this looks really great! is that the orb's original color? anyway, the whole photo suits that green. the light refracting through it makes the highlight look like a thumb or something is coming out of a black hole, which is very cool.
The shadow comes from using hard light! It is hard to pull off with a small object that can roll. Especially when the exposure time is a bit slower that I would have liked... (You can't more or it blurs badly)