Russia: Siberian miners unearth massive diamond but how valuable is it?

Russian mining company Alrosa recently dug up a huge 76.07 carat diamond from Siberia's Yubileynaya diamond field which it has valued at $430,000 (£279,000).

Alrosa has named the diamond "70 years since Victory in the Great Patriotic War", the Russian name for the war between the Soviet Union and Nazi Germany.

According to Alrosa, the rough diamond is "octahedral shape, transparent, with yellowish hue. There are small inclusions of olivine in its periphery; its superficial part contains discal crack filled with graphite and sulphide."

A spokesperson for Marlow's Diamonds, a UK supplier of ethically sourced diamonds, said: "Of course, stones of this size are incredibly rare, and you don't need to worry about getting one of these if you're trying to impress your loved one. By comparison, most diamond engagement rings hold 0.23 to 1 carat diamonds, as they're the ideal size to be worn as rings."

A diamond's value is dependent on a number of factors, including its colour, the cut, and its roughness. A smaller, well-cut diamond can command a higher price-per-carat than a larger one because of its superior appearance and due to the decreased yield from rough stones, which makes diamonds more expensive to fashion.

But at $430,000, Alrosa's isn't the most expensive by a long way, in fact it's cheap when compared to the top five highest valued diamonds in the world

5. De Beers Centenary Diamond $100m

The Centenary Diamond was found in 1986 by an electric X-ray system. Only a handful of people knew about it and all were sworn to silence until its reveal in 1988.

The rough diamond was 599 carats, making it one of the largest top-colour diamonds ever found. The cut version of the Centenary was unveiled in 1991 at 273.85 carats.

4. The Hope Diamond $350m

The 45.52 carat Hope Diamond, which according to legend brings bad luck to anyone who wears it, can be found at the Smithsonian Museum of Natural History in Washington DC.

3. The Cullinan $400m

The Cullinan Diamond was discovered in 1905 at the Premier Mine in South Africa and is named after the chairman of the mining company, Thomas Cullinan. In 1907 it was gifted to King Edward VII as a token of loyalty.

2. The Sancy Diamond (Priceless)

The Sancy diamond is 55.23 carats of pale yellow diamond that once belonged to the Moghul Empire. It is now kept in the French Crown Jewel collection housed at the Louvre.

1. Koh-i-Noor (Priceless)

The Koh-i-noor, which means "Mountain of Light" in Persian, is 105 carats and was once the largest known diamond in the world before Queen Victoria had it cut down. Prior to its resizing, it was owned variously by Sikh, Mughal and Afghan rulers.