Ideal Cut with no Excellent Finish?

[Moskva777]

Hi, can anyone clarify my understanding of the characteristics of an Ideal Cut diamond.

I have a report from E.G.L which I know isn't rated as high as GIA, but that aside its saying that it is a "Tolkowsky Ideal Cut" however its proportions cut grade is rated "Very Good" with Polish "Very Good" and Symmetry "Very Good".

Shouldn't the finish details of the diamond under this report have some form of an "Excellent" rating?

Can a "Tolkowsky Ideal Cut" diamond have nothing "Excellent" about it?

[John]

Cut, polish and symmetry are all very different.

Cut refers to the proportions of the diamond.. which take into consideration depth, table, pavilion, crown, etc. These have to fall within certain ranges to be considered Ideal.

Symmetry is how well all the facets match each other. Like if you were to draw a line through the middle of the diamond, is one side a mirror image of the other? Is it just slightly off, or way off? Very Good is still good. The human eye can not determine the difference between Very Good and Excellent.

Polish is basically how smooth the surface of the diamond is when it was cut. The more it was polished smooth, the better the polish. Again, the human eye can't really see the difference between Very Good and Excellent. You need a microscope to see any surface finish blemishes.

Hope that helps!