Mir Mine Yakutia: Status, Size and Reopening Plan

The Mir mine is in Mirny, in the Sakha Republic (Yakutia) of eastern Siberia, and Alrosa lists it as suspended since a flood in August 2017. Alrosa, the Russian diamond producer that owns it, lists the site as “on conservation” and says it is weighing a restart (Alrosa, resources and assets). The open pit, more than 525 metres deep and about 1,200 metres across, closed in 2001. The underground mine that replaced it began work in 2009 and was lost to the 2017 flood. The plan now is a new, deeper mine called Mir-Gluboky, with a final investment decision due in 2026.

This page sets out where the mine is, how big the pit is, what happened in 2017, how much diamond the deposit holds, what the restart plan says, and how the site looks from a satellite. Every figure names its source and date. The dates below come from the company’s own page and a 2023 Interfax report.

Where is the Mir mine in Yakutia

Mir sits inside the town limits of Mirny, on the left bank of the Irelyakh river, at roughly 62.53 degrees north and 113.98 degrees east (Alrosa; coordinates from Wikipedia). Mirny is in the Mirninsky district of western Yakutia. The pit is also called the Mirny mine, and “Mir” is the Russian word for peace.

The kimberlite pipe, a carrot-shaped body of volcanic rock that carries diamonds up from the mantle, was found on 13 June 1955 by Soviet geologists Yuri Khabardin, Ekaterina Elagina and Viktor Avdeenko, during the Amakinsky expedition (Wikipedia, Mir mine). Open-pit mining began in 1957. Alrosa’s page gives the discovery year as 1955 and lists the Mirny production site as operating since 1957.

Alrosa’s site also lists nearby operations. The Internationalnaya pipe, 16 km south-west of Mirny, is mined underground, and Udachnaya lies about 550 km north of Mirny near the town of Udachny. Mir is one of several pipes in the region, not the whole of Yakutian diamond mining.

How big is the Mir pit

A carat is 0.2 grams. Mining.com put the underground mine’s share of Alrosa output at about 9% in 2020 (Mining.com, January 2020), so a figure of roughly a tenth is the safest summary.

Mir mine timeline from discovery to the flood

1. 1955: kimberlite found by the Amakinsky expedition.
2. 1957: open-pit mining starts under extreme cold; the ground froze for about seven months a year and buildings were raised on piles so their heat would not melt the permafrost (Wikipedia, Mir mine).
3. 2001: the open pit finishes (Alrosa).
4. 2009: underground mining begins in the same pipe (Alrosa).
5. 2016: the underground mine reaches design capacity, 3.19 million carats in the year (Interfax).
6. August 2017: water from the old pit breaks into the workings; 151 people were in the danger zone and eight died (Interfax).
7. 2020: Alrosa starts test drilling to see whether deeper reserves justify a restart (Mining.com).
8. September 2023: Alrosa announces construction of facilities for Mir-Gluboky (Interfax).
9. 2026: Alrosa’s 2025 consolidated report says a final investment decision on Mir-Gluboky is due this year (1ru, 6 March 2026).

The 2001 end of the pit is the date Alrosa gives. Some websites say the mine closed in 2004; Alrosa’s own resources page does not support that, so it is not used here.

What happened at Mir in August 2017

Interfax reported that water from the depleted open pit above broke through into the underground mine. Of 151 people in the flood zone, eight died. The workings and equipment were destroyed and two mine levels were flooded (Interfax, 4 September 2023). Mining.com, writing in 2020, described the same mechanism and also reported that the mine’s former manager was arrested on suspicion of breaking safety rules and was found dead in detention the next day (Mining.com).

The lesson for mine planners is general: an open pit that is left behind can fill with water and sit directly above underground workings. Water control, crown pillars (the rock roof left between pit and tunnels) and monitoring of the pit floor are standard design topics. Our guide to mining safety systems ranked by hazard covers the wider safety toolkit.

Is the Mir mine open now

No. Alrosa’s resources page says mining was suspended after the August 2017 incident and the field is on conservation, and that the company is considering whether to resume. Press reports conflict: in May 2025 the Moscow Times and Diamond World said Mir had “reopened” after a 468-carat stone was found there, with a 2 million carat target and full capacity by 2030, while Alrosa’s own page, opened 26 October 2026, still lists the mine as on conservation; the two accounts differ (Alrosa). What is planned is not a repair of the old workings but a new mine, Mir-Gluboky (“deep Mir”), that would reach ore below the accident zone, at depths from 575 to 1,300 metres below the reference level (1ru, 6 March 2026).

Chart

The Mir-Gluboky plan grew between 2023 and 2026

Reserves and annual output, million carats; as reported in each source; the 2026 reserves point is “almost 200” plotted as 200

The same report gives the plan in numbers: construction cost estimated at 126 billion roubles, design capacity of about 2 million tonnes of ore a year, equal to roughly 5.6 million carats, and full capacity in 2034. It says the State Commission on Reserves has put almost 200 million carats on the balance sheet. In April 2026 Alrosa’s chief executive Pavel Marinychev said the company aims to move to the main works in 2027 but is waiting for borrowing to get cheaper, because at the current key interest rate no large project pays back, Mir-Gluboky included (TASS via InvestFuture, 28 April 2026, in Russian).

The plan has moved. In September 2023 Interfax reported an investment of 121.5 billion roubles, reserves of 173.5 million carats, mining from 2032 and about 3 million carats a year from 2 million tonnes of ore. The 2026 report has a higher cost, higher reserves and a larger carat figure for the same ore tonnage. The chart below sets the two statements side by side. On the same 2 million tonnes of ore, 3 million carats implies about 1.5 carats per tonne and 5.6 million carats implies about 2.8; the two reports do not explain the difference, so treat the carat output as unsettled until the investment decision is published.

A third set of figures appears in trade press: IDEX (May 2026) reported about US$1.5 billion and a 5.5 million carat yearly target by 2039, with operations from 2034, so the full-capacity year differs by source (1ru says 2034).

How much diamond is left in the Mir deposit

Alrosa publishes JORC-style resource tables for its pipes. JORC is the Australasian code for reporting mineral resources, and “ct/t” means carats per tonne of ore. For the Mir pipe the table lists 19.1 million tonnes in the Measured category at 3.71 ct/t (70.9 million carats), 16.5 million tonnes in the next category at 3.36 ct/t (55.5 million carats) and 1.1 million tonnes in the Projected category at 3.11 ct/t (3.3 million carats) (Alrosa, resources and assets, page opened 26 October 2026). Added up, that is about 129.7 million carats in 36.7 million tonnes, an average of roughly 3.5 ct/t. This is our sum of the published rows.

Chart

Mir’s measured grade sits between two other Alrosa pipes

Measured resource grade, carats per tonne (JORC-style tables, Alrosa)

These resource figures are not the same as the roughly 200 million carats on the Russian State Commission balance, and no source we found explains how they reconcile. Do not add them together.

Alrosa describes the diamond content of Mir as high. On the same Alrosa page the Measured resource at Internationalnaya is 7.05 ct/t, while Udachnaya’s Measured resource is 1.30 ct/t. Grade is only part of value, since carats of gem quality sell for far more than industrial stones, but it explains why Alrosa returns to Mir despite the cost.

What a Mir-scale mine could earn: a calculator

The calculator below turns an ore rate, a grade and a price per carat into carats, revenue and an operating margin before capital cost. The defaults are round examples built from the Mir-Gluboky design figure of 2 million tonnes of ore a year; they are not a forecast, and the price per carat is an input you should replace.

Chart

Mir holds about 130 million carats in three categories

Contained diamonds, million carats (JORC-style table)

Where Mir fits in Russian and world output

Alrosa said in December 2025 that its 2025 output would be 29.7 million carats, down 10% on 2024, and that it accounts for around a third of world output; the August 2026 report below puts the 2025 figure at 29.8 million (Reuters via Kitco, 23 December 2025). In August 2026 it reported a first-half net loss of 9.5 billion roubles, guided to 25 to 26 million carats for 2026 and said it had been under Western sanctions since 2022 (Reuters via Kitco, 27 August 2026). That weak market is one reason the Mir-Gluboky decision is tied to the cost of money.

The Kimberley Process, the certification scheme that tracks rough diamonds, recorded 31.5 million carats from Russia in 2025, worth US$2.72 billion, an average of US$86.46 a carat, out of 98.8 million carats worldwide (Kimberley Process, 2025 global summary). Russia therefore produced about 32% of the world’s rough diamonds by volume. Alrosa lists Mir as on conservation, so the site is not a source of that output.

For another famous gem mine that closed, see our page on the Argyle mine and red diamonds; for other gem types, see where amethyst is mined.

What to check before relying on a restart date

Consultants and investors who follow Mir can test any restart claim against a short list drawn from the sources above.

• Which mine is meant. Mir-Gluboky is a new mine below the accident zone, not the old workings. A headline about “reopening Mir” may mean either, so look for the depth range (575 to 1,300 metres) and the cost (126 billion roubles in the 2026 report).
• Which reserve system. The 129.7 million carats in Alrosa’s JORC-style table and the roughly 200 million carats on the Russian State Commission balance are different measures. Ask which one a figure uses.
• Which carat output. Reports give 3 million carats a year in 2023 and 5.6 million in 2026 from the same 2 million tonnes of ore. The grade each implies (about 1.5 and 2.8 ct/t) differs by almost a factor of two.
• The cost of money. Alrosa’s chief executive tied the start of main works to lower interest rates, so the date depends on finance as well as engineering.
• The diamond market. Alrosa reported a first-half 2026 loss and guided output down to 25 to 26 million carats, so a restart must be weighed against weak demand.
• Water. The 2017 failure came from water above the workings. A credible plan describes how the pit above the new mine is sealed or drained.

None of this is investment or legal advice. It is a way to read announcements. They come from the company and the Russian press.

What the Mir pit looks like from space

The pit is easy to find in public imagery such as that from the Copernicus Sentinel-2 satellites, which carry a 13-band imager, with 10 m resolution in its finest bands and a 5-day revisit (ESA, Sentinel-2). The summer image at the top of this page was built from that archive. In a summer scene you can see the circular pit, the town of Mirny around it, and the surrounding waste dumps and roads.

What a multispectral image can and cannot do matters for a site like this. It can map the pit outline, water surfaces, waste dumps, roads and bare ground, and compare dates to see change. It cannot see how the pit wall or floor is moving by millimetres; that needs radar interferometry or ground surveys. For exploration, it can screen a licence for alteration and surface signatures before drilling. It cannot confirm a kimberlite pipe on its own, since pipes are found by indicator minerals, geophysics and drilling.

▶ Remote sensing for mining in three minutes: the instrument families and why agreement between them matters. · 2:01

Closure, land and water at a flooded pit

A closed pit leaves a large landscape task: keeping the pit wall stable in frozen ground, managing water and handling waste rock. Alrosa’s Mir pit has had a rubble layer placed on its floor to stabilise it (Wikipedia, Mir mine). Our companion page on Mirny mine impacts on land and water looks at that side. The short video below explains the main environmental impacts of any mine in plain terms.

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▶ The seven main environmental impacts of mining, explained in clay animation with satellite maps. · 2:31

Frequently asked questions

Where is the Mir diamond mine?

It is in the town of Mirny in the Mirninsky district of the Sakha Republic (Yakutia), Russia, at about 62.53 degrees north and 113.98 degrees east (Alrosa; Wikipedia).

How deep is the Mir mine?

The open pit is more than 525 metres deep and about 1,200 metres wide (Wikipedia). The planned Mir-Gluboky mine would reach ore from 575 to 1,300 metres below the reference level, written as -575 to -1,300 m in the source (1ru, March 2026).

Is the Mir mine still open?

No. Alrosa says mining stopped after the August 2017 flood and the field is on conservation (Alrosa resources page, opened 26 October 2026).

What happened at the Mir mine in 2017?

Water from the old open pit broke into the underground workings. Eight of the 151 people in the zone died, and two levels flooded (Interfax, 2023).

When will the Mir mine reopen?

Alrosa targets main works from 2027 if interest rates fall, a final investment decision in 2026 and full capacity in 2034 (TASS, April 2026; 1ru, March 2026). These are plans, not commitments.

Who owns the Mir mine?

Alrosa, the Russian diamond producer, operates it through its Mirny production site (Alrosa resources page). Alrosa has been under Western sanctions since 2022 (Reuters via Kitco, August 2026).

How many diamonds did Mir produce?

The underground mine made 3.19 million carats in 2016 (Interfax). Wikipedia cites about 10 million carats a year in the 1960s, when the pit was in its upper, richest layers; that earlier figure comes from a secondary source.

How much diamond is left at Mir?

Alrosa’s JORC-style table lists about 129.7 million carats across its three categories (our sum), and the Russian State Commission on Reserves carries almost 200 million carats on its own basis (1ru, March 2026).

Is the Mir mine the same as the Mirny mine?

Yes. Mir and Mirny refer to the same pipe and pit. The “Mirny production site” is a wider Alrosa operation that also includes Internationalnaya and several placers.

Can you see the Mir mine from space?

Yes. With a diameter near 1,200 m, the pit covers over a hundred 10 m pixels across, so Sentinel-2 imagery shows it clearly (ESA lists 10 m resolution).

What does the name Mir mean?

“Mir” is the Russian word for peace (Wikipedia, Mir mine).