The Argyle Diamond Mine in Western Australia, owned by Rio Tinto, says it will try to keep local workers when diamond production moves underground – a process expected to be in place by 2013.

According to a report from ABC.net.au, Rio Tinto is investing $1.5 billion in converting Argyle from an open-pit to an underground mining operation with the goal of extending the mine's life past 2019.

Managing Director Kevin McLeish said that 80% of the workers at the mine (40% of whom are indigenous) come from the local population, reducing the operation's need to fly employees in and out.

The Argyle Mine is the largest diamond mine in Australia, whose total rough diamond production from 2009 stood at 15.6 million carats with a value of $312.7 million, and is also the source of at least 90% of the world's rare pink and red diamonds. The mine also produces blue, yellow, purple, and champagne colored diamonds.