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

[JohnQuixote]

Date: 11/11/2005 12:07:21 PM
Author: 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.

Hey Mara, thank you for asking for my input here. I was away for a few days and appreciate your patience.

To your original question: “Does tweaked girdle or edge to edge light return possibly make a lower color stone face up whiter?” The answer is no as far as the tweaked/treated girdle goes. A well-cut diamond returns light based on how well it is proportions, particularly crown and pavilion angle combinations, work together, and can be influenced by how clean or dirty the diamond is. So, a J is a J is a J, but if it has great proportions it may face up whiter because the amount of light returned masks body color.

Brace yourself for my 'different lighting conditions' input.

Those conditions do make manifest differences in appearance related to the diamond’s minor facet configurations (lower girdles especially), as well as how well-patterned it is.

A ‘tweaked’ girdle done in the style of cutting you’re talking about primarily influences the quality of the scintillation, not the overall look of the diamond and not diamond ‘darkness,' at least not in those I am accustomed to dealing with.

 

[JohnQuixote]

Date: 11/13/2005 1:43:04 PM
Author: Mara

Side by side when we viewed a few diamonds at WF...seriously I couldn't pick out anything, at least not until I closed my mouth and wiped off the drool. I hadn't thought of this question then but next visit I will have to spend some time trying to see if I can tell a difference with my eyes. Based on the images and Leilas where the diameters of the diamonds are the same average, it seems like the difference is there, but side by side slightly visible which may not necessarily correlate well to 'regular' viewing...unless you have diamonds side by side on a ring.

Your eyes were correct - it can't really correlate well to regular viewing. This is because diamonds are dynamic, not static. They are seen in motion, and the performance qualities that differ in these diamonds are those of dynamic contrast versus dynamic fire. Top-cut diamonds with tweaked girdles draw light from angles that are close to each other, thus they have a more matched, flowing and broadfire dispersion. Those with some contrast leakage draw light from angles that vary more, so there is a sharper on/off quality with slightly less color and more light versus dark.

Of course, in top cuts these nuances are very slight. Some of this discussion goes under the heading of: "Differences become more exaggerated in writing than in real-life."

Just as you cannot make realistic color determinations from a photo, performance qualities in a diamond cannot be judged from a static photo. I’m intrigued by the idea of video, though in order to keep it objective there are questions of standardization that arise: Home video presented as if it were scientific research just won’t cut it.


Edited to add: I want to be clear that my last answers to Mara deal with diamonds of premium cut, such as she inquired about in the original post - which was about face-up color. In a controlled situation where specific design is followed and quality controls are in place the painting technique discussed in this thread can be used to create tight relationships between main crown and upper girdle (and main pavilion and lower girdle) angles, resulting in almost no light leakage. Premium cuts that have careful attention using these techniques are considered by many to be among the finest cut diamonds in the world.

 

[JohnQuixote]

Date: 11/13/2005 2:37:11 PM
Author: Rhino

Haha... I know you're not picking on him. I was just using Garry's terminology. Amen to Garry wanting people to think outside the box!!! Also, this discussion doens't necessarily petain to elitist types of stones Mara... ie. super ideals. There are tons of stones on the market that aren't even ideal that have these painted and dug out girdles. This conversation actually applies to *all diamonds* and is not just limited to super ideals. Matter of fact it would probably apply less to super ideals and more towards regular ideals and standard type rounds. Factories looking to save weight in their cutting (which constitutes many) incorporate some of these techniques.

Righto. The original post specifically identified premium cuts, but some of the later information refers, as indicated, to more average diamonds. It's important to state that this thread has meandered from the original question of face-up color into speculation that relates neither to color appearance or the brands mentioned.

The separate topic, ‘cheated’ girdles – digging of deep diamonds in particular - may adversely influence performance and hide weight, but this cheating happens mainly in pedestrian cuts, away from the sort of diamond we see routinely on Pricescope. Such diamonds would be screened by good vendors.

It does not appear to have been explained to browsing consumers what digging and painting are, and how these techniques relate to the term 'cheating?' We need to know what digging and painting are. How are they defined and at what angular relationship? What would be the reason to use one technique or the other? What is the actual procedure used for each? What is the result in an adverse sense? What is the result in a positive sense? I’ll work on some examples/diagrams over lunch.

It might also be helpful to separate terms here, as one automatically implies something negative:

‘Cheating’ a girdle is a term to describe girdle treatment (either digging or painting) where the adjustment is done for the sole purpose of saving size or girdle thickness cut grade.

‘Tweaking’ a girdle (as in Mara's title for the thread) is a term we have used to describe treatment, such as with New Line ACA or Eightstar, that is not necessarily used to save weight (though it may), and is used to make the diamond attractive.

 

[Lynn B]

Date: 11/15/2005 2:31:40 PM
Author: JohnQuixote

Date: 11/13/2005 2:37:11 PM

...It does not appear to have been explained to browsing consumers what digging and painting are, and how these techniques relate to the term 'cheating?' We need to know what digging and painting are. How are they defined and at what angular relationship? What would be the reason to use one technique or the other? What is the actual procedure used for each? What is the result in an adverse sense? What is the result in a positive sense? I’ll work on some examples/diagrams over lunch.

Ooooh, yay! I'll really look forward to that, because (I have to confess...) this thread has me scratching my head (more than) a little bit! Thanks, John!

 

[aljdewey]

Date: 11/15/2005 2:13:50 PM
Author: JohnQuixote


Some of this discussion goes under the heading of: ''Differences become more exaggerated in writing than in real-life.''

This is SO on the money, it deserves repeating:

''Differences become more exaggerated in writing than in real-life.''

Words to live by.

 

[JohnQuixote]

Date: 11/15/2005 2:45:31 PM
Author: Lynn B

Ooooh, yay! I'll really look forward to that, because (I have to confess...) this thread has me scratching my head (more than) a little bit! Thanks, John!

Lynn, that's unfortunate but understandable. You’re not alone - A customer emailed me yesterday, pointing to this thread and wondering if he had cause for concern as well. No worries after we spoke, but I fear for the silent fearful. Alj - I guess I need to put that in my signature.

I worked up an overview on these girdle treatments (digging and painting) and their proper use (tweaking) and misuse (cheating) for the FAQ. I hope it will serve to de-escalate any apprehension caused by discussions in this thread.

Link to https://www.pricescope.com/communit...rdles-tweaked-girdles-digging-painting.36102/

 

[Lynn B]

Thanks John! I read your new thread in the FAQs forum... wow! That is so comprehensive - thank you very much for all your time and hard work with that!

Lynn