Africa’s first Black billionaire, Patrice Motsepe, has seen his fortune fall by $200 million in less than three weeks, according to Forbes, as weaker valuations for his mining interests weigh on his estimated wealth. His net worth has dropped from $3.7 billion on Sept. 4 to $3.5 billion.

The decline follows a rebound that lifted Motsepe’s fortune to $3.7 billion in late August, where it remained through the first week of September. Forbes, which tracks the wealth of the world’s richest people, values Motsepe’s fortune largely through his holdings in publicly traded mining companies and other business interests.

Mining shares drive decline

Market pressure has been particularly visible in Motsepe’s 43.66 percent stake in African Rainbow Minerals and his indirect 11.8 percent holding in Harmony Gold. Over the past month, shares of the two mining companies have fallen 10.6 percent and 17.8 percent, respectively, reducing the market value of the billionaire’s publicly traded investments.

African Rainbow Minerals’ market capitalization has fallen below $2.2 billion, while Harmony Gold’s has dropped below $12 billion. The declines have come as investors reassess mining equities, directly affecting the value Forbes assigns to Motsepe’s stakes and, in turn, the billionaire’s estimated net worth.

Kropz faces fresh pressure

Beyond his listed investments, Motsepe’s nearly decade-long backing of phosphate producer Kropz Plc is confronting a new setback. The London-listed company said Monday it would restructure its Elandsfontein mine, about 70 miles northwest of Cape Town, after investing 2.6 billion rand ($162.6 million) in the project.

Kropz plans to halt phosphate rock production as it struggles to make Elandsfontein profitable. The company said continued disruption from the conflict in the Middle East has added pressure to global fertilizer markets. African Rainbow Capital, controlled by Motsepe, owns about 90 percent of Kropz, making the restructuring significant for his wider investment portfolio.

The restructuring also threatens employment at the mine. Trollope Mining Group, which operates Elandsfontein for Kropz, warned employees in a Sept. 2 letter that its contract could be “drastically reduced if not completely terminated” by the end of November. As many as 238 jobs could be affected by the changes.