At the bottom of the world’s deepest gold mine, there is a 30-inch seam of gold called the Ventersdorp Contact Reef. This is what the miners came for, but soon they will have to dig even deeper.

Operations have been halted at the world's deepest operational mine, in South Africa, after more than one-quarter of COVID-19 tests given to those who work there came back positive.

The mine is currently owned by Harmony Gold, the country's largest gold producer. The company purchased the mine for $200 million (approximately £155 million) in 2020 and over 5,400 metric tons ...