Do ECs face up whiter?

[Karl_K]

Pear

 

[Karl_K]

same as the EC and SE above but different ratio:

 

[Karl_K]

marquises


Note these are computer generated images using the same color material for the calculations.
Changing the cut parameters will change the results.
Some less color some more, some more even some less.

 

[Karl_K]

all 3 in one post

 

[Karl_K]

6x6mm vs 9x9mm. Long ec above is modeled as 9x6mm.

 

[Karl_K]

What I find interesting is the difference between the EC and SE both at 9mm.
The more complex light paths in the SE is likely the best explanation.

Thank you to the OP for posting this thread and those that asked questions.
This is fun and I am learning stuff right along with you.
While I have played with this before, I haven't really thought this deeply about it until now.

 

[Rockdiamond]

Kewl Karl!!
One thing I've noticed is how a Pear Modified Brilliant can deal with the color inequities.
I'll leave it to you to explain the science behind it- but the "crushed ice" of a stone like this one allows the cutter to even out color.
Would it be basically removing contrast, and introducing leakage?

 

[Rockdiamond]

For comparison, this is a Pear Brilliant- both stones were graded Fancy Intense Yellow by GIA. I suppose the PB looks like it has somewhat of a bowtie in the picture.
In person the flashing was rapid, so you didn't have a sense of darkness there.
Without a doubt, there's more color at the top and bottom. It just wasn't an.....unpleasant phenomenon.

 

[Matthews1127]

On the other hand.....

Oh....Octavia....*drool*....

 

[Matthews1127]

@Karl_K:
I’m curious what the scale variation requires, as far as cutting rough: larger diamonds v. smaller diamonds.
It’s my understanding that the Octavia has not been cut under 0.50 points, yet.
Do you foresee that changing?
I’d kill to customize an Octavia Eternity band with 0.30-0.40 pointers...if they ever exist.
Thoughts? Knowledge? Explanation, please?
If you prefer to address this off the forum, l an give you contact info for me, rather than Hijack a thread. The fact that we are discussing cut & color....I’m curious about cut & size....

 

[Rockdiamond]

Hi Matthews1127!
I hope you don't mind me answering part of the question- because I've already asked Yoram to cut smaller ones.
Small Octavias are not likely to be cut. The reason is the amount of time necessary to guarantee the optical precision would not be less on a small stone.
Therefore the labor costs would make the prices...crazy.

 

[Rockdiamond]

Back to the discussion about even color.
In general, most Marquise we've seen are "Marquise Brilliant"
This little puppy was "Marquise Modified Brilliant"
It managed to have a very even color...and she was a very large puppy....

 

[Matthews1127]

Hi Matthews1127!
I hope you don't mind me answering part of the question- because I've already asked Yoram to cut smaller ones.
Small Octavias are not likely to be cut. The reason is the amount of time necessary to guarantee the optical precision would not be less on a small stone.
Therefore the labor costs would make the prices...crazy.

I had inquired with Jonathan at GOG, last year, and, at that time, they were not able to cut them that small, but they had high hopes to make that happen.
Now that Jon has moved on, on his own, l wasn’t sure what had become of the idea.
Thank you for your reply; that was my dear: exponential price increase...which makes sense, under the circumstances.

 

[Karl_K]

I had inquired with Jonathan at GOG, last year, and, at that time, they were not able to cut them that small, but they had high hopes to make that happen.
Now that Jon has moved on, on his own, l wasn’t sure what had become of the idea.
Thank you for your reply; that was my dear: exponential price increase...which makes sense, under the circumstances.

We revisit it from time to time to see if there are any changes in technology that would allow us to cut them at a profitable level.
So far there hasn't been.

 

[Matthews1127]

We revisit it from time to time to see if there are any changes in technology that would allow us to cut them at a profitable level.
So far there hasn't been.

Much appreciate it, @Karl_K! Please consider reaching out to me, if you don’t mind, if technology becomes available, and those beauties can be cut between 3-5mm squared!! That is a HUGE wish list item of mine!!
Thank you for responding.

 

[Karl_K]

Kewl Karl!!
One thing I've noticed is how a Pear Modified Brilliant can deal with the color inequities.
I'll leave it to you to explain the science behind it- but the "crushed ice" of a stone like this one allows the cutter to even out color.
Would it be basically removing contrast, and introducing leakage?

They lengthened the light paths side to side, breaking up the big virtual facets.
There are a lot of little things that make up the art of making color even and darker that only someone who cuts them would know and they are not talking.
There is a lot of closely held shared experience that goes into them.
Software can make it faster but it still takes knowledge.

 

[MarionC]

Great thread!