158.2-carat diamond unearthed in Russia NYURBA, Russia, Sept. 25 (UPI) -- A Russian diamond mining company said it has unearthed a rare 158.2-carat diamond worth more than $1.5 million. Alrosa, Russia's largest diamond mining company, said the gem was discovered this month at factory No. 16 of the Nyurbinsk mine in the Republic of Yakutia, northeastern Russia, RIA Novosti reported Tuesday. In the estimate of Alrosa's specialists, this diamond may be sold for over $1.5 million at auction. This diamond, if it is processed, may also produce several quality diamonds, each of them worth over several hundred thousand U.S. dollars," Alrosa said.