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PostPosted: Sun Jan 11, 2009 12:40 am 
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Joined: Mon May 14, 2007 11:00 am
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Location: Monterey, CA
MacGyver wrote:
You hit on a key part of GIA's "New" cut grading system. The position is that there is no single ideal cut as there can be varying designs that work well together.

Under the current grading system, even if everything ranked Excellent on table size, TDP, Pavillion Angles, Crown Angles etc., you have to go to a final chart takes into consideration how that stone's table size, pavilion angle, and crown angle interact with each other. If that pavilion angle doesn't interact well with that particular crown angle, the stone will rate accordingly.

Sorry, I disagree. If everything (dimensions and proportions) is ranked "excellent" compared to the "ideal cut," then you don't have to go to any table or chart. That stone will be beautiful and no one will say is it isn't, because it has to be. That is why it is called “ideal”.

However, if you say there is no ideal cut, then you have no standard to compare to. So, how can you make a judgment about any different combinations of dimensions and proportions interact with each other? What is your standard of beauty? You will have to make some other measurement of some kind and judge against that—but you still need a standard.

Now, how is one to grade a stone in this "standard less" world? Where is the protocol spelled out, and who is teaching it? Who is using it, and does this make all previous diamond grading reports suspect—or just the new ones?

I believe whole idea behind getting rid of the ideal cut was to salvage something out of their extensive “research” project and increase the profitability of cutters by lowering the standards required of their finished products in order to get good cut ratings.

However, I really don’t think the GIA is actually going to dump the ideal cut as a standard by which cut is graded. This would require them to rewrite all their courses and antagonize all their former students—not to mention the static they would get from the rest of the world. More than likely, their GTL will unilaterally and surreptitiously change something in their proprietary grading system. :D :D


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PostPosted: Sun Jan 11, 2009 10:04 pm 
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Location: GG, Southeast USA
Quoting Bill:
"I believe whole idea behind getting rid of the ideal cut was to salvage something out of their extensive “research” project and increase the profitability of cutters by lowering the standards required of their finished products in order to get good cut ratings. "

I agree, it looks to me like they have decided to help the fox instead of guarding the hen house. As far as their abandonment of the Ideal Cut goes, they have already done it. My instructors disregarded it as something from the past, not relevant to present grading standards. The new broad criteria makes it possible for cutters and diamond sellers to market their goods with higher grades than they otherwise could. I couldn't agree with you more regarding the standards issue. The new system wouldn't be needed if they had simply stuck to that.


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