Rio Tinto’s recent and final diamond tender included 'Once in a blue moon', a rare collection of blue and violet diamonds that were won by Kunming Diamonds, a Hong Kong-based specialist colored diamond supplier.

Read before you buy: the ultimate guide to fancy colour diamonds

Kunming Diamonds, which specialises in natural colour diamonds, has been named an Argyle Pink Diamonds Authorised Partner by Rio Tinto, which operates the Argyle Mine in Western Australia – the world’s premier source of pink diamonds.

Kunming partners with Rio Tinto for Argyle diamonds

Hong Kong-based Kunming Diamonds will visit Perth, Sydney, the Gold Coast and Brisbane with a selection of pink diamonds from Western Australia's Argyle Mine and other natural fancy colour diamonds.

Pink diamonds, rare already, about to get more scarce as the biggest mine producing them closes