Koffiefontein is one of the world’s top kimberlite mines by average value per carat. The mine produces high-value diamonds, a regular proportion of which are beautiful white diamonds between 5 and 30 carats in size and the average value per carat achieved in the financial year to June 2009 was US$252, which is high compared to the world’s kimberlite mines. In 1994, a 232.34 carat diamond was recovered at Koffiefontein, being the largest rough diamond ever produced by the mine.
Brief characteristics of the Mine
Size of kimberlite pipe – 11.1 hectares at surface
Start of mining activities – 1870
Ownership – Petra Diamonds: 70%, Re-Teng Diamonds (Pty) Limited: 30%
Operator – Petra Diamonds
Total resources – 6.0 million carats
Type of mining – Underground front cave
Depth of mining – 490 meters
The mine is located at Koffiefontein, in the Free State Province of South Africa, 110 kilometres southeast of Kimberley.
Following completion of the mine acquisition in July 2007, Petra’s mine management team has successfully turned Koffiefontein from a loss-making mine into an economically viable and profitable operation. This has been made possible by bringing the cost structure in line with the Petra Group, which as a smaller company has much lower overheads in comparison with De Beers, and by right-sizing throughput and production. The team also make key modifications in the plant, with the emphasis placed on recovery of the whole spectrum of diamonds.