Argyle diamond mine at the Ekati mine, both in Canada. However, Argyle has two to four times the concentration of diamonds (ore grade) of these mines. This makes extraction economically feasible, as mine costs are mostly related to the amount of ore processed, not the amount of diamond extracted. In 2005, Rio Tinto was given the go-ahead to a future expansion project, moving it from an open pit to an underground mine. This plan was postponed; in September 2010 Rio Tinto announced fresh plans to develop an underground mine beneath the existing pit, increasing annual production to 9 million tonnes of ore. The
Diamond mining in India was initiated during the rule of Chhatrasal, the Bundela ruler.. Diamond mining has continued in Panna region. As of 2017, there was one industrial-scale diamond mine in India, the Majhgawan mine, near the town of Panna, Madhya Pradesh. The deposit is in a kimberlite or lamproite pipe 6.5 ha in area, and yields 10 carats to the ton. Mining is done by an open pit, which was 85 m deep as of 2011. Exploration drilling has established that the pipe continues down to at least 330 m. The mine is owned by the National Mineral Development Corporation (NMDC), employs 199