THE EE WAS INSTALLING A ROOF BOLT & RESIN IN A DRILLED HOLE. A SMALL ROCK WITH A SHARP EDGE, APPROXIMATELY 4 IN. X 4 IN. X 2 IN. THICK FELL FROM THE TOP, STRIKING HIS NOSE. THE SHARP EDGE CA USED A LACERATION TO THE TIP OF HIS NOSE AND STITCHES WERE NEEDED. THE EE RETURNED TO WORK HIS NEXT SCHEDULED SHIFT.