Alluvial mining material is any clay, rocks, sand, silt or other blank material that has been deposited by the flow of ancient rivers, streams or other water bodies.
Alluvial sands and clays are known to contain dense precious minerals that are free from most containing ore bodies. This is due to years of natural exterior weathering which exposes the denser minerals inside.
A large amount of gold, gemstones and other heavy minerals can be obtained from alluvial material by employing physical separation methods, such as screening and gravity recovery. No crushing equipment is utilized on a pure alluvial process.