Russia is the largest country in terms of geographical area. As a result, it has some of the largest mineral reserves in the world. In fact, it ranks in the top three in mineral commodities such as platinum, gold and iron ore. Russia is also the world's largest producer of diamonds and palladium. (See also: Can Global Mining Stocks Outperform in 2017?)

Russia's mining industry accounts for roughly 5 percent of its gross domestic product and 16 percent of its exports – it is the country's second largest industry after oil and gas. But unlike oil and gas, which is primarily state owned, Russia's mining industry is mostly privately owned. Of the major players in the sector, only Alrosa (ALRS.ME), which is the world's largest diamond producer, is under state control. (See also: Investing in Russia: A Risky Game?)

Wondering about the largest Russian mining companies? Here are the top four based on revenue and market cap in 2017.

1. Mining and Metallurgical Company Norilsk Nickel (GMKN.ME)

Norilsk Nickel is the world's leading producer of nickel, supplying about 20 percent of global demand. The company also provides over 12 percent of the world's refined nickel production. It's also a leading producer of platinum metals, with roughly 50 percent of the world's supply of palladium (virtually the total output of that metal in Russia) and nearly the same percentage of platinum.

Headquartered in Moscow, the company operates mines in five countries: Russia, Botswana, Australia, South Africa and Finland. In 2016, the company reported revenue of $8.26 billion and net profit of $2.53 billion. While revenue was down slightly (3 percent), profits actually rose nearly 47 percent due to appreciation of the ruble. The company has a market cap of $27.44 billion. Norilsk Nickel is the eighth largest mining company in the world as of November 30, 2017, by market cap. (See also: RSX: Market Vectors Russia ETF.)

2. Polyus Gold (PLZL.ME)

Polyus Gold operates five mines in Russia that produced nearly 2 million ounces of gold in 2016. It is the largest gold producer in Russia and in the top 10 globally, with probable and proven reserves of 64 million ounces. Its Olimpiada mine is the eighth largest gold mine in the world. With 23 percent of Russia's total gold output, Polyus dwarfs its closest competitor Polymetal International (POLY.ME), which produces just 11 percent.

In 2016, Polyus Gold reported revenue of $2.45 billion and profit of $1.44 billion, an increase of 44 percent over 2015. Polyus has a market cap of $17.34 billion, making it the 14th largest mining company in the world by market cap as of November 30, 2017. (See also: Top 4 Gold Stocks for 2017.)

3. Alrosa (ALRS.ME)

This state-controlled company is the world's largest diamond producer in terms of output, which hit 38.3 million carats in 2015. Production is expected to hit 41 million carats by 2019. The Russian government recently sold off an 11 percent stake in the company, valued at $813 million, to cover a budget deficit. (See also: Russia Resorts to Asset Sales to Fund Budget.)

In 2015, the latest year for which figures are available, Alrosa reported revenue of $3.8 billion and net income of $525 million. The company has a market cap as of November 30, 2017 of roughly $12.1 billion, making it the 23rd biggest company in the world in terms of market cap.

4. Uralkali (URKA.ME)

Uralkali produces 20 percent of the world's potash supply, controlling the entire production chain, from mining the actual potash ore to supplying potassium chloride to customers. The mining company operates seven plants and five mines in Russia, with subsidiaries in Beijing, Singapore, Panama and Brazil, among others.

The company's 2016 revenue was $2.22 billion, with net profit of $1.42 billion. Uralkali's market cap is $9.85 billion. It ranks as the 33rd largest global mining company by market cap in 2017. (See also: Is PotashCorp's Recovery Near at Hand?)

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