A machine is employed for recovering heavy metals and precious or semi precious minerals, such as gold, copper, lead, diamonds, and garnets from placer, or hard rock ore. The machine employs a cylindrical, annular outer drum mounted for rotation at an inclination to the horizontal and including at least one spiral vane extending the length of its inner surface. A cylindrical, annular inner barrel is mounted within the drum and has an upper fragmentation section, an intermediate screened section, and a lower discharge section. A spray of water is directed into the inner barrel and a water spray bar is located in the annulus between the inner barrel and the outer drum. A fine sluice box is located to receive under one-quarter material input from a side trommel and a coarse sluice box located to receive discharge from the side trommel and discharge from the fine sluice box. The sluice box includes a plurality of landings, matting and screens upon which heavy materials, such as gold or precious stones, collect.