Colorless vs Fancy Colored ASET comparison- similarities?

[Rockdiamond]

It's often said that Fancy Colored Diamonds are cut with different goals, and are therefore cut differently that colorless diamonds.
In some regards, I agree- in others not so much.
Above are ASET on two stones that I consider to be extremely well cut.
Both show tremendous scintillation ( sparkle)
The FCD is a prime example of a stone that exhibits that much maligned term "crushed ice".
The colorless diamond would be considered very well cut by many in the field.

For sure there are differences we can see in the ASET.
I notice the difference in brillinadeering (sp). The facets are "painted" on the pavilion of the Fancy Colored Diamond.
The facets on the pavilion are sharper ( cut to a steeper angle) in the colorless stone- producing greater contrast.

Both stones use leakage to great advantage IMO.
This is shown in the ASET

I'd be very interested in everyone's thoughts on other similarities and differences.

 

[Dancing Fire]

Re: Colorless vs Fancy Colored ASET comparison- similarities

Both stones use leakage to great advantage IMO.
This is shown in the ASET

I'd be very interested in everyone's thoughts on other similarities and differences.

David
How can leakage be an advantage?...

 

[Texas Leaguer]

Re: Colorless vs Fancy Colored ASET comparison- similarities

It's an interesting topic David.

There is a definite difference in the ASET signatures between the two stones that fits well with the one on the top being a fancy color. Brightness can be a detriment to perceived color depth in a fancy and leakage can be beneficial. You see a lack of red (high intensity light return has been dialed down in the facet design) with quite a bit of leakage in the ASET of the fancy color.

The white stone has been cut for more brightness and that difference in clearly evident in the higher percentage of red in its ASET view.

 

[Rockdiamond]

Re: Colorless vs Fancy Colored ASET comparison- similarities

Great question DF.
Thanks for chiming in Byran!
I am genuinely looking to learn, and discuss the technical reasons why the ASET looks as it does on both these diamonds.

To me, both seem to show a lot of leakage in ASET. I think the colorless stone shows even a bit more white than the FCD... although that could have to do with the body color of the diamond. But both show leakage- do you agree Bryan?
Neither is gathering a large amount of light from the higher angles, although there's more red in the colorless stone.
I do find it interesting as both show a very "sparkly" and bright appearance in real life - in spite of the leakage shown in ASET.
Therefore leakage is an element of their brilliance and sparkle and scintillation.

It's fertile ground for learning IMO.

 

[Karl_K]

Re: Colorless vs Fancy Colored ASET comparison- similarities

what would be interesting is block light from the pavilion and take photos in different lighting.
office, home with side lighting and sunlight.
With that much white in ASET any light hitting the pavilion is going to throw off showing what the stone is actually doing.
Judging diamonds just by ASET is something I don't do so if you want more input more data is needed.

 

[Rockdiamond]

Re: Colorless vs Fancy Colored ASET comparison- similarities

Great point about trying to judge based on ASET only- I'm working on that now Karl.
I promise, I'm not trying to "catch" anyone- it really is interesting to me.
About blocking the pavilion to photograph- personally I feel that's going to provide inaccurate photographic info.
Very few settings block the pavilion completely.

 

[Karl_K]

Re: Colorless vs Fancy Colored ASET comparison- similarities

Great point about trying to judge based on ASET only- I'm working on that now Karl.
I promise, I'm not trying to "catch" anyone- it really is interesting to me.
About blocking the pavilion to photograph- personally I feel that's going to provide inaccurate photographic info.
Very few settings block the pavilion completely.

it gives a truer picture of what the facets of the diamond are doing if you block it.
Taking gemological useful images is not a fashion shoot.

 

[chrono]

Re: Colorless vs Fancy Colored ASET comparison- similarities

Great point about trying to judge based on ASET only- I'm working on that now Karl.
I promise, I'm not trying to "catch" anyone- it really is interesting to me.
About blocking the pavilion to photograph- personally I feel that's going to provide inaccurate photographic info.
Very few settings block the pavilion completely.

it gives a truer picture of what the facets of the diamond are doing if you block it.
Taking gemological useful images are not a fashion shoot.

And when a ring is worn, the finger also blocks out a good bit of light from the back.

 

[Rockdiamond]

Re: Colorless vs Fancy Colored ASET comparison- similarities

Karl- when you say blocking the pavilion gives a truer picture of what the facets are doing, how?

I agree that "glamour shots" may or may not be helpful, but not all detailed pics are like that.

 

[Rockdiamond]

Re: Colorless vs Fancy Colored ASET comparison- similarities

Hi Chrono!
How much light is blocked depends heavily on the style and construction of the setting.
Many settings allow a lot of light through the pavilion.

 

[chrono]

Re: Colorless vs Fancy Colored ASET comparison- similarities

But that is from the side only; the finger is still blocking the back unless I happen to be Mr/Ms Invisible.

 

[Karl_K]

Re: Colorless vs Fancy Colored ASET comparison- similarities

But that is from the side only; the finger is still blocking the back unless I happen to be Mr/Ms Invisible.

Rofl!!! You rock.

 

[Rockdiamond]

Re: Colorless vs Fancy Colored ASET comparison- similarities

Chrono,
If you turn a diamond upside down, there's very little "bottom" on most diamonds- the culet is the "bottom" of the stone,but occupies so little surface area.
The vast percentage of the area below the girdle of a diamond is more like "side" versus" bottom.

 

[Rockdiamond]

Re: Colorless vs Fancy Colored ASET comparison- similarities



the photo above demonstrates what I mean.
There's a bit of structure blocking the pavilions, but they can still pick up a lot of light.

 

[Texas Leaguer]

Re: Colorless vs Fancy Colored ASET comparison- similarities

the photo above demonstrates what I mean.
There's a bit of structure blocking the pavilions, but they can still pick up a lot of light.

I see what you are illustrating, but this type setting is not as popular today. Styles have moved towards halos and side profile design elements, etc.
But what I find really interesting about the photo is that it appears you can actually see the leakage happening in the diamond on the left! It looks like light rays coming out of the pavilion (unless that is lint or something).

 

[Karl_K]

Re: Colorless vs Fancy Colored ASET comparison- similarities

If you don't want to block it then hold the diamonds over some bright blue or red Mylar when you take the pic.

 

[Rockdiamond]

Re: Colorless vs Fancy Colored ASET comparison- similarities

I think what you're seeing Bryan is ....hair on the model's finger

Here's a thoroughly modern setting ( although our experience is that 3 stones rings are indeed still quite popular and "modern")

You can see how much light can potentially enter into the pavilion of the diamond.

 

[Rockdiamond]

Re: Colorless vs Fancy Colored ASET comparison- similarities

If you don't want to block it then hold the diamonds over some bright blue or red Mylar when you take the pic.

Karl, again, I promise I'm not trying to argue, or trick anyone. I want to understand where you're coming from- why is holding the diamond over something red or blue relevant to real life performance?

I mean, isn't the goal to photograph a diamond to produce a photograph that depicts as closely as possible what the diamond actually looks like?

 

[Texas Leaguer]

Re: Colorless vs Fancy Colored ASET comparison- similarities

If you don't want to block it then hold the diamonds over some bright blue or red Mylar when you take the pic.

Karl, again, I promise I'm not trying to argue, or trick anyone. I want to understand where you're coming from- why is holding the diamond over something red or blue relevant to real life performance?

I mean, isn't the goal to photograph a diamond to produce a photograph that depicts as closely as possible what the diamond actually looks like?

What I understood him to say is that he would be interested in seeing the stone in a more diagnostic mode and in different lighting environments. Blocking the light entering the pavilion and photographing it in different lighting scenarios would be informative of how the facets are processing light. (nobody said you were trying to trick anyone ...)

 

[Rockdiamond]

Re: Colorless vs Fancy Colored ASET comparison- similarities

Point well taken Brian.
I agree that it's important to use a variety of lighting scenarios.

Back to blocking the pavilion: maybe part of the issue I've always had with reflector technology in general is that it ignores light entering through the pavilion- which may be more of a factor in Radiant and Cushion diamonds cut for max scintillation ( aka crushed ice)

But again the point is well taken about a scientific methodology which requires a clinical approach.
I just don't agree a methodology that blocks the pavilion in photography does that.
There's zero doubt in my mind that what we call leakage- ( white in the ASET) is beneficial to FCD's and colorless stones cut with these goals. The ASET proves it- but not in such a way that we can easily quantify this characteristic.

Another point that goes to my statement about beneficial leakage: when a diamond IS set with the pavilion completely closed in, the life of the diamond is adversely affected in many cases.
You see a lot of FCD's set into closed cup rings- and my personal feeling is that the stone looses a lot of it's brilliance, sparkle, life, whatever you want to call it when you completely enclose the pavilion.

 

[Karl_K]

Re: Colorless vs Fancy Colored ASET comparison- similarities

sheesh it doesn't have to turn into a federal case, take em however you want.
Just don't be surprised if you get told no useful info can be gained from those pictures if anyone bothers to reply at all.

 

[Rockdiamond]

Re: Colorless vs Fancy Colored ASET comparison- similarities

I get your point Karl- if I can take a picture without something behind, I can also put something behind the diamond to allow you, and others used to looking that way to compare.
This is an interesting discussion for me- causing me to re-evaluate things.
Looking at it now, there's two stones on my desk that highlight what happens when you close off the pavilion.
An RBC, and a "crushed Ice" cushion, that has a lot of white in ASET- leakage.
The RBC is horribly cut - which makes it even more apparent that the design itself of the RBC performs far better if the pavilion is blocked.
Both diamonds are in capsules with white foam backing.
Under these circumstances, there's just no comparison in liveliness and sparkle.
Removing both stones from their capsules, and resting them on my fingers, and all of a sudden we have a horse race in terms of liveliness and brilliance.

 

[Rockdiamond]

Re: Colorless vs Fancy Colored ASET comparison- similarities





This pic illustrates a bit of what I'm talking about.
In the capsule, with the pavilion entirely closed in, you can hardly even see the cushion- yet the round is kicking back some bright reflections.
On my finger, there's not a whole lot of light coming in the pavilion, yet the cushion has come alive.
Both pics taken in the same lightbox.

 

[Serg]

Re: Colorless vs Fancy Colored ASET comparison- similarities

This pic illustrates a bit of what I'm talking about.
In the capsule, with the pavilion entirely closed in, you can hardly even see the cushion- yet the round is kicking back some bright reflections.
On my finger, there's not a whole lot of light coming in the pavilion, yet the cushion has come alive.
Both pics taken in the same lightbox.

was main Light source from girdle direction?( or light source direction is between girdle plane and diamond axis)
Light on top, table diamond is vertical, view direction is horizontal ? or slightly tilt together ?

 

[Rockdiamond]

Re: Colorless vs Fancy Colored ASET comparison- similarities

Hi Serg,
The light box has lighting coming from all sides, except directly below.

 

[Serg]

Re: Colorless vs Fancy Colored ASET comparison- similarities

David,

you need read discussions about DiamondDoc light( it was in 2006 year on PS)
https://www.pricescope.com/community/threads/how-lighting-can-influence-on-grade-appearance.38583/

https://www.pricescope.com/community/threads/gia-diamond-dock-simple-summary.42538/

DiamondDoc light is turn off on upper image and turn on for lower image
round diamond become bright when you turn off DiamondDoc light.

you need compare diamonds in more realistic ( consumer) light environments

 

[Texas Leaguer]

Re: Colorless vs Fancy Colored ASET comparison- similarities

David,
I am not sure how this relates to the topic that you started. I thought it was going to be a discussion about fancy color diamonds and how their ASET signatures differ from those of diamonds in the normal range. I was looking forward to learning more about that.

 

[Rockdiamond]

Re: Colorless vs Fancy Colored ASET comparison- similarities

I get your point Bryan- the aspect of lighting is a tangent- yet if we want to compare we do need to look at the stones how we do that is actually central to the issue.
Serg- we agree that consumers benefit from realistic pictures.
Karl suggested closing the pavilion which is why I took the photos I did above.
In fact a lot of sellers do close off the back of the stone in photography so it is relevant.
Part of what I see as the similarities of FCD and colorless diamonds has to do with leakage- the pics show how even a little light to the pavilion of a leaky stone helps tremendously.