And as Mwanza’s life demonstrates, diamond mining even outside a conflict area can be brutal work, performed by low-paid, sometimes school-age miners. “It’s a scandal,” says Zacharie Mamba ...

One such expansion, known as Cut-9, is a $2 billion (£1.5bn) investment expected to extend the mine’s life to at least 2035 while yielding around 53 million carats of rough diamonds.