HI Everyone!
Here's an unusual cut for a diamond.

I quite fancy the shape. It's got an attitude, that's for sure.
It's never been to GIA , so we'll have to grade it ourselves.
In terms of color, I feel it's a Y-Z.

The clarity......well, I have to say, I actually prefer grading SI clarities.
Why?
Well, once you see that Si1 imperfection, the ones that would have made the stone a VS1 become largely irrelevant. You still need to thoroughly inspect the stone. But calling the grade is less stressful. Anyway I searched the stone for about 5 minutes, and can't find anything- so I'll go out on a limb and call it VS1. It very well might be a VVS, but I don;t feel that any grader besides GIA should call a stone VV or IF- but that's a pet peeve of mine.
it measures :
10.68 x 9.12 x 3.78
That equates to a 41.4% depth ratio.
This is a tough one to guess the table. With certain shapes, you can lean to recognize a table size- this is especially true with round diamonds.
I'd venture a guess and say 65% table. There are special tools to measure the table.
If you look at charts published on the web, they will specify certain percentages ,and assign a diamond a "cut grade" based on things like the table size and depth percentage.
I'm not a subscriber to such principles. Many of my favorite stones fall way outside the "prescribed" percentages.
Some people confuse "Polish" and "Symmetry" for a cut grade. A stone that has "good" polish can be far more attractive than one that has "Excellent" in some cases.
The reason for this is that the difference between these two grades is virtually microscopic.
Other aspects of the cut- such as the distinctive outline and glitter of a stone like this are totally visible to the naked eye.

The shape classification?
We had a similar stone in an H color a few years back.
Here's that stone, and the GIA report for it.


It's safe to say this stone would get the same "Shape and Cutting Style" classification from GIA
Modified Shield Step Cut
Cool stone for sure.....