help comparing and understanding cushions

[confusedcushion]

Wow...after months of study on here I thought I had my purchase of a RB nailed. I could even predict HCA scores and interpret ASET images, which for a novice like me was a big deal! Then, my fiance decided on a cushion and, well---let''s just say that I''m going crazy

So, I''ve been looking at cushions on the WF and GOG websites. Haven''t spoken to anyone at these vendors yet, cause I wanted to try and understand things better first.

Here''s a cushion I found on the WF site--it''s one of their premium select stones, which is the highest quality I found listed for cushions:
http://www.whiteflash.com/premium_select_cushion/Premium-Select-Cushion-cut-diamond-2160874.htm

I''ve been comparing it to the August Vintage Cushions on the GOG site which everyone has been raving about on here. Unfortunately, their online inventory is very limited, and I couldn''t find a similar weight/color/clarity stone for comparison. However, I chose this one of similar weight, soley for the purpose of comparing the cut quality and ASET images:
http://goodoldgold.com/diamond/6209/

The immediate difference I notice in cut is that the WF stone has a much larger table (61%) compared to the GOG diamond (48%). The depth for the WF stone is also higher than the GOG vintage cushion (68.9% vs. 67.4%).

The other apparant difference is in crown heights and crown/pavillion angles. Here, the GOG stone has a much larger crown (22.6%) versus the WF stone (15.8%). Also, the angles are much more dramatic on the WF cushion (36.5%/63.5%) compared to the smaller and closer angles on the GOG stone (41.3%/40.5%). It appears that most of the GOG August Vintage stones are cut in a similar fashion to this one, and most of the WF premium select cushions have similar differences compared to the GOG vintage stones.

Notwithstanding these major differences, the ASET images for the two stones look fairly comparable, from what I can tell (although I have much more trouble reading these compared to RBs). In fact, the GOG image appears to have much more white around the center red area, compared to the WF image in which the red center is encircled by green. However, the reds on the GOG image (especially in the center) do look deeper than the WF image in which the red areas are more pinkish, but I can''t tell whether this is a real difference in the stones or just better picture quality at GOG?

Can someone please help me understand these cut differences and interpret the resulting ASET images, please? And, of course, the ultimate question--how will the different cuts affect the light performance of these diamonds?

 

[Lorelei]

Date: 11/10/2009 10:52:41 AM
Author:confusedcushion
Wow...after months of study on here I thought I had my purchase of a RB nailed. I could even predict HCA scores and interpret ASET images, which for a novice like me was a big deal! Then, my fiance decided on a cushion and, well---let's just say that I'm going crazy

So, I've been looking at cushions on the WF and GOG websites. Haven't spoken to anyone at these vendors yet, cause I wanted to try and understand things better first.

Here's a cushion I found on the WF site--it's one of their premium select stones, which is the highest quality I found listed for cushions:
http://www.whiteflash.com/premium_select_cushion/Premium-Select-Cushion-cut-diamond-2160874.htm

I've been comparing it to the August Vintage Cushions on the GOG site which everyone has been raving about on here. Unfortunately, their online inventory is very limited, and I couldn't find a similar weight/color/clarity stone for comparison. However, I chose this one of similar weight, soley for the purpose of comparing the cut quality and ASET images:
http://goodoldgold.com/diamond/6209/

The immediate difference I notice in cut is that the WF stone has a much larger table (61%) compared to the GOG diamond (48%). The depth for the WF stone is also higher than the GOG vintage cushion (68.9% vs. 67.4%). Depth doesn't always relate to face up size in fancy shapes as it does in round diamonds as there are various places weight can hide ( crown, pavilion, girdle etc). Jon from GOG has these vintage cushions cut to his specifications as his signature line, these typically feature a smaller table and steeper crown height and shorter lower girdle facets etc.

The other apparant difference is in crown heights and crown/pavillion angles. Here, the GOG stone has a much larger crown (22.6%) versus the WF stone (15.8%). Also, the angles are much more dramatic on the WF cushion (36.5%/63.5%) compared to the smaller and closer angles on the GOG stone (41.3%/40.5%). It appears that most of the GOG August Vintage stones are cut in a similar fashion to this one - yes because these are Jon's signature brand - , and most of the WF premium select cushions have similar differences compared to the GOG vintage stones. The WF and GOG cushions are of different types, the WF cushion is a modern type and the GOG a vintage style so not really comparing apples to apples. Cushions can vary tremendously in type and appearance so decide which type appeals to you the most firstly, here are some videos which might help. GOG have many cushion comparison videos which can be found on their site, would be well worth watching.

www.vimeo.com/3164922

http://www.vimeo.com/7365331

Notwithstanding these major differences, the ASET images for the two stones look fairly comparable, from what I can tell (although I have much more trouble reading these compared to RBs). In fact, the GOG image appears to have much more white around the center red area, compared to the WF image in which the red center is encircled by green. However, the reds on the GOG image (especially in the center) do look deeper than the WF image in which the red areas are more pinkish, but I can't tell whether this is a real difference in the stones or just better picture quality at GOG? The ASET images are different for each vendor, the WF images have a black background and GOG white, this accounts for some of the differences. The white in the centre of the GOG ASET is the culet of the diamond.

Can someone please help me understand these cut differences and interpret the resulting ASET images, please? And, of course, the ultimate question--how will the different cuts affect the light performance of these diamonds? Firstly read this link to learn how to interpret ASET images. This thread too will be very helpful,

https://www.pricescope.com/community/threads/a-cushion-by-any-other-name.36001/

 

[confusedcushion]

Lorelei, thanks so much for the clarifications and information.

I''m very familiar with the article you linked me about understanding ASET images. I find it quite clear insofar as RB diamonds are concerned, but not that much help with regard to interpreting ASETs for cushions.

Is there another thread more on point for how to compare ASET images for cushions, or can someone post some comparisons? It''s obvious that more white is going to be present in a cushion image, and the blues and greens won''t be evenly distributed as in a quality RB. But beyond that, I''m having trouble understanding what is an ideal, excellent, very good, good and poor image for a cushion stone?

Oh, and the antique structure is my favorite, so we can limit the answer to those.

 

[Lorelei]

Date: 11/10/2009 12:27:10 PM
Author: confusedcushion
Lorelei, thanks so much for the clarifications and information.

I'm very familiar with the article you linked me about understanding ASET images. I find it quite clear insofar as RB diamonds are concerned, but not that much help with regard to interpreting ASETs for cushions.

Is there another thread more on point for how to compare ASET images for cushions, or can someone post some comparisons? It's obvious that more white is going to be present in a cushion image, and the blues and greens won't be evenly distributed as in a quality RB. But beyond that, I'm having trouble understanding what is an ideal, excellent, very good, good and poor image for a cushion stone?

Oh, and the antique structure is my favorite, so we can limit the answer to those.

You are most welcome!

You can read this thread too by John Pollard on how to interpret ASET,

https://www.pricescope.com/community/threads/why-we-prefer-aset-to-ideal-scope-with-fancy-shapes.73949/

unfortunately there isn't much which is cushion specific for ASET comparison but I will see what I can dig up for you. But ASET is only part of the puzzle, detailed photos are very important and videos can be extremely helpful so weigh all the info you have on each diamond carefully.

Here is a quote from Karl which sums cushion ASETS up rather well I think-

"The problem is that there is no one well cut cushion as cushions come in several types and facet patterns.
Each can have a different IS/ASET appearance when well cut.
In the IS I would look for min. white and a pleasing mix of black and red.
The aset is a little more complicated but In general I would look for a lot of red, little white/black(depending on aset type) with some blue and green thrown in for contrast."
Karl K.

Useful threads and some videos.

http://www.goodoldgold.com/Technologies/ReflectorTechnologies/WhatdoReflectorsTeachUs/

http://vimeo.com/2522834

http://goodoldgold.com/Diamond_Videos/

https://www.pricescope.com/community/threads/chunky-cushion-need-to-pick-1.113609/

 

[jet2ks]

Date: 11/10/2009 12:27:10 PM
Author: confusedcushion
Lorelei, thanks so much for the clarifications and information.

I''m very familiar with the article you linked me about understanding ASET images. I find it quite clear insofar as RB diamonds are concerned, but not that much help with regard to interpreting ASETs for cushions.

Is there another thread more on point for how to compare ASET images for cushions, or can someone post some comparisons? It''s obvious that more white is going to be present in a cushion image, and the blues and greens won''t be evenly distributed as in a quality RB. But beyond that, I''m having trouble understanding what is an ideal, excellent, very good, good and poor image for a cushion stone?

Oh, and the antique structure is my favorite, so we can limit the answer to those.

With the following in mind as just the basics

"In general RED should be maximized. Some BLUE is necessary. Too much GREEN is undesirable. The distribution of the three colors is important. WHITE should be minimized."

What you are looking for in the antique style cushions is large areas of red with the larger facets, and some blue, with limited green or white. Depending on how the camera/diamond setup is oriented, one or more of the large facets sometimes shows blue in the ASET, as the facet at 12 o''clock in theASET of the GOG stone you linked. This is actually OK, as you can think of the blue and red as the off and on of a light switch, when the diamond &/or viewer moves, some of the obstructed facets (blue) will now reflect light and some of the red ones will turn "off", causing the pattern of scinitillation. For the smaller virtual facets, a nice patterning of colors in the ASET will help create scintillation and interest.

Hope that helps a little.