Mirny Mine, otherwise known as Mir Mine, is one of the larger man-made excavated holes in the world.
It is an enormous open-pit Kimberlite Diamond mine and is located in the old Yakut Autonomous Soviet Socialist Republic, now Eastern Siberia.
The Diamond rich deposit was discovered on June 13th, 1955 by Soviet geologists during the larger scale Amakinsky expedition to the Yakut ASSR.
The mine is over 525 meters deep, making it the 4th deepest of its kind in the world and has a diameter of 1,200 meters.
Open-mining operations ceased in 2001 with an emphasis on underground mining for diamonds commencing in 2009.
There are some who say it can suck helicopters from the sky but to date, there have been no confirmed accidents of this kind.
There are also plans to redevelop the abandoned open-cast pit to a city of the future...
The expedition team won the Lenin Prize for their discovery
Expedition geologists Yuri Khabardin, Ekaterina Elagina, and Viktor Avdeenko had, by pure chance, found the second only deposit of Kimberlite in Russia at the time.
Kimberlite is a type of igneous (volcanic or magmatic) rock that was first discovered in Kimberley, South Africa.
The rock forms in the Earth's crust inside vertical volcanic pipes associated with the intrusive injection of magma from the Earth's mantle.
Diatreme volcanism (highly explosive, supersonic deep eruptions) from the mantle forms distinctive Kimberlite formations.
Kimberlite formations tend to have an overall roughly upturned carrot shape of tubular dikes and associated sills and shallow craters on the surface.
Because of the magma's origin, these types of igneous rock can include Diamonds and other mantle-derived inclusions and xenoliths. Kimberlite and its associated inclusion of Diamonds are very rare around the world.
The discovery of one at Yakut was great news for the Soviet Union, especially after many failed prospecting expeditions throughout the 1940s and 1950s. The first Kimberlite formation discovery was made in 1954 at Zarnitsa mine.
The Soviet Ruling Party was particularly pleased with the team and awarded Yuri Khabardin the highly coveted, and recently re-instated, Lenin Prize in 1957. This prize was one of the high ranking awards of the Soviet Union.
Saving a country
The Diamond-laden Kimberlite deposit could not have come at a better time for the Soviet Union.
The USSR had been deeply mauled by the ravages of the Second World War and their economy was practically in ruins.
By the time of the deposits discovery, the USSR's economy had improved little thanks to the war and the ruling Socialist Party's ill-thought out, often homicidal and misguided post-war programmes.
These included, but were not limited to, prioritizing industry over agriculture and the harsh repression of the populace at large.
The resources at the site would prove invaluable for rebuilding the state. Development of the site began in 1957.
However, constructing the Mirny mining operation wasn't an easy task. For one thing, the weather conditions of the area were really tough.
Winter lasts around seven months with temperatures falling, often, as low as -40 degrees Celsius. Car tires and steel would often become too brittle to use and oil would commonly freeze.
This severely hampered engineers and scientists who often needed to resort to the use of dynamite and jet engines to melt the permafrost in order to reach the diamond deposits.
The entire mine had to be covered at night to prevent the machinery from freezing.
Things weren't much better in the brief summer months. The previously rock-hard ground would often turn to slush making site conditions pretty unpleasant, to say the least.
Most of the buildings on site needed to be raised on piles to prevent them from sinking into the melted permafrost.
Any processing plants needed to be built on more solid ground, the nearest they could find was over 20 km away from the mine.
Despite these challenges the mine was kept operational and would soon become very profitable indeed. This was a real testament to the zeal and skill of the Russian engineers and miners employed on site.
Mirny Mine was the motherload for the Motherland
The Mirny Mine would quickly become the largest diamond mine in the Soviet Union. In the 1960s, it was producing 10,000,000 carats (2,000 kg) of Kimberlite diamond per year.
Astoundingly around 20% of those extracted were of gem quality.
The upper layers of the mine (down to about 340 meters) had very high diamond content indeed. Most were around 4 carats (0.8 g) per tonne of ore extracted.
This decreased to around 2 carats, or 0.4 g per tonne further down resulting in a dramatic reduction in production rate to about 2,000,000 carats per annum near the bottom of the open-cast mine.
Some of the diamonds found were record-breakers with the largest, the "26th Congress of the Communist Party of the Soviet Union", being extracted in December of 1980.
This is still the largest gem diamond ever found in Russia (and the USSR) and one of the largest diamonds ever found in the world.
It is currently housed in the Russian Diamond Fund at the Kremlin in Moscow.
Mining operations were halted briefly in the 1990s after the bottom of the pit became flooded.
Estimates of the mine's lifetime production value the total market value of all diamonds extracted to be around £13 Billion or more.
De Beers was very interested in the mine
At the time a company called De Beers was particularly troubled by developments at the Mirny Mine.
They were the world's de facto global diamond distributor and saw trouble on the horizon.
De Beers is the company who put almost single-handedly created the diamond-craze we are all too familiar with today.
They coined the advertising phrase "Diamonds are forever" in 1947, which is widely recognized as one of, if not the best advertising slogan of the 20th Century.
De Beers also successfully presented diamonds as a symbol of love and commitment, with a successful marketing strategy.
For many years they needed to buy Russian diamonds in order to control the global market price and, as you'd expect, wanted to be 'in the know' regarding Russian mining operations.
In the 1970s they wanted to get a closer look at the site and the mining processes on site.
The company's executive Sir Philip Oppenheimer and chief geologist Barry Hawthorne sought permission to visit and were, to their surprise, granted visiting visas in the Summer of 1976.
But things didn't go quite to the plan for the pair.
On arrival in Moscow, a common Soviet tactic was employed to keep them delayed and distracted. They were treated to lavish banquets with Soviet industry experts and series' of useless meetings.
By the time they finally arrived at the mine their visas were about to expire and they only had around 20 minutes to reconnoiter the area.
Despite this, they garnered some very interesting information indeed.
One surprising finding was that the Russians didn't use water to process the diamond ore. Given the local climate, dry crushing methods were employed as any water would quickly freeze.
The closure and re-opening of the Mirny Mine
The Mirny Mine was the very first, and largest, diamond mine to go into operation in the Soviet Union.
Its open-cast mining operations would last over 40 years until they finally closed in 2001. It had long been anticipated that surface recovery of diamonds would peter out within a few decades so an underground tunnel construction program began in the 1970s.
This was completed and fully operational by 1999 with diamond mining exclusively subterranean thereafter. This also needed the surface open-cast mine, now largely abandoned, to be stabilized.
To achieve this the bottom of the pit was covered with 45 meters of rubble. After the final fall of the USSR in 1991 mining operations were transferred to the Sakha Diamond Company.
This would prove very profitable for them and frequent annual profits in excess of $600 million from diamond sales alone.
Mine operations were later transferred to Alrosa (the largest diamond processor in Russia) who still operate the mine to this day.
Alrosa recommissioned the mine in 2009 and it is expected to continue to yield high-quality gem diamonds, and industrial grade diamonds, for a further 50 years or more.
The Mirny Mine is a potential deathtrap for helicopters and people
Rumors abound that the now abandoned Mirny Mine pit can suck helicopters out of the sky if they get too close.
Although there have been no reported accidents of this nature the very fact that it is a possibility means that the airspace above and around it is strictly off-limits.
Current theories suggest that it generates an air vortex effect that could, potentially, prevent aircraft like helicopters from generating lift and thus plummet into the mine gaping maw.
This theory is explained in more detail on Fletcher DeLancey blog:
"If a hole is deep enough — and a half-kilometer deep hole qualifies — the earth will warm the air inside it. The deeper the hole, the warmer the air.
Warm air rises, and cool air sinks, so with a big temperature difference between in-hole air and above ground air, you get quite a bit of air movement.
Thus, two things are happening. First, the warm air rising from the hole is less dense and gives less lift to helicopter rotors than the cooler air it had been flying through.
Since the temperature change is extremely abrupt as the helicopter flies over the hole, the pilot may lose a bunch of altitude before managing to adjust the speed enough (read: increase the spin rate of the rotors) to compensate for the loss of lift.
At the same time, the cool air pouring into that hole from all sides is going to create quite a wind shear.
If a helicopter loses enough lift to hit the stream of cold air, it could easily be slammed into the side of the borehole before it ever developed enough lift or power to recover."
But the mine has claimed lives in the past, but not from dramatic aircraft crashes. In 2017 the mine was briefly closed after water leaked into its underground mining operations.
This trapped around 100 workers inside and all but eight were later rescued. The flooding was so severe in some places that the rescue mission was forced to stop.
Plans for the mine's future
Their proposal is to help with the rehabilitation of the Mirniy industrial zone in Eastern Siberia. The planned dome will enclose a large manmade garden city that will be shielded from the areas, particularly harsh conditions.
"The new city would attract tourists and residents to Eastern Siberia and would be able to accommodate more than 100,000 people.
The new city is planned to be divided into 3 main levels with a vertical farm, forests, residences, and recreational areas." - evolvo
The dome itself would incorporate solar cells to power the entire city and a central core of houses and other major infrastructure inside.
Sunlight would also be channeled to the lower levels where oxygen, and food, producing trees and other plants will provide breathable air for the city.
Residents would live on the upper levels where the temperature should remain relatively constant and warm compared to the bitter temperatures outside during winter months.
To date, the project still hasn't gotten off the drawing board and it's doubtful it ever will. But the future is not set in stone.
An interesting proposal to be sure and very reminiscent of the underground Institute Facility in Fallout 4. Perhaps just perhaps it was the inspiration for it?