Friendly discussion about bottomless buckets of dazzling ice

[Serg]

Re: Friendly discussion about bottomless buckets of dazzling

Serg,

We've sent two polisher partners over so far but never heard about a few of the other services - who would be the right person to talk to?

Joshua

Joshua,
Please use contacts from http://cutwise.com/about_us

 

[Garry H (Cut Nut)]

Re: Friendly discussion about bottomless buckets of dazzling

David,
Same diamond, same light, same lens, same focus plane( in to girdle)
difference is only in distance between lens and diamond that create difference in magnification and DOF.
So you do not need use "Soft focus" to show crispy facets with long ray path.

Serg,
I'm not sure what differences we are supposed to be seeing between these two images. Could you be more specific ?
Guessing here: Photo on left taken slightly further from lens with greater DOF and showing crisper focus of VF's, particularly inside table outline?

This looks like a very nice crushed ice cushion. How would you rate it for overall cut quality? And can you post ASET view so that we can translate what we are seeing in the photos?

Bryan,
Answers:
1)I try to show the difference in DOF( Depth of Field). On left image you can see more number of sharp VF's, because distance between lens and diamond is bigger. See attached photos with higher magnification for zone under table ( from same source photos).

2)Good enough for Crushed ice diamonds. This sample Garry selected for our Cut Study 5-7 years ago as best available( for his taste) . many people like such cut style because it has a lot of Scintillation. For my taste it has not good enough uniform VF's pattern ( cluster with big VF''s in one( if we account symmetry) zone and very small VF's in other zones). Also this cuts does not catch enough light from high angles( Red zone in ASET)

ASET, IS photos, different movies you can find here http://cutwise.com/stone/6_MSSCUSHION0?format=asetWhite. all MSS diamonds are available now on cutwise.com with 4 type movies and different photos.

Thanks, very helpful.

I'm posting the ASET from your page just for reference here. You can certainly see that it is drawing a lot of low angle light. But the ASET signature is interesting in that the light return is well mixed. What red is there is dispersed along with leakage in non-contiguous areas which I presume adds some positive contrast and scintillation.



Do you happen to have an example of a crushed ice cushion that is more to your taste? i.e. more red, more uniform VF's?

Correction, I selected this stone as a sample for crushed ice. There are better stones (crushed ice that is) available now that are the designs used for fancy colour enhancement.

 

[RADIANTMAN]

Re: Friendly discussion about bottomless buckets of dazzling

Garry - do you agree that the ideal "crushed ice" look for fancy colors is different than the ideal for white diamonds? IMHO white diamonds require more contrast to maximize the appearance of brilliance while fancy yellows require less contrast to maximize the evenness and intensity of color. This involves the use of different angles (especially flatter pavilion mains) for fancy colors. The ASET signatures of what is considered a well cut crushed ice fancy yellow diamond and a well cut crushed ice diamond should be a bit different.

 

[Texas Leaguer]

Re: Friendly discussion about bottomless buckets of dazzling

Garry - do you agree that the ideal "crushed ice" look for fancy colors is different than the ideal for white diamonds? IMHO white diamonds require more contrast to maximize the appearance of brilliance while fancy yellows require less contrast to maximize the evenness and intensity of color. This involves the use of different angles (especially flatter pavilion mains) for fancy colors. The ASET signatures of what is considered a well cut crushed ice fancy yellow diamond and a well cut crushed ice diamond should be a bit different.

That would certainly make sense to me. The goals of the facet design are conflicting to a significant degree. I would expect a well cut fancy color to have minimal red in ASET as high brightness would make body color appear less saturated. I can also see the point about minimizing contrast to achieve more evenness of color.

 

[Rockdiamond]

Re: Friendly discussion about bottomless buckets of dazzling

This subject has been very thought provoking.
I will throw a few ideas out for discussion.
1) What is an "Ideal Cut"?
IMO, at this point the term is a commercial label, as opposed to a gemological descriptor. We can't begin to count how many sellers are using this term.
"Ideal Light Performance" "Ideal Cut" Ideal Proportions" etc

2) As opposed to a "pinnacle", IMO the top grade should be a plateau.
A criticism of GIA's cut grade is that it's too wide- but it does avoid the pinnacle approach taken by AGSL, better or worse.
And that's only considering a round diamond.
When considering a round diamond, cut assessment has so much less room for taste and judgement.
We all know exactly how it's supposed to look, to the 98th percentile.

We can't same the same for Cushion, or Radiant Cut, or Princess, or Pear Shape.....heart, you name it.
I know that for myself, I have found amazing examples of Radiant and cushion cuts that broke free of the formula, with amazing results.
Stan cuts amazing Radiant Cut diamonds.
Among the best cut radiant cuts out there IMO.
But there are a select number of others also cutting amazing Radiant diamonds, and some have a slightly different formula than Mr Grossbard's

3) Should a crushed ice stone have contrast areas?
Is a consistent scintillation better than one that is less consistent for that reason alone?


4) how different are FCD's to colorless, and how similar?

I don't claim to have the answers- but these are important questions.

 

[Rockdiamond]

Re: Friendly discussion about bottomless buckets of dazzling

Garry - do you agree that the ideal "crushed ice" look for fancy colors is different than the ideal for white diamonds? IMHO white diamonds require more contrast to maximize the appearance of brilliance while fancy yellows require less contrast to maximize the evenness and intensity of color. This involves the use of different angles (especially flatter pavilion mains) for fancy colors. The ASET signatures of what is considered a well cut crushed ice fancy yellow diamond and a well cut crushed ice diamond should be a bit different.

That would certainly make sense to me. The goals of the facet design are conflicting to a significant degree. I would expect a well cut fancy color to have minimal red in ASET as high brightness would make body color appear less saturated. I can also see the point about minimizing contrast to achieve more evenness of color.

Cutters have told me that the differences are stark- yet I have noticed a lot of similarities in light performance of FCD and colorless crushed ice stones.
Specifically with regards to red in ASET in any crushed ice: large concentrated areas of red are a problem= translating to overly dark areas in real life.

 

[RADIANTMAN]

Re: Friendly discussion about bottomless buckets of dazzling

In addition to the diamonds I sent to the AGSL, I sent a couple of diamonds today to Sergey and the Cut Group to help with their research. I'm looking forward to sharing their analysis.

David - the difference in how fyd's and colorless crushed ice diamonds ought to be cut (in my opinion) is relatively subtle - primarily 2-4 degrees flatter on the pavilion mains, which will mean that fyd's will "leak" more by design. That's why as you know as well as any of us since fyd's are your specialty, the color of fyd's can be deepened by reflected yellow in from the setting - the "leakage" actually enables you to enhance the appearance of the diamond when its set.

Some people like that same look in colorless stones. I personally prefer the pavilion mains on a higher angle to increase contrast. I agree completely that concentrations of black which arise when the pavilion mains are too high or if the bottom halves are dug out and often appear red or blue in the ASET are not desirable characteristics meaning more red or blue is not a good thing in all cases. The elements of contrast (including the proper amount of leakage) should be disbursed throughout the diamond, not concentrated in any one area.