Reduce table reflection?

[rogue]

I''m not a particular fan of the table reflection that appears as a glassy circle/hole around the culet. I understand per Rockdoc and Garry that this is intensified the deeper the pavilion angle and the larger the table. Given any particular stone, is there anything you can do to reduce the table reflection? Can you set the diamond in such a way to minimize or exacerbate the appearance (higher v. lower, closed v. open)?

 

[rogue]

Bump.

 

[decodelighted]

Date: 7/27/2006 9:46:53 PM
Author:rogue
Can you set the diamond in such a way to minimize or exacerbate the appearance (higher v. lower, closed v. open)?

I don''t believe so. Why not just get a diamond with a smaller table? But then, the other "face" facets will sometimes reflect light too. Any reflective surface does ... Nature of the beast I''m afraid ...

Are you sure you''re talking about "table reflection" ..light flashing off the flat surface of the stone ... and not the "Fish Eye" effect ... which is more internal, dark donut hole effect? I would REJECT any stone with a "fish eye" effect.

 

[rogue]

Yep, definitely talking about table reflection, not fisheye -- see pic below (excuse the red--I was playing with blocking camera flash). Just not liking the diamond within a diamond reflection. This one looks particularly big, but it''s not really captured in the picture. It just sometimes looks like a dark hole in the bottom of the diamond. Looked at so many diamonds and this is the thing I''m finding wrong with the one I decided on. Not a particularly bad thing to find wrong with a stone I suppose. Any other fixes (other than changing the stone!)?

 

[rogue]

Date: 7/28/2006 12:39:48 AM
Author: decodelighted
Are you sure you're talking about 'table reflection' ..light flashing off the flat surface of the stone ... and not the 'Fish Eye' effect ... which is more internal, dark donut hole effect?

Oh, just reread your post - I'm not talking about table glare, but the actual internal reflection inside the diamond, present in all diamonds but to varying degrees based on pavilion angle/table size.

 

[rogue]

You can see it in the IS image - the pink circle in the center from which the arrows originate is just so large! Am I going crazy or is this large?

 

[Mara]

it seems like that is just the nature of the cut of the stone.

attached is my idealscope image...you can see that the table center area shows up smaller, it also is not quite all red in the center.

but in reality yours should be returning light to your eye as it's all red...not white and leaky. maybe if the center area of yours had a tiny bit more pink rather than straight red, it would show up not quite as a block of light. in terms of how to set the stone, not really sure what could minimize that if anything. since you are looking down directly into the middle of the stone...i don't know how easily it could be hidden.

 

[JulieN]

Rogue, what's the pavilion angle of your stone? Not sure if it's relevant or not...

 

[Garry H (Cut Nut)]

You are right Rogue - shallower pavilion, but also a smaller table.

With a shallower pavilion you will want the crown angle to be way over 36 - even as far up as 38.

Use the HCA charts on 53% table size to work out optimum %''s

They are called firey ideal cuts - FIC

 

[Cehrabehra]

Date: 7/28/2006 1:39:38 AM
Author: rogue
Yep, definitely talking about table reflection, not fisheye -- see pic below (excuse the red--I was playing with blocking camera flash). Just not liking the diamond within a diamond reflection. This one looks particularly big, but it''s not really captured in the picture. It just sometimes looks like a dark hole in the bottom of the diamond. Looked at so many diamonds and this is the thing I''m finding wrong with the one I decided on. Not a particularly bad thing to find wrong with a stone I suppose. Any other fixes (other than changing the stone!)?

I think it looks like a really cool eyeball! I''d love to see more pics of it! ::scrolling down::

 

[Cehrabehra]

Date: 7/28/2006 1:43:04 AM
Author: rogue

Date: 7/28/2006 12:39:48 AM
Author: decodelighted
Are you sure you''re talking about ''table reflection'' ..light flashing off the flat surface of the stone ... and not the ''Fish Eye'' effect ... which is more internal, dark donut hole effect?

Oh, just reread your post - I''m not talking about table glare, but the actual internal reflection inside the diamond, present in all diamonds but to varying degrees based on pavilion angle/table size.

See, I like that sort of depth - it might not be as brilliant white, but it makes the stone interesting to look at - more than just a flash to me

 

[Cehrabehra]

Date: 7/28/2006 2:24:57 AM
Author: Mara
it seems like that is just the nature of the cut of the stone.

attached is my idealscope image...you can see that the table center area shows up smaller, it also is not quite all red in the center.

but in reality yours should be returning light to your eye as it''s all red...not white and leaky. maybe if the center area of yours had a tiny bit more pink rather than straight red, it would show up not quite as a block of light. in terms of how to set the stone, not really sure what could minimize that if anything. since you are looking down directly into the middle of the stone...i don''t know how easily it could be hidden.

Mara - I think your picture has a better focus on the detail, for one... your stone is so pretty in that IS image! I think Rogue''s image is more focused on the table than the internal detail. The inner detail seems kinda blurry...

 

[Cehrabehra]

Date: 7/28/2006 2:54:11 AM
Author: Garry H (Cut Nut)
You are right Rogue - shallower pavilion, but also a smaller table.

With a shallower pavilion you will want the crown angle to be way over 36 - even as far up as 38.

Use the HCA charts on 53% table size to work out optimum %''s

They are called firey ideal cuts - FIC

::making notes:: Thanks for the info Garry!

 

[Garry H (Cut Nut)]

Here is a pretty thick girdle bad sym stone that is an extreme - hope it attached.

There is almost no spot in the center.

This also shows that the lower gridles are too short for this stone - even though they are probably longer than 85%

 

[Garry H (Cut Nut)]

That is better.

A bad sym stone extreme FIC

There is almost no spot in the center.

This also shows that the lower gridles are too short for this stone - even though they are probably longer than 85% - it takes a hit on light return - down by -6% - and if the lower girdles were longer - it would improve to maybe -3%. But the fire would blow you away.

The scintillation is also amazing on these stones - the contrast is +6% !!!

 

[Cehrabehra]

Date: 7/28/2006 3:42:24 AM
Author: Garry H (Cut Nut)

That is better.

A bad sym stone extreme FIC

There is almost no spot in the center.

This also shows that the lower gridles are too short for this stone - even though they are probably longer than 85% - it takes a hit on light return - down by -6% - and if the lower girdles were longer - it would improve to maybe -3%. But the fire would blow you away.

The scintillation is also amazing on these stones - the contrast is +6% !!!

If I end up with a round, I''d MUCH rather it have super high fire and contrast over brilliance. Thanks again Garry for this useful info

 

[Garry H (Cut Nut)]

I hope you all have Gem Adviser free software and know to click and download the file at the bottom of the post 2 above?

 

[rogue]

Date: 7/28/2006 2:44:19 AM
Author: JulieN
Rogue, what''s the pavilion angle of your stone? Not sure if it''s relevant or not...

Hey JulieN, I have one of the inverse crown/pavilion shallow/deep 60/60s: 32.5 crown, 41 pavilion per Megascope report or 41.2 pavilion per GIA report. Table 59.1%, total depth 59.7%. HCA score using Megascope''s 41 pavilion is 1.1, and using GIA''s 41.2 pavilion angle is 2.1. Huge difference!

 

[rogue]

Hrm, my gem advisor software is bugging out on me, can''t see the images right now. Mara, I think my IS image is in fact blurry, I think I remember the center not being all red when I looked in. I guess I definitely wouldn''t want a stone with no circle reflection since that would mean poorly cut. I think this 59% table with the 41 pavilion is just making this slightly larger than I''ve seen (on Spot, which was also 59% table, but had a 40.6 pavilion, the table reflection was the "normal" size). So it sounds like setting a stone in a particular way can''t really change this?