Diamonds are found across a wide belt of Africa, from southern nations like Botswana and South Africa up through central countries like the Democratic Republic of Congo and Angola, and into West African states like Sierra Leone and Liberia. Africa produces diamonds from at least ten countries, and in 2023, Botswana alone mined over 25 million carats worth roughly $3.3 billion. The continent’s diamond deposits fall into two broad categories: deep volcanic pipes called kimberlites, and surface-level gravel beds in riverbeds and along coastlines.
Botswana: Africa’s Largest Producer
Botswana is the top diamond-producing country in Africa by both volume and value. Its two flagship mines, Jwaneng and Orapa, are operated by Debswana, a joint venture between the government and De Beers. Jwaneng, located in the southern part of the country, has an annual capacity of around 30 million carats and regularly produces close to 12 million carats per year. It is often called the richest diamond mine in the world by value. Orapa, in the northeast near the Makgadikgadi salt pans, has a capacity of about 20 million carats and produced over 10 million carats in recent years. Two smaller mines, Letlhakane and Damtshaa, operate nearby. Together, Debswana’s four mines produced nearly 22.7 million carats in 2017 alone.
South Africa’s Kimberlite Belt
South Africa is where the modern diamond industry began, and the country still produced nearly 5.9 million carats in 2023, valued at about $794 million. The most famous deposits sit on the Kaapvaal craton, an ancient block of continental crust that provides the deep, stable geological conditions diamonds need to survive their journey to the surface.
The Cullinan mine, northeast of Pretoria, is one of the most storied diamond sources on earth. It produced the largest gem-quality rough diamond ever found (the 3,106-carat Cullinan diamond in 1905) and continues to yield unusual stones. Its diamonds formed at exceptionally high temperatures deep beneath the surface, and a large proportion originated in a type of rock called eclogite, which is less common at other South African mines like Venetia and Finsch, where diamonds tend to come from a different mantle rock type. The Venetia mine, in the far north of the country near the Limpopo River, is De Beers’ largest South African operation and recently transitioned to underground mining to extend its life.
Angola and the DRC: River Diamond Country
Angola is Africa’s second most valuable diamond producer, with output of 9.75 million carats worth over $1.5 billion in 2023. The northeastern provinces of Lunda Norte and Lunda Sul are the heart of Angolan diamond mining. Diamonds here are found both in kimberlite pipes and scattered through river gravel deposits, particularly along the Cuango River, which rises in the highlands of Alto Chicapa. Large-scale alluvial mining along the Cuango has been active since the 1950s.
The Democratic Republic of Congo ranks third by volume, at 8.3 million carats in 2023, though its diamonds are mostly small, industrial-grade stones. The total value was only about $65 million, a fraction of Botswana’s haul. The DRC’s diamond history dates to 1903, when the first stone was found in Katanga Province in the southeast. The famous Tshikapa alluvial fields, discovered in 1909, lie in the central-western part of the country. Further east, Mbuji-Mayi is another major alluvial center. The Kwango River, which forms part of the border between the DRC and Angola, carries diamond-bearing gravels on both sides, though many of these deposits feature thick layers of sand covering thin gravel beds with relatively small stones.
Namibia’s Offshore Diamond Fleet
Namibia takes a unique approach to diamond mining. While its 2023 production of about 2 million carats sounds modest, those stones were worth over $1.2 billion, making Namibian diamonds among the most valuable per carat on the continent. The reason is their quality: the gems were carried by the Orange River to the Atlantic coast over millions of years, and the journey effectively sorted out weaker stones, leaving behind high-quality survivors.
The diamond-bearing stretch runs along the southern coast between Oranjemund, at the mouth of the Orange River, and Lüderitz to the north. What makes Namibia truly unusual is that more than three quarters of its diamonds now come from the ocean floor. A fleet of seven specialized mining and exploration vessels uses suction equipment to recover gems from submarine gravel beds. This offshore industry has been developing since the early 1960s, when prospectors first succeeded in pumping diamonds from the seabed at depths of around 24 meters, about 20 kilometers south of Chamais Bay. Namibia is the world leader in marine diamond mining technology.
Lesotho’s High-Altitude Gems
Tiny, mountainous Lesotho punches well above its weight. The country produced just 472,000 carats in 2023, but those stones were worth nearly $139 million. The star is the Letšeng mine, perched 3,100 meters above sea level in the Maloti Mountains. Letšeng diamonds have achieved prices of $2,000 to $2,500 per carat at auction in Antwerp, making it one of the highest dollar-per-carat mines on the planet. The mine is known for producing exceptionally large, high-quality white diamonds, including several stones over 100 carats.
Zimbabwe and Tanzania
Zimbabwe produced about 4.5 million carats in 2023, valued at roughly $424 million. The Marange diamond fields in the eastern part of the country, discovered in 2006, drove a rapid increase in production, though the deposits have been controversial due to governance concerns. Tanzania’s output was smaller, at 191,000 carats worth about $31 million in 2023, centered around the Williamson mine near Shinyanga, one of the oldest diamond mines in East Africa.
West Africa: Sierra Leone and Liberia
Sierra Leone and Liberia both have alluvial diamond deposits scattered through river systems. Sierra Leone produced about 525,000 carats worth $102 million in 2023, with Kono District in the eastern part of the country serving as the primary mining area. Diamond mining in Kono has historically relied on artisanal methods, with miners using hand tools to sift through river gravel, though mechanized extraction is increasingly replacing manual labor. Liberia’s production is much smaller, at about 55,000 carats worth $18 million, also primarily alluvial.
Why Africa Has So Many Diamonds
The concentration of diamonds across Africa comes down to geology. Diamonds form roughly 150 to 200 kilometers below the surface, under extreme heat and pressure, and they only reach the surface through violent volcanic eruptions that create narrow, carrot-shaped structures called kimberlite pipes. These pipes punch through zones of weakness in the earth’s crust, following faults and fractures that tend to run in specific directions across southern Africa: northeast to southwest, and northwest to southeast. Where these fault lines intersect, kimberlite eruptions are especially likely.
Much of southern and central Africa sits on ancient, thick continental crust (called cratons) that is billions of years old. This thick, cool crust is exactly where diamonds can survive without being converted to graphite during their ascent. The Kaapvaal craton under South Africa and Botswana, and the Congo craton under the DRC, are two of the most diamond-rich geological foundations on earth. Once kimberlite pipes are exposed to weathering over millions of years, rivers carry loose diamonds downstream, creating the alluvial deposits found across Angola, the DRC, Sierra Leone, and along Namibia’s coast.