Abstract: A high speed mixing apparatus is shown for slurry materials which includes a stationary housing and a cylindrical rotor mounted for rotation within the housing. The rotor has an outer surface which is embossed with a repeating pattern of pyramidal shapes, each pyramidal shape having four triangular faces which meet at an apex. Each face has a base edge which forms grooves in the rotor for directing the flow of slurry in directions 45 degrees relative to the rotor's axis of rotation.