AVC cushion: table, depth, spread

[sparklyforever]

if looking at a AVC...
do you still analyze the table depth and spread?

If so - feedback on the numbers you like?

i think i need to find a balance between picking a stone from "the numbers", the aset, etc....

and just my eyes.

feed back please!

 

[Lorelei]

Date: 3/7/2010 3:34:33 PM
Author:sparklyforever
if looking at a AVC...
do you still analyze the table depth and spread?

If so - feedback on the numbers you like?

i think i need to find a balance between picking a stone from 'the numbers', the aset, etc....

and just my eyes.

feed back please!

I take everything into account but more important are the images, shape and your own preference. As you know Jon provides videos which are another excellent medium to assist the purchaser.

 

[ChunkyCushionLover]

Date: 3/7/2010 3:34:33 PM
Author:sparklyforever
if looking at a AVC...
do you still analyze the table depth and spread?

If so - feedback on the numbers you like?

i think i need to find a balance between picking a stone from ''the numbers'', the aset, etc....

and just my eyes.

feed back please!

Post your options we can analyze them, all of the AVCs are cut well so that isn''t really an issue. You won''t gain much from looking at the numbers except to see which ones give you a little more spread and which one are more rectangular or square.

Most important are size, LW ratio, shape outline and the ASET image.

 

[sparklyforever]

so then what do you like to see in the spread?

am i correct that "typically" a small table is desirable for a cushion? but if this is so this confuses me... as i thought a smaller table gave to a smaller surface appearance.

am i wrong?

i don''t have any hard picks yet but how do you feel about this?
http://www.goodoldgold.com/diamond/6732/

for example - should i absolutely make sure my diamond fits within the proportions on the table below? (cushion is at the bottom) or should i discount that when looking at AVC? because of the antique style of cutting?

http://www.diamondarticles.com/diamond-proportions.php

 

[Lorelei]

Date: 3/7/2010 5:12:37 PM
Author: sparklyforever
so then what do you like to see in the spread?

am i correct that 'typically' a small table is desirable for a cushion? but if this is so this confuses me... as i thought a smaller table gave to a smaller surface appearance.

am i wrong?

i don't have any hard picks yet but how do you feel about this?
http://www.goodoldgold.com/diamond/6732/

for example - should i absolutely make sure my diamond fits within the proportions on the table below? (cushion is at the bottom) or should i discount that when looking at AVC? because of the antique style of cutting?

http://www.diamondarticles.com/diamond-proportions.php

Spread refers to the face up size or diameter of a diamond, the spread or diameter can vary according to the weight and proportioning of the diamond. With the AVC the spread will be within good range for the weight/ proportion and cut quality anyway. Just compare the diameters of individual AVC's to see how each compares for face up size.

I am not sure where the proportions given in the chart above are from, they could be taken from OldMiner's charts, I haven't looked them up to compare, but with a branded specialty cut such as the AVC the use of charts and various proportion suggestions are limited anyway and won't really help you. Go by images, videos etc and your own personal taste.

The AVC you linked looks great and H VS are excellent specs.

 

[Dreamer_D]

I''d ask for a video and then pick the one I liked the look of best. I think they are all cut to great proportions, are they not? Have we seen a dog yet?

 

[CharmyPoo]

Date: 3/7/2010 5:12:37 PM
Author: sparklyforever

am i correct that ''typically'' a small table is desirable for a cushion? but if this is so this confuses me... as i thought a smaller table gave to a smaller surface appearance.

This is sort of true but not really. In my opinion, when a stone has a smaller table, it will generally have a taller crown. This means that the carat weight goes to the crown height making the face up size appear a little smaller. However, I think this difference is going to be really minimal compare to other factors. For example, I believe you lose more size to weight in a girdle or the diamond depth. Would love to hear the experts chime in.

 

[ChunkyCushionLover]

Date: 3/7/2010 5:15:46 PM
Author: dreamer_d
I''d ask for a video and then pick the one I liked the look of best. I think they are all cut to great proportions, are they not? Have we seen a dog yet?

No and there won''t be a dog because Jon is the most selective vendor I have ever met, on selecting fancy shapes based on light performance.
I have seen a few stones privately that did not pass Jon''s strict criteria (but were really close) but none of those ever made it up for sale, for this brand close only counts in horshoes and hand grenades! The ones that were close were either sent back for recutting or to other channels.

All AVCs:

Have depths 65 - 70%
Tables 48 - 55%

These are both in the ideal range for balancing light return under the table with a reasonable spread for this vintage style cut with a tall crown and steep crown angle of over 40 degrees.

To the OP the most important thing here is the light return and the outline shape of these stones. The AVC was designed to be a modern version of the antique vintage old mine cushion, using modern cutting techniques, with excellent symmetry, flatter straighter outlines and big bright mirrors under the table as a result of carefully adjusted crown and pavillion angles. Each AVC satisfies this criteria, the ASET must show four big bright red mirrors under the table in the ASET as well as red in the ASET along all edges of the stone and only minimial amount of leakage and obstruction (blue and white in the ASET). I have been nitpicking the choices for posters of one AVC over another but in real life the differences are much more suttle than as seen in magnified images or videos.

For example in your price range:

http://www.goodoldgold.com/diamond/6931/ (Larger faceup per carat 7.0mm X 6.35mm than the others(65% depth) a little more rectangular (Length/Width 1.10) 1.36 I VS2 $696
http://www.goodoldgold.com/diamond/6732/ (Slightlly Rectangular LW= 1.06) 6.52 X 6.13mm (68% depth) slightly smaller than above for same weight 1.22 H VS1 $6731)
http://www.goodoldgold.com/diamond/6932/ (Slightly Rectangular LW = 1.07) 6.59 X 6.15mm (69% depth) slightly smaller than above for same weight 1.23 G VS2 $763

Any of them are a viable choice.

 

[sparklyforever]

To you all.... your answers have all been helpful.

CCL - that explanation really helped. i am starting to understand more.

Thank you alll!!!!
okay - yes i am watching the academy awards....

 

[CharmyPoo]

Date: 3/7/2010 8:38:56 PM
Author: ChunkyCushionLover

All AVCs:

Have depths 65 - 70%
Tables 48 - 55%

Although rare, there are some AVCs that have depths below 65% - example mine which is 63% with minimal impact to performance.

 

[ChunkyCushionLover]

Date: 3/8/2010 12:45:30 AM
Author: CharmyPoo

Date: 3/7/2010 8:38:56 PM
Author: ChunkyCushionLover

All AVCs:

Have depths 65 - 70%
Tables 48 - 55%

Although rare, there are some AVCs that have depths below 65% - example mine which is 63% with minimal impact to performance.

With correct Crown Angle and Pavillion Angle 63.5% depth can be fine as well, your stone is beautiful http://www.goodoldgold.com/diamond/6267/ but the thin/very thin girdle allows your stone to have the same crown height and steep enough pavilion as a 65% depth stone. There are reasons why the experts don''t like judging fancies by the numbers too many exceptions.

 

[sparklyforever]

okay - the further conversation has been more helpful.

charmy poo... Holy Mackrel! that stone is ..... i don''t even know what to say. It is amazing! how can you stand having it - but not? Time to get that baby set!


I was thinking that the visual had to be this absolute perfect symmetry like on the Hearts and Arrows - but i dont think that is necessarily true... i think i have been looking at the asets - and misreading them..

 

[Lorelei]

Date: 3/8/2010 7:02:11 AM
Author: sparklyforever
okay - the further conversation has been more helpful.

charmy poo... Holy Mackrel! that stone is ..... i don''t even know what to say. It is amazing! how can you stand having it - but not? Time to get that baby set!


I was thinking that the visual had to be this absolute perfect symmetry like on the Hearts and Arrows - but i dont think that is necessarily true... i think i have been looking at the asets - and misreading them..

That isn''t comparing apples to apples, you won''t find a fancy shape with perfect optical symmetry like a top cut h&a, more important is the shape and overall light return of the stone and all AVC''s are cut with the best visual performance in mind.

 

[sparklyforever]

Lorelei - thanks.. I totally had the wrong impression. i was thinking it had to form this perfect visual symmetry in Aset.


then how do you evaluate the light return? just by your visual decision when looking at the stones IRL - as to what gives back the most light?

 

[Lorelei]

Date: 3/8/2010 12:01:11 PM
Author: sparklyforever
Lorelei - thanks.. I totally had the wrong impression. i was thinking it had to form this perfect visual symmetry in Aset.


then how do you evaluate the light return? just by your visual decision when looking at the stones IRL - as to what gives back the most light?

You are welcome!

Concerning ASET, this is a very useful tutorial and one I refer to others frequently. It gives an excellent overview on interpreting ASET images.

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In particular, the info below is pertinent,

RED is Direct Light (drawn from 45-75 degrees). Red will be the most intense. It comes directly from the source.

GREEN is Reflected Light (drawn from 0-45 degrees). Green has less intensity. It is light reflected from walls, the environment, etc.

BLUE represents light Obscured by the observer (your head blocks this light from reaching the diamond). When the diamond is tilted these areas will light up and other areas will become shaded. The distribution of blue is a primary factor in the diamond's "contrast pattern."

WHITE (if the diamond is backlit, as above) or BLACK (if not) is Leakage. These areas show where pavilion facets are acting as windows rather than mirrors. You see white because those windows allow you to look through the diamond and see the light underneath. White should be minimized.

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.

 

[Dreamer_D]

If I were picking an AVC, I would simply choose the price and shape and color/clarity I wanted. I would not worry about light return because you are talking increments of perfection really. I can''t imagine there are huige differences even side by side comparing them, and certainly not something noticable when you are wearing it.

 

[ChunkyCushionLover]

Date: 3/8/2010 12:01:11 PM
Author: sparklyforever
Lorelei - thanks.. I totally had the wrong impression. i was thinking it had to form this perfect visual symmetry in Aset.


then how do you evaluate the light return? just by your visual decision when looking at the stones IRL - as to what gives back the most light?

There is only one cushion which has achieved AGS0 standard for light performance and that is the Square Cushion Hearts and Arrows. Example http://www.goodoldgold.com/diamond/6983/ which really is cut like an ideal Tolkowsky round except with a cushion outline.

There are many tradeoffs in considering a fancy diamond over a round, shape of the outline, spread, cost per carat, contrast, size of the flash, brightness etc. Absolute light return is not one of the usually considered criteria, otherwise diamonds could all be designed like headlights but those would be ugly without any contrast.

 

[sparklyforever]

Lorelei..
thanks for the post/links.

this is my crazy busy time at work - so i need to sit down with this when my brain isnt fried....

but i will be reading this...

 

[Lorelei]

Date: 3/9/2010 6:55:41 AM
Author: sparklyforever
Lorelei..
thanks for the post/links.

this is my crazy busy time at work - so i need to sit down with this when my brain isnt fried....

but i will be reading this...

You are most welcome!