Probably a really dumb question

[caligirl]

Hi,

I don''t know much about diamonds so I hope that someone can answer this for me. If you have a rough diamond stone of a certain size, let''s say 5 Cs, is that a way to tell how many Cs the cut diamond will be?

 

[Kaleigh]

There is no such thing as a dumb question!! I am not an expert, but do know the question you asked is a broad one. It depends on many factors. What sort of rough you have, what the nature of the inclusions are, is it going to be one that you can maximize the size, etc... So many variables, of course you want the best cut of the rough, shape is another, some are more wasteful , so will pass this on to the experts...

 

[WorkingHardforSmallRewards]

I am curious why you are asking? any particular reason or just interested?

 

[stebbo]

Yep, lots of variables, and a single piece of rough will give birth to many diamonds. Here's a simple little pic from Octonus' site, who produce scanners and software for planning the most profitable way to chop up the rough:

You can see for instance how they've chosen to cut a smaller diamond (in red) avoid the flaw (in white), and also to keep the blue diamond well proportioned for light performance and grading rather than making it deeper.

 

[Nathan Barsky]

An octahedral crystal as picture above also dictates where the diamond has to be split apart or cleaved. Diamond being an isymetric crytal has to be properly mapped out before being cleaved to avoid the different growth patterns. The cutter wants to save the most weight as he can from the rough. Diamond cutting is more boring than traffic court.