The Origin of Diamonds

Diamonds were formed in the earth’s upper mantle layers approximately 2.5 billion years ago, 150-200km down from the crust at temperatures of about 1300°C and pressures between 45-60 kilobars. The diamond crystals are thus formed in the liquid rock mass of the upper mantle. Volcanic activity is required to bring the diamonds to the surface of the earth. It is, therefore, vital to know that kimberlites and lamproites are the only transport materials to move the diamonds to the earth’s surface.

The diamond-containing transport magma paves its way to the earth’s surface along existing deep crevices and cracks in the earth’s crust. At less than a depth of 2 km, pressure differences produce a huge explosion. This explosion leads to a large crate filled with chunks of kimberlite. However, this does not mean that diamonds are only found in kimberlite pipes; they can, for example, also be found in the dune sand along the Namibian coast.

Picture from Rio Tinto showcasing the Diavik Mine, Canada

Canada

All mines that are part of the ‘Canada Mark’ program must meet Canada’s stringent environmental regulations. Many of the mines go above and beyond these strict regulations. The most famous Canadian diamond mines are Diavik and Ekati. The Diavik mine is known for excavating extremely clean diamonds.

Russia

Russia has numerous diamond mines owned by Alrosa. Alrosa’s primary mining and processing operations are in two Russian regions: The Republic of Sakha (Yakutia) and the Arkhangelsk region in the northwest of the Russian Federation. The company has open-pit and underground mining as well as alluvial operations in Yakutia.

Picture from Alrosa showcasing the Botuobinskaya pipe, Russia

Picture from Rio Tinto showcasing Argyle, Australia

Australia

The Argyle Mine in North-Western Australia is known for producing the finest and most rare colored diamonds in the world. The mine produces 95% of the world’s supply of red, pink and blue diamonds. However, the mine is planning to shut down at the end of 2020. Thus, these colored diamonds will become even rarer in the near future. Rio Tinto, the owner of the mine, works closely with the government, indigenous groups and local communities to plan the end of their operations that leaves lasting benefits for the host communities.

Botswana

Botswana is an essential source of diamond production. Botswana is the world’s richest country of diamonds. Two major mines -Karowe and Jwaneng – are continually introducing large, high-value diamonds into the market, including exceptional stones. The start of diamond mining in Botswana helped to kick-start other business sectors, notably construction, financial services and transport. Economic growth has increased revenue, allowing for further development investment. Such growth has rapidly elevated national wealth levels.

Picture from Lucara showcasing the Lucara Mine, Botswana

Picture from De Beers showcasing the Big Hole, South Africa.

South Africa

South Africa is a well-known source for diamonds, with DeBeers owning most of the mines. Today, South Africa operates six mines. The most famous mine is the ’Cullinan’ mine thanks to the exploration of the Cullinan diamond in 1905, which, at the time, was the largest gem-quality rough diamond ever found, weighing 3,106.75 carats (621.35 g).