(CNN) -- A diamond unearthed in the southern African nation of Lesotho could yield one of the largest and highest quality round polished diamonds, according to a statement Monday from company that found it. A mining company unearthed this 478-carat diamond in the southern African nation of Lesotho. Experts in Antwerp, Belgium who analyzed the 478-carat stone determined it to be of the highest color grading available for a white diamond, said a statement from Gem Diamonds Ltd., the company that found the stone. "What makes it more remarkable is the color and quality of this stone," said diamond consultant Neil Buxton. "It's a D color, which is the highest possible graded color you can get, and we believe there is a chance -- a very good chance -- of getting a 100-carat plus" round stone with the highest color and clarity rankings. The company said such a stone would "to the best of our knowledge" be "the first one in history."  Watch more on the diamond » The diamond, which was found in September, ranks as the 20th largest rough diamond ever found, but is not the biggest ever taken from the Letseng Mine, which is co-owned by Gem Diamonds Ltd. and the Kingdom of Lesotho, a country of 2.1 million that is surrounded by South Africa. Two bigger stones -- 603 and 493 carats -- were found in the mine in 2006 and 2007, respectively, the company said. A 601-carat diamond was mined there in 1960, it said.
How many carats is the stone? What size is the diamond? What could yield one of the highest quality stones? What was found at a mine in Lesotho? What could the diamond yield? What is the carat weight of the gem? Where was the diamond mine found? Where was the diamond found? How many carats was the stone?
478-carat
478-carat
diamond unearthed in the southern African nation of Lesotho
478-carat diamond
and highest quality round polished
478-carat
African nation of Lesotho
southern African nation of Lesotho.
478-carat
Diamond could yield one of the largest and highest quality round polished stones .
478-carat stone determined it to be of the highest color grading available .
Diamond found in Letseng Mine, in Lesotho .