HONG KONG (AFP) - A mining giant is showcasing dozens of the world’s rarest diamonds in Hong Kong, as it seeks to tap into the booming Chinese jewellery market.The 75 pink, red and blue diamonds are being shown at a private exhibition by Anglo-Australian mining firm Rio Tinto, which unearthed a huge 12.76-carat pink diamond in Australia in February - the largest of the precious stones ever found in the country. Less than 0.03 percent of the world’s diamonds are pink, which command up to 50 times the price of white diamonds.Rio said the pink stones in its display could fetch up to US$1 million a carat when they go on sale later this year.“In the last five years, we really see the growth in China and India,” Rio’s Argyle Pink Diamonds division manager Josephine Johnson said Thursday, adding that Chinese buyers had shown greater interest in the rare stones.“We know that China is becoming more of an important market for us. In fact China is set to overtake the United States market by the year 2025 in terms of diamond consumption,” she added. A 1.32-carat square purplish-pink diamond called the “Argyle Siren” is star of the show at the 13-day exhibition which begun on Sunday.