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
Kelsey Lake Diamond Mine America. The gem was cut and polished by legendary New York diamond cutter Bill Goldberg which yielded a faceted stone that sold for $87,500. In July 1997, the company found two gem-quality stones weighing in at 16.3 carats and 28.2 carats. The 28.2 carat diamond was cut into a 16.86-carat stone, one of the largest finished stones ever produced in North America. The cut diamond is bigger than the gemstone produced from the "Uncle Sam" diamond, which was cut into a 12.42-carat stone. Kelsey Lake Diamond Mine Kelsey Lake Diamond Mine is a defunct diamond mine in Colorado, USA. It