Argyle shows every facet, especially red

Diamonds don't just come in all shapes and sizes: they come in a rainbow of colours, from cherry blossom pinks and the deepest ruby reds, to deep ocean blues and icy whites.

Rio Tinto had 64 of them on show from its Argyle Diamond Mine as part of its annual tender process.

For the first time in the mine's 30-year history, the tender includes three extremely rare red diamonds.

The 2013 collection also includes 58 pink and three blue diamonds.

"Since mining began in 1983, only six diamonds certified as Fancy Red by the Gemological Institute of America have been presented for sale at the annual tender," Argyle Pink Diamonds manager Josephine Johnson said. "To have three of these red diamonds on one tender is a very special moment in time."

Ms Johnson said that in 2008 the mine sold a red diamond for more than $1 million a carat.

The largest red diamond on the 2013 tender is a 1.56 carat round gem named Argyle Phoenix in honour of the newly commissioned Argyle underground mine.

Ms Johnson said different markets around the world had preferences for different coloured diamonds.

She said the Japanese preferred pink diamonds, while Europeans and the US market had a fondness for the rare red diamonds, which they buy as collector's items.

"The purplish pink ones are sought after in Japan because they reflect their cherry blossom colour," she said.

"They have a romantic view of the diamond. There's a strong engagement market in Japan."

Australia is Argyle Diamonds' third-largest market behind Japan and the United States.

Tender viewings of this year's collection will be held in Perth and Hong Kong, with previews in Sydney, New York and Tokyo.