The Mining Process
Alluvial vs Kimberlite Diamonds
Orange River Holdings is primarily involved with the mining of alluvial diamonds. Alluvium or alluvial deposits are those geological deposits and soils that are derived by in situ weathering or weathering plus gravitational movement or accumulation. Alluvial ore deposits are those such as tungsten and gold placers formed by settling and enriched by the winnowing or removal of lower density materials. Diamonds within weathered portions of kimberlites may be considered to be alluvial deposits.
Kimberlite is a type of rock best known for sometimes containing diamonds. Kimberlite occurs in the Earth’s crust in vertical structures known as kimberlite pipes. Diamond-bearing rock is brought close to the surface through deep-origin volcanic eruptions. Kimberlite mining requires the drilling of these kimberlite pipes the lines of magma.
The mining of alluvial diamonds generally involves the mining of material from the bank of a river and sifting through this material.
Process in pictures
Raw material
Beginning enrichment
Final recovery (design layout)
