In the east of Finland, in an area known as Northern Savonia or, as it is officially known, Pohjois-Savo, lies the town of Kaavi. With a population of 2,984, it covers an area of 790 square kilometers. It also happens to be home to the Lahtojoki kimberlite deposit, which in all likelihood is set to become the first diamond mine in the European Union.
The deposit is located in the Finnish sector of the Karelian Craton, which is a geologically stable section of the Earth’s two topmost layers, the crust and the uppermost mantle, stretching across northeastern Russia and northern Finland. In the Russian sector, it is home to both the Lomonosov and Grib Pipe diamond deposits, both of which are sites of operating diamond mines. Consequently, while the Finish deposit is likely to evolve into the first diamond mine in the EU, it is not the first to have been operated in Europe.
The owner of the Lahtojoki diamond deposit mining permit is Karelian Diamond Resources, which more recently discovered a new kimberlite pipe at Riihivaara in the Kuhmo region of country, the first such discovery in more than 10 years . It also has delineated the diamondiferous Seitaperä kimberlite pipe, which at 6.9 hectares in area is the largest diamondiferous kimberlite pipe identified to date in Finland.
RUSSIAN PIONEERS COLD-WEATHER DIAMONDS
For most of recorded history diamonds were discovered and mined in warmer climates for two primary reasons. Alluvial deposits, which covered almost known mining areas prior to the first discovery of diamonds in their source rock in South Africa in the mid-1800s, involved stones washed down river beds by water. This was unlikely to occur in the frozen regions of Arctic. Second, mining is already an expensive activity, and even more so in extremely cold conditions.
Cold-weather diamond mining began in Russia, where the existence of diamond deposits was rumored about already in the 18th century. Sustained exploration began only in the late 1930s, after a Russian geologist by the name of Vladimir Sobolev published his paper on the geological similarities between South Africa and Siberia.
The Lahtojoki kimberlite deposit, prospective site of Finland’s first diamond mine (Photo courtesy of Karelian Diamond Resources).
In the late 1940s, teams of prospectors were sent by the Soviet authorities to search for rough diamond deposits around the Vilyui river and its tributaries in northeastern Siberia, and in 1949 the first rough diamond was discovered in Yakutia.
In 1954, the first primary diamond deposit in the Soviet Union, the Zarnitsa pipe, was discovered. Three years later the town of Mirny was established alongside the Mir kimberlite pipe, which would eventually become the headquarters of the Russian diamond industry.
Despite the challenges of working in temperatures that in winter fell to minus 60 degrees, the Russian mining sector grew into the world’s largest.
COLD-WEATHER MINING SPREADS TO NORTH AMERICA
Cold-weather diamond mining succeeded because of techniques developed in Russia to work in areas where ground is frozen and needs to thaw before being drilled. But it was not before collapse of the Soviet Union and the consequent flow of technology and knowledge to the West that such activity was seriously considered elsewhere.
Indeed, were it not for the pioneering work of Russian geologists and miners it is unlikely that the Canadian diamond industry would have succeeded.
Prospecting for diamonds in the Finnish sector of the Karelian Craton (Photo courtesy of Karelian Diamond Resources).
An artisanal miner in Sierra Leone’s Kono region weighing a diamond, using the electronic scale that is supplied as part of the GemFair toolkit. (Photo courtesy of the WDC Newsletter).
Canadian diamond exploration began in the 1960s, but it took until 1991 before the first economically viable diamond deposit was discovered in the Lac de Gras area of the Northwest Territories. Ekati, Canada’s first diamond mine began operating in October 1998 and by 2003 the country was the world’s third largest diamond producer on a value basis after Botswana and Russia.
Today, the Diavik mine, a joint venture Dominion Diamonds and Rio Tinto is Canada’s most profitable diamond operation, but a number of other mines are operation, including Snap Lake, Canada’s first completely underground diamond mine which was De Beers’ first such facility outside of Africa.
The face of diamond mining had changed, and so too the balance of power. It’s early days yet, but the next cold-weather giant may just be Scandinavian.