'Impossibly rare' violet diamond that is the largest ever found in Australia to go up for sale for more than $5.3MILLION this week

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It may be known for its barren red sands and deadly animals, but every once in a while the Australian outback throws up a gem - this time in the form of a multi-million dollar diamond.

Mining giant Rio Tinto has unveiled the incredibly rare violet diamond - the largest of its kind ever found in an Australian mine - which is likely to cost more than AUD$5.3million when it goes to tender this week.

Discovered at the Argyle mine in remote Western Australia last August, the uncut stone weighed 9.17 carats when it was pulled from the dirt.

The largest violet diamond ever found in Australia was discovered at the Rio Tinto owned Argyle mine, in August 2015. It will go on display for the first time since it was found at a pink diamond showcase this week

However with the crevices and imperfections now polished out the oval-shaped gem is a beautiful 2.84 carats.

The find has been described by Rio Tinto's Patrick Coppens as 'impossible', with the company excited to make the stone the centrepiece of its upcoming tender.

'Impossibly rare and limited by nature, the Argyle Violet will be highly sought after for its beauty, size and provenance,' Mr Coppens said.

Pink diamonds put up for sale at the Argyle diamond tender can sell for up to AUD$2.6million per carat.

On average, pink and red diamonds are worth roughly 50 times more than white diamonds. 

The mining giant said the stone had been assessed by the Geomological Institute of America and would not put a figure on its worth, but were anticipating a lot of interest from diamond buyers.

The 2.84 carat diamond, found at the Argyle mine in remote WA (pictured), is expected to fetch up to AUD$5.3m at tender this week 

'This stunning violet diamond will capture the imagination of the world's leading collectors,' Argyle pink diamonds manager Josephine Johnson said.

The pink tinge in the diamonds are thought to come from a molecular structure distortion, occurring either when the gem forms or as it is brought to the surface. 

Only 12 carats of polished stone have been produced at the Argyle mine in its 32 years of operation.