Rare Australian pink diamonds emerged when a supercontinent broke up
Understanding how the world’s largest-known collection of pink diamonds came to the surface in Australia around 1.3 billion years ago could help us find hidden deposits elsewhere in the world
By Alice Klein
19 September 2023
Coloured diamonds from the Argyle Diamond Mine in Western Australia
Murray Rayner
Western Australia’s pink diamonds were brought to the surface from deep underground around 1.3 billion years ago when the former supercontinent Nuna broke up.
Pink diamonds are extremely rare and prized. More than 90 per cent of those found so far have come from the Argyle Diamond Mine in the Kimberley region of Western Australia.
Like other diamonds, Argyle pink diamonds initially formed at least 150 kilometres underground during Earth‘s ancient past and started out colourless.
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Then, around 1.85 billion years ago, they are believed to have turned pink when two former continents – which now form northern and western sections of Australia – smashed together to become part of a supercontinent called Nuna that once incorporated 90 per cent of Earth’s land mass.
The collision deformed the crystal structures of diamonds caught in the middle and caused them to reflect light differently, becoming pink, says Hugo Olierook at Curtin University in Western Australia.
To find out how and when the pink diamonds later came to the surface, Olierook and his colleagues analysed samples of diamond-containing rock from the Argyle Diamond Mine.
