Balian's yellow ioun stone

Balian's yellow ioun stone was a unique ioun stone that boosted a random physical or mental trait of the bearer.

Powers
When attuned, this seemingly faulty ioun stone gave an enhancement to one physical or mental trait of the bearer, as with ioun stones, but this was decided randomly each day. The stone could only be attuned once a day, and only functioned for twelve hours, after which it dropped to the floor. It couldn't be used again until twelve hours after it was last used.

History
Whilst serving as a guard at a convention of wizards, one Balian Rocksmith discovered this ioun stone on the floor, apparently lost after it stopped functioning.