ALROSA : 27.85 carat Pink diamond found

Alrosa

ALROSA has recovered a unique pink 27.85-carat diamond.

“Almazy Anabara”, a subsidiary of ALROSA, recovered a large pink rough diamond weighing 27.85 carats. This is a unique discovery: by far the largest company’s pink rough diamond had a weight of about 4 carats. If the company decides to cut this stone, it could become the most expensive polished diamond in the history of ALROSA.

The rough diamond has dimensions of 22.47 x 15.69 x 10.9 mm. The pink stone is of gem-quality and almost free of inclusions.

Most often ALROSA recovers pink and other colored diamonds at Severalmaz kimberlite pipes or placer deposits of “Almazy Anabara”. Colored diamonds weighing over 10 carats are extremely rare and recovered about once a year. As for the pink shades, by far the largest pink diamond of ALROSA weighed 3,86 ct – it was found by “Almazy Anabara” in 2012. Apart from this stone, for the last 8 years ALROSA recovered only 3 pink diamonds weighing over 2 carats.

“The unique characteristics of the diamond make it an extraordinary, rare stone of high value. Currently, experts of United Selling Organization of ALROSA and the company’s polishing division DIAMONDS ALROSA are examining the stone to make the decision: whether to auction it as a rough or cut it into polished diamond. Large stones, especially colored, are always in demand at auctions. But if the company decided to cut it, it would become the most expensive diamond in the entire history of ALROSA”, – said Evgeny Agureev, the head of USO ALROSA.

Alrosa accident at Mir mine

Alrosa

To arrange an independent analysis of the causes of the accident, ALROSA is planning to invite an auditor experienced in work at underground diamond mining facilities with similar hydrogeological conditions. A relevant resolution was passed at the initiative of the independent members of ALROSA Supervisory Board. SRK Consulting and DMT Group are among the possible candidates for the audit.

An independent audit will be conducted to make an overall assessment of all decisions and actions at the design, construction and operation stages of Mir underground mine. This will make it possible to find out the causes of the accident on August 4 and to assess the adequacy of the measures taken for its prevention and elimination.

International experts are to assess the pre-project option of the underground mining technology for the Mir pipe, correctness of the underground mine construction and operation project, and existing procedures for technical decision-making in terms of industrial safety. Among other things, there will be a comprehensive assessment of the correctness of the initial data used to calculate and model the reliability of the safety pillar, as well as technological parameters for drainage and dewatering systems, systems for integrated monitoring of safe operation and cut-and-fill system for diamond mining at Mir underground mine.

Independent experts will also assess how the design decisions were observed during the construction and operation of the underground mine and whether it was possible to prevent the emergency taking into account the existing design decisions.

Sergey Ivanov, ALROSA President:

− We are interested in the most objective and highly professional independent assessment of what happened. At the same time, we know that there are no analogous mines with similar hydrogeological conditions in our country. There are a few competent specialists in Russia with the relevant experience, and the company engaged most of them at the stage of the mine design and operation. We are counting on assessment by independent international experts who have experience in mine planning and production for deposits with similar adverse hydrological conditions.

 

Earlier, Sergey Ivanov signed an order to carry out an overall safety assessment of mining operations at all the Company’s underground mines by September 1, 2017. A special purpose expert group is to assess the potential impact of water bodies on mine workings and measures taken to prevent water breakthrough from depleted open pit mines.

Reference

SRK Consulting is part of an independent international consulting practice with 1,400 professionals in 20 countries specializing in the mining industry. It is an international expert in calculation and modeling of hydrogeological situation, strength of open and underground mine workings. SRK experts designed the majority of operating kimberlite mines in Canada, South Africa, Grib deposit in Russia, they developed a combined mining project for the Diavik diamond deposit under a water body (lake).

DMT Group is an international company providing services in geological exploration, design, consulting and geotechnics. Specialists of the company are recognized experts in industrial safety. DMT Group has experience in technical audit and engineering of objects in Russia with the combined development and surface water sources, as well as extensive audit experience in industrial safety and incidents at mining facilities. Its experts participated in the investigation of accidents at Ulyanovskaya and Raspadskaya mines.