Does tweaked girdle or edge to edge light return...

[Mara]

possibly make a lower color stone face up whiter?

I don't know if this has been mentioned on here before...but it occurred to me last nite that it may seem possible that the edge to edge light return of say the Eightstars or the ACA new lines with their blood red IS/LS/FS images and relatively little white may return more light to the eye, possibly white light in more circumstances than not? And could that contribute to the stones such as I/J/K/L etc looking more 'white' to the naked eye/casual viewer?

If this is the case, or some feel as though it may be so....how do the more classic cut stones, aka ACA classic, SC, GOG H&A etc compare to the eye for a lower color? Do they show more body color face up? Even miniscule amounts to experts?

Just a curious thought I thought I'd put out there. My J is blazing white from the top down, soft color is visible at times from the side. But I have always been amazed at how 'white' the well-cut J's can be. Led me to wondering that since my IS is a blood red wanna be ACA new line, if that had something to do with it. And if I stuck with a J in the future 2.40ct size or similar if I should be focusing on getting that same new line type tweaky girdle cut over a classic.

 

[aljdewey]

Recent info would suggest the opposite.. Dandoboy just posted an email from Superidealist that really covered the differences well.

He observed that Eightstars (and to some degree, new line ACA) can appear *dark* under the table *in direct lighting* because it returns almost all colored light and no white, thereby making the stone appear dark.

If this holds true for new lines, that would seem to suggest that new line ACA''s might return less white light?

 

[valeria101]

Good question...

All I know is that rounds in general are not a good shape for showing color, but which proportions could work better for that, no idea. The little bits of ''lickeage'' around the girdle are so minor, I am not sure what to credit that effect with though.

I just wanted to add a question to yours because it also related to color and cut. It seems that leakage and fish eye patches look the most colored in tinted diamonds - what gives?

 

[jcrow]

i could have this wrong, but...

at my last WF trip, I asked Lesley about the NewLine. She said that the NewLine had more fire (i think) but the OldLine had more contrast and i think more white light return. I believe she prefered the OldLine.

My related question - does the NewLine diamonds appear larger in size than the OldLine- of course when comparing the same size diamonds?

 

[Mara]

Having seen new and old line together at WF...I can''t say I noticed one looking more interesting, unusual or beautiful than the others. In terms of size, hard to say too, they all just looked sparkly and big.

But in a side by side viewing comparison, it''s not the same as real life. Very curious to hear what the experts say. John? anyone else chiming in?

The thing is from a realistic perspective, if its edge to edge light return, why woud the stone appear DARKER than a classic? Sure classic''s have more scintillation, I did notice that in seeing them at WF....the new line are broader, stronger flashes of light rather than tiny glass shards. But why would a tweaked girdle or edge to edge show more darkness INSIDE the stone? In the table no less. Does the girdle affect the center that much?

Lastly, I don''t feel like the stones reflect that much more color vs white light in the new line at all. From my experience looking at Greg''s stone. It''s a fireball sure but it also appears really darn white in other lighting situations.

 

[valeria101]

Date: 11/11/2005 11:40:24 AM
Author: aljdewey

He observed that Eightstars (and to some degree, new line ACA) can appear *dark* under the table *in direct lighting* ...

I didn''t quite get this when it came up: were they talking about the wider arrows (i.e reflectors) ? Or was there something else too?

If the darkness refers to wide arrows EightStar style (= short lgf), I couldn''t tell if this has anything to do with how much body color remains apparent face up. The arrows are still dark closeup and very bright in direct light in colored diamonds too. I have never came across a natural fancy H&A although apparently they exist - Eight Star has some on record at least. There are color enhanced and now fancy synthetics cut H&A-ish - i.e showing arrows but perhaps not H&A straight. Honestly, I wished the arrows were not there - their contrast brilliance doesn''t seem to do anything for the color except perhaps wash the overly strong shades of synthetics down a bit. So I would think the same effect whitens slightly tinted diamonds too.

The other sort of contrast due to small patches of leakage or light return to low angles seems to enhance color. But this is just based on a bit of hands on experience - I would love to have a techie explanation for it, but don''t

Basically, this post is kindly asking for clarification

 

[Regular Guy]

Date: 11/11/2005 11:40:24 AM
Author: aljdewey
Recent info would suggest the opposite.. Dandoboy just posted an email from Superidealist that really covered the differences well.

I''ll just say it''s unfortunate Superidealist isn''t here, he writes beautifully (and went to see this last post). And if he''s actually here frequently anyway, but just lurking...what a waste.

 

[eks6426]

I have a set of earrings from Whiteflash that is ACA. One stone is the old line, the other is the new line. They are both exactly the same mm....4.69 but one definitely appears bigger to the eye to me. Unfortunately, I have no idea which one it is.

Of course you can''t tell when they''re on my ears, but I can tell when I hold them in my hand.

 

[Rhino]

Hi Mara,

I have some interesting answers to this with graphics to accommodate but I am not at liberty to comment on competitors diamonds. Whatever I say in response to this could be construed in a wrong manner by some which are not my intentions. If you either edit your post or post a new thread to ask about "painted girdles" as opposed to "classic girdles" instead of ACA "new line" vs "classic line" I can answer your questions if you''re interested in hearing my input. If not, no prob and disregard this completely. If you do please drop me a pm/email and I''ll head back to answer at my earliest convenience.

Kind Regards,

 

[WinkHPD]

Date: 11/11/2005 11:40:24 AM
Author: aljdewey
Recent info would suggest the opposite.. Dandoboy just posted an email from Superidealist that really covered the differences well.

He observed that Eightstars (and to some degree, new line ACA) can appear *dark* under the table *in direct lighting* because it returns almost all colored light and no white, thereby making the stone appear dark.

If this holds true for new lines, that would seem to suggest that new line ACA''s might return less white light?

This would not match my experience. I have found that H&A cut diamonds and especially EightStars face up much whiter than a standard cut diamond of the same color. Hidden away somewhere I have a photo I took with an EightStar D next to an EightStar G next to a non EightStar E. The G was sandwiched between the other stones and looked more colorless than the E. This was a direct result of the cutting and the color difference could clearly be seen when the diamonds were seen from the side.

Wink

 

[strmrdr]

Lets back track and consider a few things.

1> diamond color is graded by the color of the material itself, J colored diamond is J colored diamond no matter how well its cut, why?
Because color is graded from the bottom against a white background under specific lighting.

2> face up or apparent color is influenced by cut depending on the lighting conditions

3> Fire and white light return mask color which is why well cut stones look whiter because you are seeing the light return and not the diamond material iself.

4> under lighting conditions where you can see the diamond material itself not masked by returned light the graded color will be more apparent.

Number 4 is where well cut diamonds come into play, they return light over a wider range of lighting conditions therefore they mask the color more often than a lesser cut stone.

As too does the "new line" mask color more often than the "classic" line
the only way to tell for sure would be to line up a bunch of each the same color and view them in a wide range of light conditions.

My guess is that they would be pretty close to even overall but thats just a guess.
Both lines are very well cut diamonds and will be returning light under a wide range of conditions.
There may be some light conditions where one cutting style returns slightly more light masking color better but there is likely another where its reversed.

 

[Mara]

Still waiting on an expert's opinion re: edge to edge light return stones vs those that have the typical leakage along the edges of the stone...

Rhino I'm not just talking about WF ACA and Classic..it's just terminology that I used. If you have data on unbranded stones that show that same phenomenon to help clarify this, please post it.

Of course we all know the basics: that cut helps mask color, that a stone is graded the color is appears to be, yadda yadda etc etc, but I really want to know if people who have seen these types of stones side by side could say YES or NO that edge to edge masks more color or not. If so, is it minute or is it easily visible or what.

Thanks!

 

[Rhino]

Ok...

Here are 2 stones. One has a painted girdle the other doesn't. Both are being offered as "super ideal cuts" yet vary in their appearance. Everyone in our lab can see this difference with their eyes just as you have as well. To some this would be dramatic to others, perhaps not so much. The difference is apparent enough however that GIA, in their new scheme would disqualify one as being "ideal" or top grade (their excellent). Take a stab at which one will not be ideal in the new GIA System yet remain ideal in the new AGS? Then I'll give ya some more input on the phenomena you're seeing. Video is a little nicer but this'll have to do.

btw both of these diamonds are identical in both weight and color. both are K in color.

Regards,

 

[Mara]

I would guess that the one on the right is the painted girdle or edge to edge light return stone and the one on the left would have leakage around the edges, causing more scintillation or a shard of glass sparkle.

The one on the right if it''s the painted girdle would maybe not be ideal with GIA under the new requirements?

If that is correct, then interestingly enough the stone on the left seems like it looks brighter in that particular lighting condition? Am I seeing things?

 

[Rhino]

You're spot on girl.

Here another shot I took of the same comparison outside in the shade on a sunny day. You can see the same effects here as well. These emphasize the metric of brightness as outlined in the new systems.

Here is my original response to your initial post.

The thing is from a realistic perspective, if its edge to edge light return, why woud the stone appear DARKER than a classic? Sure classic's have more scintillation, I did notice that in seeing them at WF....the new line are broader, stronger flashes of light rather than tiny glass shards. But why would a tweaked girdle or edge to edge show more darkness INSIDE the stone? In the table no less. Does the girdle affect the center that much?

The darkness under the table may be due to a number of reasons.

1. It may have been the combination of slope angles (standard crown/pavilion angles). Certain crown/pavilion combos, even with seemingly great HCA scores and optical symmetry as well can draw this darkness which some do not find appealing when it comes to comparing super ideals.

2. Another reason may have been due to the length/shortness of the lower half facets. Certain combo's do not appeal to all viewers and stones with the "fatter arrows" may take on an appearance that's too dark to some observers. At our most recent Alumni meeting Al Gilbertson stated this in GIA's observation testing.

3. While this doesn't necessarily pertain to darkness under the table, when upper half (upper girdle) facets are cut to shallower angles (also known as painted girdles) this tends to draw more light from the hemisphere (greens in ASET) while classic girdles tend to draw more light from the higher angles (45-75 degree zone). When both sources of illumination are present you will generally get the weakest input from the hemisphere, hence more darkness around the upper girdle region which you can observe in the photographs.

There is yet another girdle type that will not qualify as well which is called "digging" or "dug out girdles". Most folks here might identify with the term "cheated girdles" which Garry refers to them as. These are some of the effects of minor facet cutting which impact cut grades, optical quality and diamond appearance.

Hope this helps.

The stone on the left in this picture is the painted girdle.

 

[Mara]

Actually the edge to edge stones didn't look brighter vs not to me and I didn't recall seeing darkness under the table. But the above posts re Eightstar and the others may suggest that?

In that image, you posted it DOES appear that the unpainted would appear a bit 'brighter' from a white light perspective. Do you feel like that is the case in stones you have seen?

For the purpose of this particular discussion it doesn't matter to me what GIA or AGS considers ideal or not, I just want to know what the experts feel regarding white light return with painted/tweaked vs untouched and how it would look to the naked eye. Non-discernable differences to consumers?

Other experts? I'd like to hear from more than just one person who has seen thousands of stones.

 

[Garry H (Cut Nut)]

Good post Rhino.

Lets see if Leonid can host a video for this demo?

 

[Mara]

Garry you can't just come in here and not give your opinion on this!!!!

What do you think? Do you agree with what Rhino noted?

Has anyone else seen both types of stones? Thoughts on white light return?

 

[Garry H (Cut Nut)]

Date: 11/12/2005 6:26:16 PM
Author: Mara
Garry you can''t just come in here and not give your opinion on this!!!!

What do you think? Do you agree with what Rhino noted?

Has anyone else seen both types of stones? Thoughts on white light return?

Bossy Boots

Talk about nag a bloke to death

I actually do not have much opinion as I hear all the rhetoric - but I know that people ''see'' the color in their diamond only when the diamond is tilted. In that case a great and bad cut do not make much difference to the percieved color.

I think it is an elitest enthusiast arguement of the type we heard many times when we had lots of active EightStar enthusiasts posting here.

BTW - how are they doing? Wink et al? We do not hear as much about them lately? And I noticed they stopped advertising. Pity for Richard he never got the HoF buy out - it enabled them to keep to their game plan and really ramp up distribution. But I guess that is the difference between a marketing based organization vs a product focused company?

 

[Leila]

I just want to add my experience. I have a pair of diamond studs. One diamond always seems to be a tad brighter and bigger than the other despite both having the same diameter. This is only noticeable when comparing them side by side. And it is obvious to my eye. This is the lightscope of the brighter, bigger looking diamond.

 

[Leila]

Here is the lightscope of the other diamond.

 

[Mara]

aww Garry you can''t blame a girl for trying to hear what the cut nut has to say!!

Leila that is very interesting, so in this case the tweaked/edge to edge light return stone does not appear as bright and big as the other one.

Can you take pictures of the diamonds side by side? I''m just curious to see if we could visibly see a difference in a photo. Maybe not.

 

[Garry H (Cut Nut)]

Date: 11/12/2005 7:58:04 PM
Author: Leila
I just want to add my experience. I have a pair of diamond studs. One diamond always seems to be a tad brighter and bigger than the other despite both having the same diameter. This is only noticeable when comparing them side by side. And it is obvious to my eye. This is the lightscope of the brighter, bigger looking diamond.

Yes Leile - side by side photo''s - you probably need to do quite a few - and some with normal dirt and some with just cleaned and dry - that would be great.

Even better still - if you can video them?

Are they the exact same diameter?

 

[Kaleigh]

Leila, If you could take pics side by side that would be great. I still am a little unsure of all this. That example would really help out alot!!!

 

[Leila]

Date: 11/12/2005 8:09:50 PM
Author: Garry H (Cut Nut)

Date: 11/12/2005 7:58:04 PM
Author: Leila
I just want to add my experience. I have a pair of diamond studs. One diamond always seems to be a tad brighter and bigger than the other despite both having the same diameter. This is only noticeable when comparing them side by side. And it is obvious to my eye. This is the lightscope of the brighter, bigger looking diamond.

Yes Leile - side by side photo''s - you probably need to do quite a few - and some with normal dirt and some with just cleaned and dry - that would be great.

Even better still - if you can video them?

Are they the exact same diameter?

You''re joking right?

Actually, I''ve tried taking pictures to capture the difference between them but it''s really tough. I don''t think any of the pictures are any good. And I took A LOT. The diamonds are either slightly tilted a certain way different from one another, maybe it''s the way I''m holding the diamonds or camera. But just for fun, I''ll post a couple anyway.

The diameters are 5.01-5.06 and 5.02-5.05.

 

[Mara]

I thought it would be fun next upgrade to get a more classic looking stone rather than the tweaked ones which is what I have had up until this point, but at the mercy of inventory and my own impatience...!! The one thing I did notice when comparing stones side by side (without thinking about asking or comparing tweaked vs not...!) is that the classic type edge leakage stones have more visible scintillation. Both were really beautiful obviously, but that was what my naked eye noticed.

 

[Leila]

One of the diamonds have a cluster of small black inclusions near the center of the table. It''s not visible to my naked eye majority of the time. But in certain lightings I can make it out very easily. Anyway, when I first got my earrings I thought the brighter, bigger looking diamond was the one that didn''t have the big inclusion on the table. I was pleasantly surprised that wasn''t the case.

 

[Mara]

Leila which is which in that photo? Are they both lined up the same in each picture? To me the one on the right looks a little bigger?

 

[MissAva]

Date: 11/12/2005 9:50:16 PM
Author: Leila
One of the diamonds have a cluster of small black inclusions near the center of the table. It''s not visible to my naked eye majority of the time. But in certain lightings I can make it out very easily. Anyway, when I first got my earrings I thought the brighter, bigger looking diamond was the one that didn''t have the big inclusion on the table. I was pleasantly surprised that wasn''t the case.

I would have thought the right stone in both pictures looked more appealing, but that is the one I think I see the inclusions in.

 

[Leila]

Yes, the diamond on the right in both pictures is the diamond that looks bigger and brighter to me.