Mir diamond mine

The Mir mine, also called the Mirny mine, is a huge open-pit diamond mine in the town of Mirny in Siberia, in Russia's Sakha Republic. The pit is more than 525 m deep and about 1,200 m across, which makes it one of the largest holes ever dug by people.

It was the Soviet Union's first developed diamond mine. Geologists found the diamond-bearing rock there on 13 June 1955, and digging started in 1957 in a very cold climate. The surface mine closed in 2001 after 44 years, but in 2009 it opened again as an underground mine. The mine is a good example of how humans dig deep into the Earth for treasure.

Digging in the cold

Winters here last about seven months and freeze the ground hard. In the short summer the ground turns to slush. Buildings had to stand on piles so their warmth would not melt the permafrost under them. In winter, car tyres and steel could shatter and oil froze, so workers used jet engines to thaw the ground or blasted it with dynamite, and the machinery had to be covered at night.

What came out

In the 1960s the mine produced about 10 million carats of diamonds a year, and roughly one fifth were gem quality. Later the yield fell as the pit went deeper. Two of the largest diamonds ever found in Russia came from Mir, one in 1980 and one in 2025. Another source notes that helicopters are banned from flying over the pit because of the strong downdraughts.

On the globe

Look for Mirny in the Sakha Republic of eastern Siberia, Russia.