proportions

[carina]

How can a GIA very good or excellent symmetry grade have poor proportions?
Isn''t very good symmetry - very good symmetry all over??

 

[goldengirl]

Not necessarily....the stone could be perfectly symmetrical--all facets aligned, girdle even, crown height parallel--and still be too deep with a shallow crown = LEAKAGE.

Symmetrical could just mean it's equally poorly-cut all over.

 

[yowahking]

GIA is starting a new system for cut, as the world is demanding a little more information. I went to a meeting of "experts" as everyone had opinions as to what makes a stone beautiful. 20 people in the room and not any 2 could agree. One said that the old standard for a woman used to be 36-24-36, and he said that now (for diamonds) we are complaining about 36-24.1-36. Good laugh as we all laugh at a customer who insists that a 1/10 percentage on a crown angle can be noticed to the eye, and yet we do the same to the cutters. The average cutting of diamonds has gotten much better in the last 5 years, it will still get better, but there will always be stones that are built like us, not quite perfect but not so bad. For me a little too thick of a girdle but a nice crown.