A huge diamond unearthed in Russia is said to be one of the largest ever discovered in Europe.

The 390.7 carat whopper was found by the huge mining complex Alrosa at their Mayat mine in Russia’s Sakha Republic, on 9th September.

Based on other recent worldwide finds it could be worth up to GBP 1 billion, depending on quality and colour.

But its true value may never be discovered as the state-owned mine is banned from most world markets by sanctions on Russia over the invasion of Ukraine.

Alrosa revealed that the giant gem is a non-standard shape and bordered with a yellow-brown halo, giving, they say, a unique mix of mass, shape, and colour.

It is reportedly the largest jewellery-quality gem found in Russia in the past decade after a 401-carat stone was dug up in 2013.

It was discovered during the rinsing of rubble brought up from the mine’s Ebelyakh section.

A colourless diamond with a traditional octahedron shape weighing 37.7 carats was also found.

Company officials said both finds were sent to experts for analysis.

Alrosa CEO said in a statement obtained by Newsflash: “The discovery of one of the largest diamonds in the history of Russia is undoubtedly an unprecedented event and a great finale to the 2023 flushing season.

“Specialists have yet to study and assess in detail the potential of the mined diamond and its characteristics, but without a doubt, this is a record holder both for our company and for the country’s diamond industry.”

State-controlled Alrosa, which produces approximately the same amount of gems as industry leader De Beers, has been placing its focus on cutting and marketing its largest gems in international auction houses, such as London-based Christie’s.

However, the current sanctions by the UK which ban the import of Russian gem-quality diamonds, might prevent potential sales of the newly recovered gem.