On the occasion of celebrating the 25th edition of the Oprah Winfrey show in Sydney, Rio Tinto has tied up to gift each of the 6,000 audience members with a white gold and diamond necklace. The necklace has been designed specifically for the audience of the show and comprises of seven diamonds in an O shape – including one rare pink coloured diamond from the miner’s Argyle Mine in Western Australia. This endeavour also coincides with the Argyle Mine's 25th anniversary of production, reports say.