Mir Mine
Mir Mine also called Mirny Mine is an open pit diamond
In mineralogy, diamond is an allotrope of carbon, where the carbon atoms are arranged in a variation of the face-centered cubic crystal structure called a diamond lattice. Diamond is less stable than graphite, but the conversion rate from diamond to graphite is negligible at ambient conditions...

 mine located in Mirny
Mirny, Sakha Republic
Mirny is a town in the Sakha Republic, Russia, located west of Yakutsk on the Irelyakh River . Population: It was founded in 1955 after the discovery of a nearby kimberlite pipe by expedition led by Yuri Khabardin; it has had town status since 1959.The town is served by Mirny Airport.There is a...

, Eastern Siberia
Siberia is an extensive region constituting almost all of Northern Asia. Comprising the central and eastern portion of the Russian Federation, it was part of the Soviet Union from its beginning, as its predecessor states, the Tsardom of Russia and the Russian Empire, conquered it during the 16th...

, Russia
Russia or , officially known as both Russia and the Russian Federation , is a country in northern Eurasia. It is a federal semi-presidential republic, comprising 83 federal subjects...

. The mine is 525 metres (1,722.4 ft) deep (4th in the world) and has a diameter of 1200 m (3,937 ft), and is the second largest excavated hole in the world, after Bingham Canyon Mine
Bingham Canyon Mine
The Bingham Canyon Mine, also known as the Kennecott Copper Mine, is an open-pit mining operation extracting a large porphyry copper deposit southwest of Salt Lake City, Utah, USA, in the Oquirrh Mountains. It is the deepest open-pit mine in the world. The mine is owned by Rio Tinto Group, an...

. The airspace above the mine is closed for helicopters because of a few incidents in which they were sucked in by the downward air flow.

The mine was discovered on June 13, 1955 by Soviet
Soviet Union
The Soviet Union , officially the Union of Soviet Socialist Republics , was a constitutionally socialist state that existed in Eurasia between 1922 and 1991....

 geologists Yuri Khabardin, Ekaterina Elagina and Viktor Avdeenko during the large Amakinsky Expedition in Yakut ASSR. They found traces of volcanic rock kimberlite
Kimberlite is a type of potassic volcanic rock best known for sometimes containing diamonds. It is named after the town of Kimberley in South Africa, where the discovery of an diamond in 1871 spawned a diamond rush, eventually creating the Big Hole....

 which are usually associated with diamonds. This finding was the first success in the search for kimberlite in Russia, after numerous failed expeditions of the 1940s and 1950s. For this discovery, in 1957 Khabardin was given the Lenin Prize
Lenin Prize
The Lenin Prize was one of the most prestigious awards of the USSR, presented to individuals for accomplishments relating to science, literature, arts, architecture, and technology. It was created on June 23, 1925 and was awarded until 1934. During the period from 1935 to 1956, the Lenin Prize was...

, which was one of the highest awards in the Soviet Union
Soviet Union
The Soviet Union , officially the Union of Soviet Socialist Republics , was a constitutionally socialist state that existed in Eurasia between 1922 and 1991....


The development of the mine had started in 1957 in extremely harsh climate conditions. Seven months of winter per year froze the ground, which was hard in winter, but turned into sludge in summer. Buildings had to be raised on piles, so that they would not sink in summer, and the main processing plant had to be built on a better ground found 20 km away from the mine. The winter temperatures were so low that car tires and steel would shatter and oil would freeze. During the winter, the workers used jet engines to defreeze and dig out the permafrost or blasted it with dynamite to get access to the underlying kimberlite. The entire mine had to be covered at night to prevent the machinery from freezing.

In the 1960s the mine was producing 10000000 carats (2,000 kg) of diamond per year, of which a relatively high fraction (20%) were of gem quality. The upper layers of the mine (down to 340 meters) had very high diamond content of 4 carat (0.8 g) per tonne of ore, with the relatively high ratio of gems to industrial stones. The yield decreased to about 2 carat (0.4 g) per tonne and the production rate slowed to 2000000 carats (400 kg) per year near the pit bottom. The largest diamond of the mine was found on 23 December 1980; it weighed 342.5 carats (68 g) and was named "26th Congress CPSU
Congress of the Communist Party of the Soviet Union
The Congress of the Communist Party of the Soviet Union was the gathering of the delegates of the Communist Party and its predecessors. According the party statute, it was the supreme ruling body of the entire Communist Party....

" . The mine operation was interrupted in 1990s at a depth of 340 m after the pit bottom became flooded but resumed later.

The rapid development of the Mir mine had worried De Beers
De Beers
De Beers is a family of companies that dominate the diamond, diamond mining, diamond trading and industrial diamond manufacturing sectors. De Beers is active in every category of industrial diamond mining: open-pit, underground, large-scale alluvial, coastal and deep sea...

 company, which at that time was distributing most of the world's diamonds. De Beers had to buy Russian diamonds in order to control the market price, and therefore needed to know as much as possible about the Russian mining developments. In the 1970s, De Beers requested permission to visit the Mir mine. Permission was granted under condition that Russian experts would visit De Beers diamond mines in South Africa
South Africa
The Republic of South Africa is a country in southern Africa. Located at the southern tip of Africa, it is divided into nine provinces, with of coastline on the Atlantic and Indian oceans...

. De Beers executive Sir Philip Oppenheimer and chief geologist Barry Hawthorne arrived in Moscow in the summer of 1976. They were intentionally delayed in Moscow by arranging a series of meetings and lavish banquets with Soviet geologists, mineralogists, engineers and mine managers. When Oppenheimer and Hawthorne finally reached the Mir mine, their visas were about to expire, so that they could only have 20 minutes at the Mir mine. Even that short time was sufficient to get some important details. For example, the Russians did not use water during the ore processing at all, which was astonishing to De Beers. The reason was that water would freeze most of the year, and dry crushing was used instead. De Beers also overestimated the size of the mine's pit.

The Mir mine was the first and the largest diamond mine in the Soviet Union.
Its surface operation lasted 44 years, finally closing in June 2001. After the collapse of the USSR, in the 1990s, the mine was operated by the Sakha diamond company, which reported annual profits in excess of $600 million from diamond sales.

Currently, the mine is operated by Alrosa
ZAO ALROSA , is Russia's largest diamond company. Alrosa is engaged in the exploration, mining, manufacture and sale of diamonds. The company's operations are located primarily in the Sakha Republic/Yakutsk region. Alrosa accounts for approximately 25% of the world's rough diamond supply and 97%...

, the largest diamond producing company in Russia, and employs 3600 workers. It has long been anticipated that the recovery of diamonds by conventional surface methods will saturate. Therefore, in 1970s construction has started of a network of underground tunnels for diamond recovery. Production of diamonds by this method started in 1999 and is estimated to last for another 27 years. This estimate is based on depth explorations down to 1220 meters. In order to stabilize the abandoned main pit, its bottom was covered by a rubble layer 45 meters thick.

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