In 1955, the Soviet Union began exploring for diamonds in Siberia using airborne geophysical surveys. Their geologists were looking for kimberlite, the volcanic rock that carries diamonds from the mantle. In June 1955, geologist Larissa Popugaeva found a kimberlite pipe near the Daldyn River in Yakutia. She sent a telegram to Moscow: "I am smoking the pipe of peace", a coded message confirming she had found kimberlite. Within two years, the Mirny Mine had opened. By the 1960s, Soviet production was significant enough to threaten De Beers's market control. The discovery method, systematic geological survey rather than the chance finds of South Africa and India, established the modern exploration framework used to find every subsequent major diamond discovery. : Kanfer, S. (1993), The Last Empire, Hodder & Stoughton, London, pp. 185–190; ALROSA historical documentation

Open-pit mining

Open-pit diamond mining is used when the kimberlite pipe is close enough to the surface that removing overlying waste rock (stripping) to expose the ore is economically viable. The Jwaneng and Orapa mines in Botswana are among the world's largest open-pit diamond operations. Open-pit mining allows large equipment, electric shovels, 300-tonne haul trucks, to operate efficiently, achieving high throughput volumes. As pits deepen, the strip ratio (tonnes of waste per tonne of ore) increases, eventually making the pit uneconomical and triggering a transition to underground methods (Debswana Annual Reports, debswana.com).

Underground mining

Underground diamond mining typically uses block caving, a mass mining method where large sections of kimberlite are undercut, causing the ore column above to fracture and cave under gravity into a network of collection tunnels. Block caving is highly efficient for large, low-grade ore bodies but requires significant upfront capital for tunnelling infrastructure. The Cullinan Mine in South Africa (Petra Diamonds) and De Beers's Venetia Mine (which transitioned from open pit to underground in 2021) both use block caving (Petra Diamonds Annual Reports, petradiamonds.com; De Beers Group Venetia documentation).

Alluvial mining

Alluvial diamond mining recovers diamonds from riverbed sediments, floodplains, and beach gravels where diamonds have been transported from their original kimberlite source by water and concentrated by natural sorting. India's Golconda diamond production, the source of the world's great historic diamonds, was entirely alluvial. Angola, Sierra Leone, and the Democratic Republic of Congo have significant alluvial production, which is more accessible to artisanal and small-scale mining than kimberlite operations (historical diamond mining documentation; KPCS reporting on alluvial production in Central and West Africa).

Marine mining

Marine diamond mining recovers diamonds from the seabed off diamond-producing coastlines, primarily Namibia. Ancient rivers carried alluvial diamonds to the continental shelf millions of years ago; subsequent sea level changes and wave action have concentrated the highest-quality stones in specific seabed areas. Debmarine Namibia operates a fleet of purpose-built diamond recovery vessels that use a combination of seabed crawlers, suction systems, and on-board processing plants to recover diamonds at sea. The quality of marine production is exceptionally high because the sorting action of waves over millions of years has selectively concentrated the hardest, most durable stones (Debmarine Namibia documentation; De Beers Group Annual Reports on marine operations).

Primary sources

Debswana Annual Reports. debswana.com. [Open-pit methods at Jwaneng and Orapa; strip ratio economics; transition planning to underground.]

Petra Diamonds Annual Reports. petradiamonds.com. [Block caving at Cullinan mine; underground methodology description.]

De Beers Group Annual Reports. debeersgroup.com. [Venetia underground transition (2021); Debmarine Namibia marine operations; open-pit to underground economics.]

Kanfer, S. (1993). The Last Empire. Hodder & Stoughton, London. [Soviet Siberian discovery (Larissa Popugaeva, 1955); "pipe of peace" telegram; modern exploration methodology context.]