De Beers, the world’s largest diamond miner by value, has inked two mineral investment deals with the Angolan government granting the company exploration rights for 35 years in the country’s northeast. Each concession area will be held by a separate new joint venture between De Beers Group and Endiama, Angola’s state-owned diamond company, the parties said. De Beers, a unit of Anglo American (LON: AAL), will hold a “substantial” majority of the new joint ventures, it said, without specifying