Argyle diamond mine of tunnelling, the Argyle underground block cave development was officially completed. In 2013, Argyle is estimated to produce 10.2 million carats with an average per carat price of $25/carat. The Argyle diamond mine is also notable for being the first successful commercial diamond mine exploiting a volcanic pipe of lamproite, rather than the more usual kimberlite pipe; much earlier attempts to mine diamonds from a lamproite pipe in Arkansas, USA were commercially unsuccessful. The Argyle mine is owned by the Rio Tinto Group, a diversified mining company which also owns the Diavik Diamond Mine in Canada and the Murowa Diamond
Letlhakane diamond mine Letlhakane diamond mine The Letlhakane diamond mine is a diamond mine located in Botswana about west of the city of Francistown. Letlhakane, meaning "little reeds", is owned by Debswana, a partnership between the De Beers company and the government of Botswana. It is the second oldest of four mines operated by the company, having begun operations in 1975. Letlhakane is of open pit construction. In 2003, the mine produced 1.06 million carats (212 kg) of diamond. The recoverable ore grade at the mine was about 0.26 carats (52 mg) per ton. The ore produced at Letlhakane used to be processed