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fancy cuts and diamond rough

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Slykat12

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I was talking to a gemologist recently and he told me that fancies are often cut from a poorer quality diamond rough than rounds. I was not exactly sure what he meant by this but walked away from the conversation assuming that even if a fancy cut was a D in color, and IF in clarity that it's overall makeup was probably crapola.

Does anyone else know what he is saying? I am sure it is not always true as it seems logical that fancies are also cut dependant on the shape of the rough they are working with rather than the quality.

Do cutters seek out bad rough for fancies?
What is bad rough?
 

Madam Bijoux

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I think that gemologist if full of crapola. The shape of the finished diamond depends on the shape of the rough. Some rough is more suited to a fancy shape while other rough is best cut into a round brilliant. I don''t believe it has anything to do with the quality of the rough. Maybe he just doesn''t like fancy shapes.
 

Joane

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So glad you brought up this question, Kimberly! I''ve always been curious about the relationship between quality of rough and finished product, whether it be fancy cut or RB. Does poor quality rough automatically mean a poorer quality finished product or is it just a matter of having to cut away more? (Or something else entirely involved?)
 

diamondsbylauren

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There''s many different types of rough diamonds.This includes crystals, cubes, mackels, and ochtyhedrons. Each type of rough is generally used for a particular shape- but everything depends on financial viability.
Rough diamonds are sorted for industuial use, in addtion to gem quality. There are over 2000 different catagories for rough diamonds.
If there are deficiencies on color clarity of the rough, it will show in the polished diamond.
A D/IF marquise, which was likely cut from an irregular shaped rough diamond- is just as pure as a round D/IF
 

strmrdr

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If a piece of rough will cut a vvs1 stone of lets say e color and can be cut into a round or an oval with the oval being slightly heavier it will likely be cut into a round because it will sell faster and for likely more money.
So on some grounds its true but overall each shape has a type of rough its usually cut from.
 

Garry H (Cut Nut)

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Top quality rough is a colorless flawless crystal (octahedra or pryramid on an upside down pyramid) because it gets the highest yeild and highest quality. IT may yeild 2 princess of 70% weight or 2 rounds of 45 to 55% depending on cut quality.

You fall in value as the color, clarity and shape fall away. The more irregular the shape, the lower the likely % yeild. A makeable or chip might yeild as low as 20% and is far more likely to have a fancy shape cut from it, that would be worth less than a round diamond of the same weight.

So your friend is right, but had not the full story.
 

RockDoc

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I agree with the above, but I would add....

When a rough parcel is being examined by a potential buyer, another important factor is the ability of the diamond cutter he will be using.

Internal characteristics ( stress/ strain / graining ) all can be troublesome to a cutter. Different cutters have different abilities to deal with these issues. Stones cut by someone who isn''t good with dealing with such issues can lose the diamond entirely. It can "explode" on the wheel. Sometimes temperature is the little demon as well. There is a story about a cutter who was cutting a large piece of rough during the winter, and it was a very large stone, and it was hot in the room - so he opened a window, while cutting the stone ( heat was certain a big part of this) a frigid blast of wind blew in and the stone shattered.

A lot of the time mis-shapen rough does have varying degrees of graining and strain in them. And stone shapes that have varying facet angles - such as pear and marquise can be tough to get a facet to polish. Expressed very layman like is it sort of like sanding wood across the grain of it, as well as at different angles instead of the ease of sanding straing down the grain.

Being able to look at a piece of rough and accurately predicted the result of cutting it, is a talent very few people really have down well. Buying a cutting rough isn''t always predictable about what you''ll end up with. Fissures in the diamond can spread or open while it is on the cutting wheel, facets may be very stubborn to polish. Also brittleness is an issue too, more so when cutting larger rough diamonds, than smaller ones.

Cutting diamonds has the mental consideration of you win sometimes, and you lose sometimes.. It is sort of like gambling at the roulette table. If the cutter is good, and can deal with troublesome rough successfully, the rewards are great, as parcels of "troublesome" rough to cut can be purchased for less than the "easy" stuff that cuts like butter.

Rockdoc
 

Slykat12

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Thanks for the informative answers. Will read over and over till it sinks in . hahaha
 

Madam Bijoux

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Not to hijack the thread, but I love your avatar! That cat looks like quite a character!!!
30.gif
 

Joane

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Date: 8/8/2005 5:12:23 PM
Author: Kimberly
Thanks for the informative answers. Will read over and over till it sinks in.

I feel the same way. Thanks for the fascinating and precious information! Needs time to sink in. When you imagine all the possible pitfalls of cutting a diamond, it''s amazing so many of them make it to the market! There must be some awesomely talented people out there cutting away!

Does all that mean that in the end, if the job is well done, you can''t tell if it came from ''easy'' or ''troublesome'' rough? Now I''m wondering if my little Canadian diamond was an easy or troublesome one? Oh--and does the difficulty of cutting figure into the price or only the end result?
 

diamondsbylauren

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Date: 8/8/2005 5:33:11 PM
Author: Joane

Date: 8/8/2005 5:12:23 PM
Author: Kimberly
Thanks for the informative answers. Will read over and over till it sinks in.

I feel the same way. Thanks for the fascinating and precious information! Needs time to sink in. When you imagine all the possible pitfalls of cutting a diamond, it''s amazing so many of them make it to the market! There must be some awesomely talented people out there cutting away!

Does all that mean that in the end, if the job is well done, you can''t tell if it came from ''easy'' or ''troublesome'' rough? Now I''m wondering if my little Canadian diamond was an easy or troublesome one? Oh--and does the difficulty of cutting figure into the price or only the end result?
Although there is fact in all of what he wrote, Rockdoc has made this sound like far more of an issue than it is. We know of quite a few cutters well equipped to handle such issues.
The people we know that buy rough are also well aquainted with these issues and have a lot of skilled labor to handle the plotting and cutting.
Who buys rough diamonds to polish that does NOT have the means to polish???

It''s true graining is an issue during cutting, yet cutters using modern methods and techniques are usually well able to handle this issue. At times it may take days to polish a single facet- but ultimately it''s rare to see unfinished facets of consequence on fine, well cut diamonds.
As far as exploding diamonds- yes, it has happended- but this is also extremely rare.

SO- If a piece of rough is particualry difficult it might finsh as a smaller diamond, or take longer to cut- but generally you''ll never know the diffuclties when looking at the finished diamond
 

Garry H (Cut Nut)

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Date: 8/8/2005 4:57:14 PM
Author: RockDoc
I agree with the above, but I would add....

When a rough parcel is being examined by a potential buyer, another important factor is the ability of the diamond cutter he will be using.

Internal characteristics ( stress/ strain / graining ) all can be troublesome to a cutter. Different cutters have different abilities to deal with these issues. Stones cut by someone who isn''t good with dealing with such issues can lose the diamond entirely. It can ''explode'' on the wheel. Sometimes temperature is the little demon as well. There is a story about a cutter who was cutting a large piece of rough during the winter, and it was a very large stone, and it was hot in the room - so he opened a window, while cutting the stone ( heat was certain a big part of this) a frigid blast of wind blew in and the stone shattered.

A lot of the time mis-shapen rough does have varying degrees of graining and strain in them. And stone shapes that have varying facet angles - such as pear and marquise can be tough to get a facet to polish. Expressed very layman like is it sort of like sanding wood across the grain of it, as well as at different angles instead of the ease of sanding straing down the grain.

Being able to look at a piece of rough and accurately predicted the result of cutting it, is a talent very few people really have down well. Buying a cutting rough isn''t always predictable about what you''ll end up with. Fissures in the diamond can spread or open while it is on the cutting wheel, facets may be very stubborn to polish. Also brittleness is an issue too, more so when cutting larger rough diamonds, than smaller ones.

Cutting diamonds has the mental consideration of you win sometimes, and you lose sometimes.. It is sort of like gambling at the roulette table. If the cutter is good, and can deal with troublesome rough successfully, the rewards are great, as parcels of ''troublesome'' rough to cut can be purchased for less than the ''easy'' stuff that cuts like butter.

Rockdoc
Wow that is amazing Roc. How the world has changed with the introduction of new technology.
One of OctoNus Helium and Pacor clients predicts the weight, color and clarity of each diamond before they begin cutting the rough. The scan accuracy for inclusion is as good as the consistency or variations we see from major labs on resubmitted stones. Clarity grading at rough stage is usually done in plus and minus grades, i.e. VS2 +, VS1-,VS1, VS1+ etc.
Most of these manufacturers employ the old cottage industry experts to check the opinions of the machines and 25 year old physics and maths graduates, but Yuri is working to incorporate their wisdom into training courses for the young scanner operators.
 

RockDoc

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Date: 8/8/2005 8:27:00 PM
Author: Garry H (Cut Nut)

Date: 8/8/2005 4:57:14 PM
Author: RockDoc
I agree with the above, but I would add....

When a rough parcel is being examined by a potential buyer, another important factor is the ability of the diamond cutter he will be using.

Internal characteristics ( stress/ strain / graining ) all can be troublesome to a cutter. Different cutters have different abilities to deal with these issues. Stones cut by someone who isn''t good with dealing with such issues can lose the diamond entirely. It can ''explode'' on the wheel. Sometimes temperature is the little demon as well. There is a story about a cutter who was cutting a large piece of rough during the winter, and it was a very large stone, and it was hot in the room - so he opened a window, while cutting the stone ( heat was certain a big part of this) a frigid blast of wind blew in and the stone shattered.

A lot of the time mis-shapen rough does have varying degrees of graining and strain in them. And stone shapes that have varying facet angles - such as pear and marquise can be tough to get a facet to polish. Expressed very layman like is it sort of like sanding wood across the grain of it, as well as at different angles instead of the ease of sanding straing down the grain.

Being able to look at a piece of rough and accurately predicted the result of cutting it, is a talent very few people really have down well. Buying a cutting rough isn''t always predictable about what you''ll end up with. Fissures in the diamond can spread or open while it is on the cutting wheel, facets may be very stubborn to polish. Also brittleness is an issue too, more so when cutting larger rough diamonds, than smaller ones.

Cutting diamonds has the mental consideration of you win sometimes, and you lose sometimes.. It is sort of like gambling at the roulette table. If the cutter is good, and can deal with troublesome rough successfully, the rewards are great, as parcels of ''troublesome'' rough to cut can be purchased for less than the ''easy'' stuff that cuts like butter.

Rockdoc
Wow that is amazing Roc. How the world has changed with the introduction of new technology.
One of OctoNus Helium and Pacor clients predicts the weight, color and clarity of each diamond before they begin cutting the rough. The scan accuracy for inclusion is as good as the consistency or variations we see from major labs on resubmitted stones. Clarity grading at rough stage is usually done in plus and minus grades, i.e. VS2 +, VS1-,VS1, VS1+ etc.
Most of these manufacturers employ the old cottage industry experts to check the opinions of the machines and 25 year old physics and maths graduates, but Yuri is working to incorporate their wisdom into training courses for the young scanner operators.

I agree Garry

I think about this and visualize the usual scene between a rough broker and a cutter. Will parcels be reduced to "onesies" with each stone having a rough Helium or Pacor synopsis with it? Now would that be a change where parcels of rough are offered in groups but each stone packaged separately, so it''s high tech report of potential result after the cutting is "pre - figured out".

Then one thinks about De Beers'' SOC program, and wonder if all the good rough will be sold or kept by the sightholder, and only the troublesome ones marketed in the chain to the "customers on the llower rungs of the ladder"?

Guess I gotta get out my crystal ball.

Rockdoc
 

Garry H (Cut Nut)

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he he he.

Roc I had this exact conversation last year with 2 different heads of rough selling companies (a miner and a broker). They are each be in the top 10.

They do not care about the technology or what the cutters plan to do - they can tell all by simply observing what the buyers bid. if new technology raises the value of rough - they go with the flow.

But the old guys that you know / knew - they are not in the hunt anymore.

Have a look at the 8.97ct rough diamond with all the inclusions in the pictures down the side bar to the right. And the eventual plan for its cutting.
 

diamondsbylauren

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It''s true Garry- there has been a real shakeup- with some former major players in New York getting the shaft.
What I have found is that those cutter ( in NYC at least) that were buying "outside sydicate" goods 2 years ago, are stillclinging to life- some are actually doing quite well.
For sure , the pecking order has changed.
there''s still a lot of peckers in the biz though
31.gif
 

rough&unpolished

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i am new on here, but love looking at rough diamonds. my question is where do you get these cut, and how much does it usually cost?
 
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