The 58.6-carat diamond find follows the discovery of a 21.6 carat stone at the South African mine a week ago.

According to stakeholder intelligence firm Alva, labour relations contributed <1% material impact last quarter but it fell to -11% in Q2, as industrial action increases across the mining sector.

Scientists developed a method that avoids wasting out-of-furnace slag and extracts cast iron and Portland cement clinker from the material.