The employees of the British-Australian mining company Rio Tinto discovered an extremely rare violet diamond in Argyle mine in the Western Australia. The cost of the diamond at the auction may exceed four million dollars, reports RIA Novosti.

The diamond weighing 2.83 carats, known as the  Argyle Violet, will be the central subject of the annual auction of Argyle pink diamonds. The exact cost of the diamond is yet to be determined. As the Australian reports, consumers are assumed to give from one to two million dollars per carat. Rio Tinto reported that in 32 years of mining works, they could have for tender only 12 carats polished violet diamonds.