26th Congress of the Communist Party of the Soviet Union (diamond)

The 26th Congress of the Communist Party of the Soviet Union (26th Congress of the CPSU, Russian: XXVI съезд КПСС) is a 342.57 carat[1] fancy lemon yellow[2] raw diamond, the largest gem diamond ever found in Russia or the territory of the former Soviet Union, and one of the largest in the world as of 2016.

26th Congress of the Communist Party of the Soviet Union

Weight	342.57 carats (68.514 g)
Color	Fancy lemon yellow
Country of origin	Soviet Union
Mine of origin	Mir mine
Discovered	1980
Cut by	Raw
Original owner	Government of the Soviet Union
Owner	Diamond Fund, Moscow Kremlin
Estimated value	Never put on sale

It was mined at the Mir kimberlitic pipe (Yakutia, Far Eastern Federal District) on December 23, 1980,[3] and named after the 26th Congress of the Communist Party of the Soviet Union, opening February 23, 1981.

It is kept in the Russian Diamond Fund (Moscow Kremlin).[4]