The government has taken control of all mining in the diamond-rich Marange area after private companies were ordered to halt all operations because their licenses had expired, the mining minister said on Monday. All diamond mining will now be managed by the Consolidated Mining Company, wholly owned by the government, according to the minister, Walter Chidhakwa. Private outfits may negotiate joint ventures with the government company, he added. The nine mine operators, including Chinese and Russian companies that were already involved in a joint operation with the government, had “neglected or failed to renew their special grants,” Mr. Chidhakwa said.