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How diamonds are cut and polished using Hi Technology

Garry H (Cut Nut)

Super_Ideal_Rock
Trade
Joined
Aug 15, 2000
Messages
19,154
I have visited this factory in Surat a few times. The owners are highly ethical and very clever.
Very little is left to chance.
Enjoy:

 
Very interesting. Thanks for sharing.
 
Wow, I guess women aren't allowed to work there! There's not a single woman in that video. (Unless the hands of the person in the packing department belong to a woman.)
 
Wow, I guess women aren't allowed to work there! There's not a single woman in that video. (Unless the hands of the person in the packing department belong to a woman.)

You are correct. There are many women in that company in admin roles.
But the same problem world over is that women are not attracted to STEM fields other than medical based.
My partner Vera was in many of her jobs the only woman working in IT where a maths background was required.
As to the polishing and manual dexterity - a factory in Sri Lanka owned by Rosy Blue that I visited 15 years ago had exclusively female polishers.
Not a man to be seen.
I think the issue is that in a lot of 'paternalistic' countries mixed work forces are not without their sex related problems.
 
That was so interesting!!! It still requires a lot of work to take a diamond from rough to polished!
 
Thanks for the share Garry. I really enjoyed the video. There were a couple of things that grabbed my attention.

1. At roughly 2:59: "Planning simply means....thinking, thinking & keep thinking."

2. At roughly 3:32: "We also have to listen to what the diamond ultimately wants to be."

3. At roughly 5:56: "On average, only about 60% of the diamond rough makes it to the final polished diamond."

In regards to #3, that waste percentage seems high and I believe others have reported lower amounts of waste on this forum. Being a Venus video, I am sure this data is specific to them, but across the industry is waste truly 40% on average?
 
That planning at that point is using OctoNus software and a patent that I wrote with Sergey in 2004.
The waste issue can have 2 meanings. I am not sure which or both.
1. Venus rarely produce diamonds under half a carat - so they resell that rough.
2. Venus produce a lot of fancy shapes and I believe they end up being supplied with a lot of large irregular shaped and complex rough. (The perfect octahedra often stay in the mining countries for local benefaction). This works for them (and other advanced Indian companies) because of their technical mastery.
These images are from Venus individual grading reports.
829593
 
So much time and skill goes into each diamond - fascinating!
 
An excellent walk-thru of the technology AND artistry required to make precision cut diamonds. They don't happen by accident!

Most consumers are unaware of all that actually goes into bringing these gems to market. Trade members sometimes lose sight of this as well. This video helps us appreciate the complex technology and decision making that goes into each diamond, as well as the skill of the craftsman.
venn.JPG
 
kicken kewl thanks Garry.
 
Fascinating!

Is it so that the CVD process of lab diamonds is more straight forward than HPHT? In the CVD video the rough looked like a block whereas the HPHT looked more “natural”.

How much cheaper are lab diamonds to produce?

I found this picture online which I find interesting. I didn’t know that natural diamonds have 8 growth directions, whereas HPHT has 14 and CVD only one.

A00DB6A6-1FB9-430D-A8C1-0E2000D33228.jpeg
 
Fascinating!

Is it so that the CVD process of lab diamonds is more straight forward than HPHT? In the CVD video the rough looked like a block whereas the HPHT looked more “natural”.

How much cheaper are lab diamonds to produce?

I found this picture online which I find interesting. I didn’t know that natural diamonds have 8 growth directions, whereas HPHT has 14 and CVD only one.

A00DB6A6-1FB9-430D-A8C1-0E2000D33228.jpeg

Yes and as a result CVD tends to be cut shallower which makes better looking diamonds than natural or HPHT.
CVD can be grown to the depth required for say a 1ct order
 
Yes and as a result CVD tends to be cut shallower which makes better looking diamonds than natural or HPHT.
CVD can be grown to the depth required for say a 1ct order
Many of them require hpht treatment to drive off the defects so its not all roses.
 
Fascinating!

Is it so that the CVD process of lab diamonds is more straight forward than HPHT? In the CVD video the rough looked like a block whereas the HPHT looked more “natural”.

How much cheaper are lab diamonds to produce?

I found this picture online which I find interesting. I didn’t know that natural diamonds have 8 growth directions, whereas HPHT has 14 and CVD only one.

@nojs , here are some actual images of natural, HPHT and CVD produced crystals.

pricescope-education-601-lab-grown-diamond-growth-morphology-1024x576.jpg

You can see more images, including some cool distinctive inclusions - also related to the production process, on our page on Lab Grown Diamonds.

 
Many of them require hpht treatment to drive off the defects so its not all roses.

Aha. Another "photo opp" :)

Karl's correct. A lot of CVD grown rough finishes with brown undertone (left, below). It's typically annealed to reduce the brown or change it to gray/pink. Some CVD productions are capable of producing near-colorless and colorless rough with no undertone (right, below) but at present the majority passing through the #1 LGD laboratory has had post-growth treatment.

1621792640260.png

Related quality factors described here.
 
re:Yes and as a result CVD tends to be cut shallower which makes better looking diamonds than natural or HPHT.


this statement is very far from realty .

see real and typical example.
Originally CVD rough had mass 11.48ct.
After removed PCD( external Black polycrystalline diamond ) the mass become 8,75ct with next available options :

a client selected very shallow emerald cut 5ct( 56% total depth and high leakage)


Screenshot 2021-05-23 at 21.16.29.png
 
I have visited this factory in Surat a few times. The owners are highly ethical and very clever.
Very little is left to chance.
Enjoy:


Great promotional video which really highlights the incredible evolution of the Indian industry. really remarkable...
But..., from a company such as Venus, I would expect a bit more showing of the nitty gritty..., the advanced technical + art process..., after all, they are mentioning that very diamond is cut & polished from beginning to end by one craftsman.., this, if true is a big statement in the world of mass production..., would have loved to see it more in their video.
 
Great video. Venus is the champion of detailed gemological reporting. THANKS.
 
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