Abstract: A mill is used to break up ores or gravel in which gold particles are to be found. The mill comprises an outer casing in which an internal housing is located. Within the internal housing is a rotor which rotates at about 1000-15000 rpm. The rotor has cam surfaces on its circumference which impacts the ore and forces it onto a plurality of planar surfaces on the inside of the housing. The ore is broken up by the impacting and is then forced through an outlet passage into an outlet chamber where the heavier gold particles are removed from the lighter non-gold particles.