The deposit was discovered by Soviet scientists in the 1970s, but was left unexplored as the Soviet leadership opted for producing synthetic diamonds for industrial use. The deposit remained classified until after the Soviet collapse.

Pokhilenko said that the diamonds owe their unparalleled hardness to enormous pressure and high temperatures at the moment of explosion when a giant meteorite hit 35 million years ago, leaving a 60-mile crater.

The Siberian branch of Russian Academy of Sciences said in a statement that scientists discussed the issue at a roundtable in Novosibirsk over the weekend, saying that further studies will be needed to assess economic aspects of their potential exploration.

Pokhilenko said his institute is planning to send an expedition to the crater in cooperation with Russia's state-controlled diamond mining company Alrosa.