Much of that wealth is folded within a geological formation known as the Great Dyke: a 340-mile-long river of stone formed 2.5 billion years ago by molten rock that pushed up from the earth’s core through the Zimbabwe craton, an even more ancient chunk of continental crust. Over millenniums the rock folded and twisted back on itself, and within its layers lie rich deposits of valuable elements like platinum, nickel, copper and chromium.

According to Zimbabwe’s indigenization law, black Zimbabweans must own 51 percent of shares of foreign companies operating here. About 20 percent of the shares are supposed to go to community trust funds, which in theory will pay for local development projects, and company employees. The rest must go to black Zimbabweans.

But exactly how these aims are to be achieved is unclear. Many of these companies are publicly held, and their shares are not the companies’ to give or sell. On top of that, few black Zimbabweans have the means to buy large numbers of shares at market value.

Still, a handful of companies have already agreed to comply, under intense pressure from Mr. Kasukuwere, a 41-year-old former official of Zimbabwe’s fearsome Central Intelligence Organization.

In March, the South African mining company Implats — whose subsidiary, Zimplats, mines platinum in Zimbabwe — said it would give community organizations interest-free loans, to be repaid from dividends, for their shares, and do the same for employees.

But it said it expected full market value for the other 31 percent of shares required under the law, an amount few private investors in Zimbabwe could muster. Officials from Implats and other companies affected by the new law did not respond to requests for comment.