X-ray transmission sorter RGS-OD-3 is a diamond recovery machine designed for final concentrate treatment of dry material with size range -6+1 mm.

The principle of the sorter's operation is based on the property of materials to absorb X-rays. Diamond, consisting of the light element carbon with atomic number 6, absorbs X-rays less than the accompanying minerals containing heavier elements: silicon, calcium, magnesium, oxygen, iron and others.

The sorter consists of a sorting machine and an automatic control rack.