For the first time in the 30-year history of the Argyle Diamond Mine, Rio Tinto will be showcasing three Fancy Red diamonds at its annual Argyle Pink Diamonds Tender, the world's most exclusive sale of rare diamonds.

Debuting at a world exclusive preview in Sydney, the three red diamonds from the Argyle mine represent the pinnacle of value and ultimate rarity in the diamond industry. Argyle Pink Diamonds manager Josephine Johnson said,

"Since mining began in 1983 only six diamonds certified as Fancy Red by the Gemmological Institute of America have been presented for sale at the annual Tender. To have three of these rare red diamonds in one Tender is a very special moment in time."

The Argyle Pink Diamonds Tender showcases the best of a year's production from the Argyle mine in Western Australia. The hero of the collection, a 1.56 carat round gem is Argyle Phoenix™ named in honour of the newly commissioned Argyle underground mine.

"The intrinsic beauty and unrivalled colour intensity of this red diamond is symbolic of its East Kimberley birthplace and the treasures that lie within the depths of the new underground mine," Ms Johnson said. The 2013 Tender collection is notable for its unique combination of colours and sizes.

For the first time in eight years there is a diamond greater than three carats – the 3.02 carat Radiant, Fancy Intense Orangy Pink diamond, named Argyle Imperial™.

Equally unusual is the 0.71 carat blue heart-shaped diamond, Argyle Celestial™, which is expected to be sold with a matching heart-shaped fancy pink diamond from the collection.

The 2013 Argyle Pink Diamonds Tender comprises 64 diamonds, including 58 pink diamonds, three fancy red diamonds and three blue diamonds. All 64 diamonds in this year's collection were cut and polished in Western Australia by Rio Tinto's master craftsmen, acknowledged globally for their expertise, precision and artistic flare.

This year' s collection comprises six hero diamonds selected for their unsurpassed beauty and named to ensure there is a permanent record of their contribution to the history of world's most important diamonds. Tender viewings will be held in Perth and Hong Kong with previews in Sydney, New York and Tokyo. Bids close on 8 October 2013.