EXPLORATION ’92 — Argyle mine largest diamond producer

The world’s largest producing diamond mining project is the Argyle open pit mine in western Australia, 2,200 km northeast of Perth.

Argyle, which produced 35 million carats in 1991, is 40% owned by Ashton Mining of Melbourne. The mine was placed into production in 1986 and in its first full year of operation yielded 29.2 million carats.

Known for its “pinks,” Argyle turns out more diamonds (gems and industrial quality) than any of the world’s producers. Some three-quarters of its annual output is sold to the Central Selling Organization.

Host rock of the Argyle pipe, which is 1,600 metres long and 150-600 metres wide, is lamproite. Proven reserves currently stand at 60 million tonnes grading 6.8 carats per tonne. An additional preliminary reserve estimate of 14.5 million tonnes grading 6 carats per tonne is indicated. Diamonds were uncovered in western Australia as early as 1894.