Unhappy investors argue that Tanzania does not produce enough ore to make building a domestic smelter commercially viable. Yet, being Africa’s fourthlargest gold producer, Tanzania is also a source of graphite, diamonds, tanzanite and rare earth minerals. Under the regulations, the state can force mining and energy firms to renegotiate contracts to give the state at least 16 per cent in projects, rising to 50 per cent in some cases, and raise export royalties. The move is not so unusual in Africa. South Africa in June raised the threshold for black ownership in miners to 30 per cent. Increasing shares of royalties is also part of a wider global trend that could lead to higher prices. The Philippines, the world’s top nickel supplier, and Brazil, which produces gold, copper, tin and bauxite, are making the same push.