Cushion cut quality confusion

[TwoJs]

This site has been so helpful in terms of diamond education, but I''m trying to make sense of it all. I am looking for a cushion diamond, but I''m not entirely sure whether the methods and criteria for evaluating round brilliants are all applicable to fancy shapes, especially cushions. Do the following items apply to fancy cuts?

-AGS
-Sarin
-HCA
-Pavillion and Crown angle measurements
-H&A viewer (I''m not necessarily looking for an H&A cushion like GOG sells, but is this tool still helpful?)
-Idealscope (I''ve gathered that this will only be usefeul to compare light return between stones)

Thanks for your help!

-J

 

[Hest88]

-AGS
-Sarin
-HCA
-Pavillion and Crown angle measurements
-H&A viewer (I''m not necessarily looking for an H&A cushion like GOG sells, but is this tool still helpful?)
-Idealscope (I''ve gathered that this will only be usefeul to compare light return between stones)

Well, AGS doesn''t do cushions, so you won''t be seeing a cushion with an AGS cert.

As for the other stuff:

Even though there are no solid standards, knowing the stats will help you weed out some potentially poor performers. That means it would be good to have a Sarin so you can get proper table, crown, etc. For instance, if you know the crown is flat, you also know that you''re unlikely to get a cushion with a good amount of fire.

HCA wouldn''t be something I''d use with a cushion. H&A is only useful to view hearts and arrows, so I wouldn''t consider it very valuable. The IS, might help. If you look under the IS tips for fancy shapes you''ll at least get a sense of what kind of light return you should expect from a nice fancy. Granted, it might not be totally helpful, but it could also provide some guidance.

 

[TwoJs]

Thank you!

 

[diagem]

Hi there,

Cushion shapes are a wild bunch, they come in loads of different variations.

Different shapes, faceting, faceting arangements, dephts, angles etc, etc...

the best way to judge a cusion is with your eyes and taste. for example: i know quite a few people who look for a LOT of FIRE in their cushions, and alot of people who dont want the fire at ALL!!!!

Cushions come from the Antique world, they were one of the first shapes in the diamonds faceting history, and they came in all different various shapes and sizes, flat and heavy, long and squarish, squarish and rounded, rounded and compeletly round ect, ect.

Ive seen cushions that were very flat (i mean below 50% total depth) that were killler beauties and were sold for hefty premiums. same heavy stones 80% + depth that were considered MUSEUM quality cuts that sold for large premiums.

Take for examle the Tiffany Diamond (128 cts. appr.) which is considered by many to be one of the most beautifull diamonds in the world. the tiffany is a VERY HEAVY DIAMOND, but it looks amazing.

If you are looking for fire go for a modern cushion that has brilliant faceting arangement, and are in the modern specs ( depth: 60-70% table 58-65% etc.)

But if you are looking for an antique look (or vintage as many call it) you shouldnt go for the fire, but for the reflection of big blocky patterns!!

Good luck

 

[valeria101]

Date: 1/24/2005 12:36:23 PM
Author:TwoJs
...for a cushion diamond, [...] Do the following items apply to fancy cuts?

-AGS
-Sarin
-HCA
-Pavillion and Crown angle measurements
-H&A viewer (I''m not necessarily looking for an H&A cushion like GOG sells, but is this tool still helpful?)
-Idealscope (I''ve gathered that this will only be usefeul to compare light return between stones)

From what I know:

-AGS - definitely not, the lab does not have a cut standard for fancies

-Sarin - well, there is no way to interpret those numbers

-HCA - definitely not: only intended for rounds

-Pavillion and Crown angle measurements - same as Sarin

-H&A viewer (I''m not necessarily looking for an H&A cushion like GOG sells, but is this tool still helpful?), - it doesn''t show light return per se, I wouldn''t know how to read what this shows for fancies

-Idealscope (I''ve gathered that this will only be usefeul to compare light return between stones) - I think it does, if you do get either the instrument itself or a professional Iscope photo of a stone, it can tell you quite a bit of detail about how the diamonds'' optics work - where is light reflected from the stone. There are refference charts for some fancy shapes, but in general, mostly red with a little pink and black is good news, regardless of their pattern. The easiest thing to do with this ''scope may indeed be to compare diamonds side by side, but this doesn''t mean that the looks of one diamond cannot be interpreted at all.

Besides, unlike the other ''scopes you can always buy one and do your own reality check on the sellers'' photos if you do not trust their use of lighting conditions and want to see for yourself how the scope does it''s trick.

Just my 0.2 worth IMO, of course.