The Udachnaya pipe (Russian: тру́бка Уда́чная, literally lucky pipe) is a diamond deposit in the Daldyn-Alakit kimberlite field in Sakha Republic, Russia. It is an open-pit mine,[2] and is located just outside the Arctic circle at 66°26′N 112°19′E / 66.433°N 112.317°E.[3]