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Great article, I especially liked the survey of opinions from various members of the diamond trade. |
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Well done Coati
Do others think that this will be useful to refer newbies to, perhaps with a quote from the conclusion, or your favorite appraiser etc? Is there any disagreement about that final statement? Generally, feathers do not pose a durability risk during normal wear, but each stone must be judged individually. Diamonds that contain multiple, precariously placed feathers may cause a risk, as mentioned in the expert responses above, but if a diamond has survived mining and faceting, then it is unlikely that a feather will worsen with wear.
Garry Holloway FGAA DipDT
HCA and Ideal-scope developer http://www.ideal-scope.com and http://www.HollowayDiamonds.com.au |
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Garry, re:but if a diamond has survived .... faceting, then it is unlikely that a feather will worsen with wear. Cool polishing process could change it. Polishing process become more and more safe for diamonds and can not be more rejection tools for diamonds with low durability EOS " Stones with high stress, even in the bruting area, can be processed without any damage. " GIP |
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As for the article, Coati, can you make a small correction, though not important for the actual message of the article.
You mentioned that bearding is caused by the faceting process. Actually, it is caused by incorrect manipulations in the bruting-process. What I further miss, is the mention that certain feathers are a result of stress released during the manufacturing-process (and I can imagine that this can also occur during the mining, and even under external geophysical pressure over a period of millions of years). All in all, like many mentioned in the article, I think that feathers and durability are a non-issue, especially if I think compare to the damage I have seen resulting from simply wearing a diamond for 50 years. That really surprises me badly, and I wonder how the jeweler-setter-benchman affects such damage. Other than these small remarks, good job. Live long, |
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Thanks for the comments Paul re bearding-You are correct. Bearding results from “incorrect manipulations” during the bruting phase. (will correct this in the article-thanks) Perhaps an in-depth article on the cutting process is in order. (Video would be great) re stress on diamonds from manufacturing, mining and geophysical pressure-this is addressed in the article. If a diamond can survive emplacement, mining, and manufacturing, it is unlikely that a feather will worsen with normal wear. |
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Sergey you mean that diamonds that might have broken during traditional manufacturing processes may survive todays modern techniques? I think this is true for laser sawing and laser blocking, as well as grinding with a coolant. Coati / Paul - “incorrect manipulations” could be better worded? Perhaps: Rounding (bruting) too aggressively or fast.
Garry Holloway FGAA DipDT
HCA and Ideal-scope developer http://www.ideal-scope.com and http://www.HollowayDiamonds.com.au |
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Garry, re:Sergey you mean that diamonds that might have broken during traditional manufacturing processes may survive todays modern techniques? yes. Early cutters much more often avoid to cut diamonds with some type feathers what could be close to girdle or facets.(early they removed such feathers firstly during sawing and then polished diamond without its. ) |
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Such diamonds were considered good for oil well drilling because they could break revealing new sharp corners and edges. Do you think it means that today and in the future many more diamonds with feathers will break than what we experts have experianced in the past?
Garry Holloway FGAA DipDT
HCA and Ideal-scope developer http://www.ideal-scope.com and http://www.HollowayDiamonds.com.au |
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Garry, Yes,it could happened in near future when technology for cool polishing as GIP will widespread . even now EOS allows bruting for some diamonds what was not possible just 5 years ago. and you know 1 year old history of completely cool processing during blocking for highly stressed( leopard) very big Pink diamond. was it possible just 2 years ago? Cool polishing could cancel current historical expertise what diamonds with cracks are safe because they passed through hard cutting process. Cutting process will not hard at all just after 2-5 years. |
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Sergey, cooling during cutting and polishing has been practiced for years... Its true that the laser has become a safer world for Diamond processing . (Red-Green & now perhaps cool), but when push comes to shove, Diamond material still needs to be grind-ed for faceting.So unless you have a surprise process up you sleeve , "not hard at all" should be changed to "safer" perhaps.
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Can you give examples of cooling during cutting please Yoram?
Garry Holloway FGAA DipDT
HCA and Ideal-scope developer http://www.ideal-scope.com and http://www.HollowayDiamonds.com.au |
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Yoram, Cooling polishing and cool polishing are not same. in Cooling polishing you firstly heating diamond in polishing contact place and then cooling diamond from other part surface . So you have high temperature gradient in any case( you just reduce highest temperature) . Cooling polishing had been used mainly for very big diamonds( +100cts). Cool polishing available for any sizes In cool polishing you do not heat diamond in polishing contact. same for laser sawing . You can use cooling during red or green laser sawing, but cool laser sawing possible only for deep UV laser |
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I physically saw one prototype (not fully completed as of yet). Sorry no links and no final details yet. |
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Who could tell from the report? You are asking too much from too little info
Garry Holloway FGAA DipDT
HCA and Ideal-scope developer http://www.ideal-scope.com and http://www.HollowayDiamonds.com.au |
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Is it possible to tell from a 40* image and also idealscope images? If so, I will request these information. Another question I have is whether grading for clarity includes the consideration of structural integrity. As far as this diamond, a customer representative told me the feather is marked with red not green, so it is not on the surface. It will not crack. Is it true? She also commented that the crown angle for this diamond is not ideal so it only qualifies for the whiteflash premium. But the AGS grade and HCA score seems perfect for me. Sorry I am bringing the topic away a little bit... |
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40x is too magnified.
You did not read the entire article? I think you are obsessing in exactly the way the article was written to stop you worrying. GIA school teaches feathers are green, GIA lab only calls them feathers if they reach the surface - I believe AGS follows the same practice.
Garry Holloway FGAA DipDT
HCA and Ideal-scope developer http://www.ideal-scope.com and http://www.HollowayDiamonds.com.au |
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I agree that it needs more information to judge. I read the article and the comments. As in the article and some responses"....if it does not reach the girdle edge, or if....... then it should not be a durability issue." The way the inclusions are plotted looks like they are on the gridle edge, and "straight feather than a curvy feather". May be deceiving? I am not sure.
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GIA plots feathers in red. |
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The person physically examining the stone can give you the best info about specific inclusions-sorry, we need more than the plot. If you have concerns about this stone, then you can always have an independent appraiser look at it. Welcome to Pricescope
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Not really
Garry Holloway FGAA DipDT
HCA and Ideal-scope developer http://www.ideal-scope.com and http://www.HollowayDiamonds.com.au |
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Hi haagen_dazs, This article applies to diamonds only. Colored stones have a host of other durability issues based on their individual properties and various treatments.
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