About Argyle Diamonds:
The mine covers about 450,000 square metres (110 acres), stretching in a mostly linear shape about 1600 metres (5,200 ft) long and 150 to 600 metres (500 to 2,000 ft) wide. The mine is of open pit construction, and reaches about 600 metres (1,900 ft) deep at its deepest point. The open cut closed in 2010. An underground block cave mine is currently under development, and is likely to extend Argyle's diamond production until 2018.
The Argyle diamond mine is located in the Kimberley region in the far northeast of the Australian state of Western Australia. It is located to the southwest of Lake Argyle in the Matsu Ranges, about 550 kilometres (340 mi) southwest of Darwin Because it is 185 kilometres (115 mi) kilometres by road from the nearest settlement (Kununurra) a complete residential camp has been constructed on site. Most of the 520 workers commute from Perth over 2,000 kilometres (1,200 mi) away, for alternating two-week shifts at the mine. The mine has encouraged local employment and has a large number of indigenous local people working within the mine.
Argyle is the fourth largest diamond producing mine in the world by volume, averaging annual production of 8 million carats (1,600 kg). Production peaked in 1994, when 42 million carats (8,400 kg) were produced. Of this quantity only 5% is considered gem-quality, with the rest being either near-gem quality or industrial grade; this is somewhat below world averages of about 20% of mined diamonds qualifying as gem-grade. (Author Janine Roberts contends that the "near-gem" quality rating is subjective and misleading because these diamonds can be cut into gems if desired Since operations began in 1983, Argyle's open pit mine has produced over 750,000,000 carats (150,000 kg) of rough diamonds.