A rare history

The Argyle mine is located in the Kimberley region in the far northeast area of Western Australia, and until recently was the world’s largest single producer of diamonds.

Over 90% of the world’s rare pink diamonds were produced in the Kimberley – amazingly a whole year’s worth of diamonds, over half a carat, would fit in the palm your hand.

Already it is predicted the life of the mine will end in the year 2019, and will see world’s production of pink diamonds plummet, while the investment value of this beautiful stone increase dramatically. With this in mind, Rio Tinto, the owner of the Argyle mine, is concerned with the future of the region, which is one of significant economic and social disadvantage.

One of the organisation’s key priorities is to help build a stronger and more robust East Kimberley economy that is not dependent upon the mine’s operations.

The East Kimberly region in Western Australia is the home of the Argyle mine. Back in the 1960s, prospectors looking for gold found mineral deposits in the northern area of the region, in Smoke Creek near to Lake Argyle.

However, it was not until some time in the 1970s that suspicions began to grow that there might be a significant diamond source. Geological studies based out of the University of Western Australia indicated a similarity between the Lamproite rock common to the region, and Kimberlite, a type of rock frequently associated with diamonds. With funding from Ashton Mining Ltd, an exploration of the area commenced. The result of this was the discovery of small diamonds. In 1976 CRA Limited took over management of the budding mine. They set two clear objectives. First to locate a diamond larger than 0.25 carat, and second to pinpoint a pipe that would yield these diamonds. A great part of the company strategy was dependant on the rainy season.

The company hoped the wet conditions would lead them to exposed pipes where diamonds were washed away to the waterbeds. It is CRA that later would become what we now know as Rio Tinto Limited. The journey to making a success of the mine however presented some challenges beginning with the remoteness of the Kimberly region. Furthermore, zero access to infrastructure made the company’s efforts arduous and costly. Helicopters were needed to take sample collectors to various Kimberley waterbeds and it was years before research yielded positive results.

Thankfully all of the hard work paid off, by 1979 geologists were able to pinpoint substantial alluvial diamond deposits. It was decided that Smoke Creek in the Ragged Ranges was a good location for the mine. In the following 2 months, a diamond-bearing Lamproite pipe called ‘AK1 pipe’ was identified.