and found a green crystal in it.

Is this anything useful or should I destroy it?

When I examine it it just says green crystal, nothing about force or so.

Luke

The one handed sabers use a single crystal. The crystals don't say anything other than crystal so you've got yourself atleast 200k right there, though if you have any interest in being a jedi I suggest you keep it, so far I've only found 1 dual-force crystal cluster and 1 crystal so they're pretty hard to come by.