GIA shape question

[Cehrabehra]

I''ve noticed that my stone which is listed on its gia cert as "old mine brilliant" is essentially the same facet plot as the many other cushions listed as "cushion brilliant" and I''m wondering what the difference between the two is... I was thinking that it might have to do with the lower girdle facets, but there''s a PS stone that looks so much like mine and appears to also have short LGF and it is listed as cushion brilliant. My stone was just cut last year and graded in April 2006 so it isn''t like the term "old mine brilliant" is antiquated, but I have yet to see or hear of another cert that says "old mine brilliant" and I''m wondering what differentiated my stone from a "cushion brilliant".

My guess is that no one here will know the answer to this - but who would I contact to find out? Would GIA be helpful? They weren''t helpful last time I called them about something else...

 

[diagem]

Date: 2/10/2007 12:41:43 PM
Author:Cehrabehra
I''ve noticed that my stone which is listed on its gia cert as ''old mine brilliant'' is essentially the same facet plot as the many other cushions listed as ''cushion brilliant'' and I''m wondering what the difference between the two is... I was thinking that it might have to do with the lower girdle facets, but there''s a PS stone that looks so much like mine and appears to also have short LGF and it is listed as cushion brilliant. My stone was just cut last year and graded in April 2006 so it isn''t like the term ''old mine brilliant'' is antiquated, but I have yet to see or hear of another cert that says ''old mine brilliant'' and I''m wondering what differentiated my stone from a ''cushion brilliant''.

My guess is that no one here will know the answer to this - but who would I contact to find out? Would GIA be helpful? They weren''t helpful last time I called them about something else...

Table %''s, Crown hight and degrees, Pavilion depth, Culet

GIA or anyone else has a hard time matching plots/sketches to the actuall Cushion Shapes that get submited to their labs..., too many combinations of faceting arrangements...

I dont think its an excuse..., I think GIA and other labs should and has to be more accurate in their plot/sketches match with the actuall gems they are grading..
Its elementary!!!!

 

[Cehrabehra]

Date: 2/10/2007 1:02:22 PM
Author: DiaGem

Date: 2/10/2007 12:41:43 PM
Author:Cehrabehra
I''ve noticed that my stone which is listed on its gia cert as ''old mine brilliant'' is essentially the same facet plot as the many other cushions listed as ''cushion brilliant'' and I''m wondering what the difference between the two is... I was thinking that it might have to do with the lower girdle facets, but there''s a PS stone that looks so much like mine and appears to also have short LGF and it is listed as cushion brilliant. My stone was just cut last year and graded in April 2006 so it isn''t like the term ''old mine brilliant'' is antiquated, but I have yet to see or hear of another cert that says ''old mine brilliant'' and I''m wondering what differentiated my stone from a ''cushion brilliant''.

My guess is that no one here will know the answer to this - but who would I contact to find out? Would GIA be helpful? They weren''t helpful last time I called them about something else...

Table %''s, Crown hight and degrees, Pavilion depth, Culet

GIA or anyone else has a hard time matching plots/sketches to the actuall Cushion Shapes that get submited to their labs..., too many combinations of faceting arrangements...

I dont think its an excuse..., I think GIA and other labs should and has to be more accurate in their plot/sketches match with the actuall gems they are grading..
Its elementary!!!!

thank you diagem.... I was comparing my stone to this one: https://www.pricescope.com/community/threads/3-10ct-cushion.54090/ because they look very similar and the stats at first glance seemed similar as well.... both are 66% depth though this one has a 55 table and mine a 53 and this one has a med culet and mine is sl large (which IMO for a good omc sl large is too small!) but I"m guessing the cut offs are somewhere in there.... and of course since GIA doesn''t provide any of the angles or specific depths including crown height and IMO if they''re going to include nothing else, at least include the crown height. I haven''t seen another cert listed as old mine brilliant either.

 

[elmo]

I''d be interested in finding out what the various cutoffs are. I did see a couple of GIA OMBs that didn''t really look like the old stones I''ve seen. I wondered in that case if lower halves were making much of the difference with the look.