I looted mine off an NPC in 'The Warren' on Dantooine.
It looks like a Gobstopper candy with a 1/4 slice in it.
It acts just like a magic 8 ball novelty toy. You ask it a question & it gives a silly answer. "I have forseen it is so", "The force is with you", "Unknown, The Dark side clouds everything", etc.
I don't think there's any real purpose for it other than the neat factor.
I keep it in my house next to my crystals & holos. It's really tiny when you drop it in your house.