RAPAPORT... Grib Diamonds registered sales of $35 million at its final tender of the year as rough prices rose amid robust demand for larger goods.Prices at the December 11 sale increased around 5% compared with the company's previous tender on October 25, Grib head of sales Antony Dear told Rapaport News Wednesday. A total of 450,000 carats sold, with rough weighing 2 carats and higher most in demand, he added. The Antwerp-based company sells production from AGD Diamonds' Grib mine in Russia. It uses "multi-round ascending clock auctions," an online bidding system in which the second-highest offer wins. The sale follows De Beers' price increase of 1% to 2% for 0.75-carat stones and larger at its December sight, with customers reporting strong rough trading, especially in sizes that produce 0.50-carat polished and above.Image: Rough diamonds. (Ilan Tach?(C)/Grib Diamonds)