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 Diamond mining in India Diamond mining in India extends back into antiquity. From ancient times, India was the source of nearly all the world's known diamonds, and until the discovery of diamonds in Brazil in 1726, India was the only place where diamonds were mined. India has not been a major diamond-producing country since the 1700s, but diamond mining continues. In 2013, India mined 37,515 carats of diamonds, from one industrial-scale mine and many artisanal mines; this was less than one-tenth of one percent of the world production of 132.9 million carats. Diamond mining as an industry appears to have