That's what this look'd like to me, a frosted glass translucent ashtray with a lot of curves.  I though you called this a square but Wikipedia says that a square like n plane geometry cannot be a square in spherical geometry like this shape.    Evidently the sides can be straight, and the angles can be equal, but the sum of these angles aren't equal to that of a square from plane geometry, thus this shape is called a 'spherical cube'.   Finding out about all this was almost as much fun as shooting the thing.

The ashtray is being illuminated from below.  This is sitting on a 'top hat' extension/lensboard which is sitting on my transparency light table so that the blk of the 'top hat' blends into the background making the ashtray look as if it's suspended in space. 

With a translucent object, whatever's not transmitted through the glass is going to be reflected, and I tried to play around w/this concept by how I lit this thing.

I've still got the rear glass of the front cell wound out to the same position as I used in the previous shots.

Ciao