What makes diamonds so expensive? To understand this, a mere look will be enough at how they are produced (Chinanews)

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Like the city of Chongqing in China, the Russian town of Mirny in the Republic of Sakha also emerged in the wake of the growing diamond industry of Russia (USSR). There is a vast array of diamond ores around this small town inhabited by 35,000 people including the Botuobinskaya diamond deposit that we want to introduce to you.

Mirny is also called the diamond capital of Russia. Back in the 50s, Soviet geologists found a huge diamond deposit – the Mir deposit (closed in 2001) – near Mirny. More and more people arrived there as diamond bearing ores were extracted prompting the town of Mirny to grow. The picture shows a traveler arriving recently at the Mirny city hall, 8 am local time

The other day at about 8 am, a car drove along the road crossing the city limits of Mirny. In November, it dawns as late as 11 am in Mirny

Two travelers come to a neighborhood in Mirny. In November, Mirny is already completely coated in snow, the ambient temperature is as low as –30 ℃.

The Botuobinskoye diamond deposit is to the west of Mirny. In 2015, its exploitation was started by the world's largest diamond mining and processing company, ALROSA.

Although the deposit is not far from Mirny, just a few hundred kilometers away, it is not easy to get to it, since there is no road connection between them. Xiao Xin took an MI-38 helicopter owned by a subsidiary of ALROSA, for a one-hour flight. Then he moved to a large cross-country truck and finally arrived at the Botuobinsky diamond-bearing region.

Over years of operation at the Botuobinskoye deposit, a mine opening has been formed, the size of a soccer field. If you look from the edge, you can see an opening approximately 130 m deep spiraling down into the ground. Along the pit walls, a spiral motor way has been constructed for entry and exit of vehicles.

Botuobinskoye diamond deposit

An excavator extracting diamond-bearing rock from the opening

Dug-out diamond bearing rock loaded into heavy dump trucks

In November, the atmospheric temperature at the field drops below –30 ℃ , but hard work still continues here: large excavators extract rock from the open-pit mine and heavy trucks take it up the spiral road leaving behind a white plume of exhaust gases.

This scene of hard work is the same 365 days a year regardless of whether it is hot or extremely cold. The scene can be observed 24/7: workers ensure continued production in shifts.

In 2016, over 680 carats of diamonds were mined at the diamond deposit by this hard and patient work.

The extracted diamond ore is supplied to the nearby diamond processing plant No. 16.

View of diamond processing plant No. 16. The diamond processing plant was commissioned in 2003, the facility features full automatic functions and the plant requires only 12 men to support its continuous operation

At plant No. 16, large pieces of ore rock are first mechanically milled into 5 cm fragments and then all ore is transported by a conveyor to a special high-density liquid mixture for settling. In this very high buoyancy liquid, the rock fragments are floated on the liquid's surface. As the specific gravity of diamonds is relatively high, the diamond-containing pieces of ore settle to the pool bottom.

Ore fragments after milling

Milled ore pieces are sieved through the holes

Flushing of crushed rock pieces

After settling, the lumps of rock that have settled to the bottom of the liquid tank are transported to a pool filled with acid eroding the outer rock thus exposing only diamonds. The pieces of ore left on the surface are collected, milled to a finer grade and are subjected to the above steps again so as not to miss small diamonds. This method of processing is extremely efficient. On average, plant No. 16 is able to process 6,000 tons of ore daily extracting 20,000 carats of diamonds.

Subsequently, the plant-extracted diamonds are delivered to the Diamond Sorting Center in Mirny where workers use mechanical, manual, and other methods to screen and sort out diamonds by their size, texture, and color choosing diamonds suitable for further processing. Usually, approximately one third of all diamonds sent from the plant is rejected at this stage.

Workers manually sort out diamonds at the Diamond Sorting Center in Mirny

Diamonds are placed into sorting equipment

A worker visually inspects a diamond for clarity

The selected rough diamonds are packed and sent to ALROSA's gem department in Moscow to be cut and polished. According to Marina Ivanova, product manager at the gem department, the finished marketable stones are then sent to the Gemological Institute of America for appraisal and evaluation and can subsequently become commercially available.

Worker inspecting a polished diamond at Moscow Polishing Center

Worker demonstrating a yellow diamond that arrived recently from Mirny

Worker polishing a diamond on emery disk

Worker demonstrating a diamond after primary cutting and polishing. The picture shows two clear diamonds approximately 6 carats each of overall value more than US$650,000. The pinnacle of rarity - an approximately 15 carat violet diamond with a value that can hardly be appraised

The Botuobinsky diamond deposit is one of 11 fields currently being developed in Russia by ALROSA. According to the presentation, ALROSA annually outputs over 95% of the total production of diamonds in Russia, accounting for up to 27% of the total world production.

As a global giant, ALROSA is paying very close attention to the Chinese market. The Company president, Mr. Ivanov, told Xiao Xin that in recent years, following a steady increase in incomes, the middle class among the urban population of China has experienced rapid growth. A report by Morgan Stanley Bank confirms that the Chinese luxury products market is constantly expanding. According to statistics, the jewelry market in the Asia-Pacific region in the first and second quarters of this year rose 11% and 17% compared to the same period last year, respectively, which was mainly due to the growing demand in the domestic markets of mainland China and Hong Kong.

President Ivanov said that about 4,000 of consumers from China and the United States aged between 25 and 55 were polled last year. The findings showed that 86% of Chinese consumers were planning to purchase at least one gem jewelry in the current year, while only 59% of US consumers were interested in such a purchase.

President Ivanov stressed that ALROSA had already established long-term cooperation with 6 largest jewelery distributors in China’s markets, including Chow Tai Fook. Last year, the volume of transactions based on long-term contracts in China increased by 18%. In addition, ALROSA tried direct payments in rubles with Chinese partners for the first time last year, the payments were made through the payment offices of Russian banks, helping to avoid intermediaries, which significantly accelerated and simplified the settlement process.

Author: Wang Xiujun

This page was last updated on 18 November 2018 at 16.12