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Gia I1 diamond with a feather... durability risk ?


npana
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Sorry I do have another question as your comment got me thinking.

Why are there i1 that are completely eye clean and then si1 that have visible inclusions and both graded by GIA? Im sure there are strict guidelines that the GIA "grader" follows but can they also have a bad day and be inconsistent?

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The answer is that "eye clean" is not part of the grading criteria. This is partly a result of the "diamond anomaly" where diamonds are the only gem variety graded for clarity under 10x magnification.

Inconsistency is certainly possible, and even GIA says that they would expect uncertainty of +/- 1 grade on regrading; however do bear in mind that visibility of inclusions (even at 10x) is not the only criterion for clarity grading: the type, colour, extension and location of the inclusion are part of the grading, and for example in this I1 case I suspect there is a call on durability and integrity risk due to location that makes the feather "I1" (whereas by definition "SI" inclusions involve a judgement that there is no such risk). 

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Unlikely to be inconsistent as a stone is checked, double checked, rechecked. However for some border line decisions it can go either way but not with SI2/I1 stones. 

Clarity grade is based on inclusions - their type, location, size، colour, visibility under loupe etc. Eye cleanliness is not a factor in that. 

So if this stone had cloud or twinning wisp of same size instead of the feather in that same location the stone could've been an SI1/2 depending on thickness of the cloud or color of wisps. Feather is considered a more serious inclusion.

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17 hours ago, Furqan Shafi said:

Unlikely to be inconsistent as a stone is checked, double checked, rechecked. However for some border line decisions it can go either way but not with SI2/I1 stones. 

3

I see a fair amount of inconsistency, especially on the SI2/I1 border call.  It has a big affect on both salability and prices, and the dealers know it. They protest grades. They do minor recuts to make it a different stone and resubmit them. They use alternative labs, or just sell without papers at all. Calling it an I1 when they believe it to be an SI2 is fighting words. 

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I have recently started buying loose certified stones but came across ths article outlining the benefits of standardizing diamond grading through artificial intelligence...Is this a real possibility ? Are we heading for a single "trusted" grading report doing away with potential human inconsistencies? 

https://sarine.com/diamond-grading/artificial-intelligence-diamonds/

 

Edited by npana
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Well, 20 odd years ago AGS tried to introduce colour grading by colorimeter, and it was a flop. The technology was fine, but it was coming up with results that human graders - and above all owners of stones - disagreed with. A properly calibrated machine cannot be persuaded, bribed or suborned to change its "mind".

I may be wrong, but I suspect that "public grading" by AI would have much the same fate in the short term, much for the same reasons: there's a huge amount of stock in the diamond industry and therefore huge vested interests in keeping things as they are; I don't want to be told that (for example) my fancy intense pink is actually a fancy orangy-pink.

Behind-the-scenes large-scale sorting of goods that aren't normally lab-graded when sold (as described in the article) is a different story, and in the long run, if enough stones sorted by AI come onto the market with "AI credentials" (whether visible to the consumer or not), then things in the long run may well change. As to how quickly, it's anybody's guess: GIA's cut grade took a long time to come to market (the first published papers on GIA cut grading are from the early '90s, the grade was officially released in 2005) again for the same reasons; it's nearly 15 years, and despite a lot of calls to change some aspects of the cut grading, nothing has moved.

Finally a word of caution: while Sarine is a highly reputable company, they would have a huge amount to gain if machine grading were to be established as an acceptable standard: they would probably make a vast majority of the grading machines...

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It doesn't make them wrong, but that 'article' is an unapologetic advertisement.  

GIA has a massive investment in this being about humans, or at least THEIR machines.  Sarine is taking on a giant here and GIA has a long history of moving the goals if it suits their own personal interests to do so. Any grading system that doesn't have their blessing is going to be a tough, uphill, climb no matter how good or bad it is. 
 

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