Mir mine

[2] The diamond-bearing deposits were discovered on June 13, 1955, by Soviet geologists, Yuri Khabardin, Ekaterina Elagina, and Viktor Avdeenko during the large Amakinsky Expedition in Yakut ASSR.

During the winter, workers used jet engines to thaw and dig out the permafrost or blasted it with dynamite to get access to the underlying kimberlite.

[6][7] In the 1960s, the mine was producing 10,000,000 carats (2,000 kg; 4,400 lb) of diamond per year, of which a relatively high fraction (20%) were of gem quality.

The largest diamond of the mine was found on 23 December 1980; it weighed 342.5 carats (68.50 g) and was named "26th Congress of the Communist Party of the Soviet Union" (Russian: XXVI съезд КПСС).

[11] Later, the mine was operated by Alrosa, the largest diamond producing company in Russia, and employed 3,600 workers.

In order to stabilize the abandoned surface main pit, its bottom was covered by a rubble layer 45 m (148 ft) thick.

[1] After underground operations began, the project had a mine life estimate of 27 years, based on a drilling exploration program to a depth of 1,220 m (4,000 ft).