Sanctions-hit Alrosa, the world's biggest diamond producing company, said on Sunday it has mined the largest gem-quality diamond in Russia in the past decade.
The 390.7-carat diamond was mined at one of the company's mines in the Republic of Sakha, Alrosa said in a statement. The region, commonly known as Yakutia, lies in Russia's Far East along the Arctic Ocean.
"The found diamond is a light crystal of an irregular shape, bordered by a yellow-brown halo - a combination of mass, shape and colour that is unique today," Alrosa said.
The company mined the largest gem-quality diamond in Russia in 2013, weighing 401 ct, Alrosa said.
The word's largest gem-quality diamond ever mined - the 3 106 ct Cullinan stone - was recovered in South Africa in 1905.
Alrosa was last year placed under sanctions by the United States, which cut it off from its banking system and banned direct sales to the US market after Russia invaded Ukraine.
Last month the company reported a rise of 0.2% in revenue for the first half of the year but said net profit fell 35% year-on-year to 55.6 billion roubles.