MOSCOW, Oct. 13 (Xinhua) -- A high-quality diamond weighing 340 carats has been mined at a deposit in Russia's Arkhangelsk region, Governor Alexander Tsybulsky said Monday.

The diamond is one of the five largest diamonds unearthed in modern Russia and the biggest ever found during the industrial development of the local V. Grib deposit, Tsybulsky said.

According to the governor, the gem stands out not only for its exceptional size but also for its quality and market value. "Such crystals account for no more than 2 percent of all natural diamonds," he noted.

The V. Grib deposit is developed by AGD Diamonds, a Russian diamond mining company. Russia is the world's largest diamond producer by volume, while the Arkhangelsk region is a key diamond mining area in the country. ■