an AGS 0 with a HCA rating between 1 and 2. But I would agree, nothing is confirm until a reading by IS.

Well...no...I think I disagree with this.


You could take the position that you cannot buy without seeing.


Short of that...let's just say you'd like to recognize what the most conservative set of procedures is for identifying....what shall we call it...an attractive diamond?


Remember...just with respect to the limitations of an IS delivering a reflection of what the eye can see...a) it is a cyclops view, perhaps consistent with that, b) leakage showing emphasizes leakage seen.


That said...if you were seeking the more conservative choice, and could choose, sight unseen, and not knowing any more about the diamonds cut performance than either of these two things for each of two diamonds:


a) AGS0, between 1 - 2 on the HCA

b) a nice honking red IS


Is it clear which you'd pick?


I'd be interested to hear more opinions. But, just knowing these two aspects, I think I'd go for the first.


Further...if I did NOT see a honking red IS...where the IS view was available, but got the AGS0...and I was not lead to think the 0 was miscalculated (i.e., it's proportions comport to O otherwise)...again...I think I'd choose the AGS.


You?

I would much rather have an IS image and some numbers to run thru the hca and experience filters than just an ags0 score.
AGS0 is just a sometimes quicker but not fool proof way to find diamonds with the above.

With no other choice but to go by the grade then an ags0 is a safer bet than a gia Ex.

 

[:)]

Hi crease - too bad the others didn''t work out. I know this is stressful for you, you will get there!

Blue Nile has a great 30 d return policy, so if you choose wisely, you can maximize your chances of finding a great stone without the IS, but still have time to return it if needed. What I would recommend (as mentioned above), is shoot for those stones that fall in both the GIA and AGS boxes on the HCA tool - the green box is gia, and the white one is ags.
Make sure to check eyecleanliness - many of their stones (the ones not labeled signature ideal) are drop shipped (meaning they are at another vendor so are shipped directly to you without passing through them) - if you have them put a stone on hold, they can call to check eyecleanliness (make sure you are clear about what you mean by eyecleanliness with the sales rep you are talking with - you both need to be on the same page) - once you get the answer (presuming it is a yes for eyeclean), you can have them recheck to confirm - they will each time contact the vendor to discuss the stone and get back to you.
I would recommend if you are not getting an in house stone, that you avoid SI stones that read ''clouds not shown'' in the comments section. Long story short, IF clouds are the gradesetter for an SI grade, they can affect the performance of the stone. On a carefully checked stone with a trusted vendor this can be easily avoided, but since BN doesn''t have most stones in house, it just makes it harder to be sure, so this is a way to play it safe and maximize chances of success. If it reads ''clouds not shown'' on a vs stone, it was not a grade setter so don''t worry about that.
I also recommend that you buy the stone loose so that you can properly evaluate it yourself to see if you find it pleasing to your eye, and so that you can take it to have an independent appraiser (not a jeweler, but a true independent appraiser who can help you evaluate the stone, cut, and will not try to send you to another vendor friend to buy a stone).
One of the really good independent appraisers can do the IS for you.

What city are you in? Do you have any of the appraisers here near you?
If worst comes to worst, you can ship it to one of the appraisers - I sent mine from CA to Richard Sherwood in Sarasota, FL so that it would get all the bells and whistles data.
The bells and whistles data is also nice to have for insurance purposes, esp if your policy is one that replaces ''like with like'' - the more data you have the more leverage to make sure that a loss or damage to a stone is replaced with an appropriately cut stone.

If you decide to keep it you can get it set locally.

Ok, I''ll stop talking now!
[I do see a stone or two that I like for you there, but I am not going to post them now to avoid lurkers. Please put your stone on hold and get more confirmatory info - if you want you can post specs once you have placed it on hold (so that you know no one else will take the stone while you are deciding)].