Following the discovery of diamonds to the north of the Orange River mouth in 1928, an ore body was delineated, which is today known as Mining Area 1. The area consists of raised beaches over a distance of approximately 100km north of Oranjemund, to Chameis Bay along the present day coastline. Bordered in the east by a geological boundary known as the "east cliff", this strip of land is nearly 3km wide in the south, narrowing to about 200m in the north. A typical beach consists of a layer of gravel between ancient high and low water marks, a storm beach or ridge and a marine platform or shelf containing gravel.
	Diamonds may be found in any portion, but occur most abundantly in the beach and shelf gravel found upon and within the deeply gullied and highly contorted bedrock.  Ore deposits are about 2m thick, while the overburden thickness can reach a thickness of 20m in places. Mining involves first exposing the diamondiferous gravel by stripping away the sediments that overlie them. A variety of earth-moving machines, including bowl scrapers, bulldozers, articulated dump trucks and mass excavators have been used at various times in the past. In areas of deep overburden, bucket wheel excavators operate in overburden depths of up to 18m. The largest of these bucket wheels has the capacity to move a million tons of sand monthly. In wet areas in the southern part of Mining Area 1, a dredge capable of moving eight million tons per annum is used to strip away the overlying sediments. In places, overburden sand is used to construct protective sand walls, extending the beach high-water mark by up to 200m. These walls allow diamondiferous gravel up to 20m below sea level to be exposed and recovered. Once the overburden has been removed, the bulk of the ore is excavated mechanically using hydraulically controlled excavators. Where necessary, high capacity industrial vacuum machines are used for a final clean up of gravel on the bedrock. All the ore is then transported to ore processing plants. Four large ore processing plants accept run-of-mine ground from their respective mining areas, as well as sized gravel from one dry in-field screening plant and two wet in-field screening plants. Ore is fed into crushers that reduce all material to less than 150mm. Crushing is by impact, jaw, gyratory and cone crushers. A process of dense medium separation, using ferrosilicon as the medium, then produces a diamond-rich concentrate from the crushed gravel. The final concentrate represents around one per cent of the material originally fed to the plant and it is this concentrate that is sent to a central recovery plant, which produces a final 100% diamond product.