The project sits atop the Incahuasi Salar and it is located on the Chile/Argentina national border some 75 kilometres southeast from the Atacama Salar.
President Vladimir Putin, who attended the opening ceremony, said the new operation reinforced the state-controlled firm's position as a diamond world leader.
The Valentine Lake project is made up of four open-pittable deposits: Marathon, Leprechaun, Victory and Sprite, but Marathon and Leprechaun contain the vast majority of the gold.