Fancy yellow diamonds - leakage and color

[GreenBling]

I have a FLY that is rather shallow (58.5) and with big table (65). I have it set in double halo of white diamonds. Underneath the FLY is a yellow gold plate that the jeweler suggested to place there to enhance the stone's color. Outcome - the stone when set looks like a FY.

I read that a stone would face up whiter if cut well. could the big table combines with shallow cut somehow created an opposite effect? Or could that combination have enabled the color from the yellow gold plate beneath came through, therefore creating the illusion that the stone has more intended color than it is? Could leakage have effect on color?

I love the ring, no intention of returning or upgrading whatsoever. Just want to learn. Thanks in advance for your input.

 

[chrono]

It is more than a table size in relation to depth that concentrates colour. In fact, generally, the deeper the stone, the deeper the colour. It is likely that your stone is shallow because the rough was shallow. The facet lengths, combination of crown and pavilion angles and more are what is required to "hold" colour in a gemstone. Cutting to remove colour and cutting to accentuate colour means that these angles and designs will be different.

I agree that the plate underneath plays a role in helping reflect a stronger yellow colour back to the eye and also deepens it too.

 

[kenny]

A well-cut white diamond returns as much light back out the top as possible.
Though white diamond color is graded looking into the SIDE the WEAKER the color grade the higher the profit from white rough.

On the other hand a colored diamond is usually cut to strengthen the color as much as possible.
That usually means forcing the light to bounce back and forth with in the colored body material as many times as possible before it is directed to come out the top, because looking down into the TOP is how the color is graded IN FCDs.
The STRONGER the color grade the higher the profit from colored rough, just the opposite as white diamonds.

 

[GreenBling]

On the other hand a colored diamond is usually cut to strengthen the color as much as possible.
That usually means forcing the light to bounce back and forth with in the colored body material as many times as possible before it is directed to come out the top, because looking down into the TOP is how the color is graded IN FCDs.
The STRONGER the color grade the higher the profit from colored rough, just the opposite as white diamonds.

"...bouncing back and forth within the colored body material..." -- Is radiant cut designed to achieve this? I was told by the salesperson that radiant outperforms other cuts in "holding" the color.

 

[kenny]

On the other hand a colored diamond is usually cut to strengthen the color as much as possible.
That usually means forcing the light to bounce back and forth with in the colored body material as many times as possible before it is directed to come out the top, because looking down into the TOP is how the color is graded IN FCDs.
The STRONGER the color grade the higher the profit from colored rough, just the opposite as white diamonds.

"...bouncing back and forth within the colored body material ..." -- Is radiant cut designed to achieve this? I was told by the salesperson that radiant outperforms other cuts in "holding" the color.

Well it is one thing that does happen in a radiant, perhaps moreso than most other cuts.
Whether it was "designed" to do that I can't say, though it is an characteristic I'm sure the designer was aware of.
In white diamonds it's a bad thing; a piece of rough that might have gotten an F if cut into an emerald cut may get a G or lower as a radiant and be less valuable.

In fancy colored diamonds that bouncing back and forth is a good thing.
A piece of pink rough that might have gotten a Fancy Intense Pink grade as an emerald cut might get a Fancy Vivid Pink grade if cut into a radiant and be more valuable.

I'm not sure I'd call it "holding" the color - though you could argue the light is "held" in the diamond for a longer period of time as it travels a greater distance before finally coming out the top.

 

[GreenBling]

the jeweler who set my FLY with a YG plate under it said that "this plate method don't work the same on every stone". I did not ask him at the time why. Would that have anything to do with how the stone is cut? proportions?

 

[GreenBling]

@kenny, sorry for my never ending stream of questions...

apart from strengthening the color, what other effect does "longer time in the diamond" have on colored diamond, e.g. the fire? brilliance?

 

[kenny]

@kenny, sorry for my never ending stream of questions...

apart from strengthening the color, what other effect does "longer time in the diamond" have on colored diamond, e.g. the fire? brilliance?

Fire is white light being broken up into its component colors like with this simple prism.



That happens in a diamond when the angle between a facet and light rays is just right.
With more facets and virtual facets, a radiant should potentially have more opportunities for this to happen than an emerald cut, BUT each flash in a radiant will be much smaller than the flashes in an emerald cut. Naturally it will happen more if the diamond (of any shape) is well cut.

Brilliance IMHO is how bright a diamond is, or how well it returns light out the top and to your eyes as opposed to letting it leak out the bottom or sides, when viewed in soft lighting conditions such as mid day under a sky of solid white clouds - where there will be no fire.

The length of time the light is in a diamond does not necessarily have anything to do with either fire or brilliance.

A radiant can be cut well or poorly.
I think of a well-designed cut as a recipe and a bad cook can botch up a good recipe.
If a skilled cutter manages to follow all the proportions and polish the facets where a smart diamond designer intended the diamond will perform well.

If the cutter does a poor job of following a good recipe that's not the cut designer's fault.
Also, if the cutter does a perfect job following exactly what the Profit-driven cut designer wants (save weight and light performance be dammed) that's not the cutter's fault.

As to exactly what defines a well-cut radiant, that can of worms is 10 times bigger than the can of worms for round diamonds.
Personally I'd get properly taken ASET pics and post them here and let the community comment.

 

[Rockdiamond]

I have a FLY that is rather shallow (58.5) and with big table (65). I have it set in double halo of white diamonds. Underneath the FLY is a yellow gold plate that the jeweler suggested to place there to enhance the stone's color. Outcome - the stone when set looks like a FY.

I read that a stone would face up whiter if cut well. could the big table combines with shallow cut somehow created an opposite effect? Or could that combination have enabled the color from the yellow gold plate beneath came through, therefore creating the illusion that the stone has more intended color than it is? Could leakage have effect on color?

I love the ring, no intention of returning or upgrading whatsoever. Just want to learn. Thanks in advance for your input.

Hi Green- part of the problem with a lot of information is that much of it can be misleading.
A diamond is so complex in terms of actual shape and light path, that trying to make assumptions based on measurements will likely give you incorrect impressions. In other words, two FLY diamonds of 58.5/65 can have drastically differing appearances.

"A well cut diamond faces up whiter" is a commonly repeated, yet misleading statement.

"Leakage" is another widely misunderstood characteristic of diamonds. EVERY diamond "leaks" light.
If it didn't it would be a mirror.
Do you notice any static dark areas in your stone?
It's going to have brighter and darker areas- what might be seen as a detriment is if there's dark areas that stay dark through a range of motion.

"Brilliance" is another concept that's widely misunderstood, as it relates to diamonds.
A well cut Round Brilliant is the "brightest" of all diamond cuts.
Yet, there are people who'll see the type of sparkle that a well cut radiant posseses and percieve that to be brighter than the RBC. We can use science to prove the RBC does return the brightest light.
What we can't prove is that such a distinction is most attractive to observers.

My advice to you is to first use your eyes to tell us what you see- and maybe we can identify if there's a problem.

Trying to use information garnered off internet searches to apply it to your own situation can be problematic in terms of your peace of mind.
The ONLY way to be able to grasp these concepts for yourself is hands on experience.

 

[GreenBling]

Thank you kenny, Rockdiamond and Crono for sharing your knowledge.

I am not into purchasing another diamond 'yet'. Really just want to learn more about how different cuts perform/tend to perform in general. the knowledge is enabling me to appreciate diamonds so much more!

I am developing interest in the AVR. I will be asking questions (with photos) as soon as i secure the fund for it

 

[kenny]

Thank you kenny, Rockdiamond and Crono for sharing your knowledge.

I am not into purchasing another diamond 'yet'. Really just want to learn more about how different cuts perform/tend to perform in general. the knowledge is enabling me to appreciate diamonds so much more!

I am developing interest in the AVR. I will be asking questions (with photos) as soon as i secure the fund for it

You're welcome.

If by AVR you are referring to Good Old Gold's August Vintage Rounds I'm sure every one is superbly cut to meet the brand's strict cut standards.
I've bought from GOG and they are very reputable.