The Udachnaya pipe (, ; lit. 'Lucky') is a diamond deposit in the Daldyn-Alakit kimberlite field in Sakha Republic, Russia. It is an open-pit mine, and is located just outside the Arctic Circle at 66.43333°N, 112.31667°W.

History

Udachnaya was discovered on 15 June 1955, just two days after the discovery of the diamond pipe Mir by Soviet geologist Vladimir Shchukin and his team. It is about 640 m deep, making it the third deepest open-pit mine in the world (after Bingham Canyon Mine and Chuquicamata). The nearby settlement of Udachny is named for the deposit. , Udachnaya pipe is controlled by Russian diamond company Alrosa, which planned to halt open-pit mining in favor of underground mining in 2010. The mine has estimated reserves of 225.8 e6carat of diamonds and an annual production capacity of 10.4 e6carat.