Technical diamond industry info for nerds

[Garry H (Cut Nut)]

I just read this and can hardly find fault. Excellent research and writting:
https://mgtheboss.blogspot.it/2017/02/93-these-diamond-cutting-software.html?m=1

"There are software solutions which are used in the diamond industry for cutting diamonds. These applications have achieved worldwide reputation and have become indispensable to diamond merchants. What makes these applications different from the applications we use in our daily lives is precision.".................

 

[VRBeauty]

A couple of questions come to mind.

When it comes to rounds, at least, the cut parameters that will yield an "excellent" cut rating are well known. Why aren't all stones cut to these parameters? In this age of computerization, does the skill of the cutter still come into play?

Does the orientation of the stone, relative to orientation of the original diamond crystal, play a factor? In other words, would all stones cut with ideal angles and proportions have ideal light performance? Is it possible to cut a diamond that has ideal angles etc. but less than ideal light performance?

 

[Karl_K]

A couple of questions come to mind.

When it comes to rounds, at least, the cut parameters that will yield an "excellent" cut rating are well known. Why aren't all stones cut to these parameters? In this age of computerization, does the skill of the cutter still come into play?

The skills of the cutters and the quality of the process are even more important to producing consistent high performance level products. The tech and the better tools are needed, but it still all comes down to skill and process to execute.

Does the orientation of the stone, relative to orientation of the original diamond crystal, play a factor?
Stones are cut from more different angles relative to the rough than ever before. This is where computer mapping plays a big part.
In other words, would all stones cut with ideal angles and proportions have ideal light performance? Is it possible to cut a diamond that has ideal angles etc. but less than ideal light performance?
Yes its possible to look good by the numbers but have issues, there are a lot of variables, inclusions, graining, crystal defects, tightness of the range of angles, facet flatness, 3d variations in facet placement to name just name a few. AGS0 is much more resistant to some cutting variations than GIA EX.
An rb with the facets locked into position by the design has fewer possible issues than many fancies by a huge factor.

 

[kenny]

When it comes to rounds, at least, the cut parameters that will yield an "excellent" cut rating are well known. Why aren't all stones cut to these parameters?

Why?
So they can make more money selling more stones faster to the largest demographic of diamond buyers, those ignorant of good cut.

Good cut usually grinds away (wastes?) more of the rough diamond material than poor cut does.
A given rough diamond that could yield a 1 ct round with mediocre light performance might yield only 0.75 ct. if cut for the best light performance.

Few buyers understand good cut, but everyone understands carat weight.
IOW, follow the money.

It's business, not art, not charity.

 

[Garry H (Cut Nut)]

A couple of questions come to mind.

When it comes to rounds, at least, the cut parameters that will yield an "excellent" cut rating are well known. Why aren't all stones cut to these parameters? In this age of computerization, does the skill of the cutter still come into play?

The skills of the cutters and the quality of the process are even more important to producing consistent high performance level products. The tech and the better tools are needed, but it still all comes down to skill and process to execute.

Does the orientation of the stone, relative to orientation of the original diamond crystal, play a factor?
Stones are cut from more different angles relative to the rough than ever before. This is where computer mapping plays a big part.
In other words, would all stones cut with ideal angles and proportions have ideal light performance? Is it possible to cut a diamond that has ideal angles etc. but less than ideal light performance?
Yes its possible to look good by the numbers but have issues, there are a lot of variables, inclusions, graining, crystal defects, tightness of the range of angles, facet flatness, 3d variations in facet placement to name just name a few. AGS0 is much more resistant to some cutting variations than GIA EX.
An rb with the facets locked into position by the design has fewer possible issues than many fancies by a huge factor.

Here is a video of planning a piece of complex rough hat shows what Karl is saying.
https://www.youtube.com/watch?v=xY2VlaZBtjo&t=7s

And the process of lacing the diamond in a very high RI glass to enable placement of the inclusions without the light bending of diamond.
https://www.youtube.com/watch?v=VUO_XHxugZY

 

[Karl_K]

Here is a video of planning a piece of complex rough hat shows what Karl is saying.
https://www.youtube.com/watch?v=xY2VlaZBtjo&t=7s

And the process of lacing the diamond in a very high RI glass to enable placement of the inclusions without the light bending of diamond.
https://www.youtube.com/watch?v=VUO_XHxugZY

Thanks Garry that is really awesome!!!

 

[bunnycat]

A couple of questions come to mind.

When it comes to rounds, at least, the cut parameters that will yield an "excellent" cut rating are well known. Why aren't all stones cut to these parameters? In this age of computerization, does the skill of the cutter still come into play?

The skills of the cutters and the quality of the process are even more important to producing consistent high performance level products. The tech and the better tools are needed, but it still all comes down to skill and process to execute.

Does the orientation of the stone, relative to orientation of the original diamond crystal, play a factor?
Stones are cut from more different angles relative to the rough than ever before. This is where computer mapping plays a big part.
In other words, would all stones cut with ideal angles and proportions have ideal light performance? Is it possible to cut a diamond that has ideal angles etc. but less than ideal light performance?
Yes its possible to look good by the numbers but have issues, there are a lot of variables, inclusions, graining, crystal defects, tightness of the range of angles, facet flatness, 3d variations in facet placement to name just name a few. AGS0 is much more resistant to some cutting variations than GIA EX.
An rb with the facets locked into position by the design has fewer possible issues than many fancies by a huge factor.

Here is a video of planning a piece of complex rough hat shows what Karl is saying.
https://www.youtube.com/watch?v=xY2VlaZBtjo&t=7s

And the process of lacing the diamond in a very high RI glass to enable placement of the inclusions without the light bending of diamond.
https://www.youtube.com/watch?v=VUO_XHxugZY

Wow- that was very cool, and helped answer the question "How many diamonds can you get out of a piece of rough?"

 

[Garry H (Cut Nut)]

Here is another cute short movie
https://www.youtube.com/watch?v=Fa49BvfJLSw
Demonstrating a 3D microscope that enables better clarity grading than a loupe.

 

[gm89uk]

That's fantastic, you can view the diamond with binocular vision. Stereopsis on a 2D screen! Bit of a headache though...

 

[Garry H (Cut Nut)]

That's fantastic, you can view the diamond with binocular vision. Stereopsis on a 2D screen! Bit of a headache though...

Its a demo. Not for real 3D. But the real system is mind blowing because there are multiple layers but huge files.

 

[bmfang]

I'm geeking out with this thread!

 

[gm89uk]

That's fantastic, you can view the diamond with binocular vision. Stereopsis on a 2D screen! Bit of a headache though...

Its a demo. Not for real 3D. But the real system is mind blowing because there are multiple layers but huge files.

Hi Garry, the video you posted is 3D if you cross your eyes
https://www.youtube.com/watch?v=zBa-bCxsZDk