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 GIA/ EGL grading of vintage asschers- how to judge?

P:  3/26/2009 10:40:55 AM  
Green with Envy
Green with Envy

Ideal Rock
Total Posts: 767
Last Post: 11/21/2009
Member Since: 6/25/2007
 
Is it common to get lower cut quality grades when you have a beautiful old stone (example is 1915 asscher) and have it certified by GIA and or EGL-USA with todays modern precision cut standards?

If you find a true vintage stone that is amazing... do you just sort of disregard the quality report of the certs? Then when you are trying to analyze the specifics of the cut style (is it an asscher, or a squarish emerald, etc.) what do you do when the pictures of the stones and measurements on the GIA cert and the EGL cert are a bit different... for the exact same stone?


Is it even fair to compare and scrutinize the patterns prices and availability of modern asschers to a 90+ yr old stone? Don't have more specifics, but the asscher is GIA J VS1 with good symmetry, very good polish & has approx. 57% table and 68% depth. EGL rates stone H VVS2, which is not surprising for color difference.

How do you really compare to other stones when it seems practically impossible to get a good straight on photo of the windmill patterns? I saw Storm's post from long ago showing how the smallest tilt of stone in picture can affect the windmill patterns.

For any stone cut before 1920, I thought I read somewhere that if not marked with number and Asscher symbol... then more likely just an old generic squarish EC? But these will still have mesmerizing windmills effects?

Thoughts?



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The BIG day... June 25, 2010!

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Posted:  3/26/2009 10:40:55 AM

 There are 3 replies to this message.  There are 3 replies on this page.

P: 3/26/2009 11:24:21 AM
oldmancoyote
oldmancoyote

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Last Post: 6/26/2009
Member Since: 8/22/2008
 
Step cuts are not graded for cut quality by any major lab, as far as I know. Whether such a thing is even possible from an objective standpoint is - I am sure - very debatable and hotly debated.

For finish (polish and simmetry), colour and clarity, I don't see where the problem is. The standards are pretty clear, and particularly as far as colour and clarity go the results were set down literally in stone by Mother Nature a few hundreds of millions of years ago.

In terms of pattern beauty - since there is no generally accepted purportedly objective standard, it's all in the eye of the beholder. Old cuts have their estimators, who value their quirkyness and relative lack of precision (in some - not all - cases) far more than the aseptic coldness of a modern cut. I have seen really beautiful patterns in step cuts dating back to the 1920s and '30s, or at least I liked them. If you prefer a more modern cut, that's not a problem or an unfair comparison, surely?

Posted:  3/26/2009 11:24:21 AM
P: 3/26/2009 11:55:10 AM
strmrdr
strmrdr

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Total Posts: 23,296
Last Post: 10/9/2009
Member Since: 11/1/2003
 
sure you can compare them.
There are beautiful 90 year old stones and ones not so much just like a modern stone.
Pretty much from day 2 they were cut in many different styles.

The answer to the picture issue is multiple pictures and sometimes I just have to take the tilt into account by knowing how they react when tilted.

A vendor who knows and understands the cut is vital and very few understand them.
A good return policy is also a must.

My rule with any stone is how does it affect the face up appearance?
I have seen an asscher that one of the pavilion windmill facets looked like it was polished with 80 grit sandpaper that was beautiful.
But separating such a stone from others with the same grade that are not so pretty is impossible without the stone in hand.
Which is why its a good idea to stay vg/vg and above when having stones called in.

........... Karl has joined the diamond trade and is now posting as Karl_K

Posted:  3/26/2009 11:55:10 AM
P: 3/26/2009 1:00:50 PM
oldmancoyote
oldmancoyote

Ideal Rock
Total Posts: 754
Last Post: 6/26/2009
Member Since: 8/22/2008
 
Date: 3/26/2009 11:55:10 AM
Author: strmrdr
I have seen an asscher that one of the pavilion windmill facets looked like it was polished with 80 grit sandpaper that was beautiful.

Posted:  3/26/2009 1:00:50 PM

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