The miners failed to appear for their scheduled shift late Wednesday at two Harmony Gold mines in Free State, officials said. The 21,000 missing workers make up about 90 percent of the company's miners.
The two sites, both of which lose money, comprise about 40 percent of Harmony Gold's total output.
"Strikes have a way of focusing people, so perhaps we can use this opportunity to find common ground to resolve the issues the (National Union of Mineworkers) have put before us," said Harmony Chief Executive Bernard Swanepoel.
Celebrity Families of 2014 [PHOTOS]