I've been waiting to see if someone else will stick their hand in on this one.
I wouldn't use Super Glue on this. I'm not the best person to ask on what to use, but marble is too porous to accept the adhesion properties of super glue. I'd recomend that you look into an epoxy adhesive.
Regardless of what you use, you'll always have a crack and the marble will be succeptable to breaking again.