The European Union on Wednesday imposed sanctions on Russia's state-run diamond giant Alrosa and its CEO as part of a ban on imports of the precious stones over the Ukraine war. The 27-nation bloc added Alrosa, the world's largest diamond mining company, and its chief executive Pavel Marinychev to a blacklist subject to a visa ban and asset freeze in the EU. The EU said the company -- which accounts for 90 percent of Russia's diamond production -- "constitutes an important part of an economic sector that is providing substantial revenue to the government."