RAPAPORT... Okavango Diamond Company (ODC) has revealed a 20.46-caratpolished stone, the largest blue diamond to come out of Botswana. The Gemological Institute of America (GIA) has graded the oval brilliant-cut, type IIb diamond as fancy deep blue, with VVS2 clarity, ODCsaid. "From the first moment we saw the diamond, it was clear wehad something very special," Marcus ter Haar, managing director of ODC, saidWednesday. "Everyone who has viewed the 20-carat polished diamond has marveledat its unique coloration, which many see as unlike any blue stone they haveseen before. It is incredibly unusual for a stone of this color and nature tohave come from Botswana - a once-in-a-lifetime find, which is about as rare as astar in the Milky Way." The stone - cut from a 41.11-carat rough - was recoveredfrom the Orapa mine, belonging to Debswana, a joint venture between De Beersand the government of Botswana. ODC, based in Gaborone, has access to 15% ofDebswana's run-of-mine production. The Okavango Blue, named after Botswana World Heritage site, theOkavango Delta, will be showcased over the coming months before going up forsale at the end of the year. Image: The blue polished diamond (top) and the original rough (right). (Okavango Diamond Company)