Beware of Diamonds with Strain

[Garry H (Cut Nut)]

In the past Rocdoc and I have had some wing ding arguements about diamonds that show birefringent strain.
He said avoid them. I said they are not a risk because to survive the sawing, bruting and blocking processs, they have already undergone testing for inherent strength.

I wil be supporting Rocdoc''s approach and asking to see birefringence information on diamonds in the near future because of Sarin''s latest development:
http://www.listedcompany.com/ir/sarin/newsroom/SarinQuazer161105.pdf

 

[valeria101]

Date: 11/16/2005 2:03:26 PM
Author:Garry H (Cut Nut)
..
I said they are not a risk because to survive the sawing, bruting and blocking process, they have already undergone testing for inherent strength.

As far as I understand from the document, it is the cutting that will become less trying

Citing the document down your link:

"[the new diamond cutting tools introduces] unique advantages including minimal breakage and weight loss and ... the ability to cut damage prone 'tension stones'."

Clear enough

So what's to do? One more argument for insurance? Who is to ID problematic goods after all?

 

[oldminer]

The presence of strain in a well cut diamond is not much cause for alarm or worry. Insurance will cover any breakage and it would be a rather rare occurrence in a well cut stone.

Diamonds with thin girdles, shallow crown angles, shallow crowns, pointed corners all represent far greater damage potentials. When such problematic parameters are combined with a diamond that shows strain, then the possibility is increased further by doubling the problems.

My objection to the use of strain has always been the manner of presentation RockDOc chose to use which serves to create a degree of doubt and fear. It makes people think they MUST have the "strain" expert examine their diamond. Its a pretty good marketing tool, but strain in well cut diamonds is not such a major issue.

Certainly, there may be isolated examples that could be used to prove any point about the importance of strain. My response would be we see very few issues created by strain in finished diamonds. No doubt, diamond cutting firms have a totally different attitude about strain as it causes diamonds to break during cutting.......

 

[Garry H (Cut Nut)]

that is the point Dave - now that diaamonds are not stressed- the risk moves on to the consumer

 

[Serg]

Garry,

Information from Sarin press release is not new . It is well known information in last several years. New "Sarin" laser is more safely firstly due more short impulse. This information does not change any thing in Your or Rocdoc arguments.

 

[aljdewey]

Date: 11/16/2005 2:38:53 PM
Author: oldminer

My objection to the use of strain has always been the manner of presentation RockDOc chose to use which serves to create a degree of doubt and fear. It makes people think they MUST have the ''strain'' expert examine their diamond. Its a pretty good marketing tool, but strain in well cut diamonds is not such a major issue.

I wholeheartedly agree with this, Dave.....and it''s not limited to the issue of strain.

This "manner of presentation" has been a pretty popular tool as of late...not just for strain, but selecting potential diamonds in general. And yes, along the same line, it makes people think they are incapable of picking a nice stone unless the ''gadget-of-the-hour'' expert examines their diamond.

 

[oldminer]

The stress is there all the time the diamond is being cut on the wheel. If it can undergo that pressure, temperature and vibration, then it is darn sound material. Yes, the new laser will not damage diamonds as readily, but there are many opportunities for stress to have its way with the diamond before it reaches the finished stage.

I do appreciate the point you arer making, however. Maybe some diamonds that would have broken in sawing will now make it to market. It could have some impact. Somehow, I think that the real problematic part of cutting is the bruting, faceting and polishing. More diamonds will now blow up on the wheel than before because they made it past sawing. I think if they get past the cutting step intact, they stand an excellent chance of being quite durable.

 

[Paul-Antwerp]

First, it is very important to note a language-problem. Almost all technical diamond-terms go back to Dutch (or actually a specific Flemish dialect from around the town of Antwerp). The cutters in Israel were mostly working in Antwerp before the war, and almost all factories in Asia were set up with the help of Belgian trainers. Because of this, we have also imported mistakes into the diamond language.

When Sarin talks about cutting in this release, it means bruting. Bruting in Antwerp diamond language is ''snijden'', and when we translate it to English, we think about the action which is done with scissors, thus comes the term ''cutting''.

What we call ''cutting'' here on Pricescope, the technical diamond people call ''polishing''. Whenever people from the trade try to get information out of me, I confuse them by talking about our special ''cutting-organisation'', and it confuses them to such an extent, that they move heaven and earth in order to find out more about our bruting.

Anyway, Garry, this should not change your position on strain or stress. This is just another laser, which is used on stones that are difficult or peculiar to work on. It is definitely not the first, and probably not the last one.

Live long,

 

[Roughdealer]

Personally , I saw near Hundreds of stones with high stress , and this is only problem 4 "The cutter" and the Owner of the Rough Stone.After the stone leave the polish Works , They will virtually has "NO" problem. But in some rare cases, I could detect some "rainbow" spectrum inside the stones ( In Rough). This highest stressed stones in some ways could cause the stones "Jumping" up and down in one color grade, making it difficult to Grade in color.