Rio Tinto has launched its Argyle pink diamonds collection to be sold at the company's annual tender during the ‎fourth quarter of 2012. This year’s collection showcases 56 single pink diamonds, including two ‎red diamonds and an additional 19 lots of blue diamonds. ‎

The collection will be previewed in September and October with tender viewings scheduled to ‎be held in Perth, Hong Kong and London. Bids will close on October 15, 2012.

“We are delighted to offer a highly sought after collection of rare pink, red and blue diamonds ‎which are destined for investment portfolios or heirloom pieces of jewelry,” said Josephine ‎Johnson, manager of Argyle Pink Diamonds.‎

Rio Tinto explained that the collection showcases several “hero” stones that have been named ‎in keeping with the theme of desirability and adoration of something beautiful and rare. ‎Featured in the collection is Argyle Siren, a 1.32-carat, square radiant cut, fancy vivid purplish ‎pink diamond, and Argyle Satine, a 1.02-carat, cushion cut, fancy intense purplish pink ‎diamond.‎

The 19 lots of rare blue diamonds, titled “Once in a Blue Moon,” which have been collected ‎over the past two years, showcases the Argyle Allure, a 0.33-carat, heart-shaped diamond. ‎Other stones from the collection which also take their reference from the feminine mystique ‎are the similar sized oval and pear shaped blue and violet diamonds, Argyle Elektra and Argyle ‎Heloise, Rio Tinto explained.‎

‎“Excitement around this year’s Tender collection is understandable as Argyle pink diamonds ‎are a diminishing natural treasure distinguished by their uniqueness, their limited availability, ‎their exceptional craftsmanship, their rich provenance and their natural beauty,” said Jean-‎Marc Lieberherr, Rio Tinto Diamonds chief commercial officer.‎