A longwall mining machine comprises a rotatable cutting head having a configuration in the form of an equilateral triangle viewed along its axis of rotation and formed with a continuous auger along the outer surface of the head. Cutter bits are located on apexes of the auger. The cutting head is mounted on a boom adjacent the longwall and is geared to produce an eccentric Cardan motion to the head causing the cutter bits to follow a substantially square trajectory in a plane normal to the axis of rotation of the head. Production of coal dust is minimized by deep linear vertical and horizontal cuts extending downwardly from roof to floor. During rotation of the head, cut coal is augered outwardly from the longwall and dropped into a conveyor for removal to a collection area.