Photo provided by global mining giant Rio Tinto on April 28, 2016 shows the 2.83 carat polished oval shaped Argyle Violet diamond. The tender attracts private bids for Rio's most exclusive diamonds with prices fetching over one million Australian dollars per carat. The 2016 Argyle Pink Diamonds Tender will commence private trade viewings in June and travel to Copenhagen, Hong Kong and New York. (Photo/Xinhua)
