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
Victor Diamond Mine crater facies and hypabyssal facies, and is considered to have a highly variable diamond grade. It is an open-pit mine; the equipment there is 100 tonne trucks, large front-end loaders, bulldozers and other necessary support equipment used in the mining operation. The annual production rate is 2.7 million tonnes a year, which comes to about 600,000 carats a year in diamond grade. There is year-round access via air travel and only seasonal access over land depending on whether the weather permits travel. On the property are warehouses for storage, a processing plant, workshops, offices, fuel storage facilities, pit-dewatering machinery and